Fungal community assessment in Canadian arctic soils from Alexandra Fiord, Ellesmere Island, Nunavut.

摘要

Fungal communities in arctic soils tend to be less diverse compared to the communities in temperate forest soils due to the harsher environmental conditions. Even in a single arctic site such as Alexandra Fiord, considered a terrestrial arctic oasis, fungal diversity is expected to be lower compared to soils in less extreme environments. We hypothesized that variations in environmental factors would play an important role in determining fungal community structure, as the Alexandra Fiord soils exhibits considerable environmental variation in a small geographic area. To test this hypothesis, we collected soil samples from three sites across the landscape and performed length-heterogeneity polymerase chain reaction (LH-PCR) analyses using ITS3 and NLB4 primers, which have been used successfully to characterize complex communities. Our results showed that there were large relative differences in fungal community structure between the sites. At the Alexandra Fiord Highland Dolomitic site diversity was low with genotypes relatively evenly distributed, whereas Alexandra Fiord Highland Granitic and Alexandra Fiord Lowland sites had higher diversity and a less even distribution of genotypes with a few occurring at a high frequency and many rare species. Among environmental variables, soil moisture, temperature, DOC, DON, C:N ratio and soil pH were significant influential factors in determining fungal community structure. Among these environmental factors, pH showed the strongest correlation with the fungal community data. --P. ii.