EATER-NS OF VARIATION 3N ROOT SYSTEMS OF SCOTCH Pé-NE PROVENMCES Thesis for ihe Degree of Ph. D, MICHEGAN STATE UNIVERSITY JAMES H. BROWN 19167 __- r A MA'A >1 -1 1 {i - I 4" M‘r‘ C’lng [ll “WAR? ’ Unix/(mt)! r. This is to certify that the thesis entitled PATTERNS OF VARIATION IN ROOT SYSTEMS OF SCOTCH PINE PROVENANCES presented by James H . Brown has been accepted towards fulfillment of the requirements for M degree in £91m \ ‘1'7-b’21/v‘w/fl/:/fl g- ’7—‘ ' ' ‘ Major professor/f7— July 31, 1967 Date 0-169 , ‘p- .\| v... n u.‘ .Qv. -—--P.. M m‘.m,—‘_“mm-m '— M.“ ' . 7 \ ABSTRACT PATTERNS OF VARIATION IN ROOT SYSTEMS 0F SCOTCH PINE PROVE'NANCE‘S by James H. Brown Root development of nursery and greenhouse grown seedlings of Scotch pine (Pinus sylvestris L.) provenances from throughout the range of the species was studied. Significant differences were found between origins in type of root system, rate of growth, root regener- ation potential and growth at different moisture-fertility combina- tions. Root systems of #5 origins that had been grown in the greenhouse for periods of four and eight months were analyzed. Northern origins were distinctly tap-rooted, with lateral rooting confined to branching from upper portions of the tap root. Root length was well correlated with average annual temperature of the area of seed collection. Cen- tral European provenances had more moderate expression of the tap root character. Laterals were long, much branched, and occurred along most of the tap root. Differences in root characteristics could not be correlated with climate. Sources from isolated, southern portions of the range were dis- tinctly tap-rooted. Branching of laterals was low. There was con- Siderable variation in other characters and individual root types ap- Parently developed in response to differences in precipitation and Past evolutionary history. Provenances from southern France had root types similar to those of northern origins. Lateral rooting was James Harold Brown confined to branching from upper portions of the tap root. Root sys- tems of Spanish origins had a narrow, columnar appearance. Tap roots were long and laterals were short and extended from along most of the tap root. Greek origins from cool, moist climates had root types in- termediate between those of other southern origins and those of cen- tral EurOpean sources. Provenances from Turkey and the Georgian SSR were deeply tap-rooted and individual laterals were longer than on Spanish provenances. Rates of root growth during the first 80 days after germina- tion were studied for greenhouse grown seedlings of eight origins. Differences were related to temperature and precipitation of areas of seed collection. Initial root growth was confined to tap root elon- gation. Lateral growth was not pronounced until after tap root growth began to decline. Rate of root growth was most rapid for northern sources from areas having short growing seasons and was slowest for southern origins from moist climates. Five nursery grown provenances were transplanted at monthly in- tervals during the first growing season and survival, root growth and root regeneration were studied. Results varied with time of trans- planting, seed source and intensity of root pruning. Survival was closely correlated with amount of roots present at transplanting and growth of new roots after transplanting. Root growth and root re- generation were slight while tOp growth was active. Survival of trees transplanted during this period was very low. Root growth and regen- eration increased significantly after top growth st0pped. Survival was nearly 100 percent fer trees transplanted after this time. Var- iations in seasonal patterns of root growth and survival were correlated mg .____ -- - —.__ . James Harold Brown with growth patterns of origins used. There were differences between provenances in root regeneration potential. It was highest for south-Swedish, south-French and Span- ish origins and lowest for north-Swedish and German sources. Inten- sity of root pruning also affected survival and root regeneration. Survival was lowest for fully root-pruned trees and approximately the same for no and half root-pruned trees. Trees with half root pruning produced the greatest amount of new roots after transplanting. Three provenances were grown in the greenhouse for 90 days under different moisture-fertility treatment combinations. There were dif- ferences between origins in optimums for growth and in requirements for shoot and root growth. Sources from Germany and Sweden showed similar reactions to different treatment combinations. The Spanish origin reacted differently and had lower fertility and higher mois- ture requirements. Fertility levels for best root growth were lower than those for best shoot growth. RATTERNS 0F VARIATION IN ROOT SYSTEMS OF SCOTCH PINE PROVENANCES By ‘3 a“? James H. Brown A THESIS Submitted to Michigan State University in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY Department of Forestry 1967 ACKNOWLEDGEMENTS The author wishes to acknowledge the assistance of the guidance committee: Drs. JOnathan W. wright, Donald P. White, Gerhardt Schneider, Boyd G. Ellis, and Stanley K. Bias. The study was financed in part by funds from the Cooperative State Research Service of the U. S. Department ovagriculture as part of regional project NC-Sl entitled "Tree Improvement through Selection.and Breeding." This project involves active cooperation of numerous federal, state, and private agencies in the Nbrth Cen- tral United States. TABLE OF CONTENTS Page ACKNOWLEDGEMENTS . . . . . . . . . . . . . . . . . . . . . . . ii LIST OF TABLES . . . . . . . . . . . . . . . . . . . . . . . . v LIST OF ILLUSTRATIONS . . . . . . . . . . . . . . . . . . . . vii CHAPTERS I. INTRODUCTION . . . . . . . . . . . . . . . . . . . . 1 II. OBJECTIVES . . . . . . . . . . . . . . . . . . . . . 3 III. VARIATION IN ROOTS OF GREENHOUSE GROWN SEEDLINGS OF DIFFERENT SCOTCH PINE PROVENANCES . . . . . . . 1+ Procedure Results The Northern Varieties The Central European Varieties The Southern Varieties .Evolutionary Development of Root Systems IV. EARLY ROOT DEVELOPMENT PATI‘ERl‘JS OF SCOTCH PINE PITO‘JE‘IIUJCES . o o o o o o o o o o o o o o o e o o 0 A8 Procedure Root Development Patterns Northern Provenances Central European Provenances Southern Provenances Relation of Root Types and Growth Patterns to Climate of Area of Origin v. mm or? AGE AND ROOT MIINO ON ROOT nmrmonvxmm OF SCOTCH PINE ssan-Ics OF DIFFERmrr Psovm-mmcrs . 7h Procedure Results iii Page V. CONTINUED Survival Top Growth Total Lateral Root Length Absorbing Lateral Length Absorbing Root Length Ratio: __ Total Root Length Root-Shoot Ratios Relation of Top to Root Growth Relation of Survival to Root Growth and Root-Shoot Ratios VI. SHOOT.AND ROOT GROWTH OF DIFFERENT SCOTCH PINE PROVENANCES.AT VARYING MOISTURE‘FERTILITY mmms e o o o o o o o o e o o o s s e s o s 0 11-2 Procedure Results Top Growth Root Growth Shoot-Root Ratios Relation of Moisture and Fertility Requirements to Climate, Soils and Evolutionary History of Area of Origin VII.SUMMARY.......................1A8 LITERATURECITEDIsh ....160 VITA C O C O O O O O O O O O O O O O O O O O O O O O 0 APPENDIX: LIST OF GMON AND SCIENTIFIC NAME OF er TREE 161 SPECIES iv Table 10. ll. 13. LIST OF TABLES Location and climate at place of origin of Scotch pine provenances used in the study of differences in root tms O C I I O O O O I I O O O O O O O O O O O O O I O 0 Summary of analyses of variance for tOp and root growth factors studied in sampling Scotch pine provenances after four and eight months growth in the greenhouse. . . . . . Shoot and root develOpment of Scotch pine provenances grown four months in a greenhouse. . . . . . . . . . . . Shoot and root development of Scotch pine provenances grown eight months in a greenhouse. . . . . . . . . . . . Growth data for Scotch pine provenances grown in the greenhouse for four and eight months, summarized by variety 0 O O O O O O O O 0 O O O O O O O I O O O O O O 0 Number of lateral roots per tree and proportion of lat- eral roots having no, one, two, three and four branches of Scotch pine at ages four and eight months. . . . . . . Location and climate at place of origin of Scotch pine seed sources used in study of root develOpment patterns . Analyses of variance for root growth of Scotch pine progenies sampled at lh-day intervals . . . . . . . . . . Root lengths of Scotch pine provenances measured at 11*-day intervals. 0 o o o e o o o o o o e o o o o o o o 0 Dry weights of roots and relative dry weights of tap roots of Scotch pine provenances measured at lh-day intervals 0 O O O C O O O O O O O O O O O O O O O O O O O Percentages of maximum (80-day) tap root and lateral root length attained at lh-day intervals in eight seed sources of Scotch pine. . . . . . . . . . . . . . . . . . Number of lateral roots per tree and proportion of Lat- eral roots branched.once or twice. . . . . . . . . . . . Location and climate at place of origin of Scotch pine seed sources used in transplanting study. . . . . . . . . Page 13 16 20 31+ 50 52 5h 57 59 63 76 Table 1h. 15. 16. 17. 18. 23. 2h. Survival and height growth of Scotch pine seed sources one month after transplanting with various intensities Of IOOt I'nlnitlg e o e o o o o 0 0 0 0 Analyses of variance for survival, height, and lengtn of absorbing portions of lateral roots of Scotch pine seed sources one month after tranSplanting with various 0 9 8'2 intensities of root pruning . . . . . . . . . . . . . . Percentage of end-of-season growth attained at various measurement dates (30 days after lifting dates) . . . . . . 86 Lateral root length of Scotch pine seed sources one month after tranSplanting with various intensities of I‘OOt P'mning o o o e o o o e o 0 Analyses of variance~ggg,tgtal length of lateral roots and for the ratio 23%Ef§%33 lateral root length of Scotch pine seed sources measured one month after trans- planting at various dates . . . . . . . . . . . . . . . . 90 r) o o o o o o o I o e e e 098 Root-shoot ratios of Scotch pine seed sources after transplanting with various intensities of root pruning. . .lOl Analyses of variance for root-shoot ratios of Scotch pine seed sources one month after transplanting with various intensities of root pruning . . . . . . . . . . . .102 Location and climate at place of origin of Scotch pine pine seed sources used in moisture-fertility study. . . . .llS Analyses of variance for top and root growth of three origins of Scotch pine grown at nine moisture-fertility . .120 treatment combinations. . . . TOp and root growth of three seed sources of Scotch pine grown at different moisture-fertility treatments . . .12h Lateral roots per tree, proportion of branched lateral roots and shoot-root ratios of three origins of Scotch pine grown at different moisture-fertility treatments . . .lhO 10. ll. 13. 1h. LIST OF ILLUSTRATIONS Natural distribution of Scotch pine and provenances included in the study of differences in root types. . . . 10 Seedling of MSFG 25h, a seed source of var. mongolica in northeastern Siberia, after four months growth . . . . 23 Relationship between eight month growth of seedlings of Scandinavian origin and average annual temperature of the area from which seed was collected . . . . . . . . 26 Seedling of MSFG 5h9, a seed source of var. lapponica in northern Sweden, after four months growth. . . . . . . 2T Seedling of MSPG Shl, a seed source of var. rigensis in south-central Sweden, after four months growth . . . . 28 Seedlings of MSFG 550, a seed source of var. rigensis from the southern tip of Sweden, after four and eight I I I 29 months growth I I I I I I I I I I I I I Seedling of’MSFG 23h, a seed source of var. altaica in central Siberia, after four months growth. . . . . . . 3l Seedlings of’MSFG 530, a seed source of var. baguen- ensis in Belgium, after four and eight months growth. . . 35 Seedlings of’MSFG Shl, a seed source of var. haguen- ensis in northeastern France, after four and eight 36 maths growth I I I I I I I I I I I I I I I I I I I I I I Seedlings of'MSFG 20h, a seed source of var. hercynica from Germany, after four and eight months growth. . . . . 37 Seedlings of MSFG'2hO, a seed source of var. uitana in southern France, after fOur and eight months growth. to Seedlings of MSFG 218, a seed source of var. iberica in Spain, after four and eight months growth. . . . . . . h2 Iii; I I I I Seedling ofFMSFG 263, a seed source of var. armena in the Georgian SSR, after fOur months growth . . Root growth of eight seed sources of Scotch pine grown 80 days in tile greenhouse I I I I I I I I I I I I I I I I 56 Figure P359 15. Root development of seedlings of MSFG 5h? from north- cexltral SWGdCU o o a e a I I o o o o o I e I o O I O 60 16. Root development of seedlings of MSFG 5A3 from south- central S‘Jeden I I I I I I I I I I I I I I I I I I I I I 61 17. Root development of seedlings of MSFG 256 from central Siberia. . . . . . . . . . . . . . . . . . . . . . . . . . 62 18. Root development of seedlings of MSFG 307 from Czech- o SlovaLXia I I I I I I I I I I I I I I I I I I I I I I I 6h 19. Root development of seedlings of MSFG 253 from western we 8 t Gernany I I I I I I I I I I I I I I I I I I I I I I 65 20. Root development of seedlings of MSFG 239 from the Cen- tral Massif of France. . . . . . . . . . . . . . . . . . . 67 21. Root develOpment of seedlings of MSFG 2&5 from the 68 I I I I I I I I I I I mountains of Spain . . . . . . . . . 22. Root development of seedlings of MSFG 2H3 from the mountains of Greece. . . . . . . . . . . . . . . 70 I I I I I 23. Height and total lateral root length for five seed sources of Scotch pine transplanted with no root prun- ing at five different times. . . . . . . . . . . . . . . . 85 2h. Length of absorbing (white) roots of Scotch pine as affected by date of transplanting, intensity of root pruning at transplanting time and seed source. . . . . . . 93 Absorbing 25. Ratio of *‘T‘jgf-'*.Lateral root length of Scotch pine tranSplantegofrom September through November and sub- Jected to no or one-half root pruning. . . . . . . . . . . 99 2’ Root-shoot ratios of five seed sources of Scotch pine O o as affected by transplanting date and intensity of root pruning I I I I I I I I I I I I I I I I I I I I I I I la 27. .Moisture loss from potting mixture consisting of 98 percent (by weight) coarse, quartz sand and 2 percent organic matter. I I I I I I I I I I I I I I I I I I I I I I 11.8 28. Top growth of three seed sources of Scotch pine at nine moisture-fertility treatment combinations . . . . . . 126 29. Tap root growth of three seed sources of Scotch pine . . . 131 at nine moisture-fertility treatment combinations. . viii . 5...... Figure 30. 31. 33. 3h. Page Lateral root growth of three seed sources of Scotch pine at nine moisture-fertility treatment combinations. . 133 Growth of Spanish MSFG 219 at two moisture-fertility combinations: low moisture-high fertility and high mOiSturE’low' fertility. o o o o o o 0 o a 0 O 0 0 ' 0 ‘ ‘ 1'35 Growth of German MSFG 253 at two moisture-fertility combinations: low moisture-high fertility and high moisture-low fertility. . . . . . . . . . . . . . . . . . 136 Growth of Swedish MSFG 5&3 at two moisture-fertility combinations: low moisture-high fertility and high HIOiSCure-IOW fertility. o o o o o o o o o o e o o e o o o 13? Shoot-root ratios of three seed sources of Scotch pine grown at nine moisture-fertility treatment combina- tions 0 o o o e o o a o o o o o e e o e e o o o o o e o . 1&3 ‘ ‘ ... .,.A . “N .. I~ ‘-s “‘IJ ..~ ‘Qqfl. ‘-.‘J 'I CHAPTER I DETRODUC TION Scotch pine (Einus sylvestris L.) is native over a wide geogra- phic area in Europe and Asia. Its range reaches from above the Arc- tic Circle in northern Scandinavia to Spain and Turkey in the south and from Scotland in the west to northeastern Siberia near the Pa- cific Ocean in the east. In southern and western EurOpe the range is discontinuous. In other areas it is generally continuous over large areas (Figure l). Scotch pine has also been introduced exten- sively outside its native range. It is now the most commonly planted species for Christmas tree use in the united States. Many trees are also planted for reclamation, stabilization and wood production. Within its natural range Scotch pine shows wide variability. This variation has been the subject of a number of provenance stu- dies (reviewed by Wright and am, 1963 and Ruby, 1961;). Ruby (1961+) recognized at least 21 geographic varieties of the species. In the late 1950's an intensive provenance study of Scotch pine was initiated at Michigan State University as part of the NC-Sl pro— Ject, ”Forest Tree Improvement through Selection and Breeding." With the cooperation of researchers and seed dealers in Europe, lots of Scotch.pine seed were collected from 186 stands throughout the range of the species. These were sown in the Bogus FOrest Research Nur- sery on the Michigan State University campus in the springs of 1959 and 1961. Five replicates were used. The first four of these com- Prised a randomized complete block experimental design. These were used to study characteristics of seedlings of different origin in 1 ui-I: “a... 0 . O‘~v-‘ -y- ung- ‘A' . no... a» 'V'dvy b._. '~-, "v (‘ " _u Ct" v .1. hi 2 the nursery. Results of this study were published by wright and Bull in 1963. The fifth replicate provided seedlings for field planta- tions. These replicated plantings were made at 33 Permanent loca- tions in eight north central states, plus New York and Maryland. Initial results from these plantings were reported by wright et_§l. in 1966. Measurements made in the nursery and outplantings revealed sig- quicant differences between provenances in a number of shoot charac- teristics. These generally showed definite geographic trends. In most instances there was little interaction between seedlot and lo- cation of test plantation, despite the wide variety of sites on which plantations were established (King, 1965a and 1965b; Wright 393;” 1966). When seedlings were lifted from the nursery for outplanting there seemed to be distinct differences in root types. These also appeared to exhibit geographic trends, although this was not substan- tiated'by detailed studies. In general, southern origins appeared to be more tap-rooted than those from further north. In lifting half or more of the tap root and most of the lateral roots were often lost on southern origins. On more northerly origins less of the root sys- tem was damaged or lost in lifting. In subsequent outplantings, how- ever, there was no apparent correlation between damage to root sys- tems during lifting and survival. It was generally best for southern Provenances and poorest for northern ones. CHAPTER II OBJECTIVES The general objective of the studies reported here was to inves- tigate variations in root types of different geographic origins of Scotch pine in‘an effort to help explain differences in top growth and survival after outplanting. Specific objectives were: (1) Tb classify the root systems of Scotch pine provenances and to relate differences to the climate of place of origin. (2) To study the pattern of root develOpment of different Scotch pine origins for the first twelve weeks after seed germination and to relate these patterns to differences in the climate of place of origin. (3) To determine the survival, root growth and root regeneration Potential of Scotch pine of different origins when transplanted at different times of the year. (h) To study the growth of Scotch pine from widely separated Portions of the species range when grown at varying moisture and fer- tility levels. CHAPTER III VARIATION IN ROOTS OF GREENHOUSE GROWN SEEDLINGS OF DIFFERENT SCOTCH PINE PROVENANCES There have been numerous studies of variations in root systems of different tree species. Touney (1929) classified the root types of tree species into two general groups: those with tap roots which grew rapidly downward and penetrated deeply; and those with slowly growing primary roots and extensive, rapidly growing lateral roots. Holch (1931), found that each of the several species of tree seedlings which he studied had its own characteristic root tyre. Studies have shown pronounced differences in root types of vari- ous conifer Species. These include investigations of Corsican pine (Aldrich-Blake, 1930), Douglas-fir (icMinn, 1963), Jack pine (Cheney, 1932; Day, 19h), Kaufman, 19%)), loblolly pine (Gruschow, 1999), lodgepole pine (Preston, 1942), longleaf pine (Heyward, 1933; Lemort, 1939; Pessin, 1935), pitch pine (McQuilhen, 1935), ponderosa pine (Curtis, l96h), red pine (Day, l9hl), shortleaf pine (Turner, 1938; Reed, 1939), and white pine (Stevens, 1931). There has been only limited study, however, of racial variation in the root systems of forest tree species. Snyder (1961) found teat roots of longleaf pine from southeastern Georgia appeared to be more fibrous than those of seedlings from farther west in the range of the Species. He theorized that the more fibrous root types had evolved in response to wetter summers and falls which prevail in the eastern part of the species range. Leibunigutiamd Dafis (1962) observed differences in root types and extents of four provenances of European h V1 larch. Son differences have also Teen noted for Scotch pine. ) excavated roots in native Scotch pine stands in Laitnknri (1929 central and southern Finland and found differences in both type and extent of root systems. The study of Leibundgut and Dafis (liil) with four central European provenances showed variations ‘1 dry weights and diameter distribution of roots. Bibleriethor (l96h) worked with a number of German provenances o” Scotch pine which had been planted in 193/ and found that tap roots of sources from the East Prussian area were more clearly defined, deeper and less branched than those of provenances from west-central Germany. 