Results/Conclusions

Regional metapopulation size did not differ between the heterogeneity treatments. However, temporal heterogeneity compared to spatial heterogeneity in resource supply was found to have a greater impact on the variation in regional population size.  At the local scale there was a strong positive correlation between resource availability and population size. Variation in local population size was greatest in metapopulations under temporal heterogeneity.
Net dispersal was greatest in spatially heterogeneous metapopulations. In this system, dispersal was density dependent such that colonization direction was from high density patches to low density ones.
Regionally, metapopulations varied in their composition of sources and sinks with spatially heterogeneous systems supporting consistently larger numbers of sinks. At a local scale, patches in spatially heterogeneous systems were more likely to exhibit a fixed pattern, either acting as sources or sinks. Conversely temporal heterogeneity resulted in much more dynamic behavior with patches frequently changing between sources and sinks.
We propose that it is important to classify the dynamic nature of source and sink patches more carefully, differentiating the mechanisms that drive differences in patch state. Understanding the dynamics of source-sink metapopulations is relevant in the context of any fragmented landscape undergoing habitat loss or degradation. It is also essential in order to gain a comprehensive understanding of landscape function for conservation, landscape management and reserve design.