Investigations of site factors affecting regeneration on a forested community irrigated with treated municipal wastewater in central Pennsylvania

Forest communities on Pennsylvania State Gamelands 176 (Toftrees) have been irrigated with treated municipal wastewater since 1983. The understory of the irrigated forest communities was dominated by herbaceous vegetation and lacked tree regeneration. The objective of the research presented was to determine which site factors influenced regeneration including canopy coverage, understory vegetation, and white-tailed deer (Odocoileus virginianus ) browsing.; Canopy coverage and the presence of herbaceous vegetation did not affect establishment of natural regeneration. After two growing seasons, the density of seedlings from natural regeneration was <1 seedling m−2 . However, artificial regeneration responded to open canopy treatments with high survival and height growth. On open canopy treatment plots, seedlings were 1.6 times more likely to survive than on closed canopy treatment plots. Mean height growth of planted seedlings on open canopy treatment plots was 33 cm, ten times the mean height growth of seedlings on closed canopy treatment plots (3 cm).{09}Removal of herbaceous vegetation also improved the survival of artificial regeneration.; Effects of simulated deer browsing on planted seedlings were evaluated in a greenhouse and field study. Under controlled environmental conditions in the greenhouse, regardless of degree or frequency of tissue removal, height and root growth, and root biomass production were reduced compared to the control. In a similar field study, the effect of canopy coverage was added as another factor to determine seedling response to leaf area removal. Seedling response to degree and frequency of leaf area removal were not different from the control. However, seedlings that were planted under open canopy conditions had the greatest height growth, root length, and root dry weight compared to seedlings under a partially closed canopy.; The results of these studies indicate that establishing a forest community on State Gamelands 176 (Toftrees) was possible through artificial regeneration. Small openings made in the canopy, a herbicide treatment to control herbaceous vegetation, and planting species that are well-adapted to the site conditions will ensure a new forest stand. Natural regeneration failed to become established. Fencing any regeneration area can eliminate browsing by white-tailed deer and its negative effects on seedling growth.