Habitat Suitability Models as a Conservation Tool for a Rare Mint, Macbridea alba

Sara Johnson, Department of Natural Resources and Environmental Science at University of Illinois: UrbanaChampaign

Brenda Molano-Flores, Illinois Natural History Survey, University of Illinois: Urbana-Champaign

Janice Coons, Eastern Illinois University

Many rare and at-risk species exhibit a paucity of research, leaving gaps in the knowledge required to conserve them. Macbridea alba Chapman (White birds-in-a-nest, Lamiaceae) is a federally threatened and state endangered herbaceous mint restricted to a narrow distribution in the longleaf pine ecosystem of the Florida panhandle. Habitat conversion and destruction are among the primary reasons for Macbridea alba’s decline. Populations are highly fragmented by plantations, clear cuts, or development resulting in extirpation in some areas. Whereas known Macbridea alba populations are primarily found within Apalachicola National Forest, it is uncertain exactly how many exist, and few are documented outside of protected areas. There are many unknowns regarding the ecology of this species; however, previous research suggests that microhabitat differences and disturbance play an important role in its reproduction and survival. Habitat suitability models are a useful tool for gaining insight into the potential drivers of species distribution and persistence on the landscape. These models can define the environmental predictors of occurrence and facilitate the discovery of previously unknown populations. Additionally, these models can guide conservation of areas for potential reintroduction based on habitat conditions and proximity to known source populations. We have created preliminary habitat suitability models using known occurrence records for Macbridea alba as well as open sourced environmental spatial data to identify new areas of potentially suitable habitat. In 2019, field surveys were conducted for the purpose of model verification resulting in the discovery new populations. In the future, models using a disturbance variable such as fire season or time since fire, will be used to determine if the models could be improved. The results from the improved models will help us understand the specific role of fire management and fire frequency on the persistence and survival of this species. Additionally, it will assist us in defining range limits and environmental parameters for Macbridea alba’s distribution and whether it is a candidate for reintroduction or ex-situ conservation efforts.