Fungal Community Shifts in Structure and Function across a Boreal Forest Fire Chronosequence.
Forest fires are a common natural disturbance in forested ecosystems and have a large impact on the microbial communities in forest soils. The response of soil fungal communities to forest fire is poorly documented. Here, we investigated fungal community structure and function across a 152-year boreal forest fire chronosequence using high-throughput sequencing of the internal transcribed spacer 2 (ITS2) region and a functional gene array (GeoChip). Our results demonstrate that the boreal forest soil fungal community was most diverse soon after a fire disturbance and declined over time. The differences in the fungal communities were explained by changes in the abundance of basidiomycetes and ascomycetes. Ectomycorrhizal (ECM) fungi contributed to the increase in basidiomycete abundance over time, with the operational taxonomic units (OTUs) representing the genera Cortinarius and Piloderma dominating in abundance. Hierarchical cluster analysis by using gene signal intensity revealed that the sites with different fire histories formed separate clusters, suggesting differences in the potential to maintain essential biogeochemical soil processes. The site with the greatest biological diversity had also the most diverse genes. The genes involved in organic matter degradation in the mature forest, in which ECM fungi were the most abundant, were as common in the youngest site, in which saprotrophic fungi had a relatively higher abundance. This study provides insight into the impact of fire disturbance on soil fungal community dynamics.
Department of Food and Environmental Sciences, University of Helsinki, Helsinki, Finland Department of Forest Sciences, University of Helsinki, Helsinki, Finland hui.sun@helsinki.fi.
Hui
H
Sun
Department of Food and Environmental Sciences, University of Helsinki, Helsinki, Finland.
Minna
M
Santalahti
Department of Forest Sciences, University of Helsinki, Helsinki, Finland.
Jukka
J
Pumpanen
Department of Forest Sciences, University of Helsinki, Helsinki, Finland Institute of Forestry and Rural Engineering, Estonian University of Life Sciences, Tartu, Estonia.
Kajar
K
Köster
Department of Forest Sciences, University of Helsinki, Helsinki, Finland.
Frank
F
Berninger
Department of Forest Sciences, University of Helsinki, Helsinki, Finland.
Tommaso
T
Raffaello
Division of Biology, Kansas State University, Manhattan, Kansas, USA.
Ari
A
Jumpponen
Department of Forest Sciences, University of Helsinki, Helsinki, Finland.
Fred O
FO
Asiegbu
Department of Food and Environmental Sciences, University of Helsinki, Helsinki, Finland.
Jussi
J
Heinonsalo
D044822:Biodiversity; D058893:DNA Barcoding, Taxonomic; D005387:Finland; D005390:Fires; D005658:Fungi / Q000502:physiology*; D059014:High-Throughput Nucleotide Sequencing; D012621:Seasons; D017422:Sequence Analysis, DNA; D012988:Soil Microbiology; D066188:Taiga