Urban Fragmentation Disrupts Soil Microbiomes and Their Interactions with Plant Communities

Anthropogenic habitat fragmentation – the breaking up of natural landscapes – is a pervasive threat to biodiversity and ecosystem services worldwide. Despite the substantial attention to this disturbance in ecological and conservation literature, these studies have largely ignored some groups of important organisms, such as microbes, which hinders our understanding of how entire communities persist and change in these human-modified landscapes. Microbes are important for many crucial ecosystem functions/services (e.g., nutrient cycling, bioremediation), community processes (e.g., succession, community assembly), and the health and productivity of many plants and animals; however, very little is known about how fragmentation impacts these hidden players and their interactions with other taxa. This dissertation addresses this critical knowledge gap by using a combination of field surveys, microbiome sequencing, manipulative greenhouse experiments, and bioinformatics to investigate how habitat fragmentation influences microbial communities in a critically imperiled ecosystem (the pine rocklands) and how those changes in the microbiome affect native plant performance and plant community productivity. Taken together, my dissertation elucidates how different aspects of habitat fragmentation (e.g., habitat loss, habitat isolation, matrix effects, edge effects) shape microbiomes and demonstrates these shifts have important consequences for plant communities, emphasizing the need to incorporate a microbial perspective in future studies of habitat fragmentation.