JJ Weis

Graduate Student

jerome.weis@yale.edu

C.V.

In general my research is concerned with how the community structure of ecosystems influences key functions such as biomass production, nutrient uptake, and energy transfer.  When addressing this broad topic community ecologists often group diversity into two functional forms; (i) horizontal diversity, the diversity of genes, species, or functional groups within a single trophic level and (ii) vertical diversity, the number and complexity of trophic levels in the community.  Historically, the influences of these two forms of diversity have been studied separately and now represent two converging disciplines within ecology.  Our knowledge of the influences of vertical diversity comes from ‘top down’ and ‘trophic cascade’ studies that show that top trophic levels can have substantial and cascading effects on the biomass of lower trophic levels.  Our knowledge of horizontal diversity comes from the discipline of biodiversity ecosystem function research where many theoretical and manipulative experiments have shown that, in general, increased consumer diversity tends to increase consumer biomass and decrease resource biomass across a range of consumer trophic levels and in both freshwater and terrestrial systems.  My goal is to use a combination of theory, manipulative laboratory experiments, and observational surveys to increase our understanding of how both horizontal and vertical diversity can influence the functioning of ecosystems.