Hjem
Institutt for biovitenskap (BIO)
Gjesteforelesnig

Ellen Dorrepaal

Cryoecology - How arctic ecosystems matter for our changing climate.

Hovedinnhold

Arctic tundra are the coldest ecosystems of our planet and have long acted as cooling elements for our climate. The two main reasons are that treeless, snow-covered tundra strongly reflects incoming solar radiation, and that storage of large amounts of organic carbon in permanently frozen soils (permafrost) has long reduced the concentrations of greenhouse gasses in the atmosphere. Above-average climate warming and changes in snow cover at northern high latitudes will likely change this, by stimulating establishment of trees in the tundra, and by accelerating microbial breakdown of carbon in thawing permafrost. The rate of these changes and the magnitude of the resulting positive climate feedback are, however, highly uncertain, because treeline shifts and permafrost carbon losses are not only controlled by the climate, but also by ecological processes, which are still poorly understood. In this seminar, I will explain how interactions among plants and between plants and soil-microbes strongly regulate the responses of treeline and permafrost ecosystems to climate change.