Aquatic plant (macrophyte) diversity and structure is important for freshwater littoral zone community dynamics, primary production, and ecosystem function. Yet, little research of macrophytes has focused on native macrophyte communities in protected or undisturbed lakes. In our research, we ask what among-lake environmental factors shape native macrophyte richness, diversity, and community structure (i.e. growth form). We identified what relationships exist between these macrophyte metrics and 1) dispersal and introduction potential (i.e. the hydrologic connectivity among water bodies that facilitates new introductions) and 2) establishment and growth potential (i.e. lake and catchment features that determine growth success). To answer our question, we collected physical, chemical, and biological data from 15 connected and isolated inland lakes on Isle Royal National Park (ISRO) during the summers of 2012 - 2013. Results from partial least square regression (PLSR) analyses found that while the drivers of macrophyte communities included measures of 'dispersal and establishment', the most important and recurring predictors of macrophyte richness, diversity, and structure were those corresponding to 'establishment and growth'. Because ISRO is a remote Lake Superior hemi-boreal archipelago that has been a designated wilderness area since 1950, our results provide information about macrophyte reference conditions that can be used when identifying and understanding future responses to pressures such as climate change and invasive species introductions.
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