Methods for determining viability of wildlife populations in large landscapes

Abstract

This chapter reviews methods of population viability analysis (PVA) as applied to wildlife populations in large landscapes. For these populations, viability analysis requires careful consideration of the issues of spatial heterogeneity and scaling of ecological processes, habitat connectedness, and temporal dynamics of the landscape. Spatially structured models used for large-scale PVA include occupancy models, grid-based lattice models, demographically structured metapopulation models, and individual-based models. Population viability analyses in large landscapes often require the definition of distinct subpopulations, which in turn depend critically on the spatial scale of, and barriers to, dispersal in relation to the distribution of suitable habitat. Another important factor is the effect of landscape dynamics on the temporal variability of the habitat, and hence on the dynamics of the wildlife populations. Viability of species in dynamic landscapes depends on the interaction between landscape change (the pattern, scale, rate, and direction of landscape changes in size, structure, and quality) and the species' ecology (its ability to disperse between and grow in the habitat patches or make use of the matrix). Spatial separation of populations can also provide the opportunity to validate the generality and applicability of model predictions in the absence of long-term monitoring data. © 2009 Elsevier Inc. All rights reserved.