Tree-fungi-soil interactions in the subarctic-alpine forest-heath ecotone
The warming climate is shifting forest northwards into the arctic tundras currently storing a large proportion of the global soil carbon stock.
The biotic feedbacks from these ecosystems to future climatic changes are highly uncertain. In this project we study how trees through their association with ectomycorrhizal fungi could affect soil carbon storage if forests expand into former heath tundras.
Our field studies are carried out in the area around Abisko in Northern, subarctic Sweden, and comprise both natural gradient and manipulative experiments. Our main hypothesis is that the increasing abundance of shrubs and trees along the heath-to-forest ecotone is linked to increasing abundance of symbiotic ectomycorrhizal fungi and consequently decreasing stocks of soil carbon due to a more efficient recycling of organic matter from the soil.
To link fungal communities to carbon and nitrogen dynamics, we combine 454-pyrosequencing to characterize fungal communities with measurements of carbon and nitrogen pools and stable isotope abundance in fine-scaled organic soil profiles along the natural gradient. We also characterize field vegetation (point-intercept), tree biomass (biometrics) and estimate fungal biomass (qPCR) and production (in-growth bags) across the heath-forest transition, to facilitate analyses of the main driving forces behind composition and functioning of the fungal communities.
Funded by: 7th European Framework programme, Wallenberg Foundation
Contact: Karina.Clemmensen@mykopat.slu.se, Phone: +45 (0)18-67 15 79
