Herbaceous‐Layer and Overstory Species in Clear‐cut and Mature Central Appalachian Hardwood Forests

Abstract

The current interest among resource managers in ecosystem management necessitates a better understanding of the response of plant species diversity to forest management practices. This study attempted to assess the effects of one forest management practice–clear‐cutting–on plant biodiversity in a mid‐Appalachian hardwood forest by comparing species composition and diversity between two young (≈ 20 yr following clear‐cutting) and two mature (> 70 yr following selective cutting) watersheds. Sampling was confined to the herbaceous layer (vascular plants ≤ 1‐m in height) and woody overstory (stems ≥ 2.5 cm diameter at 1.5‐m height). The important tree species occurred on all watersheds, but the relative importance of these species varied greatly with stand age. Less shade‐tolerant species, such as black cherry (Prunus serotina) and tulip poplar (Liriodendron tulipifera), are replaced by more‐tolerant species, such as northern red oak (Quercus rubra) and sugar maple (Acer saccharum), as the stand matures. Analysis of tree species richness per plot suggests that the competitive thinning process decreases species evenness as the stand develops. Important herb‐layer species included stinging nettle (Laportea canadensis), violets (Viola spp.), seedling of striped maple (A. pensylvanicum), and several fern species. In sharp contrast with the trees, these species appeared to vary little with stand age. Species diversity (H') did not vary with stand age for either the overstory or the herbaceous layer. Detrended correspondence analysis showed a significant correlation between species composition of the two strata for the mature watersheds, but not the young, clear‐cut watersheds. Thus, we suggest a temporal shift in processes influencing species composition following disturbance from allogenic factors (e.g., soil characteristics) to autogenic factors (e.g., stand characteristics), which lead to a linkage between forest strata later in succession. The degree to which forest management alters species composition in these central Appalachian forest ecosystems may be tied to the degree of alteration of the link between strata.

Relationship between fragmentation, degradation and native and exotic species richness in an Andean temperate forest of Chile

“…Then, this result is concordant to other studies documenting negative effects of fragmentation on native biodiversity (e.g. Saunders et al 1991, Soulé et al 1992, Gilliam et al 1995, Laurance et al 1998, Tabarelli et al 1999, Hersperger & Forman 2003, Lindenmayer & Fischer 2006, Echeverría et al 2007, Schmitt et al 2010. As with exotic species, environmental changes produced by fragmentation (Chen et al 1995, Murcia et al 1995 may be detrimental for some forest-specialist native species.…”

“…Saunders et al 1991, Soulé et al 1992, Gilliam et al 1995, Laurance et al 1998, Tabarelli et al 1999, Hersperger & Forman 2003, Lindenmayer & Fischer 2006, Echeverría et al 2007, Schmitt et al 2010, as well as increases in exotic species diversity and abundance (Brothers & Spingarn 1992, Hobbs & Huennecke 1992, Wilson et al 1992, D'Antonio 1993, Mooney & Hobbs 2000, Hobbs 2001, Rouget et al 2002, Pauchard & Alaback 2004, Sax et al 2005. These fragmentation effects may be related to micro-environmental changes in the new edges, such as increase of light, higher temperatures and the potential release of other resources (Saunders et al 1991, Brothers & Spingarn 1992, Chen et al 1995, Hobbs 2001).…”

Vegetation and Acidification

“…Despite large differences in stand age among these watersheds, with WS3 and WS7 trees being approximately 20 years old versus 80-100 years for WS4 and WS13 in 1991, there were minimal differences in herb layer composition, cover, biomass, and species diversity (Gilliam et al 1995, Gilliam 2002. This was in sharp contrast to measures of tree communities, which varied more predictably with stand age along a successional gradient.…”

“…Foliage was sampled in 1992 from WS3 and WS7 (sweet birch, yellowpoplar, black cherry and red maple) as part of a total biomass sampling for nutrients (Adams et al 1995). In 1997 and 2002, foliage was collected from the upper crown of five trees from each of six species (the four listed above plus northern red oak and sugar maple) from WS3 and WS7, and in 2002 watersheds using these data.…”

“…All of these heretofore unpublished data were collected by personnel with the USDA Forest Service, Northeastern Research Station at Parsons, West Virginia. All tissue nutrient analyses were conducted at the University of Maine Soil and Plant Testing Laboratory, using protocols described by Adams et al (1995). Samples were collected from the upper crown of two trees per species per treatment plot, where present.…”