Herbaceous competition and herbivory have been identified as critical barriers to restoration of native tree species in degraded landscapes around the world; however, the combined effects of competition and herbivory are poorly understood. We experimentally manipulated levels of herbivory and herbaceous competition and analyzed the response of tree seedling performance over three growing seasons as a function of species and habitat in north-central West Virginia. Four native tree species were planted in old field and forest experimental plots: Castanea dentata (American chestnut), Quercus rubra (red oak), Acer saccharum (sugar maple), and Picea rubens (red spruce). Red spruce demonstrated the highest growth increment and greatest survival (64%) and most consistent results among treatments and habitats. Red spruce survival was not reduced in the presence of Odocoileus virginianus (whitetailed deer) browse and herbaceous competition; however, growth was improved by suppression of herbaceous competition. We suspect that this deciduous forest landscape would regenerate to a red spruce dominated forest if seed source was available. In contrast, the other three species tested had very low survival when exposed to deer and were more responsive to competing vegetation and habitat type. American chestnut had low survival and growth across all treatments, suggesting basic climate limitations. Vigorous natural regeneration of Prunus serotina (black cherry) occurred in forest plots where both competing herbs and deer were excluded. Our results demonstrated the importance of testing multiple potential recruitment barriers and species at once and the need for species and habitat-specific restoration treatments.
Edaphic and Land Use Influences on Central Appalachian Fens Sarah Deacon Local and landscape-scale factors influence peatland floristic assemblages. Our goal in this paper was to assess the interactions between wetland vegetation communities, edaphic factors, and surrounding land cover in central Appalachian peatlands. Specifically we quantified plant community dynamics in relation to edaphic factors and land cover and identified species level responses to human altered landscapes. Cluster analysis on vegetation data identified 3 vegetation groups; an emergent floristic assemblage, a shrub dominated group, and a group with mixed shrub and emergent vegetation. We found that wetlands with emergent vegetation cover were more often associated with natural land cover, higher pH and lower NH4-N. Shrub dominated floristic assemblages were associated with higher anthropogenically altered landscapes, higher pH and higher NH4-N. The mixed floristic assemblage was associated with lower pH and lower mining in the surrounding watershed. Recursive partioning results indicated edaphic factors were more influential than land cover for our three vegetation groups. The only landscape-scale factor that was used as a classifier was mining. Nutrient and pH-alkalinity gradients and to a lesser extent surrounding land cover influenced floristic assemblage. We found that vegetation did reflect changes in the landscape; however, species level response proved to be an ineffective technique for detecting the subtle changes in rural landscapes. Wetland vegetation at the community level can be an effective indicator of watershed degradation even in areas with less pronounced anthropogenic disturbance.
The recovery of natural ecological processes after disturbance is poorly understood. Some disturbances may be so severe as to set ecosystems onto a new trajectory. The Canaan Valley National Wildlife Refuge in West Virginia protects a unique high-altitude wetland that was heavily disturbed by logging 100 years before present (BP) and has since transitioned to a new ecological state (shrub wetland). Refuge managers interested in preserving and restoring ecosystem states expressed concern about lingering impacts of previous disturbances (logging, railroads, beaver, deer, fire). Available data suggested hydrologic impacts from a remnant railroad grade, but managers had insufficient quantitative data to assess these impacts. We initiated a fine-scale assessment of topography, vegetation distribution, and hydrology to assess impacts from the remnant rail grade using lidar data, vegetation surveys, and piezometers. We developed topographic models, hydrological models, and mapped vegetation distribution. We developed statistical models to assess relationships between vegetation communities, hydrology, and distance to the rail grade. Surprisingly, we found that hydrologic flow paths did not conform to expectation and were not restricted by remnant land use features. For the most part, vegetation communities are responding to topographic and environmental gradients that existed prior to disturbance. Use of highly detailed topographic data (lidar), field hydrology, and vegetation studies allowed us to more accurately assess hydrologic and vegetation regimes, eliminating the need for mitigation, thus saving significant resources.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.