6 mocmms For this study #5 seed sources of Scotch pine were selected from throughout the range of the species. The seed was originally collected for a provenance study conducted by Wright and Bull (1963). Each seedlot was gathered by cOOperators in EurOpe and.Asia from ten or more average trees in stands of several acres (Table 1, Figure l). The climatic data were compiled by'JOhn L. Ruby (196%) and are from weather stations located as closely as possible to the stands from which the seeds were collected. In most cases the data apply to the area of collection; in a few cases to stations some miles from Poca- tions of collection. .An "Index of.Aridity“ was calculated using De- Martonne's (1926) formula: Index.= precipitation in mm. . The temp. inUé‘T». 10 smaller the index value, the drier the climate. Seedlings were grown in the greenhouse for periods of four and eight months using a randomized complete block design‘with four rep- lications and two trees (containers) per plot. Seed was sown in Jane nary 1965 in individual containers, with five seed per container. The containers were approximateky 8 inches deep and h inches square. Germination began nine days after sowing and was completed eight days later. TWO weeks after germination the seedlings were thinned to one per container. The potting mixture consisted of one-third (by volume) each of builders sand, peat moss, and a sandy loam nursery soil. {A complete fertilizer had been added to the mixture to give the equivalent of approximately Sijpm.each of N, P205, and.K20. This coarse, porous mixture permitted unrestricted rooting and recovery of the root systems with a minimum.of damage. The seedlings were watered at intervals to keep the moisture Table 1. Location and climate at place of origin of Scotch pine provenances used in the study of differences in root types. 8 We" ta. 12mg. 11". :5;- nfiro Wei Rama 1?:de of minty (a) I I Inna; Kin-Ho Elma! Apr-1L Audit! Sb) Sept. Sept. Anus Apri - “pt. 0 {cit “E 5i; Iii‘flloterl nunbor at. 3055011113 - 258 313 60.8 131.6 2500 -11.6 8.1 188 185 188+ 8.0 255 518 52.8 117.7 2000 * 3.3 11.3 377 382 28.8 16.1 var. la lice 589 sue 68.5 18.7 800 0.6 8.0 893 310 86.7 17.2 588 aw: 63.5 18.7 700 2.0 8.5 568 299 87.3 16.2 587 swx 62.5 15.7 700 2.9 9.1 525 332 80.7 17.8 5&6 3w: 60.9 13.8 1500 1.2 8.6 617 383 55.1 20.6 var. oeptentrlomlil 523 an: . 16.0 700 8.8 11.3 557 358 37 6 16.6 588 sun 60.8 18.9 800 6.2 12.6 630 387 38.9 15.8 222 SUE 60.2 15.0 800 8.8 11.3 557 358 37.6 16.6 583 sue 59.9 12.0 700 6.2 12.6 630 387 38.9 15.8 273 SN: 59.7 9.5 600 3.2 10.0 811 882 61 8 28.1 var. rtgeuil 582 sws 58.8 18.3 800 6.2 12.6 630 387 38.9 15.8 581 sun 57.0 15.6 500 6.2 11.8 533 338 32.9 15.3 550 sun 55.9 18.1 100 6.9 12.0 868 266 27.7 12.1 var. sluice 256 SIB ” 56.7 96.3 1300 1.8 9.3 289 191 21.1 9.9 238 513 56.0 95.0 600 1.8 9.3 289 191 21.1 9.9 var. pglonicn 317 pox. 53.7 20.5 500 7.1 13.6 568 372 33.2 15.8 var. here ice 208 can EL' '50.8 9.7 1300 8.6 18.1 592 337 31.8 18.0 527 can 50.8 13.7 1800 7.5 13.1 786 829 82.6 18.6 528 023 50.6 12.0 1500 7.7 13.8 608 388 38.8 16.6 311 as: 50.5 18.7 1000 9.0 15.6 890 335 25.8 13.1 526 can 50.8 12.2 1700 6.2 11.9 762 87.0 20.3 307 oz: 89.9 17.9 800 8.8 15.5 630 807 33.5 16.0 306 c2: 89.2 18.0 1500 8.2 18.1 606 828 33.3 17.6 var. h 211011018 318 BEL c .2 5 5 -- 9.3 13.8 825 816 82.7 17.5 530 BEL 3c; 50.0 5 0 -- 7.8 11-9 1251 570 71.9 26.0 2&1 m &9.1 7.8 800 9.2 18.7 738 388 38.2 15.5 251 can 89.1 8.1 500 9.9 15.5 536 305 26.9 12,0 253 can 89.1 7 8 1300 9.5 15.0 612 338 '31.8 13.5 237 PEA 88.8 7 8 500 9.8 15.7 777 881 39.2 17.2 Var. illaicn 282 rue 83.9 19.8 1300 9.5 16.0 791 881 80.6 17.0 var. rhodo 283 cfii?"£===81.5 28.2 5600 7.8 12.7 2860 1190 181.8 52.8 551 can 81.3 23.8 5000 7.8 12.7 2860 1190 181.8 52.8 var. (Ir-on. 221 m " 80.5 32.7 5000 11.6 17.7 385 187 16.0 5.3 263 can 81.8 83.8 3800 12.2 19.1 533 357 28.0 12.3 268 GED 81.7 83.5 900 12.2 19-1 533 357 28.0 12.3 261 050 81.6 82.6 3800 12.2 19.1 533 357 28.0 12.3 var. aqua- 235 PEA 88.2 7.2 2200 8.9 18.5 1372 699 72.6 28.5 239 FRA 85.3 3.7 3100 9.0 13.9 780 503 81.1 21.0 316 228 85.1 3.5 3200 9.0 13.9 780 503 81.1 21.0 320 IRA 85.0 8.0 3000 9.0 13.9 780 503 81.1 21.0 238 m 88.7 3.8 2900‘ 9.0 13.9 858 885 85.2 18.6 280 ran 82.6 2.1 8700 5.9 9.9 799 812 50.3 20.7 var. iberica 285 sai“"' 80.7 -8.2 8900 11.9 17.5 508 268 2 .2 9.6 218 spa 80.0 -5.3 3700 10.0 15.3 366 178 1 .3 6.9 m. Influx-0 are thou and T- the “ch. 8510 hnfifiutlc oceanic- record. The countries m Eula, ”ho-lent“, Mice. Wu m, outlay, “loco, Davey, 8301-10, 8111:, Mel, “My. mm. (b) 1.8.; .f "a“, . Precipitation 1- Inn-tor. 1‘ . o. (c) Good chained fro- M“... Figure 1. Natural distribution of Scotch pine (shaded) and pro- venances included (numbered dots) in the study of differences in root types. In addition to those provenances shown, four additional sources from the eastern portion of the range (MBFG 238, 258, 255, 256) were also used. 10 11 level near field capacity. At the end of the growing periods, con- tainers were taken from the greenhouse, dumped and the root systems carefully washed. The trees were measured immediately. All analyses of variance were conducted by using means of the 2-tree plots as items. ProvenanCe me a: were need as itecs in ccr~ relation calculations. v — 12 RESULTS The data were grouped by the geographic varieties proposed by Ruby (1968). The patterns of root development generally followed Ruby's varietal patterns based on seed and 2—year growth character- istics and 5- to T-year growth in rec-51 plantations (Wright 3111;, 1966). Departures from Ruby's groupings are discussed whenever appro- priate. Summaries of analyses of variance are given in Table 2. Results obtained at four and eight months were similar. Corre- lation coefficients between measurements made at the end of the two sampling periods ranged from 0.856 for tap root lengths to 0.988 for height (significant at 1 percent level with 83 d. f.). In general the amount of growth during the second four—month period was considerably less than during the first four-month period (Tables 3,8,5). Top growth, in terms of both length and weight, was very slight, ranging from O to approximately 15 percent. Tap root growth was also rela- tively slight, the second four-month increase in length varying from 6 to 22 percent; in weight from 0 to 30 percent. Lateral growth dur- ing the second fbur-month period was greater; increases in length varied from 10 to 70 percent and increases in weight from 25 to 75 per- cent. The percentage increase between the feurth and eighth month was not correlated with location or climate at place or origin (Table 1). There were decided differences in root characteristics of seed- lings from different origins. Many'were adaptive characters which could be correlated.with environmental conditions in the areas from which seed was collected. Some could not be correlated. Seedlings of all provenances were tap-rooted. The degree to which this 13 Table 2. Summary of analyses of variance for tOp and root growth factors studied in sampling Scotch pine provenances after four and eight months growth in the greenhouse. lb. Factor F ratios for sampling at Four Months Eight Months pr Length 7.02*** 27.25*** Tap Root Length lh.22*** 18.08*** Lateral Root Length 8.92*** l3.h0*** 'Ibp Weight 20.33!“ 23.2%» Tap Root Weight 1.6.66”! 59.33% Lateral Root Weight 8.62% 11+.51fl-H Tap Root Weight/Unit Length 22.19%H 27.18am TbtaieRogg Length 3'51*** 9-59*** 292 weight . Total Root Weight 1‘20"“ 5 99"" Total Lateral Root Length 1+. 25*“ 5.61m Taproot Length Loggest lateral Root Length 5.59”, Lesmm Taproot Length Lateral Root weight *** No.: Total Lateral Boots 9.28*** 15.68*** No.: Lateral Roots, Unbranched 9.15*** 15.h6*** No.: Lateral Roots, l branch 8.68“ 10.38*** No.: Lateral Boots, 2 branches 9.72*** 10.90*** No.: Lateral Boots, 3 branches 5.98”“ 11.112!“ None 2.85*** No.: Lateral Roots, h‘branches (a) With Rh degre *** Significant at 0.1 percent level. es of freedom in treatment (seed source) mean square and 132 degrees of freedom for error mean square. 15 Table 3. Shoot and root development of Scotch pine provenances grown four months in the greenhouse. U. M 331:] I \ 16 W th 6 fl. of W $6?th Ratio-1‘30“. Ratios country or m p . loot 10111701527. Orw- Root Root th ".1Eat. 551 Eng": 71 Unit 5;. E. lateral Lateral :ngth ungth Height fipmot Tlproot 7!";er 2: :1- 2 «alluigrul-I- moles. 3E;- -— var. IO lien 255 315 a: 13 80 2£ 7 16 .23 .036 1.03 6.1 1.16 2.3 255 an 22 112 £0 10 25 . 6 .029 1.15 5.0 . 2.» var. 12 ea 5£9 s 30 18 89 16 7 15 .38 y .029 .75 5.0 .70 2.£ 5£8 8w: £1 19 12£ 25 7 22 .35 .028 .88 6.5 .90 3.3 557 an £0 20 116 25 8 2£ . 3 .030 .78 6.0 .80 2.9 5£6 av: 37 19 92 2£ 7 20 .38 .033 .89 £.9 .67 2.8 var. amnion-118 523 av: 22 126 31 10 27 .£3 .029 .87 5.6 .73 2.7 5“» M £5 23 127 28 12 29 .52 .031 .9£ 5.£ .81 2.1. 222 swx £3 21 115 30 9 32 .£3 .032 .93 5.£ .63 2.6 5£3 swx £2 21 117 32 11 33 .51 .030 .95 BA .77 2.2 273 you 35 22 99 27 12 22 .51 .029 .80 .£ .79 1.9 var. 1159.818~2 912 m 22 117 32 9 25 .£1 .030 .9. 5. 3 .80 2.9 551 m £3 21 133 31 9 25 .£2 .028 .78 6.3 .95 2.8 550 an ££ 2k 1£2 37 - 12 28 .51 .027 .93 5.9 .83 2.3 m. duh}. 256 sha— £2 2£ 159 39 11 3£ .£5 .023 .86 6.6 .78 3.2 23£ 8n £3 2£ 150 37 9 38 .39 .025 .79 6.3 .89 £.2 var. lonica 317 2%_— £8 2£ 187 55 1£ £0 57 .023 1.02 7.6 1.00 2 9 var. Mug 2 20£ OER c 7 2£ 156 £9 1£ 36 .57 .026 .99 6.6 .78 2.6 527 am £7 2£ 161 £2 12 32 .£9 -026 ~96 6-8 a 2-‘95 528 on 1:9 27 161 ££ 12 31 do .027 1.0£ 5-9 .68 g 311 cz: £6 26 1££ ££ 11 29 . .028 1.11 5.6 .78 2.2 526 on ££ 22 1£1 £1 11 29 .£9 .027 Lot 2.3 - 2.“ 307 (2.: £8 26 158 £0 12 29 .£7 -026 -97 t -79 2- 306 cu ££ 26 1£0 £3 12 28 .£6 .027 1.08 5. .53 -3 var. not. 318 an. 25 173 £8 13 36 .53 .025 1.00 7.1 .89 2.: 530 an. 55 30 276 79 17 56 .56 .018 1.09 9. .90 3.7 2£1 m 51 32 222 5': 13 39 .£5 .020 1.01 6.9 1.33 2.9 253 am 5£ 25 230 59 1£ 51 .58 .021 .91 9.3 .81 2.0 237 m 53 25 192 £3 1£ 27 . .02£ 1.09 7.9 . . var. 111 m 100 £9 23 187 59 18 51 .79 .02£ .86 8.2 .95 2.8 var. rhodo .£ .99 2.6 253 on: 9 27 201 67 16 1.2 .60 .022 1.20 7 551 can 50 26 162 59 16 3h .60 .026 1.20 6.3 .97 2.2 m. m - 221 m‘ _ £7 30 166 65 21 £3 .72 .32 1.02 2.2 g: :3 263 on) £8 28 159 61 21 £2 .73 - 59"? 7-8 1.00 2. 6 26's on) £9 26 198 78 23 59 -90 .022 1.16 6.1 79 1.9 261 cm £7 25 1£7 67 20 38 . .027 . . . 7». flattens 235 m u. 25 1£8 £3 12 29 .50 3 1'35 2'3 :3; it 239 m ££ 2£ 16£ 58 17 to -70 .026 93 6.2 .17 2.3 316 m ‘3 25 157 ‘9 15 3S '61 ' 1°10 6.0 .71 1.7 320 m ££ 23 1110 £9 11 28 .72 .027 .9“ 6:2 .85 2.3 238 m £2 23 1£1 50 16 37 .71 .025 - 87 S 2 .85 1.3 2% m £2 25 130 £5 22 29 .89 .027 - - ‘ at. 1661-16. . as 5.7 .36 -9 255 an"— 50 36 168 80 £1 £3 1.32 .025 - . 1.0 218 an 52 £2 11» 89 £5 £8 1.09 at .95 J! 1" k . .16 .55 “0.10 3‘1 2’8 29 9 2.7 a .03 .3 1.: is; 'm .“ 0.05 2'7 3'3 5 1° 3'3 9 '0“ .03 '22 2.0 J5 -'7 an... .9 £. 1 n to 12 as - . . 17 Table h. Shoot and root development of Scotch pine provenances grown eight months in the greenhouse. 18 ms... L. th of ‘17.: ht or filo-Roofing“. Foot Ratios country of 5533! E:p L35. 5535? Top [38. Root ’pr th Wei 0:121:- Root Root Root Root wt./ 1.. th weight TBS-roacot “—guu Unit t. ht. Rt. Mural Lateral Length Length 1701 M. '“' 926935: 25£ an 32 15 90 2 8 255 an £0 2£ 119 £2 11 g :2: 8:8 1:22 3 3 1:82 :3 VII. 1. ‘eg 5‘9 STE-mg 20 105 18 5‘3 3“ W 21 13£ 26 g 23? “8 m2 '58 5 ‘ .75 2.3 5..., 8“ £2 21 172 26 10 £ .39 .02 .66 6 £ 1.02 3.9 SR6 av; 50 20 118 ° “6 '09? ~53 8 3 1.05 £.2 33 7 28 .36 .029 . 6 0 1.03 3.9 52;. sleztentrionaliu 5“ m 1. 25 158 3£ 10 35 .£1 .023 .75 6.£ .90 3.7 222 5 25 13° 38 13 £1 .55 023 72 7 2 1 3“ ‘3 22 171 35 10 £2 16 '02 '63 ° '03 2‘1 25:3 53': ‘3 26 187 3" 1* 35 '5». '02? '68 :2 1'3; 2'3; 38 25 155 30 13 31 .51 .021 .70 6:3 :97 2:£ :zz. risencie ' 39 27 175 3£ 1£ 55 , 511 an I12 2£ 175 33 11 36 :2 .020 .58 6 8 .92 3.7 55° N ‘7 28 o 422 .70 7 2 .38 3.3 195 *1 12 ‘19 .£5 .021 .68 7 2 .99 £.1 2:2. altaica sIB *3 25 206 £3 12 h a 9 0‘1 .019 072 801 1.01 ~02 3‘ sn “3 26 191 *1 9 '13 .3£ .031 .81 7 £ .87 £.9 var. Ionics 3" “’1‘ 5° 27 268 58 1£ 61 .53 .018 .78 9.8 1.08 £.2 var. here ca 9 28 202 2 1£ ££ . . . 527 cm: £9 28 217 27 15 56 .2; $8 26 8 g 138 §; 528 0'3 52 28 265 £7 13 59 .£5 :018 :66 9.3 .95 £.6 311 cu: ’39 28 23* #6 12 62 .b3 .019 .62 8.£ 1 01 5.1 3376 22!: :2 22: 2£2 53 15 35: .56 .018 .81 9.3 1:16 3.7 195 5 13 . .023 .95 7.£ .83 2.8 30‘ CZ! *8 27 198 £3 11 38 A: .021 .89 7.3 .81 3.2 var. cuensis . 318 am. 27 308 57 15 6o .56 .016 .75 11.6 1.10 £.0 530 BEL 58 31 36k 82 18 81 .60 .015 .82 11.6 1.09 £.£ 2'11 m 53 32 312 £7 1£ 67 .£5 .015 .60 9.8 .88 £.5 251 can 29 296 91 1£ 68 .50 .017 .78 10.2 1.16 £.7 253 01:3 53 26 328 60 16 70 .60 .015 .70 12.6 1.26 £.5 237 m 57 26 276 1.7 15 £7 .57 .020 . 10.3 1.0£ 3.1 var. 111 ice 21.2 m-a-E— 53 29 aka 69 18 61 .66 .019 .87 8.8 .93 33 var. rhodo 21. a 0 270 69 18 50 .57 .017 1.01 8.5 .86 2.7 552 (033: 21 3% 259 62 20 52 .67 .018 .88 8.5 .90 2.6 gifting 51. 36 306 71. 32 85 .92 .016 .2; 2.5 1.3; 2.6 . .01 . . . . 263 am 5" 3“ :33 SS 3; :3) .51 .018 .81 9.5 1.05 3.3 :21; cm 23 33 255 70 29 53 .95 .017 .77 8.5 1.28 2.2 cm var. aquitonl 11. 1.5 .50 .020 .65 7.2 1.20 3.5 ease-'— :: 2°: 33 1. .. ~71 2° 3-2 239 m £6 1 19 70 .63 .016 .5 .7 1. 9 3. 16 31 269 5 01 78 8 £ .91 2 £ 316 m 1.8 27 228 l'9 :3 ‘ 2:; :23 01? :77 8.9 1.01 2:7 3238 m "“ 28 :63: 3;: 2h 66 .71 -°16 -55 7'3 '93 2'7 21.0 m "5 3" ‘ . .015 .6h 6.9 .61 1.5 var. 1berict 5“ #6 312 81 21 76 {.33 .020 .79 5.2 .51 1.£ 215 521 58 .5 2£5 9° 9 218 521 / 8 2.1 10 em .Om I: :0: 0;; o; 2.8 3'0 :3 10 3-3 12 ‘09 $3 :06 2:6 .28 1:1 ”p.10 3.3 3.6 a 13 “.3 16 .11 ' 180.05 1.3 "°° III El»;|‘\.’v .1 x 11"], L§>x> 111". I‘ ) .x7ll 19 Table 5. Growth data for Scotch pine provenances grown in the greenhouse for four and eight months, summarized by variety. fli— 112-1715 -I' ' 5L 1:1); 'n-M—k 2O :4 mm. o.w «w. So. 84 we. on 8 m5 E on 328.4 o.m 84 m6 mo. So. 1%. 3 m4 om 3m mm 3 303:? emu 84 hum mp. So. 8. E. mm 1:. 4% mm mm 83.8 ohm mm. no mo. So. mo. 4m m4 .8 3m 4m 4m 3383." m.m mm. mo 5. So. 8. 4o 3 mm gm mm mm 84.8344 4 . a mo. 4 o. 44 in 26. mm. mm m4 8 4mm mm mm 3808483 ohm mm. :6 2.. omo. on. on :4 w: mum E 3 848803 «.2 84 m.m we. m8. mm. 6 :4 mm mom S on 882cm 0: E. 6;. 3.. omo. 4:. 3 44 m: 34 mm m... 84348 h. m mo. 4. e. mm. 4.8. 3 . 13 «4 mm .54 mm m: 3303.4 m.m mm. o.h HP. mmo. ad. hm NH :m ova :m N: maadnoauanmvmmm 3.. 84 no 8. moo. m2. om m mm «M4 on on 848.84 w.m 84 a. m 4m. :8. .5. mm 3 mm 84 9 mm 82°38. 550.6 68.28. Emma 03.2 o4 mm . 12.: 4m. :8. .84 m... mg 3 4S mm .3 8834 do no. do 84 omo. mo. mm 3 m: 54 1a m: 334:3 do w». No mo4 mac. 2.. m: mm mo 84 S m: 88.8 :4 mm. mo 84 :«o. 8. on 3 mm mm." mo on 8888;.» o4 no. mo 8. :«o. 9.. 4m m4 3 54 mm m: 84.93 mg... 5. o6 S4 moo. mm. m: :4 mm «a S No 388203 9m N». do No4 So. 3. om «4 m: .34 mm 3 8486.23 mo 84 one. 84 mmo. R. 3 1.4 mm 54 :m w: 848400 ohm 8. no mo. :8. m2. om o4 mm :3 :m m: 84348 to cm. ma mo. moo. 3. mm o4 mm o? mm m... 3303." :.m mp. h.m om. omo. mg. om 0H mm mad NN a: waadaoauuampmmm m . m t. . o. m 8. omo. mm . ow 1. mm 84 S S 848384 m.m 3. ea 84 «mo. om. om m om mm S S 844098. 2858 22:3. naoh 03.2 IIIII 'III-HQEIIIIIIIII IIIIIIOH” III|§§II| CEO 05 DE 08023 E poo." 8.. a 3 682 438.3 3.803 4m 58.. .E .89 fig: 41833 $238 430m... 238: £33 \43 poem poem poem poem 0mm: 03 593 may moo poem . 0.3 08.4. 082m . 03 009 003m :1 mogoom moupmm pgmumoa mus m0 mamas 30.3.01? 21 characteristic was expressed, particularly in relation to the type and extent of lateral root development, varied greatly between individual sources and between different varieties. 22 The Northern Varieties These varieties cover the more northerly and colder portions of the Scotch pine range and include the following, as designated by Baby (196“): mongolica from northern Siberia; lapponica from north- centrsl Scandinavia;_§gptentrionalis from southern Norway, south- central Sweden, southern Finland and.adJacent parts or the USSR; Eéfisgfiég from southern Sweden, Lativia, and adjacent parts of the USSR; and altaica from southern Siberia. All northern varieties were characterized by distinct tap root development, with lateral root extension generally restricted to branching from the upper por- u‘m" 01’ the tap root. There was very limited lateral extension from the lower portions of the tap root (Figures 2, h, 5, 6, and 7). One source of var. mongolica, msm 25h from northeastern Siberia, "38 distinct in a number of ways (Figure 2). It was the smallest of all seed sources in all aspects of t0p and root development. Depth Of tap root was limited, more so than lateral root extension, so that the length ratio of longest lateral to tap root was high for this source (Tables 3, ’4, S). The area from which seed of MSFG 251+ was collected has a very severe climate (Table 1). The average annual temperature is extremely low (-11.60 C), the growing-season temperature is relatively warm (8.10 C), and rainfall is extremely low (115 milli- It appears that root systems of this source are adapted to meters)- ti n of factors. Shallow depth or r°°t1n3 18 probably'an this combina ° ter correlated with Permafm8t at a shallow depth in adaptive charac ion. of the reg 8 5h was collected is low and the large lateral The growing season aridity index fer the the soil area from VhiCh'MSFG 2 23 Figure 2. Seedling of 11816 25%, a seed source of var. mogolica in northeastern Siberia, after four months growth. 2h root extension in relation to tap root length may be a response to the dry growing season. Root characteristics of the Scandinavian varieties generally varied on a north-south gradient. However, MSFG 5h5 and 273 had much less lateral root growth than did many sources from further north. Root development (in terms of both depth of rooting and lateral ex- tension) and top growth were better correlated with annual tempera- ture than with latitude of origin (Figure 3). First year height growth data for seedlings of the same sources grown in the nursery (from Wright and Bull's data) also showed correlation at the one percent level with average annual temperatures (r = 0.86). Lateral root develOpment of seedlings of north-Swedish.MSFG 549 was similar to that of Siberian 25h. However, tap roots were much longer in 5H9 than 25k, possibly because average annual temperature was much higher (0.60 C) in northern Sweden than in northeastern Siberia (-11.60 C). Permafrost, if present, was probably deeper in the soils of the area from which MSFG 5kg was collected. This same characteristic of relatively greater tap root lengths in relation to lateral extension which was shown by MSFG 5H9 was common to all of the Scandinavian sources. Maximum tap and lateral root growth of the Scandinavian sources was shown bthSEG 550, the provenance from the most southern -- and warmest -- area from which seed was collected. Root development of three Swedish sources (usm 5&9, Ski and 550) is illustrated in. Figures h, 5, and 6. Attempts to correlate root development of Scandinavian sources with annual or growing season precipitation failed, possibly because moisture is not a critical factor in Scandinavia. (thice the Figure 3. Relationship between eight month growth of Seedlings \ -‘\ V H Scandinavian origin and average annual temperature of the area from which seed was collected. a. ? TAPjROOT IENGTII. . 