title: Species richness and community composition of mat-forming ectomycorrhizal fungi in old- and second-growth Douglas-fir forests of the HJ Andrews Experimental Forest, Oregon, USA.
abstract: We investigated the species identity of mat-forming ectomycorrhizal (EM) fungi associated with old- and second-growth Douglas-fir stands. Using molecular analyses of rhizomorphs and EM root tips, we characterized 28 unique internal transcribed spacer sequences and considered them proxies for mat-forming EM species. In both stand age classes, one Athelioid species in the genus Piloderma dominated our sample of the mat-forming fungal community. In second-growth stands, the second most frequently encountered mat-forming EM species belonged to the genus Hysterangium. In old-growth stands, several Ramaria species were associated with a frequently encountered mat morphology but no species dominated the community. After using rarefaction analysis to standardize sampling effort, the total species richness did not differ statistically between old- and second-growth habitats. Both an abundance of infrequently encountered species and incomplete sampling of the mat-forming EM community may have limited our ability to detect potential differences in species richness. Several frequently encountered Piloderma species appear to have broad (holarctic) distributions and diverse host associations and their potential importance in forest ecosystems warrants further study.
authors.affiliation: Department of Botany and Plant Pathology, Oregon State University, 2082 Cordley Hall, Corvallis, OR, 97331, USA. Susie.dunham@oregonstate.edu.
authors.forename: Susie M
authors.initials: SM
authors.lastname: Dunham
authors.affiliation: Department of Plant and Environmental Sciences, Göteborg University, P.O. Box 461, 405 30, Göteborg, Sweden.
authors.forename: Karl-Henrik
authors.initials: KH
authors.lastname: Larsson
authors.affiliation: Department of Botany and Plant Pathology, Oregon State University, 2082 Cordley Hall, Corvallis, OR, 97331, USA.
authors.forename: Joseph W
authors.initials: JW
authors.lastname: Spatafora
mesh_terms: D001483:Base Sequence; D004271:DNA, Fungal / Q000737:chemistry / Q000235:genetics; D021903:DNA, Ribosomal Spacer / Q000737:chemistry / Q000235:genetics; D017753:Ecosystem; D014644:Genetic Variation; D008969:Molecular Sequence Data; D038821:Mycorrhizae / Q000235:genetics / Q000254:growth & development*; D009922:Oregon; D010802:Phylogeny; D018517:Plant Roots / Q000382:microbiology; D016133:Polymerase Chain Reaction; D028224:Pseudotsuga / Q000382:microbiology*; D016415:Sequence Alignment; D012988:Soil Microbiology; D014197:Trees
chemical_list: D004271:DNA, Fungal; D021903:DNA, Ribosomal Spacer