Dissertation

Peeking into the future: Fungi in the greening Arctic

Promotor: E.F. Smets, Co-promotor: J. Geml

Author: Luis N. Morgado
Date: 24 March 2016
Links: Thesis in Leiden Repository

In the last decades, average land surface temperatures in the Arctic have increased at rates up to six times higher than the global average increase. Similarly, precipitation in the Arctic also increased, especially during the cold season when most precipitation falls as snow. In this thesis, the long-term effects of summer increased temperatures and increased winter snow depth in arctic soil fungal community composition in dry heath and moist tussock tundra were addressed using long-term ecological experiments at Toolik Lake, Alaska. Soil fungal composition was assessed through soil DNA extraction and massive parallel sequencing of rDNA ITS2. The fungal community composition responded strongly to summer warming in the moist tundra, but not in the dry tundra. Although total fungal richness was not significantly affected by warming, there were clear correlations among richness of various ecological and taxonomic groups and long-term warming. Regarding the effects of increased winter snow depth, the ectomycorrhizal fungal community composition of the dry tundra had a stronger response than the moist tundra community. The observed changes will likely affect ecosystem functions, such as C storage and N turnover, and have the potential to feedback to climate changes.