28. r = 0.87“ 550.. 5 514.20 0. 26" 518' u E 213 5£3 5M4.- E 2‘”- 5hl. - E L ’32 22 - a h 51:8 5:7 20 " 509 ‘ 200 - b. LATERAL ROOT LENGTH 550.“ B. r = 009% $2.51”; 0 '1 g. 18° + 51:7 252 5151:5142 2 3 o '+ E 160L I 523 g IMO r 538 - .4 120 "’ 1 E 539 q 100 - S c. 10? mmm 5500 #6 _ 1‘ .—.. 0,73%!- 222 5“. . 5' h 557 . 2:3: . 2 " 5&8 5" . 5&3 5&2' 38 _ - g 2'73 m 3* - 5&9 ‘ 8 30 - ' I J L L J_ 2 3 h 5 6 . 7 AVERAGE ANNUAL MATURE, 0 c. 27 Figure ‘4. Seedling or MSFG 5&9, a seed source of var. Jamaica. in northern Sweden, after four months growth. l/ * V ' 545 3 . i- '9 IE‘I 12.? ‘_§WF 28 Figure 5. Seedling of MSFG Shl, a seed source of var. rigensis 1n south-central Sweden, after four months growth. 1’ 541 III 29 Figure 6. Seedlings of MSFG 550, a seed source of var. rigensis from the southern tip of Sweden, after four (top) and eight (bottom) months growth. ( l/ ‘V \. _ .!_ M 550 W 5“" 30 uniformly high aridity index values for Scandinavian provenances in Table 1). Ruby recognized two varieties of Scotch pine in central and eastern Siberia -- var. mongolica (25h, 255) in the north and east and var. altaica (23k, 256) in the Altai Mountain region of central Siberia. In doing this he used previous varietal descriptions pub- lished by the Russians, while recognizing the possibility' that recognition of more taxonomic entities might be warranted. In my work, the two seedlots of var. altaica were similar to each other and similar to seedlings of var. rigensis from southern Sweden, despite the fact that the Siberian climate is much more rigorous than that of southern Sweden (Table 1). The two seedlots of var. mongolica differed markedly, as they did in Wright and Bull's (1963) earlier study. usm 25h, from the far north, had very slow top growth, a short tap root, and a high ratio of lateral to tap root length. AMSFG 255, from southeastern Siberia, had faster top growth and a moderate ratio of lateral to tap root length. Root characteristics of’MSFG 255 were very simiLar to those of the central Scandinavian var. septentrionalis. 31 Figure 7. Seedling of’MSFG 23%, a seed source of var. altaica in central Siberia, after four months growth. 32 The Central European Varieties Origins from the following varieties from the central European area were used in the study: polonica from northeastern Poland; hercynica from Germany and Czechoslovakia; baguenensis from Belgium, northeastern France (VOSges Mountains), and western West Germany; and illyrica from Yugoslavia. Root characteristics of seedlings from central Europe were distinctly different from those of Scandi- navian sources. Central Eur0pean sources had more moderate expres- sion of the tap root characteristic and more extensive lateral root . extension along the major portion of the tap root than did origins from further north (Figures 8, 9, 10). Varieties haguenensis and polonica were similar in root charac- teristics, but were different from other central EurOpean types. Seed- lings from these varieties had much longer lateral roots than did provenances from almost any other portion of the species range. Bel- gian seedlings (MSFG’SBO) of var. haguenensis had the greatest lateral length of all. Because of the extensive lateral lengths, origins from these varieties had the most favorable balance between top length and lateral root length. In some cases side extension of lateral roots was very great in relation to depth of rooting (Figure 8). In other cases, lateral roots were concentrated in a columnar area close to the main tap root (Figure 9)- The origins from.varieties polonica and haguenensis were also more branched than those from other portions of the species range (Table 6). Wright and Bull (1963), Wright and Baldwin (1957), and Wright Table 6. Number of lateral roots per tree and proportion of lateral roots having no, one, two, three or four branches of Scotch pine at ages four and eight months. 3h O. O. O. o. O. oomnfi O. o. o. O. o. o. o. O. comps moose comps H. I”. O. O. o. O. O. o. o. m. o.H m.a m.a o.a H.m o.m o.m e.a m.H m.a m.H :.H m.m m.H w.a H.N H.N m.a m.m O.N H.m m.m N.N N.N o.m m.mm H.bm m.em H.mm m.mm o.wm m.mm m.mm m.mm a.mm m.wm m.wm m.wm o. o. o. O. O.H H.H H.H m.H m.H N.H o.H N.H o.a N.H m. m.m m.m m.w N.N m.m N.N m.m H.N m.m m.m m.m m.m w.m m.mm m.mm m.mm m.om m.mm m.mm 0.0m s.mm e.om m.mm m.mm m.mm s.mm nuunnunuununauuuudmuop mo unooaomnnuuuanuuunnuun :. m N A O omnosden mo amoadz mopqoa m as masthead Hence no noepsomshm m N H o monocmhn mo Masada mnpooa.m,vm mafia mma mafia mmm mmm mafia mm» bmoa no» cam sow Ozm wow m 0mm awn mo» owe me» :wm 4mm mom mm» own man mm: Mm: unpoos, menace :, memo pm weep non mpoou Hmaoumq Hmpoa seasonw deceased unease doomedosn sunshade manomsoswnn seashoamn wofisoaoa «canvas mHmGoMHu maamslopcopmmm mafioommna woaaomqos hpoaaw> 35 Figure 8. Seedlings of MSFG 530, a seed source of var. haguenensis in Belgium, after four (top) and eight (bottom) months growth. ml l 530 IBM 36 Figure 9. Seedlings of IBFG 2&1, a seed source of var. nensis in northeastern Rance, after four (top) and eight (bottom) months growth. ~_. / ~§ ”*6 ‘N .‘ \3 H. ~ a-~ * v F r __ \ _ .0 ‘ ‘ \. ~ __‘, \\ \ ‘ ‘_ J. '«M‘ I ‘N “ii .;"‘ -7-” E 1-.- ‘1 “ ’0' ' 1 \>\, .. r ' 7” " ». ." “’ , -- —— . 37 Figurelo. Seedlingsofmzoll,aseedswrceofvar.hemca frm Ger-any, after four (top) and eight (bottom) months growth. {l J g. “A i «’4 raw-.. . ~ ‘9'.- ..n_._r. k, _ 204 L GEE l 4f ‘f -1.“ I“, .1" ”’3 1 , , ,- a 204 Ml _ 1-15:8. 38 et al. (1966) found that the fastest growing provenances of Scotch pine came from varieties polonica and haguenensis. It seems probable that the rapid growth of these varieties is associated with the extensive lateral lengths and branching of the root systems. Roots of these seedlings occupy very completely the volume of soil in which they are growing, making maximum use of soil moisture and nutrients in the rooting zone. The sources from variety herecynica were similar to those of var. haguenensis except that they had consistently smaller lateral root lengths and they were less branched (Figure 10). MSFG 2&2 from Yugoslavia (var. illyzica) had root characteristics unlike those of other central European provenances to which it is similar in foliage and growth. This source, from an isolated portion of the range to the south of the continuous range common to the central European types, had roots similar to some of the southern varieties. Unlike the Scandinavian sources, root characteristics of central European sources, were not correlated closely with climate at place of origin. This is possibly the result of free interchange of genes in the more or less continuous pepulation and climatic fluctuations in post-Pleistocene time. There is usually a lag between climatic change and evolutionary response to that change so that one need not expect perfect adaptation of modern genotypes to their particular microenvironments. 39 The Southern Varieties These varieties cover the discontinuous southerly portions of the Scotch pine range and include the following varieties: var. aguitana from the Central Massif of France; var. iberica from Spain; var. rhodopaea from.Greece; and var. armena from Turkey and the Georgian SSR. As a group these varieties differed from those of northern and central Europe. In many characteristics the southern varieties also varied from each other. .All southern origins were tap rooted. This was eXpressed in general appearance and high weight per unit length of the roots. They also had less branching of the lateral root systems (Table 6). Tops of southern seedlings were heavier per unit length than those from northern and central EurOpean varieties (Tables 3, h, 5). Seedlings from.the Central Massif of France (var. aguitana) had root systems similar in appearance to those of northern varieties. They were tap-rooted and the majority of lateral roots grew from the upper portions of the tap root (Figure ll). Lateral root lengths fer this variety were generally longer than those of the northern varieties and were comparable to those of central European var. hercynica. Root systems of var. aguitana were less branched than in var. hercygica however (Table 6). Top weight per unit length was also higher for var. aguitana than for central European or northern origins. Root length was not correlated with climate at place of origin within var. aguitana. Neither could the similarities in root types between these sources and northern ones be explained on the basis ’40 Figure 11. Seedlings of were 21:0, a seed source of var. gsuitana in southern France, after four (top) and eight (bottom) months growth. W 240 . FDA ‘ “9 1'15 ‘51.! alt-uh an? t hl of climate. Temperatures in the central Massif are generally much higher than in northern Sweden and Siberia. It is possible that this root type may reflect an evolutionary response to weather con- ditions during Pleistocene gLaciation. At that time, prevailing temperatures in the Central Massif would have been much colder than at present. This might have favored the develOpment of types having lateral rooting near the surface areas, Just as in present northern varieties. The two sources from Spain (var. iberica) had the most dis- tinctive root systems of all sources investigated (Figure 12). They had significantly longer tap roots than all other origins. Weight per unit length of the tap root was also significantly greater than in any other source, northern or southern. Lateral roots were generally short, but numerous and extended from along most of the tap root length. As a result the root systems had a narrow, columnar appearance, with the highest percentage of total root weight in the tap—root. Lateral roots of var. iberica had the fewest branches per unit of length of all sources. The tops of Spanish seedlings were also significantly heavier in relation to their length than in other origins. This was not due to greater number or weight of needles, but to diameter (and possibly density) of the stem. The strong tap roots of Spanish origins appear to be adaptive to Spanish climatic conditions (Table 1)- Temperatures there are relatively high and precipitation is low. Effective precipitation is very low, as indicated by the small aridity index values. There are periods during mid-summer when precipitation 112 Figure 12. Seedlings of NSFG 218, a seed source of var. iberica in Spain, after four (top) and eight (bottom) months growth. i to :9. LIII ha is only 10 to 20 millimeters per month. Under these conditions seed- lings having a deep tap root with laterals concentrated along its length have a decided advantage in withstanding soil moisture deple- tion and drought conditions in the surface layers. The seedlings of var. armena and var. rhodopaea came from three isolated areas in southern portions of the Scotch pine range -- from Greece, Turkey and the Gerogian SSR (Figure 1). All of these sources exhibited less branching than sources from further north, but none had the narrow, columnar root type of var. iberica nor lateral root- ing confined to the upper portion of the tap root as in var aquitana (Central Massif of France). Greek origins (var. rhodopaea) were characterized by less pro- nounced tap root development than those from Georgia and Turkey (var. armena). The Greek provenances exhibited lower weights per unit length and more branching of lateral roots than did seedlings of var. armena. The Turkish and Georgian sources (Figure 13) were nearly alike except that the Turkish origin had deeper tap roots. Differences between var. armena and var. rhodopaea are probably associated with climatic differences. The Greek provenances were collected from areas with very high rainfall and comparatively low temperatures, resulting in very high aridity index values. The Turkish and Georgian seed, on the other hand, were collected in areas of limited precipitation and comparatively high temperatures, re- sulting in very low effective precipitation. The lower weight per unit length of tops and root systems of the Greek sources was appar- ently a reflection of the more moist conditions under which they grow naturally. In this respect the Greek and south French sources Figure 13. Seedling of MSFG 263, a seed source of var. armena in the Georgian SSR, after four months growth. are similar. The distinct differences between the<3eorgian-Turkish and Greek populations may be explained by the migration barrier between the two, and the relatively slight differences between Turkish and Georgian sources to the absence of a distinct migration barrier. h6 Evolutionary Development of Root Systems The root characteristics of different geographic origins of Scotch pine are as distinct in many ways as the tOp characteristics described by wright and Bull and Ruby for the same seed origins. In most cases the variation in root type coincided with the varia- tion in top characteristics. In a few, however, variations in root type should be used as the basis for modification of the described varieties. EVOlution of root systems appears to reflect the degree of isolation, Pleistocene history, and prevailing climatic conditions in the area of seed collection. In southern areas the trees grow in more or less isolated stands located at high elevations. These threats were south of the polar ice cap during Pleistocene times. ENolution has probably proceeded uninterrupted for a much longer time than in central or northern EurOpe where the species was oblit- erated during glaciation except for remnants in some of the higher mountainous areas. Exchange of genetic material between the Central Massif of France, Spain, Greece, Turkey, the Georgian SSR, and pos- sibly Yugoslavia was limited. The distinct root types are apparently a reflection of this isolation. Turkish, Georgian and Spanish origins show adaptation to the warm, dry climate which prevails while Greek origins reflect the more moist climate of the area from which seed was collected. In the Central Massif of France, isolation has appar- ently contributed to a distinct genetic lag between root types and prevailing weather conditions. Seedlings from this area have root systems which appear to have develOped in reaponse to Pleistocene 1:7 climatic conditions. During Pleistocene glaciation, most of the range of Scotch pine in northern Europe and Asia was obliterated. The surviving remnants, probably in the Scandinavian highlands, the Ural Mountains or a part of Siberia, were well differentiated prior to glaciation. Reintro- duction of the species occurred from these well-differentiated rem- nants and extensive and more or less continuously forested areas were eventually formed. Exchange of genetic material has probably been quite free over large regions. Root types within regions ap- parently developed in response to selection pressures operative in particular areas, although it is also probable that sources still reflect their pre-Pleistocene ancestry to a considerable extent. Temperature variations appear to have been the principal factors af- fecting differentiation in the northern areas. The central European region had a different evolutionary his- tory. Most of the region was covered by Pleistocene glaciation. Repopulation probably occurred from the north and south -- from the Scandinavian highlands and possibly the urals in the north and from the Alps and Carpathian Mountains in the south. This rein- vasion from well differentiated pre-Pleistocene remnants eventually formed extensive and nearly continuous stands. This provided for a free interchange of genes in most areas. Because of the diversity 0f pre-Pleistocene remnants, the genetic base from which the modern central European populations evolved was probably much greater than in the northern or southern portions of the Scotch pine range. Root tYPeB of provenances from the central European.area appear to re- flect this free interchange of genetic material and diverse gene pool. CHAPTER IV EARLY ROOT DI‘JVLSIOPIEITI.‘ PATEHIS or SCOTCH PETE PROVEIEANCES A number of investigators have studied the seasonal patterns of root growth of different tree species. As reviewed by Kramer (l9h9) and.Kramer and.XOZlowski (1960), these studies have generally demon- strated large differences between species in such factors as rate of growth, total amount of growth, length of the growing season, cyclic nature of growth periods and optimum gr wth requirements. There has been little work, however, relating differences in root development for provenances of the same species. Leibundgut and Dafis (1962 and l96h) found variations in rates, duration and total amount of root growth of different central European origins of Scotch pine and European larch. They noted differences in time of completion of the grand period of root growth, but not in the time when growth started. Differences in root elongation might also be implied from dif- ferences in top growth patterns. wright and Bull (1963) reported variation of over two months in date of first-year bud set between the most northerly and southerly provenances of Scotch pine used in their stump Brown (1967} found differences in seasonal rate of top growth and length of the growth period for five provenances of Scotch pine from western Europe. h9 PROCEDURE Eight seed sources of Scotch pine were selected representing a north-south transect through western EurOpe, plus one source from the southeastern part of the range and one from central Siberia (Table 7). Each seedlot was originally gathered by c00perators in Europe and Asia for use in the Scotch pine provenance study conducted by wright and Bull (1963). Seed collections were made from ten or more average trees, usually in stands of several acres in size. The climatic data were compiled by Jehn L. Ruby (l96h) and are from weather stations 10cated as closely as possible to the stands from which the seeds were col— lected. In most cases the data apply to the area of collection; in some to stations some miles from locations of collection. .An "Index of.Aridity" was calculated using DeMartonne's (1926) formula: Index = precipitation in'mm.’ The smaller the index value, the drier the temp. in 0C. + 10 climate. Seed was sown in individual containers in the greenhouse in Jan- uary 1965, with five seed per container. The containers were approxi- mately 8 inches deep and h inches square. Five replicates, with two tree plots, were used and the two trees in each plot were located in adjacent containers on the greenhouse benches. Germination began nine days after sowing. Five days later the seedlings were thinned to one per container. The seedlings were two days old and still retained their seed coats. The potting mixture used consisted of one-third (by volume) each of builders sand, peat moss, and a sandy loam nursery soil. A complete fertilizer was added to this mixture to provide approximately 50 ppm each of N, P205, and K20. This medium provided conditions for 50 OH + .00 3H waspwammaoa .88 CH noapwpfimgomhm I NonH momma .mqqoppaemnv ”spueaa¢_ao ameaH Any .UHOOoa Gowmmoooo moflposoo vmouom madam nmmfinofiz map a“ com: mmonp who mamnfidz Amv o.m m.mm sew mOm m ma m.ea m.aa com: m.:- v.0: gamma mam :.mm :.H:H omHH omsm a oa e.ma a.» comm m.:m m.H: «emote mam o.am H.H: men one > ma m.ma o.m ooam ~.m m.m: mondnh mmw m.ma :.Hm mmm mam a ma o.ma m.m cema w.» H.ms suaanmo mam o.wa m.mm ho: 0mm b m m.mH m.w com m.~a m.m: .Aoono hem m.m a.am Hod Hem m m m.m w.a OOMH m.mm h.mm mauvnum wmm : . 