Travonya Kenly's Graduate Exit Seminar

Travonya Kenly will present Variability in Ecological Trophic Networks of Aquatic Insects along Stream Nutrient Gradients Thursday, May 8th in Heffner Building (Olentangy River Wetland Research Park), Room 101.

Food webs, which describe biotic interactions and integrate energy pathways in ecosystems, represent one of the principal categories of ecological networks. To date, the impacts of nutrient enrichment – a global stressor in aquatic ecosystems – on the structure of trophic networks remain largely unresolved. To address this knowledge gap, I addressed the following questions: (1) How do aquatic insect network properties, such as food-chain length, connectance, and linkage density shift along gradients of nutrient (nitrogen, phosphorus) enrichment? and (2) Do species traits such as body size mediate network complexity along gradients of nutrient enrichment? My study system was located in Central Ohio, northwest of Columbus, in the Upper Big Walnut Creek watershed, where I collected, identified, and characterized macroinvertebrates and water chemistry/nutrients at fourteen stream reaches from 2016-2017. Total phosphorus, phosphate, and nitrate were related to linkage density, connectance, invertebrate richness, and the relative abundances of basal and intermediate consumers. Individual traits were also correlated with network characteristics. For instance, body size was negatively associated with linkage density, connectance, density, and richness. Understanding how ecological networks respond to nutrient enrichment is an important contribution to interpreting community and ecosystem effects of nutrient enrichment in streams.