PARENT SESSION
Oral Session #89: Biodiversity and Ecosystem Function III.
Presiding: R. Washington-Allen
Thursday, August 8. 1:00 PM to 3:45 PM. Coconino Meeting Room, TCC.
Environmental conditions modulate the impact of species richness on community and population variability: evidence from natural and artificial aquatic microcosms .
ROMANUK, TAMARA*,1, KOLASA, JUREK1, 1 McMaster University, Hamilton, Ontario, Canada
ABSTRACT- We examined the relationship between species richness and temporal variability of both community and population abundances of micro- and meio- invertebrates inhabiting natural and artificial rock pool microcosms. Using both long-term data and experimental approaches, we show that while community abundances may be less variable in species-rich microcosms, the relationship is idiosyncratic and does not appear across all rock pool communities or in all experimental treatments. Specifically, richness is related to decreased variability in (i) temporary but not permanent rock pools, (ii) pools with stable pH, temperature, oxygen and salinity, but not pools in which these variables are unstable, and (iii) oligotrophic but not eutrophic microcosms. The latter dichotomy also applies to variability in population abundances. These results show that for rock pool invertebrates, richness either stabilizes abundance or has no effect on variability and appears to be modulated by environmental conditions.
KEY WORDS: biodiversity, stability, eutrophication, disturbance