The purpose of this study, carried out at the Sicamous Creek Silvicultural Systems Trial located in the southern Interior of British Columbia, was to investigate the effects of cut block size and distance from the forest edge on patterns of ectomycorrhizal colonization and diversity at a subalpine forest. Non-mycorrhizal Picea engelmannii Parry ex Engelm. × Picea glauca (Moench) Voss seedlings were planted across cut blocks of three sizes (0.1, 1.0, and 10 ha) and in the uncut forest. In 1996 and 1997, seedlings were harvested after 13 weeks and examined for mycorrhizae. In 1996, diversity and richness of ectomycorrhizal types were significantly greater at forest plots and at plots located 2 m from the forest edge as compared with plots located >16 m into the cut block. In 1997, richness was again significantly reduced beyond 2 m. No differences in any of the diversity measures were detected between the different cut block sizes. The results of this study suggest that proximity to overstory trees may be more important than cut block size for patterns of ectomycorrhizal diversity and colonization. Additionally, polymerase chain reaction - restriction fragment length polymorphism (RFLP) analysis was used to assess the accuracy of morphotyping and, in some cases, to identify the associated fungus by comparison with RFLP patterns generated by sporocarps.

The objective of this study was to examine the effects of stand age and tree species composition on the abundance, diversity, and community composition of epigeous fruit bodies formed by ectomycorrhizal (ECM) fungi in the Interior Cedar Hemlock zone of British Columbia. Fruit bodies were collected and identified in May, June, August, September, and October of 1996, 1997, 1998, and 1999 from transects located in new (5 year old) plantations and mature (75–125 year old) wild forests composed of relatively pure Betula papyrifera Marsh. (paper birch), relatively pure Pseudotsuga menziesii var. glauca (Beissn.) Franco (interior Douglas-fir), and mixtures of the two tree species. A total of 187 fungal taxa were collected during the study, of which 185 occurred in mature forests and only 17 occurred in the plantations. Thirty-four taxa were unique to mature predominantly birch forests, 35 were unique to mature predominantly Douglas-fir forests, 17 were unique to mixed mature forests, and 68 taxa were found in all three mature forest types. The abundance of fruit bodies in mature forests varied widely among sampling years and generally increased with annual precipitation. ECM species richness differed between stand ages but not among forest compositions in both plantations and mature forests. Lactarius glyciosmus , Hygrophorus eburneus var. eburneus , and Cortinarius armillatus were more abundant in mature birch than mature Douglas-fir forests. Lactarius torminosus , Leccinum scabrum var. scabrum , and Rozites caperatus were also found predominantly in mature birch and mixed forests, whereas Gomphidius subroseus was more abundant in Douglas-fir forests than in birch and mixed mature forests. Russula brevipes was also found predominantly in mature Douglas-fir and mixed forests. Our results indicate that clearcutting has a profound effect on abundance and composition of ECM fruit bodies, and that changes in forest tree species composition may lead to shifts in ECM fungal community composition.

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