Habitat Assessment and Conservation Status of Endangered Northeastern Bulrush

Abstract

Scirpus ancistrochaetus (Northeastern Bulrush) is a federally endangered sedge that grows in temporary wetlands. We performed surveys of 90 wetlands in Pennsylvania, Maryland, West Virginia, and Virginia, measuring areal extent, stem density, and number of fl owering stems of Northeastern Bulrush. We also measured percentage of tree canopy closure, presence of threats, and size of wetland. Percentage of tree canopy closure was negatively correlated with wetland area, percentage of wetland area occupied by North- eastern Bulrush, total number of stems, stem density, and percentage of fl owering stems. Wetland area was positively related to percentage of fl owering stems and had a tendency to be positively related to stem density, likely in part due to larger wetlands having lower tree canopy closure. Invasive Phalaris arundinacea (Reed Canarygrass) and Microstegium vimineum (Japanese Stiltgrass) were present at 7% and 21% of the wetlands, respectively. Odocoileus virginianus (White-tailed Deer) and Ursus americanus (Black Bear) damage were present in 38% and 17% of wetlands, respectively. Modifi cation of habitat was noted at 27% of wetlands. For wetlands with previous data on population size, 14% had increased, 34% were stable, 25% had decreased, and 27% were absent or had severely decreased. Our recommendations for management include reducing tree canopy closure with control of invasive species and White-tailed Deer where needed.