The proposed research programme will increase understanding of ecosystem dynamics at the forest-tundra ecotone in northern Europe. In particular, it will quantify the dynamics of the response of this ecotone to changes in climate and in land use. In order to achieve this overall objective, the following more specific objectives will be addressed:
- To establish the principal environmental determinant(s) of the position of the forest-tundra ecotone in northern Europe;
- To evaluate the long-term stability of the position of this ecotone;
- To test the extent to which stabilising feedback controls determine the sensitivity of the ecotone to environmental changes;
- To investigate the extent to which potential dynamic responses of the ecotone to environmental changes are modulated by other limiting factors, including propagule dispersal, seedling establishment, disturbance régime and herbivore impacts;
- To evaluate the impacts of a transformation from tundra to birch woodland upon carbon sequestration, trace-gas fluxes, soil organic matter mineralisation rates and catchment hydrology;
- To construct a landscape-scale model of ecosystem dynamics able to simulate the response of the ecotone to a variety of scenarios of environmental change;
-To simulate the impacts of alternative environmental change scenarios upon the ecotone.
These objectives will be addressed through a combination of field measurements, experiments and modelling at 6 study sites in Fennoscandia. Palaeoecological data will be used to provide a longer time perspective where appropriate, whilst the programmes of measurement and field manipulations will establish bases for longer-term monitoring of the ecotone. The study sites will be arranged along two complementary transects within environmental space. Northern Europe exhibits a strong oceanic-continental climate gradient along which the first transect will extend. The topographic diversity of Fennoscandia leads to recurrence of the forest-tundra ecotone across a wide latitudinal range and thus under diverse conditions of insolation and photoperiod; the second transect will extend along this gradient. The contemporary climate, trace-gas fluxes and soil organic matter mineralisation rates will be monitored; tree seedling establishment and growth and propagule flow, will be measured; the role of outlying trees in ecotone response will be assessed; the past position of the ecotone and the palaeoclimate will be investigated; time-series of snow-cover data will be obtained from satellite data; experiments will investigate the influences of temperature, snow-cover, the presence of a canopy, herbivory and disturbance upon tree seedling establishment; and models will be developed of landscape-scale hydrology and ecosystem dynamics.
Funding SchemeCSC - Cost-sharing contracts
901 87 Umeå
413 19 Göteborg
752 36 Uppsala