3 m .wm Sm 08 w w m. «a m . m 02. o . ma m. an 532m men s . S v.3 mmm mmm m a. 1m m. m ooh e. 3 name 533m 5m -------amaa:nu--uc- --mumpmaaaaaauu -uuamnase--- .oo .oo ammo o o .pmmm .pmmm .amum namauo -Hasme HannaMI -Hnnae damage .000 ..000 uaauae Hugged .m .2 mo Adv .oz. 332:3 mo 33 833335 $3.4 manual mfipflmmame :68 .33 2.23 .9258 E .msuoppom pawsaoambuo noon mo gauge a“ eons mova50m doom comm mafia nopoom mo sawaao «0 woman as massaao and soapwooq .h manna 51 unrestricted rooting and recovery of root systems with a minimum of damage. The seedlings were watered at intervals to keep moisture near field capacity. Ten days after germination the first lot of containers was taken from the greenhouse and the root systems were carefully washed and measured. This procedure was repeated five more times at two week intervals, giving a sequence at ages 10, 2h, 38, 52, 66, and 80 days after germination. Data for each individual sampling were ana- lyzed separately by analysis of variance using means of the 2-tree plots as items (Table 8). m Table 3. Analyses of variance for root growth of Scotch pine progenies sampled at lh-day intervals (a). ihctor F ratio at ages 4_ 10 2E 38 52 76 ‘56 Gal? days days days days days Tap root length 3.h** 5.3*** 1h.1*** ll.5*** 8.7*** 7.3*** Lateral root length 2.6* 2.2 5.u*** 6.1*** 6.8*** l3.2*** Tap root weight -- -- -- 28.9*** l9.9*** 52.0*** Lateral root weight -- -- -- ll.7*** 8.3*** 8.8*** Total root weight ll.T*** lh.2*** 2h.6+** 22.3*** 15.9*** 21.9*** Tap root weight per unit length -- -- -- 12.3*** l0.0*** lT.O*** No.: Total Lateral Roots 2.3* lh.2*** 2.8*** 3.3* 8.8*** 12.5*** No.: Lateral Roots, 2.8* 2.1 2.7* 3.3* 8.5*** l2.l*** Unbranched No.: Lateral roots, l branch —- -- 2.9* 5,5*** 5.3*** 6.5*** No.: Lateral roots, 2 branches -- -- -- -- 3.S** l2.0*** Lateral Root Length 2.6* h.5** h.h** u.3** u.o** 6.9*** Tap Root Length (a) With 7 degrees of freedom in treatment (seed source) mean square and 28 degrees of freedom for error mean square. * Significant at 5 percent level. ** Significant at 1 percent level. *** Significant at 0.1 percent level. 53 ROOT Davaomnnr name All sources exhibited distinct tap root development throughout the eighty-day sampling period. The lengths of the tap and lateral roots varied considerably among sources however. Initial root development of all origins was confined exclusively to tap root extension (Table 9, Figures 15-22). At ten days a few sources showed traces of lateral root formation, but there were no appreciable number of laterals until 38 days after germination. In general, lateral root length did not exceed tap root length until 52 days after germination. The rate of tap root elongation remained nearly constant for the first 2h to 38 days, depending on seed source. Then the rate generally declined. Lateral root elongation showed an opposite type of de- velopment. It was very slow during the time when tap root growth was greatest. After tap root elongation declined, lateral length increased rapidly in each successive lh-day period (Figure 1h, Table 9)- Northern Provenances. The northern origins were MSFG 5h? and 5N3 from Sweden and.MSFG 256 from central Siberia. They had some characteristics in common to distinguish them from.more southern origins. Early tap root elongation was more rapid than in more southern provenances. This was particularly so in Siberian 256. At each of the first five samplings, seedlings of this provenance attained the highest proportion of total tap root elongation of all sources. They completed over 90 percent of 80-day tap root extension by the 52nd day (Table ll)- Sh Hm. mm. mm. Hm. 0H. mmo. omH Add Mb .aaemm .eoemmo .eecemm .sueemme .enxusoaeosomno .ennmmHm .aoemzm “av 111 mam men so no we m an on om mm mm oH Ho.nmq oH.H we. ms. as. ea. smo. as me H mm mm mm an we a mo.nmq mm.m om.a oa.a am. am. :00. ms» on: How mma om moans mam «mm mmm mma one gm emm new as.m mm.a es.a me. we. woo. 0mm so: :Hm waa Hm mma an a mmm man can manna bmm Hem mam oma maa m: are mam om.m mm.H OH.H :h. om. NHO. Ame mzm mum Jam mea am a mam mam mom sea oaa a: mac mmm has «0.: om.m mm.a mm. cm. omo. wmaa Hum ms.m Hm.m em.a mm. mm. mmo. mum an: men find em a Hmm How me.m Om.m os.fl em.H mm. nee. mam mum «mm mam ms m Hum mum mom om.m ma.m mo.a mm. mm. mmo. mos em: dam asa mm H saw mad mwa Hm. moo. me: can mom oaa an a wsa sea mma mud mm new a m an“ to Bosfioz m~.m m©.H mm.H mm. IIlIIIIII!I-%MII‘I$I'IIIII In...I!!III&.H®P®SHH.HHBIIIIIIII| IIIIIIIIIQHQPOGHHHIHHSIIIIIIIII Imwde when name name when made om on mm mm am omi. when made when made mane made made when name name made made onnamfiao n. 0A 000% Hmonmwfis WUWQH 900% mama... «903.90% Summoa poem adhopmq .mam>nopna hoouaa pm conducts moosmsm>oam mafia nopoom mo mspwsod poem .m manna 55 Figure 1%. Root growth of eight seed sources of Scotch pine grown 80 days in the greenhouse. 56 8 8 3 ‘HLSNH'I .LOOH mm ‘UJD § gage Em ES mama so menses ow on. om 8 L3 0m om S ow 2. ow on 0: om om oa I d I - 1 q . new I ........ mam .II.|I.|I mmm-.l.l.lii mum 5m. I....l....l .. h..--..--..-.. mew—find Boom gas .9 mac? Boom mg .6 n p n p n p T n b p b n p h b - ‘ 0 OJ 57 Table 10. Dry weight of roots and relative dry weights of tap roots of Scotch pine provenances measured at lh-day intervals (a). “seedlot, fair Root Weight at Age Tap Root Weight TapToot Weight Country of 10 2h 38 52 ’66 ’80 as percent of per unit of Origin(b) days days days days days days total root length at day: weight at 25%: 52 66 #80 52 -------- dmilligrams---------- ---§ of total-- --mg.ZmétEr--- Northern Ori ins 557 SW3 1 3 5M3 SHE l 3 256 SIB 1 3 1 h 8 10 15 69 113 no 36 31+ 31+ 7 12 1h 22 61 h? 82 38 38 #2 o 15 21 29 53 113 37 38 1+0 119 Central EurOpean Origins 307 can 1 3 7 11 16 26 6o 51 A3 33 12 A8 253 GER 1 3 7 1h 22 31 61 86 38 A9 h6 h8 Southern Origins 239 FRA l 3 8 12 15 25 68 58 13 no no 53 2A3 GRE 1 h 9 15 19 31 6o 58 hi #2 h? 50 2h5 SEA 2 7 17 25 32 uh 75 60 58 78 77 88 LSD.05 .3 1.1 2.2 3.0 1.7 5.3 8 16 15 h 10 11 LSD 01 .h 1.5 3.0 h.o 6.3 7.2 12 21 18 5 11 15 (a) Tap roots and lateral roots were not separated during weighings at days 10, 2h, and 38. (b) SWEden, SIBeria, CZEchoslovakia, GERmany, FRAnce, GREece, SEAin. 58 Lateral root elongation also started early in the northern origins. They exhibited the highest percentages of maximum lateral elongation at ages 2% to 66 days (Tables 9, 11). This characteristic was also very pronounced in MSFG 256. The northern provenances had another distinctive trait. Most of the lateral roots grew from the upper portions of the tap root (Figures 15 - 17). Central European Provenances. The central European provenances used were MSFG 253 from western West Germany'and.MSFG 307 from Czech- oslovakia. Their rates of tap root and lateral root growth (expressed as a percent of the maximum attained during the study) were consis- tently less than those of northern sources. However, the ultimate lengths attained were greater for central EurOpean than for northern provenances. The German and Czech origins had two characteristics in common to distinguish them from other sources. These were: the lateral roots were more branched than those of other sources (Table 12); and lateral roots grew from the entire tap root. Seedlings of MSFG 253 had the longest lateral roots, but only moderately long tap roots. The ratio of lateral to tap root length was greatest for seedlings of this source. The number of branched lateral roots in 80-day seedlings was significantly greater for this than for any other provenance. The lateral roots of MSFG 307 were not so extensive as those 0f MSFG’253. The ratio of lateral to tap root length was approxi- mately the same in the Czech source as in MSFG 2H3 from Greece and MSFG 256 from Siberia. 59 Table 11. Percentages of maximum (80-day) tap root and lateral root length attained at lh-day intervals in eight seed sources of Scotch pine. Seedlot, Percent of maximum tap root Percent of maximum lateral Country of length at age of root length at age of Origin(a) 10 2h 38 52 66 80 10 2h 38 52 66 *80 days days days days days days days days days days days days ----------- percent----------- -----~-----percent----------- Northern Origins 5h? sws 23' A8 73 87 98 100 .1 6 23 #2 60 100 5&3 SWE 2o #6 71 87 92 100 .2 6 21 an 62 100 256 SIB 23 #7 75 93 100 100 .3 5 26 #3 67 100 Central European Origins 307 CZE 18"‘Hh 68 85 87 100 .2 h 18 31 5h 100 253 GER 19 Ah 67 82 88 100 .1 3 19 31 A8 100 Southern Origins 239 FHA 17 #1 6h 82 86 100 .1 3 19 35 53 100 2&3 GRE 19 A5 70 81 85 100 Trace 2 12 31 L6 100 2A5 SPA 18 M6 67 81 90 100 Trace 5 19 35 56 100 (a) SWEden, SIBeria, CZEchoslovakia, GERmany, FRAnce, GREece, SRAin. 60 .nogmafiahmm nevus was“. was Hangs 23 33.35 wfigoom nude beach. among." 56625 Equal—anon 8.£ Sm cam: no $5388 no pqmsnofisoe poem .3 683a 61 a; 2.. 1 @Qm 1 N106! 1 . 1 .nosmqfiaumm ARCH 936 no 90955 93 3.335" mqfigmom nose rodeo. 2095.2 1.. gm 1 .3625 gaooufisou an.“ men E Ho mwuamom Mo 3250.353 noon .3. gm 62 ‘ll/ .aoapSfiEom 338 926 no guess 65 383 3.388 n68 8H8. 235.: .6238 338 39G mum Eu. .8 @5863 no egg poem .5 swam 63 Table 12. Number of lateral roots per tree and proportion of lateral roots branched once or twice(a). Seedlot, ‘Lateral roots per tree at age Prgportibn of lateral: branched Country of 10 ‘2H2 38 52 66’ ‘80 Once Twice Origin(b) days days days days days days 38’ 52 65* ‘80 56’ 280 days days dais days days days --------- --numger----------- ----- ercent------ -percent- Northern Origins 557+SWE 1 20 53 102 136 192 6 6 5 5 o 1 5u3 SWE 2 22 71 150 206 288 7 h 5 5 o 1 256 SIB 3 25 9h 155 231 329 8 5 5 5 Trace 1 Central Eurgpean Origins 367—023 2 2h 75 136 216 305 6 6 6 5 Trace 2 253 GER 2 28 83 166 258 395 6 7 6 5 1 2 Southern Origins 239 FRA l 21 68 131 197 266 8 7 S 5 0 Trace 2H3 GEE l 19 71 138 202 325 6 6 6 5 Trace l 2h§ SEA Trace 17 88 138 176 263 S 8 7 T O l LSD,05 1.6 7.3 22 31 3h #9 - - - - - - LSD.01 2-3 9-8 30 h2 h6 65 - - - - - _ (8) Through the 28th day all laterals were unbranched. Remainder of lateral roots (to total of 100 percent) were unbranched. (b) SWEden, SIBeria, CZEchoslovakia, GERmany, FRAnce, GREece, SRAin. 6h .11. 503358 head was no .8935 on» 3.83.95 manage some 3H3. 939852 .dabamonoouo Eon.“ 8m E mo mwfigmmm Mo uncamoaobme poem .ma 0% 65 .noapmqfiahmw your? when no 93:5: 23 3.8.33 gamma nose ~5an 938.5: .58 use: 5368. 8.£ Rm ca .8 $3868 .8 engages poem .3 chasm 66 Southern Provenances. The three southern provenances were col- lected from stands in isolated portions of the Scotch pine range. MSFG 239 came from the Central Massif of France; 285 from the moun- tains of Spain; and 2&3 from the mountains of Greece. In type of root system these origins varied from more northern sources and from each other. They had three characteristics in common: long tap roots; relatively little branched lateral root systems (Table 12); and a significantly low ratio of lateral root to tap root length (Table 9). Seedlings of MSFG 239 resembled northern trees in some ways. Tap roots were pronounced and laterals confined principally to the upper portion of the tap root (Figure 20). Rate of growth of tap and lateral roots (as a percent of the maximum) was slower than for northern origins. In fact, tap root development was slower for 239 than for any other source up until the 52nd day. Seedlings of MSFG 2h5 had the longest and heaviest tap roots of all sources. This was true at all sampling times. Rate of tap root extension (as a percent of the maximum) was approximately the same as for the Greek, German and Czech sources, but was slower than that for the northern origins (Table 11). The weight per unit length of the tap roots of MSFG 2115 was nearly double that of any of the other seven provenances (Table 10). Lateral root lengths of seedlings of'MSFG 2h5 was moderate and occurred as relatively short extensions along much of the tap root. The root systems of Spanish No. 2&5 assumed a narrow, columnar appearance (Figure 21). Rate of lateral root growth was slower for Greek.MSFG 243 than any other origin despite the fact that total lateral length after 80 days was the second longest of all origins. Lateral extension occurred 6? <5. 1 new 1 1 1 503330» Mourns 903 no hoe—5n 23 3335 goon some 1.6.39 gonna—z .33 H0 Huang H9380 23. 8h mmm OE MO ogre HO naugdgou voom .ON 0.33% 68 me 1 mo 1 1 ht rt. 1 //u1 I) ‘1. /1T.. an 11. (1%)!) (I- x o— m 5&1. xuxzmr 1 1 -H..Hfi7-.€fl / .- x ,. 7 1 i. r ._.. 7 _ “#72 .nogmqaahom Mourns choc no 9085.5 3.... 3.63.05 wagon node sodas 0.3956 .515 .8 33:83 B» so...“ 3m 89 .8 85.868 .8 peaceagoe room .3 char— 69 along much of the tap root of seedlings of 2&3 and individual lateral roots were not so restricted in length as in MSFG 2h5 (Figure 22). The rate of tap root growth of 2h3 was not so slow as that for Lateral root growth. It was approximately the same as that of the Spanish, German and Czech origins, but was slower than that of the northern provenances. 7O ”10 “(N .noapaanom .3de E36 Ho Hon—En can 333 33.33 :03 33.3. «.3955 .3095 no 3358. on» an.“ mam E no 55.303 no psmBAOHobod 900% .mm 0.3th 71 RELATION OF ROOT TYPES AND GROWTH PATTERNS TO CLIMATE OF.AREA OF ORIGIN The rapid rate of root elongation of the northern provenances is probably related to low temperatures in the areas of seed collec- tion. Temperatures were lower for the three northern areas than those of the locations from.which the other five seed sources were col- lected (Table? ). The length of time during which growth would occur in the northern areas was also less than that for the other regions. .Average monthly temperatures were above freezing for five, seven, and eight months, respectively, in the areas of origin of 256, SHT, and 5%3; they were above 60 C. for five, five, and six months, respectively. The rapid rate of root growth of the nor- thern origins would enable seedlings to make maximum use of the limited period when temperatures would be favorable for growth. Variations in rates of root growth.of the three northern provenances seem.to further substantiate this conclusion. Per- centage rates of root extension were greatest fer the Siberian provenance. The area from which this seed was collected also had the lowest average annual temperature and the shortest period when temperatures were above freezing. MSFG 5h? had the second fastest rate of root growth and was collected from the area having the second coldest climate. msm 5&3, with the third fastest growth rate, came from the third coldest area of seed collection. Root types of northern origins also appear to reflect the cold environments in which they evolved. Lateral root extension was con- centrated near the top of the tap root. This could be an adaptive 72 character related to permafrost or relatively low temperatures at shallow depths in the soils of the areas of seed collection. Root development of seedlings of Spanish 245 also appear to be related to climatic factors in the area of seed collection. Mois- ture, rather than temperature, was probably the factor governing development of the distinctive root type of this provenance. The region of origin is relatively dry and warm (Table 7). Tbtal precipi- tation during the year averages slightly over 500 millimeters and growing season rainfall is only about half this amount. Precipitation during the growing season (April-September) is low and in.August it averages less than 20 millimeters. Temperatures were the highest of all areas of seed collection. The growing-season aridity index, which is a measure of effective precipitation, is lowest in Spain. Soil moisture loss would be great under such conditions. Rapid and deep penetration of the tap root, with extension of laterals along much of its length, would be particularly'beneficial adaptive characters for the establishment, survival and.growth of seedlings. Root development of the other four provenances could not be cor- related with climatic data for the regions of seed collection. This possibly indicates that climate is not particularly critical. Aver- age temperatures were not extreme: average annual temperatures ranged from 7.h° C. for the Greek provenance to 9.50 C. for the west German area and growing season temperatures ranged from 12.7° C. to 15.50 C. Precipitation did not appear to be limiting either. Growing season rainfall ranged from 338 millimeters fer the West German source to nearly 1200 millimeters fer the Greek origin. There were no months when precipitation was critically low and averages were generally 73 50 millimeters or greater per month. Aridity index values appeared to be favorable for all sources. No clues could be found in the weather data as to why percent- age rates of root elongation were unusually low for tap roots of French 239 and lateral roots of Greek 2h3. Precipitation-tempera- ture data for the areas indicate very moist conditions. The aridity index for the Greek area was the highest of all areas of seed col- lection and that fer the French area was second. CHAPTER V EFFECT OF AGE AND ROOT PRUNING ON ROOT DEVELORIENT OF SCOTCH PINE SEEDLINGS OF DIFFERENT PROVENANCES Numerous studies have noted variations in survival of tree spe- cies when transplanted at different times of the year. In general, these have shown that survival is lowest when transplanting is done during the period when top growth is most active. Drought has been given as the major cause of seedling mortality and this has been re- lated to the inability of seedling root systems to supply moisture as rapidly as it is lost from the tops. This is caused, in part, by greater use and loss of water during the period when height growth is most active (Kramer, 1932 and 19h3; Kozlowski, 19h3; Gibbs, 1958). It has also been shown that regeneration of new roots following transplanting varies with time of year. It is apparently greatest in late fall after top growth is completed and in early spring before top growth commences and is lowest during the spring and summer months when top growth is taking place (Neff and O'Rourke, 1951; Wilcox, 1955; Stone, 1955; Stone et al., 1959a, 1959b, 1962, 1963). 7k 75 PROCEDURE For this study, five seed sources of Scotch pine were selected, representing a north-south gradient through western Europe (Table 13). These sources are identical with those of the same MSFG number re- ported by Bull, Ruby, wright, King, and various other NC-Sl members (Wright and Bull, 1963; Ruby, 1961+; King, 1965.3 and l9o5b; Wright ‘gt_gl., 1966). Seed was sown in the Michigan State University Forest Research Center Nursery at East Lansing, Michigan inlMay 1965 using a randomized complete block design with four replications. On July 20, approximately one month after germination, six seed- lings from each seed source in each replicate were lifted from the nursery beds without visible damage to any roots. Two seedlings from each seed source and replicate were then subjected to one of three intensities of root pruning. These three were: removal of all lat- eral roots over three millimeters in length; removal of half of the lateral root system; and removal of no roots. After root-pruning, each seedling was transplanted into an in- dividual container and the roots were covered with a potting mixture consisting of two-thirds (by volume) 20 to ho mesh quartz sand and one-third shredded peat moss. This mixture contained complete fer- tilizer sufficient to provide SOppm each of N, P205, and.K20. The seedlings were then placed in a greenhouse in the same order as in the nursery beds. The seedlings were grown in the greenhouse for 30 days. They were watered at intervals to maintain moisture at a level slightly below field capacity. The trees were then removed from the pots and 76 Table 13. Location and climate at place of origin of Scotch pine seed sources used in tran3planting study. MBFG no. and ngation Average Months Annual Country of Lat. Long. Elev. Annual Above Precip. Origin (a) N E Temp;_ 6° C. o 0 feet 00. No. mm. 218 SPAin 140.0 -5.3 3700 10.0 7 366 21:0 FRAnce 12.6 2.1 1:700 5.9 6 799 251 GERmany 1.9.1 8.1 500 9.9 7 536 550 SWEden 55.9 1h.l 100 6.9 6 1:68 51:8 SWEden 63.5 18.7 700 2.0 1+ 568 (a) Numbers are those used in the Michigan State Forest Genetics accession record. 