Importance of trophic interactions for mycorrhizal dynamics across the Arctic
Short description
The expansion of shrubs in the Arctic is likely to have global implications. However, the current ideas about the effects and feedbacks of shrub expansion are oversimplified, as they are based upon the ecological features of tall deciduous species only (such as reduced albedo and an increased input of high-quality litter). The fact that several studies also show a strong increase of evergreen shrubs across the Arctic, in some cases aided by selective herbivory, has been largely overlooked. Unlike ectomycorrhizal (EcM) deciduous shrubs, a majority of arctic evergreen shrubs form ericoid mycorrhizal (ErM) associations, which has contrasting implication for C dynamics.
Aim
By utilizing a Pan-Arctic approach using long-term herbivore exclusion experiments at multiple sites across the Arctic we will:
- determine the production and turnover of extramatrical mycelia (EMM) biomass at multiple sites across the Arctic in relation to mammalian herbivory
- determine how mammalian herbivory affects soil fungal and EMM community dynamics across the Arctic
- define the soil fungal and EMM community dynamics under ErM and EcM shrubs and separate the 'active community' contributing to mycelia production
- disentangle the effect of ErM and EcM shrubs on ecosystem C dynamics
By utilising a pan-arctic distribution of experiments (through our large international networks) together with site specific process-basedexperiments, we will detect key linkages across trophic levels (from the large herbivore to thesoil microbes) and test how these hypothesis hold on a circumpolar scale.
