The Impacts of Maple Syrup Production on the Herbaceous Layer in Appalachian Hardwood Forests

Vegetation data were collected from eight maple syrup farms (sugarbushes) and eight undeveloped maple-dominated sites to examine potential differences in understory plant communities due to disturbance effects. Understory plants were identified to the species level and percent cover of aboveground leaf-area for each species was estimated within 600 total quadrats. Overstory data and environmental data were collected to help determine if they had any effect on herbaceous-layer plant communities. Species richness, Shannon diversity, and Pielou’s evenness were calculated, with the analysis showing no significant differences between the site types. The absolute cover of plant functional groups was also compared between the two site types, again with no significant differences found. In addition, the leaf-area cover and presence/absence data of non-timber forest product (NTFP) plant species and non-native invasive plant species were analyzed and compared between the two site types. Some differences in cover and likelihood of occurrence (estimated from the presence/absence data) for these species were found between the two site types. Blue cohosh, one of the NTFPs, had greater cover on the control sites. In addition, several of the NTFPs were positively associated with north and east facing slopes, as well as the cover of other understory plants. The likelihood of occurrence and cover of several non-native invasive species was also significantly higher on the sugarbush sites compared to the control sites, as was the combined cover of all non-native invasive species. It was hypothesized that non-native invasive understory plant species have greater cover on sugarbush sites due to increased disturbance effects and altered site conditions. Sugarbush owners wishing to stop the spread of non-native invasive species within their stands or protect NTFPs from disturbance impacts may therefore wish to alter their management practices and/or utilize invasive species control methods