77 the root systems were carefully washed. Measurements were then made on survival, top length, total lateral root length, and absorbing lateral root length (Tables lb and 17). The latter was defined as the white or unstberizcd portion of the lateral root system and was also approximately equal to the amount of root elongation which oc- curred during the 30 day period when seedlings were in the greenhouse. This procedure was repeated at monthly intervals until November 20, when the final (fifth) transplanting was made. The entire study therefore used a split-split plot experimental design, with time of transplanting as the main effect, the seed sources as the sub-plot effect, and intensity of root pruning as the sub-sub-plot effect, with 2-tree plots replicated four times. Two variables, survival and absorbing lateral length, were con, sidered of primary importance because they were affected most by the transplanting. The other two factors, total lateral root length and top length, were measured because they indicated stage of seedling development at time of transplanting. Complete statistical analyses were made for three of the vari- ables measured, survival, top length, and absorbing lateral root length (Table 15). Analyses of total lateral root length were made only for seedlings transplanted in September, Octdber and Nbvember with no root-pruning (Table 18). High mortality after July and Aug- ust transplantings resulted in many missing plots. Statistical analy- ses of the fifth variable studied (length °f ‘1‘)”er lateral 1’00“) total lateral root length were confined to seedlings which had received no or half root pruning and which had been transplanted in September or later (Table 18). Analyses of root~shoot ratios were made for total lateral length shoot length 78 absorbing lateral length shoot length for trees with no, half and full root pruning (Table 20). for trees with no root pruning and for 79 RESULTS Survival Survival varied significantly due to time of transplanting, seed source, and treatment (Tables 1h, 15). Survival was low for all trees transplanted in mid-summer, especially for those which suffered the most drastic root pruning. It was moderately high for trees trans- planted in September and nearly 100 percent for trees tranSplanted later. The differences between August, September, and October trans- plantings were statistically significant (1 percent level). There were significant (1 percent level) time-seed source inter- actions. The three most southerly origins (MSFG 218, 2h0 and 251) had very low survival after transplantings in July and August and achieved 100 percent survival only after November transplantings. The two Swe- dish origins (nape 5&8 and 550) had appreciably better survival in midsummer and reached 100 percent survival after October lifting. When seed sources were considered independently of time of trans- planting, MSFG'5h8 had significantly more (67 percent) living trees than other sources. .MSFG'SSO, also from Sweden, had the next highest survival (57 percent). Average survival of the three southern sources was h6 to #7 percent. The effects of transplanting on survival also varied with inten- sity of root pruning. Removal of all the lateral roots gave signifi- cantly lower survival than did treatments which removed none and one- hslf of the lateral root systems. Treatment-seed source interactions were not significant, but treatment-time interactions were. Trees hav- ing no or one-half root removal had low survival from July and August 80 Table 114. Survival and height of Scotch pine seed sourCes one month after transplanting with various intensities of root pruning. fate of MS??? Survival after removal Heighflb) Lifting No. (a) of the following portion of lateral roots present at the time of lifting None Half All ---------Ercent ----- ----- 9.1.3.: July 20 218 SPA 12 12 O 31 240 PM 12 12 O 26 251 GER 0 l2 0 31 550 SWE 25 12 0 30 5118 SHE 25 12 O 29 Aug. 20 218 SPA l2 l2 0 55 2% FRA o 12 0 1+7 251 GER 12 O O 63 550 SWE 38 25 0 51+ 5148 SEE SO 38 12 41+ Sept. 20 218 SPA 62 75 o 72 21:0 FHA 50 62 o 60 251 GER 50 62 0 101 550 SWE 75 75 0 70 51:8 SHE 100 100 62 53 Oct. 20 218 SPA 100 100 25 70 21K) FRA 100 100 50 61 251 GER 100 100 62 100 550 SHE 100 100 100 71 5118 SHE 100 100 100 51 Nov. 20 218 SPA 100 100 88 71 21+o FRA 100 100 100 62 251 GER 100 100 100 100 550 SHE 100 100 100 70 51:8 swn 100 100 100 53 (a) SPAin, FRAnce, GERmany, SWEden (b) Amount of root pruning did not affect height growth signifi- cantly . 81 tranSplantings. In later liftings the number of living trees in- creased, reaching 100 percent in October and November. For trees having full root pruning, there was no survival (except for MSFG 548) until after the October transplanting. 82 Table 15. Analyses of variance for survival, height, and length of absorbing portions of lateral roots of Scotch pine seed sources one month after transplanting with various intensities of root pruning. 'Source of variation Degrees of P ratios for freedom Survival Height Length of absorbing lateral roots Replication 3 -- -- -- Date of lifting u 572.0!“ 370.6%“ 3924.1”; Error a 12 -- -- ~- Seed Source h l3.8*** h09.3*** lhl.0*** Source x Date 16 3.0*** 32.9*** h5.5*** Error b 60 -- -- -- Treatment 2 59-8*** 209 355-5*** Treatment x Date 8 7.8*** .5 70.2*** Treatment x Source 8 1.6 .2 21.8*** Treatment x Date x n Source 32 1-8 °h 6°‘*** Error c 150 -- -- -- *** Significant at 0.1 percent level. 83 Top Growth Most t0p growth occurred before transplanting. Therefore, it was affected significantly by time of measurement, seed source, and time-seed source interaction, but not by intensity of root pruning (Tables it, 15). In all five seed sources tOp growth was completed by September 20. As shown in Figure 23 and Table 1h, MSFG 251 from Germany had a relatively rapid and constant growth rate throughout the growth per- iod. Approximately one-third of the total elongation occurred be- tween June and July, July and.August, and.August and September. MSFG 5h8 from northern Sweden had a decidedly different pattern. Over one- half of the total growth was completed by July 20 and over 80 percent was completed by August 20. Growth patterns of the other three sources were similar, with #3 percent of total elongation completed by'July’2O and approximately 75 percent completed by August 20. Seedlings of German 251 grew 100 mm. tall, nearly 30 mm. more than the next best sources, Spanish 218 and south-Swedish 550. Total top growth for south-French 2&0 was about 60 mm., while the maximum attained by north-Swedish 5h8 was a little over 50 mm.. 8h Figure 23. Height and total lateral root length for five seed sources of Scotch pine transplanted with no root pruning at five dif- ferent times. 85 .>oz .ooo .haom .ms< sash .>oz OZHBZ¢Ammz¢MB mo $8202 .ooo . gammy. ewflw¢ haze d .Inlo'oll Iv Emma OH 'CBHDIEH 'UIO Table 16. Percentage of end-of-season growth attained at various measurement dates (30 days after lifting dates). MSFG' Lifting Height ‘Tbtal length'wiength of absorbing No. (a) Date of lateral roots after removal roots of following portion (Applies to trees of lateral roots at with no lateral lifting time roots removed) None Half All "mu-Percent of end-of-season growth ------- 218 SPA July 20 #3 l l 2 ~- Aug. 20 76 5 9 6 -- Sept. 20 100 26 39 60 -- Oct. 20 100 95 100 100 9h Nov. 20 100 100 100 100 100 21+O FRA July 20 1+3 1 1+ 0 ~- Aug. 20 76 -- -- 6 .. Sept. 20 100 31 36 1'7 '- Oct. 20 100 89 88 9o 86 Nov. 20 100 100 100 100 100 251 GER July 20 31 -- -- 1 .. Aug. 20 63 6 6 -- .. Sept. 20 100 23 33 22 -— Oct. 20 100 97 100 96 100 NOV. 20 100 100 100 100 100 550 sws July 20 #3 S u l -- Aus- 20 78 7 7 5 -- Sept. 20 100 27 31+ 37 -- Oct. 20 100 9b 98 98 100 Nov. 20 100 100 100 100 100 5&8 SWE July 20 53 13 15 13 -- Aug. 20 83 18 31 25 38 Sept. 20 100 )+1 52 50 82 Oct. 20 100 89 98 98 100 Nov. 20 100 100 100 100 100 (a) SEAin, FRAnce, GERmany, swsden. 87 Total Lateral Root Length Only data for those trees which received no root-pruning and were tranSplanted from September to November were analyzed statis- tically. Differences due to time of transplanting, seed source, and time-seed source interaction were significant. The growth pattern was very different from that for top growth. Root growth was very slow during early- to mid-summer when top growth was greatest, but root growth continued much later than did top growth (Tables 17, 18). .Although data for July and.August transplantings were not ana- lyzed statistically, there were probably time-seed source interactions. After the first transplanting the two Swedish sources had the great- est total lateral root lengths. By the time of the August trans- planting, the laterals on German 251 were about as long as on MSFG 5H8. .After that the German source was constantly ahead. Spanish and French trees produced few lateral roots in the early months and did not catch up to the north Swedish trees until October. The German seed source, MSFG 251, had a maximum total lateral root length of over 1100 cm., nearly 70 percent more than for Swedish 550, the source with the next longest lateral root length. MSFG 218 and 2&0 had total lateral lengths of about #00 cm., while trees of Swedish 5&8 attained a maximum lateral extent of 3&0 cm. The significant time-seed source interaction can be attributed mainly to differences between September transplanted trees and those transplanted later (Tables l6, l8) . or trees transplanted in Septem- ber, MSFG 251 had only about twice as long a lateral root system.as MSFG 5&8. In contrast, after OctOber and.November transplantings Table 17. 88 Lateral root length of Scotch pine seed sources one month after transplanting with various intensities of root pruning. 'fiate of .MSFG Lateral roots one month Ratio: "‘ lifting No.(a) after removal of the fol- Absorbing lowing portions of lateralsi_ Total "Totnl Length Absorb..Length Roots Removed— None Half All None Half_§ll None Half All_ --------- centimeters---------- ---number---- July 20 218 SEA & 6 -- 2 3 -- .38 .50 -- 2&0 FRA 5 1 -- 5 1 -- 1.00 1.00 -- 251 GER -- & -- -- 2 -- -- .50 ~- 550 sws 32 2 -- 8 2 -- .25 1.00 -- 5&8 sws && 21 -- 10 13 -- .22 .62 -- Aug. 20 218 SEA 21 17 -- 8 10 -- .&0 .59 -- 2&0 FRA -- 19 -- -- 10 -- -- .50 -- 251 GER 65 -- -- 15 -- -- .23 -- ~- 550 sun &6 19 -— 1& 1& -- .29 .71 -- 5&8 sws 63 38 15 20 2& 15 .31 .63 1.00 Sept. 20 218 SPA 108 1&6 -- 38 100 -- .36 .69 -- 2&0 FRA 125 115 -- &9 80 -- .39 .70 -- 251 GER 26& 1&9 -- 88 89 -- .33 .59 -- 550 SWE 188 158 -- 62 107 -- .3& .68 -- 5&8 SWE 1&2 82 27 32 &8 26 .23 .59 .98 Oct. 20 218 SPA 393 360 30 100 168 27 .26 .&7 .90 2&0 FRA 362 319 50 92 152 &3 .25 .&8 .36 251 GER 1125 878 98 265 390 90 ..2& .&& .92 550 sws 6&2 599 59 178 282 55 .28 .&7 .93 5&8 sws 308 228 && 60 95 &0 .20 .&2 .98 Nov. 20 218 SEA &1& 332 50 98 155 &6 .2& .&8 .92 2&0 FHA &08 338 3& 103 170 50 .25 .50 .93 251 GER 1162 900 90 256 &05 86 .22 .50 .95 550 sws 685 580 58 181 288 53 .26 .50 .92 5&8 swE 3&5 226 &o 62 97 38 .18 .&3 .93 (a) SBAin, FRAnce, GERmany, SWEden 89 MSF'G 251 had nearly four times as 10% lateral roots as did msm 5&8. The roots of October transplanted trees of all seed sources were 90 to 97 percent as long as cm;Nbvember-transplanted ones; there were no significant time-seed source interactions fbr these months. For individual months, ranking of total lateral lengths remained rela- tively constant for the different seed sources. 90 Table 18. Analyses of variance for total length of lateral roots and for the ratio.§2%§%2%§§ lateral root length of Scotch pine seed sources measured one month after transplanting at various dates (a). Source of variation Degrees of Tbtal length . Ratio of freedom of lateral Absorbing roots Total lateral root 162591.. Replication 3 -- -- Date of lifting 2 105.3*** 207.2*** Error a 6 -- -- Seed Source h 89.3*** 8.&*** Source x Date 8 l£.6*** .3 Error b 36 -- -- Treatment 1 -- &10.0*** Treatment x Date 2 -- 7.0*** Treatment x Source & -- .& Treatment x Date K Source 8 -- .1 Error c 1+5 " " (a) Due to high mortality after the July and.August transplantings these variables were analyzed for only a portion of the data. *** Significat at the 0.1 percent level. 91 Absorbing Lateral Length The "absorbing" (white) lateral roots were approximately equal to the amount of lateral root growth which took place during the 30 day period when seedlings were in the greenhouse. This new lateral growth originated from two sources: new growth on the tips of exist- ing laterals present at the time of tranSplanting and new roots which originated near the ends of cut laterals. The majority of new growth on trees which received no root pruning was of the first type. Essen- tially all new root growth on root-pruned trees was of the second type. There were significant differences in length of absorbing lat- eral roots due to date, seed source, and treatment (Figure 2&). Also, all second- and third-order interactions were significant. There was very little new lateral root elongation on any source trans- planted in July and August. Progressively greater amounts of new growth were associated with September and October transplanting. There was than a leveling off, with essentially the same amount of new growth after November transplantings as after those made in October. All monthly differences except the JulybAugust and October- November comparisons were significant. There were pronounced differences among sources in the total length of absorbing laterals produced'by the end of the season (Novem- ber). The German source, MSFG 251, had the greatest absorbing lateral South SWedish 550 had the next greatest amount and root extent. north Swedish 5&8 the least. For trees with no root pruning, MSFG 251 reached a maximum of approximately 230 cm. of absorbing lateral Figure 2%. Length of absorbing (white) roots of Scotch pine as affected by date of transplanting, intensity of root pruning at trans- planting time and seed source. 93 waging .mo mazes .>oz .uoo .uaum .ms< hash .>oz .uoo .uaom .m:< ease .>oz .ooo .paom .ms< hash u .11 . . mam::.:.:..: . 0mm.l.llunll oom Hmm IIIIIIIII O+~N ell.l.|.'.' mam------ul I l 8: .0ng Boom E .o oZHZDmm Boom Egtfizo .9 0555mm Boom oz to n u - a p n P p F n h n - ‘Hmm moon ‘an 9h length after October and November tranSplantings, compared with 180 cm. fer MSFG 550, approximately 90 cm. for MSFC 2&0 and 218 and only about 50 cm. for MSFG 5&8. .Averages for trees receiving half or full root pruning were different from these values, but ranking of seed sources was the same. The ranking of seed sources also varied with transplanting date. North-Swedish 5&8 had the longest absorbing laterals after the July and August transplantings although it had the least amount of ab- sorbing laterals from September on. Conversely, German 251 had intermediate absorbing lateral lengths after the first two trans- plantings, but had the greatest amount when trees were tranSplanted in September or later. The pattern for absorbing lateral root length at different inten- sities of root pruning was very different from that described for sur- vival. Whereas survival was approximately the same for trees with no or half root pruning, average length of absorbing laterals was significantly greater on trees having half root pruning. There were also noticeable differences in amount of new absorbing laterals as- sociated with treatment after various transplanting dates. For trees transplanted in July and.August, the length of absorbing laterals was nearly the same fer trees which had lost half their laterals as for trees which had not been root-pruned. For trees transPlanted in October and November, the length of absorbing laterals was approx- imately 50 percent greater if the trees had lost half their laterals than if no root pruning had been done. Another dissimilarity‘between absorbing lateral length and survival was in the size of the treat- ment-seed source interaction. The average absorbing lateral root 95 length for half root-pruned trees of MSFG 251 and 5h8 was #5 percent greater than for unpruned trees. For MSFG 2h0 and 218 removal of half the laterals caused an increase of 75 percent in the amount of absorbing lateral length; for MSFG 550 the corresponding increase was 60 percent. Conversely, the reductions in absorbing lateral roots associated with complete removal of laterals was greatest for sources MSFG 218, 251 and 550 (75 percent), intermediate for MSFG 240 (60 percent) and least for MSFG 5h8 (#0 percent). 96 , Absorbing Root Length Ratio: Total Root Length If the amount of new root develOpment, or absorbing lateral length, which develops after tranSplanting is examined as a pro- portion of the total lateral root length, results are different than for the two variables considered independently. Although German 251 had the greatest absolute lengths for both total and absorbing laterals, this seed source produced significantly less relative absorbing surface than did.MSFG 218, 2&0 and 550." MSFG 5&8, on the other hand, the source with the least total and absorbing lateral lengths, had the lowest relative absorbing lateral root surface. Although Swedish 550 had much greater total and absorbing lateral root lengths than MSFG 218 and 2&0, all three seed sources had _absorbing length ratios. tmallugui Also, the proportion of relative absorbing surface decreased nearly the same constantly between the third transplanting in September and the fourth in October, despite the fact that absolute amounts of both total and absorbing lateral root lengths increased significantly during the same period. In other words, the amount of absorbing surface did not increase as fast as did total length. This pattern was similar for all sources and the time-seed source interaction was not significant (Figure 25, Table 17). The effects of root pruning were also significant. Those trees th which were half root-pruned had greater total length ratios than did unpruned trees. Of course, practically all roots were white and apparently absorbing on trees from which all original roots were removed. 97 There was a significant date-treatment interaction. The de- absorbi len th crease in relative totaIpfiengtg ratio from September to Octo- ber transplantings was greater for half-pruned than for unpruned trees (Figure 25). This decrease in relative absorbing surface con- tinued slightly from October to NOvember for half-pruned trees, but unpruned trees retained about the same ratio. 98 Figure 25. Ra io of Absorbigs Total t’iVlD +~w~v~r~~§1 V1..- n s a . ‘ 1c .lahsplanued 110m Septenrer thror no or one-half root pruning. 'I lateral root length of Scotch :gh no? fiber and susjected to uZHazegmm2¢ma ho_mazcx . >02 . poo . anew . >02 . poo . anew q 1 ommlllul Hum 9am .Iliiii Hm ............. . 02Hz=mm Boom muamnmzo .p m _ OZHZDmm Boom oz m D P If k D b 3OI$VH HIDEET I008 TVHEINT DHIEHOSEV HEDNET &OOH TVHHINT TVIOE 100 Root-Shoot Ratios There were significant differences in root-shoot ratios due to date of transplanting, seed source and intensity of root pruning (Tables 19 and 20 and Figure 26). All second- and third-order inter- actions were also significant. Root-shoot ratios were low for all origins transplanted in July and August. There were then signifi- cant increases in root-shoot ratios after September and October. transplantings, followed by a leveling off of ratios for seedlings which were transplanted in November. The ranking of seed sources varied considerably with transplant- ing date. North Swedish MSFG 5h8 had the highest (most favorable) root-shoot ratios after July and.August transplantings. By the time of the September lifting, ratios for the other sources generally equalled or exceeded those of MSFG 5&8. After October and November transplantings only those ratios for Spanish MSFG 218 which had been calculated using .Laial_%ggefgég%finaih were lower than the root- shoot ratios for msrs 5A8. There were pronounced differences among seed sources in root- shoot ratios at the Last transplanting in November. Based on ratios of totaltégtigiéfiength German.MSFG 251 had ratios which were nearly 20 percent greater than those of south-Swedish 550 and which were about twice as large as those for MSFG 2&0, 218 and ShB. Final root- shoot ratios based on absorbing lateral lengths were somewhat dif- ferent from those based on total lateral root lengths. MSFG 251 and 550 had ratios which were about equal and the ratios for these two sources were 150 to 225 percent greater than those for the other 101 Table 19. Root-shoot ratios of Scotch pine seed sources after transplanting with various intensities of root pruning. bite of MSFG .ii, Rootifihoot Ratio Lifting No. (a) Tot. Lat. Leigh AbsorbinLIateral Length Shoot Length Shoot Length (No root No Root Half Root Full Root ppruning) Pruning Pruning, Pruning July 20 218 SPA 1.33 0.50 0.92 -- 2&0 FRA 1.89 1.13 0.19 -- 251 GER -- -- 0.65 -- 550 swE 9.6& 2 &1 0.36 -— 5&8 sws 15.27 3.30 &.51 -- Aug. 20 218 SEA 3.85 1.56 1.75 -- 2&0 FRA -- -- 2.01 -- 251 GER 10.13 2.3& -- -- 550 swE 8.1& 2.