Compensatory Dynamics in Zooplankton Community Responses to Acidification: Measurement and Mechanisms

Abstract

JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact support@jstor.org.. Ecological Society of America is collaborating with JSTOR to digitize, preserve and extend access to Ecological Applications. Abstract.Previous studies indicate substantial variation in ecological responses to perturbation. In some cases, ecosystems are resilient to perturbation due to compensatory dynamics in which losses of sensitive species are offset by population increases of species that perform similar ecological functions. Here, we report a detailed evaluation of compensatory dynamics in zooplankton community responses to the experimental acidification of Little Rock Lake, Wisconsin, USA. We used a variance ratio to quantify compensatory dynamics in functional groups of zooplankton containing species that use similar resources and are vulnerable to the same predators. We also used first-order autoregressive models to explore mechanisms driving the dynamics of each functional group. Our results indicate that responses of functional groups to acidification can be highly variable. Herbivorous copepods and medium-sized herbivorous cladocerans exhibited significant compensatory dynamics in response to acidification, whereas other functional groups exhibited independent or synchronous dynamics. First-order autoregressive models indicated that groups exhibiting compensatory dynamics contained both acid-tolerant and acid-sensitive species that competed. In contrast, groups that contained only acid-sensitive or acid-tolerant species exhibited more independent or synchronous dynamics. Overall, our study highlights the combined roles of sensitivity to environmental perturbation and species interactions in determining the extent of compensatory dynamics in zooplankton functional group responses to acidification.

Environmental Fluctuations Induce Scale‐dependent Compensation and Increase Stability in Plankton Ecosystems

“…In our study, zooplankton populations oscillated strongly in all treatments, resembling naturally occurring plankton ecosystems that typically show strong population oscillations due primarily to consumer-resource dynamics (McCauley et al 1999. Previous attempts to document the role of compensatory dynamics in stabilizing community responses to environmental fluctuations (Fischer et al 2001, Vasseur et al 2005) may have underestimated the importance of community dynamics since the reduction of synchrony rather than the presence of compensation may actually provide the stabilizing mechanism (see also Huber and Gaedke 2006). 4).…”

“…4). While a number of studies (Klug et al 2000, Fischer et al 2001, Bai et al 2004, Descamps-Julien and Gonzalez 2005, Vasseur et al 2005, Huber and Gaedke 2006 suggest a role for compensatory dynamics in fluctuating environments, Gonzalez and Descamps-Julien (2004) is the only study to previously show a reduction of aggregate community variance due to compensatory interactions between species in an experimental setting. The ubiquity of synchronous oscillations in natural communities has been reasonably well documented (Houlahan et al 2007), and the largely synchronous dynamics observed in this experiment resemble the dynamics observed in natural communities.…”

“…The first possibility is that fluctuating environments reduce both the amplitude and the likelihood of fluctuations in individual species for unknown or complex reasons. For example, Fischer et al (2001) showed that acid-tolerant species compensated with acid-sensitive species over long timescales (multiple years) during acidification and neutralization of lakes via a process that might be termed ''environmental tracking.' A second mechanism is destructive interference of internal population oscillations by exogenous forcing.…”

“…One possible mechanism that has been credited for producing compensation at longer timescales within trophic levels in previous work is direct consumer-resource interactions (Micheli et al 1999, Klug et al 2000, Fischer et al 2001). One possible mechanism that has been credited for producing compensation at longer timescales within trophic levels in previous work is direct consumer-resource interactions (Micheli et al 1999, Klug et al 2000, Fischer et al 2001).…”

Cross‐taxon congruence in lake plankton largely independent of environmental gradients

“…Moreover, trophic interactions may promote diversity through assembly processes, as colonization by one group may facilitate the colonization of another (Grover 1994). Studies examining long-term time series across a set of lakes have often found that large-scale environmental factors like climate change, acidification, or eutrophication/re-oligotrophication may promote coherent temporal changes in a set of lakes in a landscape (Magnuson et al 1990, Fischer et al 2001, Anneville et al 2005. Studies examining long-term time series across a set of lakes have often found that large-scale environmental factors like climate change, acidification, or eutrophication/re-oligotrophication may promote coherent temporal changes in a set of lakes in a landscape (Magnuson et al 1990, Fischer et al 2001, Anneville et al 2005.…”