Demographic studies of plants and animals have a rich history and literature in ecology, and are important for both fundamental and applied ecology and conservation biology. Almost all demographic work has focused on intensive studies in which statistics such as births, deaths, growth of individuals and reproduction are quantified in a single population or a few populations. In contrast, many important ecological problems concern the demography of multiple populations, among which there is likely to be heterogeneity in these individual statistics, in their contributions to population growth, and in population growth itself. We introduce the conceptual framework of landscape demography, defined as the study of the demographic properties of populations and their drivers at multiple spatial scales, where the relationships among populations and their drivers at any one scale may influence demographic outcomes at other scales. Landscape demography generalizes the special case of metapopulation ecology, integrating and extending three important areas of ecological thought: metapopulation ecology, landscape ecology, and demography. Consideration of ensembles of populations at different spatial scales can advance progress in thinking about ecological issues of pressing current interest and importance including biological invasions, range expansions and contractions due to climate change, and the decline of threatened species, as well as fundamental ecological and evolutionary questions.
Results/Conclusions
We consider how the conceptual framework of landscape demography can be applied to populations of a threatened, commercially exploited fish species, a newly invasive plant in the eastern U.S., and bird populations in urban environments. These studies suggest that heterogeneity in measured and modeled demographic parameters may be ubiquitous, and that consideration of spatial scale cannot be ignored for many demographic questions. Although the components of landscape demography are familiar, we illustrate what emergent insights can be gained by integrating these elements, and why it is useful to have a new name for this new conceptual framework. Expanding demographic research to embrace a landscape perspective can potentially have major ramifications for how we understand the dynamics of natural populations.