COS 90-2 - Long-term success of Chrysopsis floridana introductions depends on continued fire management

Abstract: Population introductions are a critical tool for the conservation of endangered and endemic plant species. However, establishing new populations is likely not enough to rescue species from the brink of extinction, and requires proper land management. Populations of many Florida scrub plant species, including endangered and endemic herbaceous plants, are fire-dependent and require prescribed burns to remain viable. Here, we investigate the role of management in maintaining introduced populations of the federally endangered Florida goldenaster Chrysopsis floridana. Chrysopsis floridana is limited to only 5 counties in west-central Florida, and following efforts to introduce new populations, is being considered for de-listing. From 2008-2013, 8 introduced populations were established, and detailed demographic data were collected from 2017-2022 at 5 of these sites which we report on here. Specifically, we asked whether population size and vital rates (e.g., recruitment, growth, and reproduction) of the introduced populations were positively associated with prescribed burns. Prescribed burning was infrequent at most introduction sites; sites that did receive prescribed burns between 2017-2022 showed comparatively higher population densities than sites that did not. Time-since-fire was negatively associated with average annual survival, reproduction, and recruitment. Our results demonstrate the importance of ongoing, multi-year species specific management plans that include controlled burns to optimize the long-term success of endangered plant introductions in the Florida scrub.