The Effect of Ventilated Shelters on Tree Seedling Growth Within a Restored Riparian Site in Virginia
Riparian forests perform valuable ecological services such as improving water quality, increasing ecological diversity, increasing carbon sequestration, and decreasing stream temperature. Within the Chesapeake Bay most riparian forests have been removed as agricultural practices have intensified. Large-scale agricultural practices increase nutrient loading into the watershed causing a decline in water quality. Restoring riparian forests offsets negative effects of agricultural land use. Restoration techniques, such as protecting planted trees from herbivory with plastic tree shelters, have been utilized by programs such as the Conservation Reserve Enhancement program (CREP) for 20 years. Some studies suggest that trees within un-ventilated shelters benefit from increased temperature and humidity while other studies indicate that adding ventilation to tree shelters may result in certain species to accumulate 55% more biomass than trees grown in un-ventilated controls. The purpose of this study is to quantify the effect of ventilated (shelters with holes) and non-ventilated shelters on seedlings. In the spring of 2022, 162 tree seedlings (Liriodendron tulipifera, Platanus occidentalis, Amelanchier canandensi, and Asimina triloba) were planted on an active cattle farm in Linville, VA. Seedlings were planted in ventilated and non-ventilated tree shelters. Field data were collected in the spring of 2022 for initial height and diameter measurements and at the end of the growing season in 2022. Chlorophyll content and stomata density were also collected at the end of the growing season. Internal tree shelter temperature and relative humidity was collected three times at random throughout the growing season. Preliminary results suggest seedlings grown in unventilated shelters develop significantly less chlorophyll (p-value <0.001) and experience significantly higher overall levels of relative humidity (p<0.05), than seedlings in ventilated shelters. Correlation between internal shelter climate, shelter type, and plant health could potentially lead to the development of more specific guidance in the creating of riparian restoration planting plans which utilize protective tree shelters.