MSA - Ecology/Pathology
Lim, SeaRa , Berbee, Mary L. .
Site-specific tree productivity and ectomycorrhizal fungal diversity of western hemlock on northern Vancouver Island, Canada.
To better understand factors controlling the belowground diversity of ectomycorrhizal fungi on northern Vancouver Island, BC, Canada, we compared ectomycorrhizal fungal species of western hemlock from 100 year old second-growth hemlock-amabilis fir forest, from 300 year old old-growth cedar-hemlock forest, and from fertilized and unfertilized 24-year old regenerating cedar-hemlock forest. Tree productivity measured as site index (SI) was low on old-growth cedar-hemlock sites (SI=20) and also on regenerating cedar-hemlock plots that were either unfertilized (SI=19) or fertilized only with nitrogen (SI=19). Site indices were higher on the regenerating cedar-hemlock plots fertilized with nitrogen and phosphorus (SI=28) and on hemlock-amabilis fir plots (SI=32). Does site index predict fungal diversity and composition? To test the correlation between site indices and fungal species, we established three replicate plots per stand type and took four soil samples per replicate plot. From each sample, a DNA clone library was generated with 100 ectomycorrhizal root tips. We detected 158 Operational Taxonomic Units (OTUs) among 1676 fungal clone sequences. Shannon and Simpsonís indices showed that second-growth hemlock-fir had the highest ectomycorrhizal fungal diversity. Cantharellus tubaeformis was dominant in old-growth cedar-hemlock (36% of occurrences) whereas the other forest types had many low-frequency OTUs rather than a single dominant species. Leucophleps spinispora was found only on old-growth cedar-hemlock and Russula xerampelina on second-growth hemlock-amabilis fir. None of the fertilization treatments of regenerating cedar-hemlock plots significantly changed fungal species composition according to Principal Component Analysis and Non-metric Multidimensional Scaling results. Species composition of the 24-year old cedar-hemlock plots was more similar to the old-growth cedar-hemlock than to the hemlock-amabilis fir stands. We concluded species composition was related to stand type rather than site index. Change in productivity as measured by site index led only to minimal changes in fungal species composition.
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1 - University of British Columbia, Botany Department, 3529-6270 University Boulevard, Vancouver, British Columbia, V6T 1Z4, Canada
tree species composition
Presentation Type: Oral Paper:Papers for Topics
Location: Cottonwood B/Snowbird Center
Date: Tuesday, July 28th, 2009
Time: 9:15 AM