Species richness, abundance, and composition of hypogeous and epigeous ectomycorrhizal fungal sporocarps in young, rotation-age, and old-growth stands of Douglas-fir (Pseudotsuga menziesii) in the Cascade Range of Oregon, U.S.A.

Abstract

Knowledge of the community structure of ectomycorrhizal fungi among successional forest age-classes is critical for conserving fungal species diversity. Hypogeous and epigeous sporocarps were collected from three replicate stands in each of three forest age-classes (young, rotation-age, and old-growth) of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) dominated stands with mesic plant association groups. Over four fall and three spring seasons, 48 hypogeous and 215 epigeous species or species groups were collected from sample areas of 6300 and 43 700 m2, respectively. Cumulative richness of hypogeous and epigeous species was similar among age-classes but differed between seasons. Thirty-six percent of the species were unique to an age-class: 50 species to old-growth, 19 to rotation-age, and 25 to young stands. Seventeen species (eight hypogeous and nine epigeous) accounted for 79% of the total sporocarp biomass; two hypogeous species, Gautieria monticola Harkn., and Hysterangium crassirhachis Zeller and Dodge, accounted for 41%. Average sporocarp biomass in young and rotation-age stands compared with old-growth stands was about three times greater for hypogeous sporocarps and six times greater for epigeous sporocarps. Average hypogeous sporocarp biomass was about 2.4 times greater in spring compared with fall and for epigeous sporocarps about 146 times greater in fall compared with spring. Results demonstrated differences in ectomycorrhizal fungal sporocarp abundance and species composition among successional forest age-classes.Key words: ectomycorrhizal fungi, sporocarp production, forest succession, Pseudotsuga menziesii, Tsuga heterophylla zone, biodiversity.

Mycorrhizal mushroom diversity and productivity—an indicator of forest health?

“…Several studies have demonstrated that the composition of fungal communities changes during the forest succession (Hintikka 1988;Last et al 1987;Dighton et al 1986). Smith et al (2002) and Kranabetter et al (2005) showed that, in older mixed conifer stands, the fruit-body biomass and the frequency of several 'late-stage' fungi were greater than in younger stands. Recently, however, Twieg et al (2007) demonstrated that simple categories such as 'early stage', 'multi stage' and 'late stage' were insufficient to describe fungal species' successional patterns in Douglas fir (Pseudotsuga menziesii) stands.…”

“…Of these, 70% occur in forests and about half of them are mycorrhizal. Forest fungi play important ecological roles in forest ecosystems, acting as mycorrhizal symbionts, decomposers and pathogens (Smith and Read 1997;Dighton et al 2005). In addition, picking their fruit bodies is a popular pastime and a recreational activity for many people in a substantial number of countries (Boa 2004).…”

Ectomycorrhizal communities in a Mediterranean forest ecosystem dominated by Quercus ilex: seasonal dynamics and response to drought in the surface organic horizon

“…This may suggest that our sampling effort was insufficient to detect many rare taxa. However, the dominance of rare taxa occurs in species-rich ECM assemblages of old sampled stands (old-growth stage; O'Dell et al 1999;Richard et al 2005;Smith et al 2002). The ECM communities may thus reflect more the age of the tree individuals (age of root systems) than the age of stems since the last clear-cut.…”

Implementation of the fire and fire surrogate study— a national research effort to evaluate the consequences of fuel reduction treatments

“…Impacts on truffle production, however, were brief. The long-term impacts of forest management on truffle production remain unclear, with inconsistent results from across the region , Smith et al 2002. Induced heterogeneity increased sporocarp diversity to a richness that rivals that in old growth .…”