PARENT SESSION
Contributed Oral Session 92: Biodiversity: Aquatic Systems
Wednesday, August 10, 1:30 PM - 5:00 PM, Meeting Room 513 C, Level 5, Palais des congrčs de Montréal
Species richness changes across two trophic elevels simultaneously affect prey and consumer biomass.
Gamfeldt, Lars*,1, Hillebrand, Helmut2, Jonsson, Per1, 1 Göteborg University, Göteborg, Sweden2 University of Cologne, Köln, Germany
ABSTRACT- Increasing species richness of either primary producers or consumers has been proposed to increase primary and secondary production. However, the consequences of biodiversity change across trophic levels are poorly investigated. We used a controlled marine microbial system to investigate the effects of simultaneous changes in biodiversity of consumers and prey species. Consumers (ciliates) and prey (algae) diversity and identity were manipulated independently in a complete factorial design. The results show clear biodiversity effects of both consumers and prey, both within and across trophic levels. We found reduced prey and increased consumer biomass with increased consumer richness. This effect was enhanced when prey diversity was high. The most diverse prey assemblage supported the highest biomass of consumers at the highest diversity of consumers. At lowest consumer richness there was an increase in prey biomass with increasing prey richness. This was due to increased inedibility of prey at higher richness levels. The results point at important links between producer and consumer richness levels, which, together affect energy transfer efficiency.
Key words: biodiversity, function, multitrophic