Species richness–variability relationships in multi‐trophic aquatic microcosms

Abstract

J. 2006. Species richness Á/variability relationships in multi-trophic aquatic microcosms. Á/ Oikos 113: 55 Á/66.While species loss may affect the temporal variability of populations and communities differently in multi-versus single-trophic level communities, the nature of these differences are poorly understood. Here, we report on an experiment where we manipulated species richness of multi-trophic rock pool invertebrate communities to determine the effects of species richness, S, on the temporal variability of communities, populations, and individual species. As in single-trophic level studies, temporal variability in community abundance decreased with increasing species richness. However, in contrast to most studies in single-trophic level systems, temporal variability of populations also decreased as species richness increased. Furthermore, the variability of the constituent populations strongly correlated with variability of community abundance suggesting that, in rock pools, S affects community variability through its stabilizing effect on component populations. Our results suggest that species loss may affect population and community variability differently in multi-trophic versus single trophic level communities. If this is so, then the mechanisms proposed to underlie the effects of S on community variability in single-trophic communities may have to be supplemented by those that describe contributions to population stability in order to fully describe the patterns observed in multi-trophic communities.

Effects of anthropogenic disturbance on richness-dependent stability in Napahai plateau wetland

“…The positive relationship between plant richness and community stability observed in this study was in agreement with the findings of many other studies [26,29,[35][36][37][38][39][40][41][42]. We further explored the possible mechanisms, and found that statistical averaging, overyielding, and component population effects were likely mechanisms to account for the stabilizing effect of plant richness.…”

“…It is worth noting that we found a positive relationship between population-and community-level stability. Previous studies reported positive [37,39,41], negative [26,29,40], and neutral relationships [36,38,42] between the two, but the causes of these different patterns are still unknown. Future work should examine the general nature of the relationships and elucidate the associated mechanisms.…”

Relationships between biodiversity and the stability of marine ecosystems: Comparisons at a European scale using meta-analysis

“…total abundance): their variability becomes less affected by the scaling coefficient, z, determining the strength of the relationship between the mean and the variance (Doak et al, 1998;Vogt et al, 2006).…”

Non-omnivorous generality promotes population stability

“…Second, an increase in species richness could increase the number of distinct feeding pathways leading to any one species from a single trophic level by increasing non-omnivorous generality. Recent empirical studies show that populations can be stabilized by increasing species richness (Petchey et al 2002;Kolasa & Li 2003;Valone & Hoffman 2003;Romanuk & Kolasa 2004;Vogt. et al 2006), but the mechanisms (e.g.…”