&0 2.59 -- 5&8 SWE 13.76 &.26 5.2& 3.80 Sept. 20 218 SPA 1&.75 5.20 13.85 -- 2&0 FRA 20.77 8.13 13.29 -- 251 GER 26.1& 8.66 8.86 -- 550 sws 27.72 9.22 1&.81 -- 5&8 sz 25.73 5.91 9.27 5.18 Oct. 20 218 SPA 55.51 1&.12 23.76 3.87 2&0 FRA 60.62 15.30 2&.21 7.&1 251 GER 111.39 26.23 ' 38.&2 9.1& 550 sws 89.&8 2&.72 &0.2& 8.11 5&8 SWE 59.71 11.75 18.55 7.78 Nov. 20 218 SEA 58.&7 13.77 21.99 6.52 2&0 FHA 65.’0 16.56 27.20 8.0& 251 GER 118.02 25.99 &0.10 8.57 550 SWE 98.1& 25.93 &0.61 7.57 5&8 swE - 6&.8& 11.65 18.03 7.01 (a) SPAin, FRAnce, GERmany, SWEden 102 Table 20. Analyses of variance for root-shoot ratios of Scotch pine seed sources oneinnnth after transplanting with various intensi- ties of root pruning. Source of variation Degrees of fiatios for: freedom Tot. lat. Length Absorb. Lat. Length Shoot Lerggthia) 1 Shoot Length Replication 3 -- -- Date of Lifting & 205.9*** 607.3*** Error a 12 -- -- Seed Source 1+ 35.59"”? 140.11% Source X Date 16 lO.1+*** 16.?“ Error b 60 —- -- Treatment 2 -- 3&&.8*** Treatment 2: Date 8 -- 6’+.3"HHt Treatment x Source 8 -- 9.6*** Treatment 1: Source X Date 32 -- 3.11m Error c 150 "' "' (a) Root-shoot ratios calculated using total lateral root lengths were analyzed only for those trees with no root pruning. *9" Significant at the 0.1 percent level. 103 2o. Root-shoot ratios of five seed sourCes of Scotch pi by transplanting date and intensity of root pruning. ”0 “V 10h .>oz .ooo .aom .ws< sash magmag ho mazes (52 Save .mmm .93. hfihb £62 :50 .mvm 13¢. SHE. cameos ace summon Acheson moaoaoooa aggomgé IF -L b F mam..:.:.:.. 03 I I. II I Hmm 7|: OJN I.'.l.'.ll.ll..| mam ............ spasms mos sumooq aoa £93 Heathen 33.822 homes: H833 33.8» Q "oaoem ozuzsmm Boom anaminzo .o oszsmm scam oz .a p P [r L L L b b n - .>oz .eoo .aom .m:¢.sflsn sumsoq mos apweoq boom Hobos "oapmm ommzsam7aomm oztwm r OLIVE LOOKS " .LOOH 105 three origins. _ Different intensities of root pruning also produced significant .n ' 1,-1- -«' . of absorbing lateral length . After mid-sum- 'f r c s in rat 05 d1 fe ence c i a top length mer tranSplantings, those ratios for trees with no and half root pruning were approximately the same. At the time of the September transplanting, ratios for half-root-pruned trees were higher and after October and November liftings root-shoot ratios for half-root-pruned trees were 55 to 60 percent greater than those of trees with no root pruning. Trees with full root pruning had root-shoot ratios which were significantly lower than for no and half-root-pruned trees. All sources with full root pruning had ratios which were about eqaal at the time of the last transplanting. 106 Relation of Top to Root Growth During the period of most actch height growth (July-September) root growth was relatively slight. It was not until after terminal shoot growth had slowed down or was completed that the majority of the root growth took place (Figure 23). Nearly half the total root elongation occurred during September and October on seedlings of MSFG 5&8. During that same period the prOportion of total root growth achieved was approximately 60, 66, and 70 percent, respectively, for MSFG 2h0, 550 and 218. Fast growing German 251 had the highest percentage of total root growth during this interval; 72 percent of root elongation took place after the completion of height growth in September. These relationships can'be stated statistically by cor- relations based on date-seedlot-treatment means for all five trans- planting periods as items. The correlation coefficient between height and total lateral root length (for trees with no root prun- ing) was —O.87. Those between height and absorbing lateral roots were ~O.85 and -O.82, respectively, for trees with no and half root pruning. Similar trends in shoot versus root growth have been fOund in citrus and other fruit trees; Norway and Sitka spruce; European larch; red, white, Scotch, longleaf, slash, ldblolly and shortleaf pines (Harris, 1929; Stevens, 1931; Laing, 1932; Kienholz, 193&; Turner, 1936 ; Huberman, 19&0; Marloth, 19&9; Reed and ruched-3:1, 1937). This inverse correlation between periods of active height and root growth is apparently associated with availability of manufactured carbohydrates. Growth of the Scotch pine seedlings used in this 107 study was dependent initially on food materials stored in the seed, then on currently manufactured photosynthate, with little or none available for storage. Initially this photosynthate was used pri- marily for t0p growth. Kramer and Kozlowski (1960), reviewing ear- lier work, reported a tendency toward polarity in translocation of food in plants. Carbohydrates and other metabolites tend to move toward actively growing regions at the expense of more slowly grow- ing regions, including root systems. The cause of this apparent polarity in translocation is not fully understood. Kramer and Kozlowski felt that the level of auxin production partly controls the direction of translocation through its effects on metabolic activity. 108 Relation of Survival to Root Growth ani Root-Shoot Ratios Survival was closely correlated with the amount of roots present at transplanting, the growth of new roots after tranSplanting, and with root-shoot ratios of the seedlings. During the early part of the growing season root-shoot ratios were very low and neither the amount of roots present at transplanting nor the new growth after transplanting was sufficient to supply the moisture needed by the actively growing 'rees. Of the five seedlots transplanted during July and August only 5&8 from northern Sweden survived even moder- ately well and that was the origin with the largest root system at time of tranSplanting, the most root growth during the subsequent months and the most favorable root-shoot ratios (Tables 17 and 19). Of the trees transplanted during September, those with half their root systems removed actually produced more absorbing roots during the subsequent month than did unpruned trees. Root-shoot ratios based on absorbing lateral lengths were higher for these half pruned trees than for those with no root pruning and they generally survived a little better. As transplanting was done later in the fall, the amount of lateral growth increased, height growth de- creased and root-shoot ratios increased (Figures 23 and 26). Sur- vival of trees transplanted in October and November was 100 percent for all trees which had no or half root pruning, although there was considerable variation in root-shoot ratios of seedlings. Trees with all laterals removed at transplanting time could produce relatively few new roots in the subsequent month and did not survive well except after the last transplanting. 109 Time of completion of height growth also apparently affected survival. Seedlot SMS from northern Sweden survived as well or better than all other sources after all treatments and times of trans- plantings although it had the most lateral roots and most favorable root-shoot ratios only during the early part of the season. The early completion of height growth of this source may have accounted for its good survival after later transplantings. Studies on other trees (reviewed by Kramer and KOzlowski, 1960) have shown that water metabolism and transpirational losses are greatest during the season of active height growth. This reduced water use and loss for MSFG 5&8 apparently counterbalanced its lower root-shoot ratios. The same sources used in this study (and 103 others) were field planted during 1761 and 1962 at 31 locations in the north-central states as part of the NC 51 project (Wright et al., 1966). Two-year- old seedlings were used. The survival pattern differed somewhat from that reported here. Survival was poorest in sources from nor- thern Scandinavian var. lapponica (includes MSFG 5&8) and was best for var. iberica from Spain (includes MSFG 218), var. aquitana from southern France (includes MSFG EhO), and var. rigensis from southern Sweden (includes MSFG 550). Survival of sources from central Europe, including var. haguenensis (includes MSFG 231),was also rather low. Differences in results between the two studies seem to be related to root-top ratios and to differences between field and greenhouse conditions. In the earlier study north-Swedish seedlings had excellent but short root systems which apparently were incapable of penetrating the soil fast enough to keep ahead of surface drying which takes place 110 in the open during the summer. Results from the study reported here also indicate that root-top balance of north-Swedish seedlings is unfavorable. After October and November transplanting, MSFG 5&8 had the lowest ratio of absorbing lateral root length to top length of the five origins used. It is also probable that if the seedlings used in the older study had been transplanted to greenhouse conditions where the soil was constantly moist that they would have shown very little transplanting shock and survival would have been good. In the earlier study poor survival of 2-0 seedlings of central European origin was apparently related to unfavorable root-shoot balance of seedlings which had been grown in crowded nursery beds. Excellent survival was obtained from plantings of 2—l seedlings of central European origin planted in Minnesota. The study reported here showed that seedlings of German 251 grown in uncrowded beds had ex- cellent root-shoot ratios. This study also showed that root-shoot balance was very high for seedlings of south-Swedish 550. The high field survival of the Spanish trees was somewhat surprising in view of the low root regenerating ability and low root-shoot ratios shown by seedlings in my study.. B. 0. Stone and his associates (Stone, 1955; Stone et al., 1959a, 1959b, 1962 and 1933) have studied seasonal variation in root regener- ation of ponderosa pine and Douglas-fir. Trees transplanted in late spring and early summer had the lowest root regenerating potential and survival rates. Both increased gradually in early fall, sharply in late fall, and stayed constant until early spring. There were genetic differences in ponderOIa pine, with high elevation sources 111 having the most rapid rate of increase in root regeneration potential and survival percent in the autumn. This is similar to the trend fbund in my study in which seedlots from the coolest climates de- veloped the highest survival potential earliest in the season. Nurserymen have practiced partial root pruning fer many years, usually doing this one year prior to field planting on the theory that new laterals would develop during the ensuing season. This is undoubtedly good practice. Extensive root pruning at the time or field planting has not been generally recommended unless root systems are unusually large and can not be planted conveniently. Hewever, my results indicate that partial root pruning at the time of transplanting could be very beneficial in stimulating more new absorbing roots than might grow on the intact root system. The desirability of removing as much as one-half of the root system would be questionable. A number of studies have shown that although the rate of water and nutrient absorption is greatest through the unsuberized, white area of the root systems, considerable quantities of these materials can move through suberized roots as well (Kramer, l9h9). The best root-pruning treatment would probably be one that provided a large number of severed lateral root tips without appreciably reducing the total length of the lateral root system. CHAPTER VI SHOOT AND ROOT GROWTH OF DIFFERENT SCOTCH PINE PROVENANCES AT VARYING MOISTURE-FERTILITY TREATMENTS There has been considerable work relating differences in fertility requirements of different species of forest trees. Wilde (1938 and 1958) reported large differences in nursery soil requirements of lif- ferent species. Rennie (1955) showed that forest trees generally have lower fertility requirements than do agricultural crOps. Others, including those of Rennie (1955), Leyton (1957) and Ovington (1953a and 1956b), have shown that hardwood species generally have higher fertility requirements than do conifers. The studies of Mitchell and Chandler (1939) with hardwoods and of Heiberz and White (1951) with conifers also indicate considerable lifferences in nutrient re- quirements within the broad groupings of hardwoods and conifers. A number of greenhouse studies have also shown differences in opti- mum fertility requirements for different Species, including those of Mitchell (193A) with white and Scotch pines, Fowells and Krauss (1959) with loblolly and Virginia pines, Ingsted (1957, 1959, and 1960) with birch, spruce and pines, and Sucoff (1961) with loblolly and Virginia pines. Variations in optimum fertility levels for growth of different varieties or origins of the same species have been noted for a num- ber of agricultural and horticultural species. Studies with peaches (Hayward £33., 19%) and citrus (Haas, 1945:: and 1916b; Smith, l9h9; Jones, 1957) showed that variety of rootstock used in grafting 112 113 caused differences in mineral. nutrient requirements and growth of scions. Haas (19h?) found differences in nutrient requirements of different varieties of date palm and Borden (1936) noted significant variations in growth of three varieties of sugar cane on the same soils. There has been only a limited number of studies, however, which have been concerned with differences in nutrient requirements of dif- ferent varieties, origins or clones of the same species of ferest trees. Some work has been done with seed orchards and in tree im- provement research prOgrams. Studies with poplars (Mayer-Krapoll, 1952; Muller and Mayer-Krapoll, 1953) and slash pine (Goddard and Strickland, 1966) showed significant differences in the fertility requirements of different clones of the species concerned. 11!: PROCEDURE For this study, three origins of Scotch pine were selected: MSEG 5&3 from south-central Sweden; MSFG 253 from Germany; and MSFG 219 from Spain (Table 21). Earlier studies had shown that their top growth rates were very different (wright and Bull, 1963) and that root systems of seedlings from the three areas were different in both type and extent (Chapter III). Seed was originally collected for use in the Scotch pine provenance study conducted by Wright and Bull (1963). Seedlings were grown in the greenhouse for a period of 90 days under three levels of moisture and three levels of fertility, using a factorial design with four replicationsland 2-tree plots. One-gallon glazed pots were filled with #000 grams of a mixture consisting of 98 percent (by weight) of an inert, coarse (20 to 60 'mesh) silica sand and two percent organic matter. The organic matter was added to increase the water holding capacity of the potting med- ium. One of three levels of a 20-10-20 fertilizer were mixed thor- oughly with the potting mixture: (1) 250 milligrams to give approxi- mately 10 ppm 11, 5 ppm P205, and 10 ppm K20; (2) 1250 milligrams to give approximately 60 ppm N, 30 ppm P205, and 60 ppm K20; and (3) 2250 milligrams to give approximately 110 ppm N, 55 ppm P205 and 110 ppm K20. The middle level of these three approximates the opti- mum range reported by Wilde (1938 and 1958) for growth of Scotch pine seedlings in the nursery. Five of the pots which had been prepared as described above were selected at random. They were saturated with water and weighed. Over 115 Table 21. Location and climate at place of origin of Scotch pine seed sources used in moisture-fertility study. MSFG No., Lat. Long. Elev. Temperature Precipitation Aridity Index(b) Country of N. E. Annual April- Annual April- Annual April- 0rigin(a) Sept. Sept. Sept 0 0 feet TUE. OC. -millimeters- ---number---- 219 SPA no.8 41.0 11900 6.8 11.8 1097 1461+ 65 21 253 GER &9.1 7.8 1300 9.5 15.0 612 338 32 11+ 513 swn 60.0 12.9 625 6.2 12.6 630 350 39 15 (a) Numbers are those used in the Michigan State Forest Genetics access- ion record. The countries are SRAin, GERmany, and SWEden. (b) Aridity Index: (DeMartonne, 1926) Index = Precipitation in nun- Temperature in 0C. + 10 116 a four-day period the pots were reweighed at intervals and percent moisture was calculated for each time of weighing. All values were plotted on a moisture depletion curve (Figure 27). Field capacity of the mixture was taken as that moisture content where the loss of water had essentially ceased and the weight of the pot and contents had become stable. The value used was 20 percent, by weight. Pots were regulated to one of three ranges of moisture during the study: (1) between field capacity and 75 Percent of field capacity; (2) between field capacity and 50 percent of field capacity; and (3) between field capacity and 25 percent of field capacity. Each indi- vidual pot was marked with the level which it was to receive and the container and dry potting mixture were weighed. The weight at field capacity was calculated and this value recorded on the side of the pot. (Weight at field capacity a weight of pot + MOOO grams + hOOO x 0.2.) The weight at the lower moisture limit was calculated and this value was also recorded on the side of the container. (For example, pots receiving the middle moisture treatment would have a lower limit of: Weight at 50 percent of field capacity = weight of pot + #000 grams + #000 x 0.1.) During the study moisture levels in individual pots were regulated by placing each container on a pLathrm scale. If the weight was at or below the lower moisture limit, water was added to bring the weight up to the upper recorded level. If the weight was above the lower recorded limit, no water was added. Demineralized water was used to avoid the addition of unequal amounts of dissolved bases and other impurities present in tap water. Seed was first sown in flats filled with the sand described 117 Figure 2?. Moisture loss from potting n‘xture consisting 0f 98 percent (by weight) coarse, quartz sand and 2 percent organic matter. mazes .Eofissim 433E 5E5 eds «1 e s s s s 1.. s m ma 3N mm times In. ‘sanmmm immense 119 previously (with no organic additive or fertilizer). One week after seed germination, seedlings were transplanted to the 108 individual pots used (3 sources x 3 moisture levels x 3 fertility levels x h replications), with two seedlings in each pot (two tree plots). Seed- lings were grown for a 90-day period in the greenhouse, maintaining moisture at desired levels during this period. After 90 days, pots were taken from the greenhouse and the potting mixture was carefully washed from the root systems. Top and root measurements were made immediately on all seedlings (Tables 23, 2h). Analyses of variance for a factorial design with 27 treatment combinations were made using means of the 2-tree plots as items (Table 22). Trend analyses were run using orthogonal polynomials and treatment sums as items. Ass: assets do as ssssflfismnm it. .Ho>vH somehow H as vsoamflawflm ** U- II " '8 In- -8 'I II- -' wk. OHOvHsHm *sw.m ***m.m: ***w.ma ***A.ba ***H.ma ***@.OH ***N.m ***H.m *#*m.m w hpaaflpaom_x showman: x summon ***m.aa ***o.a: ***N.Am ***:.o: ***o.mm ***N.mm ***H.mm ***b.om ***H.w : mpwaaphoh N phoneme: EQN 111.0.m: $1.5.w $H.NH iméa Edam Eddm $m.m+~ £13 deflfiohxoohflom .d' ***©.m ***N.Nw ***N.OH ***H.NH ***m.ma ***m.am ***w.ma ***N.w: *ssm.o : oaspmaoz x condom ***m.w ***b.mma ***¢.hm ***m.mo ***m.:: ***m.:m ***h.mm ***o.mm ***:.mm m Ho>oa hpfiafivhoh than: Ismdwa imfima Elam» iméwa Ixmdb $1945 $4.3 #393 m H33 snowman: ***®.mm ***N.Q:H *sew.w: assm.m: ***H.:m ***w.m~a ***m.ma ***:.me ***m.wwa m meadow doom nu nu In in nu in I: n: In : aoavmofidnom II .II '8 I... .l' I- -8 -8 8' 8.” H6908 sews: fimsoq massed: amass: summed Ewes: fiesta Ewes: fists... seasons 033“ p8m-soosm .oz .89 poem H.233 . poem mes a8. mo schemes? you weaves m. moonmon mo condom .mooapdsfiQEOo passpwehp hfiwdapnomnvhspmwoa mafia pa macaw moan nouoom mo unawauo momma mo apaoaw noon one new mom ooqsaam> mo nowhfimnm .mm odoma 121 RESULTS Results showed that two of the sources, mass 253 and 2113, reacted similarly to the moisture-fertility treatment combinations used in the study. The third source, MSFG 219, generally showed a different type and wider range of response to the different treatments. In the sec- tions that follow, discussions are concerned primarily with differences and/or similarities between the origins used and of interactions of the seed sources with moisture and fertility levels. Main effects of fertility and moisture are not discussed for two reasons: it was not the purpose of the study to investigate variations caused by these factors, but rather to see if different origins of Scotch pine reacted similarly as these factors were varied; and because of significant dif- ferences in growth of origins at different moisture and fertility combinations, averages or main effects for these two factors would be meaningless when considered independently. 