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MIGRATION AND SPATIOTEMPORAL VARIATION IN POPULATION DYNAMICS IN A HETEROGENEOUS ENVIRONMENT
Author(s) -
Engen Steinar,
Lande Russell,
Sæther Bernt-Erik
Publication year - 2002
Publication title -
ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.144
H-Index - 294
eISSN - 1939-9170
pISSN - 0012-9658
DOI - 10.1890/0012-9658(2002)083[0570:masvip]2.0.co;2
Subject(s) - variation (astronomy) , ecology , population , dynamics (music) , geography , biology , demography , sociology , pedagogy , astrophysics , physics
A continuous stochastic population model in space and time is presented. The model includes migration and spatially correlated environmental noise, and it accounts for spatial heterogeneity in habitat quality using a general spatial autocorrelation in the local carrying capacities. The model is analyzed by Fourier methods based on linearizations which are realistic when the population fluctuations are not too large. An expression for the spatial autocorrelation for the population density is derived together with some relatively simple relations for the scaling of these autocorrelations under the assumption that the migration rate is constant. For strong local density regulation, the spatial density pattern is approximately the same as the pattern of spatial heterogeneity in habitat quality. For weak density regulation the scaling increases with migration rate and distance and is approximately the same as the scaling of the environmental noise if the migration rate and distance are large. A required distinction between the spatial autocorrelation function and the function describing the spatial variation in the synchrony of population fluctuations is made. The effects of migration distance, migration rate, heterogeneity in carrying capacities, strength of local density regulation, and the magnitude and spatial autocorrelation in the environmental noise are discussed. Numerical examples illustrating the general findings are presented.