2023 Early Hearing Detection & Intervention Conference
March 5-7, 2023 • Cincinnati, OH
5/20/2019 | 2:30 PM - 2:45 PM | NICHE DIMENSIONALITY AND HERBIVORY CONTROL STREAM ALGAL BIOMASS VIA SHIFTS IN GUILD COMPOSITION, RICHNESS, AND EVENNESS | 251 DE
NICHE DIMENSIONALITY AND HERBIVORY CONTROL STREAM ALGAL BIOMASS VIA SHIFTS IN GUILD COMPOSITION, RICHNESS, AND EVENNESS
We developed a framework for the hierarchical pathways of bottom-up (niche dimensionality) and top-down control (herbivory) on biomass of stream algae via changes in guild composition (relative abundance of low profile, high profile, and motile guilds), species richness, and evenness. Implementing a combination of field and lab experiments that manipulated for the first time in benthic algae herbivory and/or niche dimensionality, i.e. the number of added nutrients (Nnutrients), including nitrogen, phosphorus, iron, and manganese, we made the following discoveries. First, guild composition was primarily determined by herbivory; richness, by guild composition and/or Nnutrients; evenness, by guild composition and herbivory; and biomass, by guild composition and Nnutrients. Second, species richness increased with Nnutrients—a pattern inconsistent with resource competition theory. Third, supplementation with manganese and/or iron increased richness, indicating that micronutrients, which have generally been overlooked in stream ecology, added dimensions to the algal niche. Fourth, the richness-evenness relationship depended on herbivory and the size of the species pool. Finally, the greater dependence of biomass production on guild composition and Nnutrients than on richness and evenness suggests that more comprehensive, trait-based approaches are necessary for the study of the biodiversity-ecosystem function paradigm.
- Disturbance
- Nutrients
- Functional Ecology
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Presenters/Authors
Sophia Passy
(), University of Texas - Arlington, sophia.passy@uta.edu;
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Chad Larson
(), Washington State Department of Ecology, clar461@ecy.wa.gov;
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