122 Top Growth TOP growth varied significantly due to seed source, moisture level and fertility level. .All second- and third-order interactions were also significant (Tables 22, 23). It was also feund that there were differences in growth patterns for top lengths as opposed to those for tOp weights of seedlings. .Average shoot length was greatest fer seedlings of’MSFG 253 and least fer MSFG 5h3 (Table 23). Growth at different fertility levels (independent of moisture level) varied between origins. Longest shoots of German 253 and Swedish 5h3 occurred when seedlings were grown at the medium fertility levels. At the low and high levels shoot length was approximately the same. For Spanish 219, seedlings grown at the low fertility level had the greatest top length and shoots became shorter as fertility level increased. When moisture treatment was considered independently of fertility level, top length was greatest fer 253 and 5h3 when trees were grown at high and medium.moisture levels and was significantly lower at the low moisture treatment. Greatest shoot length of 219 occurred at the high moisture treatment and growth decreased at successively lower moisture levels. Shoot length also showed significant seed source-moisture-fer- tility interactions (Figure 28). um sh3 and 253 had their greatest top length at the medium fertility level for all three moisture levels. Growth at low and high fertility levels was approximately the same. However, top length of'MSFG 219 was greatest at the low fertility level when seedlings were grown using high or medium moisture 123 . ‘ ‘ J—A “. - Taole 23. Top and root growth of three sees. source of Scotch sir-‘3 grown at different moisture-fertility tree. :nents. I ________.___... 12h ‘iéio No., Tfioist. Fert. pr Tap Root Lateral Root Country of Level Level Length Weight Length Weight Length Weight Origin(a) 2E2. .Edi 22: 9%; £22. .fldi 219 SBA High High h8 57 180 10 612 11 Med. 50 67 181 10 553 11 Low 59 95 291 19 10h8 21 Med. High as 28 86 6 25 1 Had. h8 78 189 it 562 13 Low 53 97 207 1h 7H9 18 Low High 3h 18 32 h 6 1 Mad. as hi 156 9 2h6 8 Low 1&0 35 73 6 38 3 Averages for MSFG 219 A7 57 155 10 427 10 253 GER Hish High 50 37 17h s not. ' 7 Med. 60 58 176 8 878 lb Low 58 60 257 9 11u6 2o Med. High 55 68 182 6 581 11 Med. 66 811 188 8 59h 11 Low 5h 60 158 6 3M1 6 Low High h9 57 136 6 357 9 Med. 57 62 11w 6 558 13 Low 1+5 39 97 5 71 1+ Averages for LBF‘G 223 55 59 158 6 558 ll 5&3 sws High High #1 28 156 6 263 5 Med. 1+3 38 116 7 £181 10 Low hi 36 177 8 552 13 Rbd. High A3 29 1H9 5 263 5 Med. 15 1+5 156 7 332 7 Low 37 31 123 6 182 u Low High 38 2 1112 5 166 3 Med. 39 1+1 153 7 #15 9 Low 37 2h 91 5 182 3 Averages for hBFG ii; 110 33 1143 8 “33 9 LSD's, .05 level for: 1. Main Effects 1.5 3.0 9.2 .5 no.7 .9 20 lSt Order Into 2e? Sol 1508 as 80.3 1.6 3. 2nd Order Int. h.6 8.9 27.h 1.h 137.6 2.7 (a) SPAin, ashram, SWEden. Figure 28. Tap growth of three seed sources of Scotch pine at nine moisture-fertility treatment canbinations. AME EHQHBKE a s a AH ed 58% 38 canoes: a8 .a E392 amass .EoHas a2. a massage was Beam: 8 126 mam I ..I.|.l.l mmm m 3331!.-- reggae,“ :8 Page”: nos .6 gas: gnawfisg doe .o. .5302 2on Manama a8 .o P - Ln 0! O In ‘1HsIHM and In 1. '20.! 8 H .9. 8 ‘Hmorm JQL 8 127 treatments and at the medium fertility level when they were grown at low moisture. Per the nine moisture-fertility treatments, maximum shoot lengths occurred at the medium.moisture-medium.fertility combination fer seed- lings of German 253 and Swedish Sh3 and at the high moisture-low fer- tility combination fer Spanish 219 (Figure 28). Weights of seedling shoots showed some decided differences from the patterns described fer top lengths. Average top weights were approximately equal fbr MSFG 219 and 253 and were significantly lower for MSFG 5&3 (Table 23). There were significant differences, however, when seedlings were grown at different moisture and fertility combina— tions. .At high moisture levels (independent of fertility level) tOp weights were greatest fer'MSFG 219. ,At the medium.moisture treat- ment, weights were approximately the same fer 2S3 and.2l9 and sig- nificantly lower for 5113. At the low moisture treatment, seedlings of 253 were heaviest, while those for 219 and Sh3 were about the same. Similar patterns were noted when fertility level was considered in- dependent of moisture level. Highest shoot weights of 253 and 5h3 occurred when seedlings were grown.at medium.fertility levels and heaviest shoots for 219 when seedlings were grown at the low fertility level. Heaviest shoot weights for the nine moisture-fertility treatments were recorded when 253 and 5&3 were grown at the medium.moisture- medium fertility treatment. The maximum.f0r 219 was found when seed- lings were grown at the high moisture-low fertility combination (Figure 28). 128 Because of differences in patterns for top lengths and top weights, there were prounounced differences in the weight per unitfilength of seedling shoots. Fbr MSFG 253 and 5h3 values were approximately equal and varied only slightly at different moisture and fertility levels. .Average weight per unit length was generally greatest for seedlings of MSFG 219. It was found, however, that weight per unit length of shoots of this source increased as moisture level increased and decreased as fertility level became higher. Trend analyses (using orthogonal polynomials) showed that the nature of the relationships between seed sources and varying moisture- fertility combinations were not the same. Trends (lengths and weights) for Swedish 5&3 and German 253 were generally curvilinear in relation to increasing or decreasing fertility levels. At high and medium moisture treatments these trends were strongly curvilinear, while at the low moisture level it was slightly curvilinear. Trends for 219 were linear at high and medium moisture levels in relation to varying fertility treatments. At the low moisture level, trends for 219 varied from slightly curved fer shoot weight to curved for shoot length. The major cause of trend differences for Spanish 219 as opposed to those for German 253 and Swedish 513 was restricted growth of seedlings of the Spanish source at high fertility levels, particularly in combination with low'and medium moisture levels. 129 Root Growth Root growth showed significant differences depending upon the particular combination of moisture and fertility at which seedlings of the three origins were grown (Table 23). Seedlings of MSFG 5&3 had the smallest average root systems in terms of laterals and tap roots, lengths and weights. .Average lengths of laterals and taproots were greatest for'MSFG 253. However, as was noted with seedling t0ps, weight per unit length was generally greater for roots of Spanish 219. This was particularly true of the tap roots. At many moisture-fer- tility combinations roots of 219 were heavier than those of 253 and 5&3 (Figures 29, 30). As a result, there were no significant differ- ences in average lateral root weights fer MSFG 253 and 2l9 and the tap roots of 219 were significantly heavier than those of the other two origins. This high weight per unit length of roots of Spanish origins of Scotch pine is a character noted in cmspter III- There were a number of major differences between the patterns for root growth and those for top growth. When moisture treatment was considered independently of fertility level, length.and weight of lateral and tap roots of all sources were greatest at the high moisture level. This was contrasted to top growth where maximum growth of 253 and 5&3 occurred when seedlings were grown at the medium moisture level. There were also differences when fertility level was considered independently of moisture level. MSFG 219 showed greatest lengths and weights of tap and lateral roots at the low fertility level and growth decreased as fertility level increased. Growth of roots of 130 Figure 29. Tap root growth of three seed sources of Scotch pine at nine moisture-fertility treatment combinations. u, 131 tn 2 ‘ mains zoos m «A s a o: as is. . a. as? .. 38 .9533 98m are .u 239m: .51ng 98m as .o noun an \ Tam .l.|.....li . \ mum , \ \ \ \ \ x 2 ‘mom soon as. um 1.32 Figure 30. Lateral root growth of three seed sources of ScotCh pine at nine moisture-fertility treatment combinations. $5999 33 arena: .88 as . means: 232% .9553 Son armada sages mode greens noon arenas .e 133 mam .......... mmm ma -""|"' gag 30A .3025 room g5 . \‘ ‘ \\ \ Egg Eon—”9m: .5923 98m images . :g . 'm ‘m woos 1mm SEES was a .595 98m g5 .s U\ .43“ 8 °8m ‘tsoisn mos mm 3 131: 219 was very restricted at the high fertility level (Table 23). Ferti- lizer salt concentration appeared to be near the toxic level when seedlings of 219 were grown at the high fertility level in combination with low moisture (Figure 31). Growth of the root systems of MSFG 5113 and 253, on the other hand, was greatest at the medium fertility level. Although growth of these two origins was least at the high fertility level, it was not so restricted as was that of'MSFG 2l9 (Figures 32, 33) - Tap and lateral root lengths and weights were maximum at the same moisture-fertility combination for all three seed sources -- that of high moisture and low fertility (Figures 29, 30). This was opposed to top growth where lengths and.weights of’MSFG 253 and 5&3 were greatest at the medium moisture-medium fertility treatment. This same phe- nomenon of lower fertility levels for maximum.root growth than those fer best shoot growth has been recorded in a number of other studies, including those of Demortier and Fourase (1938) with Scotch Pine. Mitchell (1939) with white pine, Bensend (l9h3) with Jack pine, and Fowells and Krauss (1959) with Virginia pine. There were also differences in development for seedlings grown at different moisture-fertility combinations. All sources showed significant linear trends in relation to varying fertility levels at the high moisture treatment, with greatest root lengths and weights at the low fertility level, At medium.and low moisture levels, root growth was similar to that for shoot growth, MSFG 253 and 5&3 had greatest root weights and lengths at medium.fertility levels. Trends in relation to varying fertility levels were curvi- linear. .At the medium.moisture treatment, root growth of 219 was 135 Figure 31. Growth of Spanish mm 219 at two moisture-fertility combinations: lav moisture-high fertility (left) and high moisture- low fertility (right). J * 213 ._SEA.. 136 Figure 32. Growth of Gm were 253 at two moisture-fertility combinations: law moisture-high fertility (left) and high moisture- low fertility (right). 137 Figure 33. Growth of Swedish m 513 at two moisture—fertility combinations: low moisture-high fertility (left) and high moisture- low fertility (right). 138 greatest at the low fertility level, with a linear trend in relation to differing fertility levels. At the low moisture treatment, growth of roots of 219 was greatest at the medium fertility level and the trend was curvilinear. The total number of lateral roots which formed and the degree of branching was generally closely correlated (r = 0.9h) with lateral root length. There were differences associated with seed source and treatment, however. The root systems of MSFG 219 were approximately 30 percent less branched than those of nsm 253 and 5&3. 11er 253 had the greatest amount of'branching and.this source had the highest number and greatest percentage of lateral roots which were branched twice (Table 21+). This character of low branching of Spanish ori- gins of Scotch pine has been noted in Chapter ITI. Different moisture and fertility treatments also affected the number of lateral roots and degree of branching of the root systems. In general, the greatest number of laterals and highest degree of branching occurred on seedlings grown at high moisture levels and decreased as moisture level decreased. The reverse occurred with changes in fertility level. Maximum.numbers and.branching were found on trees grown at low fertility levels and numbers and branch- ing decreased as fertility became higher. These patterns varied somewhat with seed source. The greatest number of laterals for MSFG 253 and 219 occurred on trees grown at the high moisture-low fer- tility combination. For new 51.3 maximum numbers were found on seedlings grown at the high moisture-medium fertility combination. 139 Table 21+. Lateral roots per tree, proportion of branched lateral roots and shoot-root ratios of three origins of Scotch pine grown at different moisture-fertility treatments. 1&0 MSFG No., Moist. Fert. Total Proportion of total Shoot-Root Ratio Country of Level Level Lateral lateral roots with §hoot Wt. Shoot LTf Origin(a) Roots number of branches Tot. Rt. Tot. Root _[trec 0 1 2 Wt. Length number ----- percent ------------- ratio- ------ 219 SBA High 121 78 22 0 2.8a .063 Med. 118 80 19 1 3.20 .072 Low 25M 80 19 1 2.h1 .0u6 High 2h 100 0 0 n.2l .h35 had. 122 7A 25 1 2.92 .06h LOW' 178 77 23 Trace 3.19 .056 High 4 100 0 0 n.30 .910 had. 83 81 19 0 2.u3 .114 Low 16 93 7 0 3.93 .351 Averages for MSFG 219 102 79 21 Trace 3.27 .23h 253 GER High 130 78 22 0 3.10 .077 Med. 223 80 19 1 2.70 .058 Low u01 8h 15 1 2.08 .042 High 165 7h 23 3 3-95 -072 men. 167 76 22 2 b.63 .087 Low 119 72 28 0 n.83 .109 High 8h 71 29 0 3.87 .099 had. 150 78 21 1 3.22 .083 Low 35 69 30 l n.6’ .267 Averages for MSFG 253 16h 78 21 l 3.67 .099 5h3 sws High 77 70 30 0 2.60 .099 Med. 192 86 13 1 2.25 .068 Low’ 153 79 20 1 1.72 .059 High 80 7h 26 0 2.91 .10h Med . 537+ 83 1'? Trace 3 . 17 . 092 Low 73 70 2h 0 3.h3 .12h High 79 81 19 0 3.00 .122 Med. 10k 73 26 1 2.h7 .073 Low 63 72 28 0 3.1% .133 Averages for MSFG 5M3 100 78 22 Trace 2.7% .097 LSD's, .05 level for: 1. Main Effects 15 -- -- -- .25 .018 2. lat Order Int. 26 -- -- -- .h2 .032 30 2116- Order mt. Mt "" "" "' .72 0052+ (a) SPAin, GERmany, SWEden. lhl Shoot-Root Ratios Shoot-root ratios are most commonly calculated using weights of seedling tops and root systems. Such ratios are more easily de- termined than those requiring measurement of the length of root sys- tems. For seedlings grown in this study, there were decided differ- ences in shoot-root ratios obtained using weights and those calcu- lated using lengths. These were primarily differences in averages for the three origins and in ranking of ratios for the sources at different moisture-fertility combinations (Table 2h, Figure 3h). Average shoot-root ratios calculated using seedling weights were significantly highest (most unfavorable) for MSFG 253 and were lowest fer MSFG 5&3. However, when ratios were determined using seedling lengths, averages were approximately the same for 253 and 5&3 and were highest for 219. These differences were caused by variations in weight per unit length of seedling tops and root systems and‘by severe restriction of growth of’MSFG 219 at some moisture-fertility combinations. There were significant seed source-moisture, seed-source fertility and seed source-moisture-fertility interactions (Table 22). Ratios for 253 and Sh3 (independent of moisture treatment) were approximately the same when seedlings were grown at all fertility levels. Fbr MSFG 219, however, ratios were most fhvorable at low to medium fertility levels and significantly highest at the high fertility treatment. At different moisture treatments (independent of fertility levels), ratios for all sources were best at the high moisture level. Lowest shoot-root ratios (based on lengths and weights) occurred 12:2 Figure 3h. Shoot-root ratios of three seed sources of Scotch pine grown at nine moisture-fertility treatment combinations. REESE 0&3 g .33 I; as .3 men l.|.|.|.l mmm mam uuuuuuuuuu ..... . Hwn......H..vfi.!..i...... y 0.: $55 gas. vane: EB EEG. moan . E J hauls 98m 32 a ESE 98% Ban: Scam H. N. . m. g gag ~59 . Ewes: 98m .298 . 502.3 98mm #1! U E3 gag 5H: . flung 98m .298. . w 5% 80mm b 01:1;sz moon - moss lid: for all origins with seedlings grown at the high moisture-low fer- tility combination. This was the treatment at which root weights and lengths were greatest for all sources. It was also the treatment at which top growth of 219 was generally highest (Figures 27, 28, 29). At other moisture-fertility combinations, there were a number of differences between origins. These were primarily variations between ratios for seedlings of Spanish 219 as opposed to those for German 253 and Swedish 5&3. At high moisture levels, shoot-root ratios for all origins were lowest when seedlings were grown at low fertility levels. When the medium moisture level was used they were minimum fer 253 and 5&3 at the high fertility levels and fer 219 at the low fertility level. At the low moisture treatment, ratios fer all sources were minimum.at the medium fertility level (Figure 3h). Trend analyses indicated that MSFG 253 and 5&3 exhibited linear relationships to varying fertility levels when grown at high and medium moisture treatments. Trends for MSFG 219 were slightly to strongly curvilinear at these moisture levels. .At the low moisture treatment, trends for all sources were strongly curvilinear in re- lation to varying fertility levels. 