Mechanisms of Native Shrub Encroachment on a Virginia Barrier Island

• Main Author: Thompson, Joseph
• Format: Others
• Published: VCU Scholars Compass 2016
• Subjects: Microclimate; shrub encroachment; barrier island; Virginia; botany; ecology; Botany
• Online Access: http://scholarscompass.vcu.edu/etd/4297; http://scholarscompass.vcu.edu/cgi/viewcontent.cgi?article=5372&context=etd

Species composition, temperature, soil nutrients, and leaf area index (LAI) were recorded across three encroaching Morella cerifera thicket edges and three free- standing shrubs on Hog Island, Virginia to characterize the effect of shrub thickets on the plant community and microclimate. Electron transport rate (ETR) was taken on shrub leaves to determine if microclimate benefits M. cerifera physiology. Species richness was lowest inside shrub thickets. Soil water content and LAI were higher in shrub thickets compared to grassland. Soil organic matter, N, and C were higher inside shrub thickets. Summer and fall maximum temperatures were more moderate in shrub thickets and at free-standing shrubs. Fall and winter minimum temperatures were higher inside shrub thickets. ETR was higher at the free-standing shrubs compared to the thicket edge. Morella cerifera impacts microclimate characteristics and species composition immediately upon encroachment. Improved shrub physiology was neither supported nor rejected by the research presented here.