The spatial influence of Pseudotsuga menziesii retention trees on ectomycorrhiza diversity.
Authors:
Luoma, D.L. Stockdale, C.A. Molina, R. Eberhart, J.L. USDA, FS
Source:
Canadian journal of forest research. 2006 Oct., v. 36, no. 10, p. 2561-2573.
NALT Subjects:
Pseudotsuga menziesii forest trees basal area spatial distribution ectomycorrhizae stand structure stand density forest stands species diversity mycorrhizal fungi uneven-aged stands uneven-aged management roots photosynthesis tree growth sapwood tree and stand measurements soil sampling Washington Oregon
Other Subjects:
green-tree retention soil cores
Issue Date:
Oct-2006
Abstract:
Living retention trees are being used in managed forests to promote a variety of values, including the maintenance of biological diversity. Federal forest plans for the northwestern USA include guidelines that require the retention of a minimum of 15% basal area in harvest units, with the goal of facilitating the development of late-seral stand structure, which is an important habitat element for old-growth forest-dependent species. However, effective levels and patterns of green-tree retention are unknown. We present results of a treatment consisting of 15% basal area, evenly dispersed retention (15%D). We quantified changes in the ectomycorrhiza (EM) community after the 15%D treatment, both near and away from retention trees. Pretreatment samples were obtained between 1 and 24 months before tree harvest. Post-treatment samples were collected within 14-25 months of harvest. In areas 8-25 m from retention trees, there was a 50% decline in the number of EM types per soil core from before to after treatment. Soil cores taken >5 m from retention trees exhibited a shift in EM community structure. EM-type richness was positively correlated with fine-root-tip density. We demonstrate the potential for retention trees to act as refugia for recolonization of newly established seedlings by ectomycorrhizal fungi.