1&5 Relation of'Moisture and Fertility' Requirements to Climate, Soils and Evolutionary History of.Area of Origin In the previous sections it was shown that two origins of Scotch pine, German 253 and Swedish 5H3, reacted similarly to the nine mois- ture-fertility treatments used in the study. The third source, Span- ish 219, reacted quite differently and generally had lower fertility and higher moisture requirements than did 5&3 and 253. It was impossible to determine from the information available exactly why fertility requirements for MSFG 2l9 might be lower than those of'MSFG 253 and 5H3. Exact soils information was not taken when the seed was collected in Europe. However, the Instituto Forestal, the agency which collected the seed of MSFG-2l9, stated that collec- tions had been made in the Sierra de Guadarrama, Spain from a relatively small stand growing on siliceous, sandy soils that had originated from granitic parent material. It was also stated that the area had been under forest management for more than 150 years. Positive conclusions regarding the fertility of this particular soil from such scant information would.be impossible. HOwever, soils of such origin have often.been found to be of low fertility status (Wilde, 1958; Lutz, 1958). Evolution on such soils could produce a species or origin in which individuals of low fertility requirement would have an adaptive advantage. Over a long period of time individ- uals of higher requirement might well be eliminated from the popula- tion. This probability is strengthened when the evolutionary history of the Spanish origins of Scotch pine is considered. The range in 1116 Spain is restricted to isolated stands at higher elevations and there is little exchange of genetic material between areas. Wright and Bull (1963) postulated that inbreeding had acted in the isolated Spanish populations, leading to genetic drift and gene fixation. Spain was well below the ice cap during Pleistocene glaciation and these pro- cesses have continued more or less uninterrupted for a longer period of time than in most areas of northern and central Europe. Forest management could also be a factor in eliminating certain genotypes from the stand in which seed of’MSFG’2l9 was collected. In management of species such as Scotch pine which are intolerant of reduced light intensities it is common to thin out smaller or slower growing trees from stands in favor of continued rapid growth on larger dominants and codominants. If evolution had produced an origin having low fertility requirements, continued thinning over the past 150 years would tend to remove trees of slower growth and higher fertility re- quirement. No soils or geologic information was available for nsm 5&3 and 253. However, seed collections were made in areas having evolutionary histories considerably different from that of MSFG'219. The modern Scotch pine pepulations in northern and mid-European areas prdbably evolved from remnant stands which survived Pleistocene glaciation in the Scandinavian highlands or to the south of the ice cap, probably in the Alps or Carpathians (wright and Bull, 1963). After the retreat of the ice cap, the species reinvaded the glaciated areas and even- tually formed extensive and often continuous forested.areas. There would have been a free and constant interchange of genes between neighboring populations. Genetic drift and gene fixation would 11:? probably have been very low or entirely absent. As a result, these origins could well display intermediacy in a number of characters, including fertility requirement. It also appeared that there were differences between origins in moisture requirements. Seedlings of'MSFG 219 showed a tendency toward better growth at higher moisture levels than those required.by'MSFG Sh3 and 253. The annual precipitation of the area from which 219 was collected was over 1000 millimeters, while that IOr the areas from which MSFG 5&3 and 253 were collected.was 630iand 612 millimeters, respectively. Precipitation fOr the growing season was h6h milli- meters for MSFG 219, 338 millimeters for MSFG 253 and 350 millimeters for msm 5&3 (Table 21). For the whole year, Aridity Index values (which are measures of effective precipitation) for the three areas were 65 for msm 219, 39 for usrs 5143 and 32 for MSF‘G 253. For the growing season months, the values were 21, 15, and 1h, respectively, for msm 219, 5&3 and 253. It would appear, therefore, that the Spanish origin evolved under conditions which were considerably more moist than those of the German and Swedish origins. ,As a consequence it would be entirely possible fOr MSFG 219 to have higher moisture requirements than 5h3 and 253. The time periods and evolutionary histories discussed previously would also be pertinent to differences in moisture requirements. The long evolutionary history, with isolation and inbreeding, could favor gene fixation and high moisture requirement in the Spanish population. In the Swedish and German areas, shorter evolutionary histories and ready exchange of genetic material could have favored intermediacy in moisture requirements. CHAPTER VII BUT-331123: Root types, patterns of root growth and growth after different cultural treatments were studied for greenhouse and nursery grown seedlings of different Scotch pine provenances. Significant differ- ences were noted in a number of characteristics. In many instances it was possible to relate these variations to climatic conditions and past evolutionary history of the areas from which seed had been collected in Europe and Asia. Analyses were made of root systems of #5 orig ns of Scotch pine which had been grown in the greenhouse for periods of four and eight months. These provenances, from throughout the species range, showed significant differences in tap root development, extent and character of lateral root growth and degree of branching of the lateral roots. Sources from northern portions of the range (including provenances of vars. mongolica, lapponica, septcntrionalis, ri cnsis and a taica) had pronounced tap root development, with lateral root extension gen— erally restricted to branching from the upper portions of the tap root. Length of tap roots and lateral roots was closely correlated with average annual temperature of the area of seed collection but was not correlated with precipitation. Central European origins of vars. polonica, hcrcynica, hagucncn- .gis and illyrica had more moderate expression of the tap root char- acteristic. Lateral roots were more extensive and occurred along most of the tap root. Sources of these varieties were also more branched than those of origins from other portions of the species 1118 1&9 range. Other studies have shown that origins of these varieties are generally the fastest growing of all Scotch pine provenances. It seems probable that the fast tOp growth ~ates are associated with the extensive lateral lengths and high branching of roots. This would allow seedlings to occupy the soil very completely and to make maxi- 'mum utilization of soil moisture and nutrients. Root t es of cen- tral EuroPean origins could not be correlated closely with climate, possibly because of free interchange of genes in the more or less con- tinuous populations. The southern provenances (including origins of vars. gguitana, iberica, rhodo sea, and armena) came from isolated portions of the range and exchange of genetic material between areas was probably very limited. As a result there were a number of differences between origins from different areas. In general all southern varieties were distinctly tap-rooted. This was expressed in general appearance and high weight per unit length of roots. Lateral roots were also less branched on southern provenances than on origins from farther north. There were a number of differences, however, in lateral roots of southern provenances. Lateral rooting of south French origins (var. aguitana) was similar to that of northern varieties, with laterals extending primarily from upper portions of the tap root. This may be a reflection of colder weather conditions which prevailed during Pleistocene glaciation. Root types may have persisted because of the relative isolation of the area from other portions of the range. Spanish origins (var. iberica) had significantly longer tap roots than did all other origins. Lateral roots were short but numerous and extended from along most of the tap root. This gave the root 150 systems of Spanish origins a narrow, columnar appeara ce. These were considered to be adaptive characters related to low total and growing season precipitation in the areas of seed collection. Greek prove- nances (var. rhodopaea) originated from moist areas and had lateral root characters which were intermediate between those of other south- ern varieties and those from central Europe. Thrkish and Georgian SSR origins (var. armena) were deeply tap-rooted and lateral rooting was extensive. Individual laterals were not so short as those of Spanish origins, however. Through periodic sampling of greenhouse—grown seedlings, patterns of root elongation of eight provenances were studied for the first 80 days after seed germination. Variations were shown to be related to climates of the areas from which seed had been collected. There was an apparent interplay between tap and lateral root growth of all sources. Initial root growth was confined to tap root extension. No laterals appeared until 10 days after germination and there was no appreciable amount of lateral growth until after tap root growth began to decline 30 to #0 days after germination. After this lateral root lengths increased rapidly. Percentage rates of tap and lateral root growth were fastest for northern origins and slowest for southern provenances from moist cli- mates. Throughout the study period actual tap root lengths and weights were greatest for the Spanish origin used. It was postulated that the rapid percentage rates of growth of the northern provenances was related to the shortened growing seasons in the areas of seed collec- tion. This would allow seedlings to make maximum use of the limited period during which temperatures would be most favorable for growth. 151 Rapid and deep penetration of tap roots of the Spanish source were probably adaptive characters related to the relatively warm, dry conditions in the area from which seed was collected. Root growth of central European sources and southern origins from moist climates could not be correlated with temperature or pre- cipitation. This could be related to the fact that climate is not particularly limiting for the growth of Scotch pine in those areas. Nursery grown seedlings of five provenances of Scotch pine were transplanted at monthly intervals for the first five months after seed germination. Three intensities of root pruning were used at the time of transplanting. There were significant differences in tOp growth, survival, root growth and the ability of seedlings to regenerate new root systems. A definite inverse periodicity in root and top growth was noted for all origins. During the period when top growth was most active, root elongation and root regeneration were relatively slight. It was not until after terminal shoot growth began to slow down or was completed that the majority of root growth or root regeneration took place. Survival was closely correlated with the amount of roots present at transplanting and the growth of new roots after transplanting. During the early part of the growing season root-shoot ratios were low and neither the amount of roots present at transplanting nor new growth after transplanting was sufficient to supply moisture for the actively growing trees. Survival was very low; After the major increase in root growth which took place after height growth was com- pleted, survival increased markedly. 152 Variations in seasonal patterns of survival and root growth were closely correlated with the origins used. After earlier transplant- ings survival was somewhat better for the two northern (Swedish) pro- venances. These sources were also found to have the most rapid initial rates of root growth and root regeneration. Intensity of root pruning was found to affect survival and root regeneration after transplanting. It was significantly lower for trees which had received full root pruning than for those which had received no or half root pruning. No significant differences in aver- age or periodic survival were noted between seedlings receiving no or half root pruning. However, seedlings which had been half root pruned produced significantly greater amounts of new root growth after transplanting than did trees which had not been root pruned. Provenances from Spain, Germany and Sweden were grown from seed for a 90-day period in the greenhouse using nine moisture-fertility treatment combinations (3 moisture x 3 fertility). Significant dif- ferences were noted between sources in fertility and moisture re- quirements and in optimums for shoot and root growth. Growth of the Swedish and German sources was very similar in relation to varying moisture and fertility levels, although the actual amounts of growth were significantly different. The Spanish source reacted quite dif- ferently and generally had lower fertility requirements than did the German and Swedish origins. Tap growth was greatest for the Swedish and German origins at the medium moisture and fertility levels and was least at low mois- ture and low fertility treatments. TOP growth of the Spanish source appeared to be closely related to fertilizer salt concentration in 153 the soil solution. It was greatest at treatments where concentration was lowest (high moisture-low fertility) and poorest when salt con- centration was maximum (low moisture-high fertility). Optimum fertility levels for best root growth appeared to be lower than those for best shoot growth. Root lengths and weights were greatest at the same treatment combination for all sources -- that of high moisture and low fertility. At other treatments, how- ever, there were significant differences between sources in root growth. These differences indicated.that, in general, fertility levels for best root growth were somewhat lower for the Spanish provenance than for the Swedish and German origins. Weight per unit length of shoots and roots of the Spanish ori- gin was affected by varying moisture and fertility treatments. It increased as moisture level increased and decreased as fertility level increased. Values for German and Swedish origins were ap- proximately constant at different moisture and fertility treatments. As a result, differences were found when shoot-root ratios were cal- culated using weights as opposed to those calculated using lengths. Based on weights, shoot-root ratios were most favorable for the Swe- dish origin and most unfavorable for the German. When lengths were used, ratios were best for the German and Swedish origins and most unfavorable for the Spanish provenance. This factor could be quite important in evaluating the effects of cultural treatments on growth and seedling balance. LITERATURE CITED Aldrich-Blake, R. N. 1930. The plasticity of the root system of Corsican pine in early life. Oxford For. Mem. l2. Bensend, D. W} 1943. 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The root system of pine (Pinus sylvestris): a morphological investigation. (In Finnish with 75 p. English summary). Acta Forestalia Fennica hl(2): 1-216. Leibundgut, H. and s. Dafis. 1962. Periodizitat des Wurzelwachstum von Larchen vers chiedener Herkunft. XIII IUFRO-Kongress, Wien, 1961. Ber. 2. Tail, Bd 1. . 196b. Untersuchungen fiber das Wurzelwachstum verschiedener Baumarten. Schweiz. Zeitschr. f. Forstw. 115: nth-#50. Lenhart, D. Y. 193R. Initial root development of longleaf pine. J. For. 32: h59-h61. Leyton, L. 1957. The mineral requirement of forest trees. Ohio Jo SCie 57: 337“3)+50 Lutz, H. J. 1958. Geology and soil in relation to forest vegetation. Proc. First N. A. For. Soils Conf. 75-85. MCMinn, R. G. 1963. Characteristics of Douglas-fir root systems. Can. J. B013. #1.: 105-1220 157 McQuilkin, W. E. 1935. Root development of pitch pine, with some comparative observations on shortlcaf pine. U. S. D. A. Jour. Agro R08. 51: 983‘10160 Marloth, R. H. l9h9. Citrus growth studies. I. Periodicity of root-growth and top-growth in nursery seedlings and budlings. Jburo Hort. SCio 25: 50-570 Martonne, E. 3e. 1926. Aréism et indice d'aridité. Compt. Bend. 182: 1395-139p. Mayer-Krapoll, H. 1952. Contributions to the nutrient supply of forest plants. The fertilizing of poplars. Pappelwirtschaft, 1‘10. 3. Mitchell, H..L. l93ho Pot culture tests of forest soil fertility, with observations on.the effect of varied solar radiation and nutrient supply on the growth and nitrogen content of Scots an? white pine seedlings. Black Rock For. Bull. 5. . 1939. The growth and nutrition of white pine (Pinus strobus) seedlings in cultures with varying nitrogen, phosphorous, potassium and calcium. Black Rock For. Bull. 9. , and R. F. Chandler. 1939. The nitrogen nutrition and growth of certain deciduous trees of the northeastern United States. Black Rock For. Bull. 11. Muller, R. and H. Mayer-Krapoll. 1953. First report on fertilizer te7ts in the district of Koln. .Allgcmeine Forstzeitschrift, 8, 18 19. Neff, M. S. and E. O'Rourke, Jr. 1951. Factors affecting the initia- tion of new roots in newly transplanted tung trees. Proc..Am. Soc. Hort. Sci. 57: 186-190. Ovington, J. D. 1956a. The form, weights and productivity of tree species grown in close stands. New Phytologist 55: 289-38“. . 1956b. The composition of tree leaves. For. 29: 22-28. Pessin. L. J. 1935. Root habits of longleaf pine seedlings. U. S. For..11rv. South..lFor. Exp. Sta. Occas. Pap. #3. Preston, R. J., Jr. 19h2. The growth and development of the root systems of juvenile lodgepole pine. Ecol. Monog. 12: hh9—h68. Reed, J. F. 1939. Root and shoot growth of shortleaf and loblolly pines in relation to certain environmental conditions. Duke Univ. For. Bull. h. Reed, H. S. and D. T. MacDougal. 1937. Periodicity in the growth of orange trees. Growth 1: 371-373. Rennie, P. J. 1955 . Tile uptake of nutrirn s 11 mature foru,st trowth. Plant and Soil '{z 1H 1-95 Ruhr, J. L. l96h. The correspondence between genetic, morphological, and climc .tic val iation patterns in Scotch pine. Ph. D. Thesis, Michigan State Univ. Smith, P. F. 19h9. The insluence of rootstock on the mineral co- pos'tion of Valencia orange leaves. Plant. Phys. 2h: #55 Snyder, E. E. 1961. Racial variation in root form of lon3leaf pine seedlin3s. Sixth South. Conf. on For. Tree Improve. Stone, 1955. Poor survival and the physiological condition of plant- ing stock. For. Sci. 1: 90—9h. , J. L. Jenliinson a.nd S. L. Kru3man. 1962. Root regeneration potential of Douglas-fir seedlin3s lifted at different times of the year. For. Sci. 8: 288-297. , and G. H. Schubert. 1959a. Root regeneration of ponderosa pine seedlings lifted at different times of the year. For. Sci. 5: 322-332. , and . 1959b. The physiological.condition of ponderose pine (Pinusgpondero osa laws.) planting stock as it affects sur- vival s.fter cold storage. J. For. 57: 837-841. , , R. W. Bensler, F. J. Baron, and S. L. Krugman. 1‘9 :3. Variation in root regeneratin3 potentials of ponderosa pine fro four California nu*series. For. Sci. 9: 217-225. Stevens, C. L. 1931. Root growth of white pine (Pinus strobus L.). Yale Univ. Sch. For. Bull. 32. Sucoff, E. I. 1961. Potassium, mag esium, and calcium deficiency fimptoms of leololly and Vir3inia pine seedlin3s. U. S. For. SQI'V'. ITOlthtaStcrn FOI‘. EST. Sta. Pup. l'J’to Toumey, J. W. 1929. Initial root habit in.American trees and its bearing on regeneration. International Cong. Plant. Sci. Proc. (1926) l: 713-72C. Turner, L. M. 1938. Root growth of senilin3s of Pinus echinata an? .3 v 3‘ A... e ‘ .3. )0” t ) Pinus taeda. L. o. D. A. Jour. A31. lcb. 53. lwp-lLS. Wilde, S. A. 1938. Soil-fertility standards for 3rorin3 northern conifers in forest nurseries. U. S. D. A. Jour. er. Res. 57 935-972 . 1958 8. Forest soils. The Ronald Pres sCompanU, Lew York 159 Wilcox, H. 1955. Regeneration of injured root SJStCflS in noble fir. Bot. Gas. 221-23%. The 1933 Inte~national Wright, J- w., and H‘ 1' raldWin' 1:5 Silvae Union Scotch pine provenance test in New Hampshire. Genetica 6: 2-lh. , and W. I. Bull. 1963. Geographic variation in Scotch pine, results of a 3-year Michigan Sb fly. Silvae Genetiea 12: l- S. , S. S. Pauley, R. B. Polk, J. J. Johela, R. A. Read. 1966. Performance of Sec ch pine varieties in the north cen ral re- gion. Silvae Genetics 15: 101-110. James Harold Brown Candidate for the degree of Doctor of Philosophy Place of birth: Richwood, West Virginia Date of birth: November 9, 1931 Marital status: Married Yvonne Ann Beery, October 10, 1953 Children: Sharon Lee Brown, born July 1+, 1960 Education: West Virginia University BSF, 1953 Yale University, MF, 1951+ Michigan State University, Ph. D., 1967 Experience: Research Assistant, Northeastern Forest Emeriment Sta- tion, Sumner 1952, Summer 1953, June 1951; to Larch 1955 U. 3. Arm, March 1955 to March 1957 (Counter Intelli- gence Corps) Assistant Silviculturist, West Virginia University Agri- cuétural Experiment Station, April 1957 to June . 19 1 Assistant Professor of Silviculture, Division of Forestry, West Virginia University and Assistant Silvicultur— ist, West Virginia University Agricultural Experi- ment Station, July 1961 to July 1967 Honorary societies : XiSignaPi AlphaZeta GeznnaSingelta SigmaXi 160 LIST OF COMMCN AND SCIENTIFIC N14133:) DF BURST '1‘st SPJJCISD' Common 1.1:. :1"; Scientific Name w”... -___...- Douglas-fir . . . . . . . . . . . I‘seudotsuga menziesii (Mirb.) Franco larch, European . . . . . . . . . Bria: decidua Mill. pine, Corsican . . . . . . . . . Finns nigzra Arnold var. poirotiana (AntJ Schneider pine, jack . . . . . . . . . . . Pinus banicsiane Lamb. . Pinus taeda L. pine, loblolly pine, bfllfipole o o o o o o o o o Finis contorta DOugl. pine, longleaf . . . . . . . . Pints palustris kill. Pinus rigida Hill. pine: pitCh ' ° Pinus ponderosa Laws. pine , ponderos a me, red 0 o 0 O. o o o O D o o 0 P111118 rGSimsa Aito pine, SCOtdl o o o o o o o o o o Finns sylV§triS Lo pine, shortleaf . . . . . . . . . Pinus echinata Mill. PinLB elliottii Engelm. pine, slash . . pine, Virginia . . . Pinus virginig hill. Pinus 8 trObus Lo pine, white . . Picea abi_eg (1..) Karat. spruce, Norway Picea sitchemis (Bong.) Carr. spruce, Sitka . 161 "'TlTli‘flfllTlLflflL‘lflflfiHj11151111111111”