Abstract
The aim with the present project is to analyze how expected changes in climate will affect the population dynamics of birds and mammals, and how these dynamical influences will cause shifts in the geographical distribution of abundances within the distributional range of a species. Our approach will be to analyze in detail some carefully selected model systems for which long time series of individual-based demographic data as well as a mechanistic understanding of how climate influences the demography are available. This will allow us to parameterize stochastic population models that can be used to quantitatively evaluate climate influences on the population dynamics. By comparing systems with different population dynamical characteristics, we will identify by sensitivity analyses whether some demographic parameters are more critical for strong responses to changes in climate than others. We will then develop theoretical models to identify conditions under which conditions temporal changes in climate are most likely to cause shift in the geographical distribution of abundance within a species' distributional range. We will focus these spatiotemporal analyses on three economically important systems of game species (Norwegian moose, grouse in Fennoscandia and North American waterfowls) in which population fluctuations are influenced by climate variation. By combining stochastic population models with regional scenarios for expected changes in climate as well as in environmental phenology, we can calculate how changes in climate will affect the spatial synchrony of the population fluctuations and how this will cause differences in the distribution of the abundance of the species within their distributional range. Such shifts will in turn affect the regional variation in the yield of these commercially important species. We will therefore examine whether the effects of climate changes can be modified by altering the harvest strategies of these species.
Norway