Different Effects of Species Diversity on Temporal Stability in Single‐Trophic and Multitrophic Communities

Abstract

The question of how species diversity affects ecological stability has long interested ecologists and yet remains largely unresolved. Historically, attempts to answer this question have been hampered by the presence of multiple potentially confounding stability concepts, confusion over responses at different levels of ecological organization, discrepancy between theoretical predictions, and, particularly, the paucity of empirical studies. Here we used meta-analyses to synthesize results of empirical studies published primarily in the past 2 decades on the relationship between species diversity and temporal stability. We show that the overall effect of increasing diversity was positive for community-level temporal stability but neutral for population-level temporal stability. There were, however, striking differences in the diversity-stability relationship between single- and multitrophic systems, with diversity stabilizing both population and community dynamics in multitrophic but not single-trophic communities. These patterns were broadly equivalent across experimental and observational studies as well as across terrestrial and aquatic studies. We discuss possible mechanisms for population stability to increase with diversity in multitrophic systems and for diversity to influence community-level stability in general. Overall, our results indicate that diversity can affect temporal stability, but the effects may critically depend on trophic complexity.

Biodiversity loss and its impact on humanity

“…But theory and data both support greater temporal stability of a community property like total biomass at higher levels of diversity. Five syntheses have 40 summarized how diversity impacts variation of ecosystem functions through time [38][39][40][41][42] , and these have shown that total resource capture and biomass production are generally more stable in more diverse communities. The mechanisms by which diversity confers stability include overyielding, statistical averaging, and compensatory dynamics.…”

Resilience, reactivity and variability: A mathematical comparison of ecological stability measures

“…Finally, to compute deterministic invariability I D , we must solve (11). Here this formula takes the simple form of…”

“…[10][11][12][13]. Although theoretical studies have also considered stability measures based on variability [14][15][16], the link with resilience is not obvious.…”

From Structure to Function: the Ecology of Host-Associated Microbial Communities

“…Both empirical and theoretical studies indicate that diversity enhances stability; however, aspects of stability can be affected differently, and these relationships play out in multiple ways in different ecosystems (e.g., see references 101, 139, 156, 292, 325-327, 334, 340, 351, and 375). For example, it has been shown that while diversity increases total community stability, it decreases the stability of populations within a community (156,188,340). These ecological concepts have been studied in a wide range of communities (Table 2).…”