Forest edge effects on the mycorrhizal communities of the dual mycorrhizal tree Alnus glutinosa

During hundreds of years, forests around the world have been converted into agricultural land, leading to a continuous decline in forest cover and a reduced size, increased isolation and edge-to-core ratio of the remaining fragments. Forest edges are more directly exposed to sunlight, wind and pollutants and the resulting changes in evapotranspiration, nutrient cycling and other ecological processes might have a large impact on the communities inhabiting forests. Moreover, the magnitude and distance of edge effects may vary greatly and depend on which parameter is studied, but also on the structure and orientation of the edge. Few empirical studies, however, have focused on the effects of forest fragmentation and the effect of edges on mycorrhizal fungal communities. Here, we studied how soil conditions and communities of arbuscular mycorrhizal (AMF) and ectomycorrhizal fungi (EcMF) in the roots of the dual mycorrhizal tree Alnus glutinosa and in the soil changed with increasing distance from the forest edge in a landscape consisting of fragmented forests embedded in an intensive agricultural matrix.