Arianta

Oecologia 105:475-483 (1996)

Effects of population subdivision and catastrophes on the persistence of a land snail metapopulation

H. Resit Akçakaya
Applied Biomathematics, 100 North Country Road, Setauket, NY 11733, USA

Bruno Baur
Zoology Institute, University of Basel, Rheinsprung 9, CH-4051, Basel, Switzerland
Present address: Conservation Biology Research Group, Basel University, St. Johanns-Vorstadt 10, CH-4056 Basel, Switzerland.

Summary

        We modeled the dynamics of a metapopulation of the land snail Arianta arbustorum in northeastern Switzerland to investigate the effect of population subdivision on the persistence of a land snail metapopulation and to analyze the interaction between spatial factors, population subdivision, and catastrophes. We developed a spatially structured, stochastic, age-structured metapopulation model with field data from previous studies on the metapopulation in Switzerland as well as experimental and meteorological data. The model incorporated distance-dependent dispersal through stream banks, correlated environmental fluctuations, and catastrophes resulting from heavy rains. The results point to various complex interactions among factors involved in metapopulation dynamics, and suggest that in some cases population subdivision may act as a way to decrease threats from environmental fluctuations and catastrophes.