Heterotrophic succession in carrion arthropod assemblages.

摘要

A study was conducted to determine whether carrion communities in an urban site (site A) and a forest site (site B) in Parana, Brazil, exhibit a discrete or continuous succession pattern. Carrion attendant arthropods on rat carcasses were sampled during 1994-95. The permanence time, visitation pattern and species richness during each season were calculated. Results revealed that carrion attendant species were divided into nonrecurring and reoccurring groups. The average percentages of reoccurring taxa were 40 and 46% at sites A and B, respectively, except in the winter when it reached 95% at site B. The proportion of reoccurring taxa between saprophagous and predator/parasite species did not differ. There was no apparent pattern with respect to permanence time, with most of the species having a permanence time below 10%. Species richness was significantly greater at site B than at site A. In general, the pattern of species increase showed an exponential growth and then a decline. This exponential growth presented a single peak corresponding to the decaying stage, but during the winter there were more than one peak. At both sites, the great majority of species arrived during the fresh/bloat and decaying stages. The successional patterns of saprophagous and predator/parasite species tended to be complementary during most part of the process, with saprophagous species being more numerous during the fresh/bloat stage while the predator/parasite species being more numerous during the decaying stage. In the last stages, the predator/parasite species were more numerous at site A, while saprophagous species were more numerous at site B. At both sites, no clear boundaries were observed between the decomposition stages, suggesting a continuous succession pattern..