Effects of population level aggregation, autocorrelation,and interspecific association on the speciestimerelationship in two desert communities
Evolutionary Ecology Research
Question: Can population-level patterns be used to model the species-time relationship? Which non-random patterns in population time-series are necessary for modelling the species-time relationship? Statistical modelling methods: The presence of aggregation, autocorrelation, and interspecific association was determined using Morisita's IM, Moran's I, and Ive's C respectively. Models for the species-time relationship were constructed from these sub-patterns using a combination of analytical models and randomization methods. Data studied: Observational time-series of rodents and annual plants in the Chihuahuan Desert. Conclusions: Aggregation was observed in the majority of population time-series. Most rodent species, but fewer than 10% of plant species, exhibited significant temporal autocorrelation in abundance. Models that included temporal autocorrelation as well as aggregation provided the best fit to the species-time relationship. The species-time relationship is intimately connected to the population dynamics of individual species. Models that attempt to connect the apparently general behaviour of the species-time relationship to the complex dynamics of populations are important for understanding the dynamics of ecological communities.
White, E.P., and M.A. Gilchrist. 2007. Effects of population level aggregation, autocorrelation, and interspecific association on the speciestime relationship in two desert communities. Evolutionary Ecology Research 9:13291347.