Abstract
Microtus voles and lemmings are functionally important species in most terrestrial Arctic ecosystems; they are both prey and predators (herbivores), and are the hosts of many parasites. The key role of these small mammals is primarily due to their population dynamics with recurrent years with high numbers/biomass. The project aims to predict how climate change may affect the ecosystem functions of arctic small mammals through the properties of ice and snow. For this purpose the project will study a metapopulation of the sibling vole Microtus rossiameridionalis at Svalbard and its interaction with a predator, the arctic fox, and a parasite, the tape-worm Echinococcus multilocularis. The parasite has both the vole (intermediate) and the fox (final) as host species. This predator-prey/host-parasite system has many favourable model system characteristics that should enable us to establish: <h>1. How the variability of winter climate determines qualitative/quantitative properties of the snow cover in space and time; <h>2. How properties of the snow cover in turn shape the spatio-temporal density dynamics in the vole populations; <h>3. How the spatio-temporal variation in vole dynamics and the snow cover in turn shapes the functional response of the arctic fox to their vole prey; <h>4. Finally, how this chain of processes (1-3) determines spatially and temporally varying prevalence of Echinococcus multilocularis both in its intermediate (i.e. the vole) and final host (i.e. the arctic fox). The project aims to use field data to estimate the parameters necessary for building an empirical (statistical) model that will allow one to investigate how the dynamics of the system, including the likelihood of persistence of the parasite, may change under different scenarios of winter climate variability. The data/analysis can also be used to predict under which climatic circumstances whether Microtus vole and their associated parasites may spread further on Svalbard and other high Arctic terrestrial ecosystems.
Norway