Bryophytes are often overlooked in ecological studies of plant communities, and there is often little knowledge of the ecological importance of bryophytes within local environments. Modern forestry practices generally lack a focused examination of bryophyte species; thus, species’ responses to management activities are not well known. The goal of this investigation was to explore changes in bryophyte communities associated with the common forestry practices of understory burning and overstory thinning over a range of substrates in mixed oak forests of southeastern Ohio. Study sites were within the design of the USDA Forest Service Fire and Fire Surrogate (FFS) Research Program located in three southeastern Ohio forests. Each of these forests contained four treatments: untreated control, prescribed fire only, overstory thinning only, and combined prescribed fire and overstory thinning. During the summer of 2007, bryophyte cover by species was estimated on soil, standing stems, and woody debris within 540, 2 × 5 m quadrats evenly distributed along a gradient of moisture classes. Associated environmental variables that were also measured included substrate abundance and type, topography, and available light. Bryophyte vouchers will be deposited in the Bartley Herbarium, Ohio University (BHO) bryophyte collection.
Results/Conclusions
A relatively small number of taxa were commonly encountered, including Platygyrium repens, Thuidium delicatulum, Polytrichum ohioense, Atrichum angustatum, Ditrichum pallidum, Leukobryum glaucum, and Steerecleus serrulatus. Several additional species were noted as first occurrences within Vinton County, Ohio. This study has contributed to an increase in the number of known species in this county from fifty-four to over one hundred species.. Treatment effects on forest floor conditions, and therefore microsite suitability for bryophytes, were pronounced in relation to light availability, abundance of understory vegetation, percent bare soil, and coarse woody debris inputs. Species distribution and abundance is clearly influenced by scale. Detailed abundance analyses suggest strong community differences among silvicultural treatments and along moisture gradients (stand-level effects), but it is clear that substrate type also strongly influences bryophyte community composition (microsite-level effects). Managing forests to maximize bryophyte diversity will necessitate multiple scale related decisions.
