Influence of vegetation on food web complexity
University of Delaware
In light of the increasing environmental pressures of habitat loss and expanding human development, these studies sought to explore how changes in vegetation impact biodiversity and ecosystem function. My first study investigated the effects of invasive plant species in unmanipulated hedgerows on the abundance, richness, and biomass of Lepidoptera larvae. Invaded transects produced significantly fewer individual caterpillars, less biomass, and fewer species than did transects not heavily invaded by evolutionarily novel plants. These reductions were also much greater than those observed in controlled settings testing similar effects, indicating that the effects of invasive plants are compounded in hedgerows where uncontrolled colonization occurs. The second study examined how land management and vegetation structure influenced local breeding bird populations. I conducted point-counts within mowed turf sites, meadow sites, and forest sites, and compared avian species richness, diversity, and evenness among each land use type. I found that forested sites had significantly greater diversity and richness than both meadow and turf sites, demonstrating the reduced ability of turf grass to support nesting and foraging needs of breeding birds. These studies may have beneficial implications in encouraging land management techniques that promote reducing area devoted to turf grass (lawns) and using native plantings to support greater biodiversity.