Influence of climate change on the invasibility of subarctic plant communities
Climate change influences both the invasibility of subarctic plant communities and the invasion success of potentially new colonizing species. Plant species are expected to expand their ranges further north, as climatic conditions for germination and growth may become more suitable due to warmer temperatures. At the same time, climate warming will affect the extant vegetation, which might become taller and denser, and therefore less invasible. To find out how climate change might affect the invasibility of different vegetation types in subarctic tundra and how different colonizing species respond to a changing climate, we set up a large seed-sowing experiment in Abisko, Northern Sweden.
In this experiment, we examine the effects on invasibility of plant community type (meadow, sparse dwarf shrub heath, dense dwarf shrub heath, Salix scrub) and disturbance treatment (undisturbed, gaps in different sizes) along an altitudinal gradient (400 – 900 m a.s.l.). As potential colonizers we used seeds from 22 species belonging to different growth forms and varying in their current distributions. The effects of community type, disturbance treatment and elevation are studied on seedling emergence, seedling survival and plant establishment. Also the effects of a series of co-variables, e.g. soil temperature, soil moisture, nutrient availability, light penetration, pH, snow depth, species richness, productivity, cover of mosses and litter are examined. In addition, germination experiments with the same 24 species are carried out in incubators with different cold stratification periods and germination temperatures.
This project is funded by Umeå University, the Fund for Scientific Research Flanders – Belgium, the University of Antwerp and the Kempe Foundation