COS 272-1 - CANCELLED - The contribution of composition: Is species richness or community composition more important for the functioning of ecosystems?

Thursday, August 18, 2022

3:30 PM – 3:45 PM EDT

Location: 513F

Presenting Author(s)

KB

Kathryn E. Barry, n/a

Assistant Professor
Utrecht University, Netherlands

Coauthor(s)

MS

Merel Soons

Utrecht University
Utrecht, Netherlands
BV

Betty Verduyn

Utrecht University
Utrecht, Netherlands
MH

Mariet Hefting

Utrecht University
Utrecht, Netherlands
GK

George Kowalchuk

Utrecht University, Netherlands
EP

Edwin Pos

Utrecht University, Netherlands
Mv

Marijke van Kuijk

Utrecht University, Netherlands
YH

Yann Hautier

Utrecht University, Netherlands

Background/Question/Methods

Global change is driving global biodiversity loss at unprecedented rates. This global biodiversity loss alters how ecosystems function and provide services to humans. Current evidence suggests declines in the number of species (richness) will lead to declines in ecosystem functioning. Yet, at the local scales represented by biodiversity experiments, the composition rather than the richness of the community is more likely to change initially as species go locally extinct but are replaced by other species. Here, we leverage the initial design of the Biodiversity and Climate Variability Experiment at Utrecht University to answer the question: How important are changes in community composition for biomass production?

Results/Conclusions

We find that species composition in terms of the community identity, the proportion of the community that is composed of a specific species, and the identity of individual species are all more important for biomass production than species richness by an order of magnitude. However, community composition variation depends on the species richness of the community, especially through time. Higher diversity communities vary more during establishment and lower diversity communities vary more under stress. These findings indicate that changes in community composition are likely to alter ecosystem functioning even without concurrent changes in species richness.