Quantifying Ecological Stability: From Community to the Lake Ecosystem

We performed a methodological study aimed at extending our previously developed approach to quantify the ecological stability of biotic communities and an entire ecosystem, using Lake Kinneret as a case study. The ecological stability of the biotic communities (phytoplankton and zooplankton) of Lake Kinneret was estimated using two different aggregating schemes. The first scheme used the combined stability index, based on the combined indices of the individual phytoplankton (SI[Comb](P)) and zooplankton (SI[Comb](Z)) taxonomic groups. The total community stability index was calculated based on the total abundances of these communities. The stability of the entire ecosystem was estimated for two sets of ecosystem state variables, a lake trophic state set and a water quality set, which provided considerably different estimates of the lake ecosystem stability. Good agreement between the results of this study and qualitative estimates of Lake Kinneret stability validates the suitability of this approach to estimate the stability of different ecological units.