Rare, Threatened and Endangered Plant Inventory at Antietam National Battlefield 2024 - 2025 - Open Format Dataset

Antietam National Battlefield (ANTI), established in 1890, preserves the cultural and natural resources tied to the 1862 Battle of Antietam. In addition to protecting historic farmsteads, monuments, and the battlefield landscape, ANTI is increasingly recognized as an important refuge for native vegetation, rare plant species, and water resources in a region experiencing ongoing development. Guided by its 2021 Cultural Landscape Report, the park has launched new management strategies focused on watershed protection, grassland, and forest block restoration. Because these restoration efforts may affect rare, threatened, and endangered (RTE) species, ANTI conducted a comprehensive inventory of RTE plants across five key forest tracts—Snavely, Roulette, Union Advance, West, and Sherrick Woods—covering 172 acres. Surveys between June 2024 and June 2025 recorded 326 occurrences of 17 RTE target species, including two species new to the park. The study found that RTE species are disproportionately associated with historically forested areas (78% of occurrences fell within 1936 forest boundaries), steep slopes, Opequon-Rock outcrop soils, and Ridge and Valley Limestone Oak-Hickory Forest communities. Results highlight the lasting influence of historical land use, geology, and limited dispersal ability on present-day species distributions. Many RTE species remain confined to limestone outcrops and steep slopes that escaped agricultural clearing, while secondary forests on former farmland often lack suitable conditions for recolonization. Dispersal limitations, competition with invasive plants, deer herbivory, and site-specific factors such as dense pawpaw thickets further constrain population expansion. Management recommendations include prioritizing protection of calcareous forest habitats, maintaining continuity of historically forested areas, mitigating invasive species, and addressing deer impacts. These findings will inform future restoration planning, deer management, trail siting, and long-term monitoring to safeguard ANTI’s most sensitive plant populations while achieving broader habitat restoration goals.