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Updated: Jul 10, 2026
10:20
Linking Predation Risk, Herbivore Physiological Stress and Microbial Decomposition of Plant Litter
Published on: March 12, 2013
Consumers affect prey biomass and diversity through resource partitioning
1Department of Botany, University of Stockholm, 106 91 Stockholm, Sweden. Sonja.Raberg@botan.su.se
Ecology
|November 22, 2007
Summary
Nutrient enrichment increased marine epiphyte biomass, but diverse grazers with complementary diets effectively controlled growth. Grazer composition and productivity are key to maintaining algal diversity.
Area of Science:
- Marine ecology
- Ecosystem dynamics
- Biodiversity research
Background:
- Nutrient availability and consumer presence interact to influence plant diversity.
- Understanding these interactions is crucial for managing coastal ecosystems.
Purpose of the Study:
- To investigate the effects of nutrient supply and grazer composition on marine epiphyte biomass and algal diversity.
- To test the hypothesis that consumer effects on prey diversity depend on productivity and consumer specialization.
Main Methods:
- A factorial experiment manipulated nutrient levels and the presence of two grazer species (individually and combined).
- Measured epiphyte biomass and algal (micro- and macroalgal) diversity in response to treatments.
Main Results:
- Nutrient enrichment increased epiphyte biomass.
- Single grazer species partially controlled epiphytes, but complementary feeding by both species was needed for effective control.
- Algal diversity varied with grazer identity; microalgal diversity decreased with nutrient addition when grazers were inefficient but not with specialist grazers.
- Macroalgal diversity decreased with specialist macroalgal grazers in ambient conditions.
Conclusions:
- Grazer composition and feeding complementarity are critical for controlling epiphyte overgrowth.
- Both productivity and consumer traits (specialization, composition) determine whether consumers enhance or reduce algal diversity.
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