The Ecosystem Service Impacts from Invasive Plants in Antietam National Battlefield

Abstract

Following their memorialization as protected landscapes, battlefield parks can provide a blend of cultural and other ecosystem services. Among the many threats to providing these services are non-native invasive plants. In this chapter , we assess the threats imposed by biological invasions of non-native plants in battlefield parks and discuss management strategies. We use evidence from the scientific and economic literature and the expert judgment of biologists, economists, and park managers to identify the harms caused by invasives and to characterize their effects on park ecosystem services. Based on this evidence, we propose four generic stressor-response relationships to describe the relationships between invasion extent and ecological endpoints such as park vegetation structure and diversity. Using Antietam National Battlefield as a case study, we tailor the general stressor-response curves to four specific species representing different functional groups of invasive plants: trees, shrubs, vines, and herbaceous forbs. We next link the ecological response of changes in vegetation structure and diversity to relevant ecosystem service impacts using interviews with national park service personnel and the economic literature. We identify four broad categories of parks users who might be affected by these losses of services: causal visitors, avid recreationalists, park neighbors, and non-use beneficiaries. Our findings reveal a general lack of experimental evidence quantifying the ecosystem service impacts of invasive plants. This lack of evidence, combined with the likely non-linear effects of non-native plant invasions on ecological endpoints, could catch managers unaware of dangerous thresholds in long-term resource management of battlefield landscapes.