Clipping Response of Nine Bunchgrasses Native to the Blue Ash-Oak Savannah of the Inner Bluegrass Region of Kentucky

Nine native bunchgrasses were used to do an experimental restoration/community assembly project of the Blue Ash-Oak Savannah of the Inner Bluegrass Region of Kentucky. Since there are no existing reference systems of a native grassland matrix, nine native grasses were chosen for this project that was likely a part of this system. These nine species include six C3 species, and three C4 species. Since disturbance is an important component to savanna systems, a greenhouse clipping experiment was completed the summer of 2010 that mimics disturbance in the form of simulated herbivory or mowing. Herbivory imposes complex and multifactorial impacts on vegetation, including biomass removal. Two important dimensions of biomass loss are the extent (intensity) of loss at each disturbance, and the frequency of disturbance. How different species respond to various combinations of frequency and intensity of disturbance, and how to explain and predict these differences is of both practical and theoretical interest. This experiment imposed two clipping intensities and two clipping frequencies in a factorial design to study this question in a restoration context. Regrowth was variable, as expected the most complete recovery (compensation) or even increased production (overcompensation) was in the lowest disturbance (monthly at 6 inches). These species showed little evidence for overcompensation. Overall plants recovered more poorly to high intensity clipping compared to high frequency, especially the Elymus species. Exceptions to this were D. clandestinum's unique branching response and remarkable compensation. Generally, the C4 species regrew better than the C3 species. Non-timber forest products are widely used and loosely regulated in terms of how much biomass can be harvested from wild populations. Forest management primarily focuses on timber because non-timber forest products have not been extensively studied or modeled. In 2005, two long-term study sites were established near Reddish Knob and Mount Rogers, Virginia, to study the sustainable harvest of Black cohosh (Actaea racemosa). The roots and rhizomes of this native Appalachian herb are used commercially to treat menopause symptoms, with nearly all harvested Black cohosh coming from natural populations. To simulate practices of local harvesters, the largest plants from plots were harvested and measurements of both above ground and below ground biomass were recorded. The objective of the current analysis was to model the relationship between above ground and below ground measures in hopes of providing forest managers with a practical tool to predict yield. A linear mixed effects model was used to account for different …