Poster

         Ecology

Assessing fitness of a rare plant, buffalo clover (Trifolium reflexum), in response to environmental factors

Presenting Author
Ingrid Felsl
Description
The conservation of Threatened and Endangered (T&E) plants is important for preserving global biodiversity and supporting ecosystem function. The largest threats to T&E plant species are anthropogenic climate change, habitat destruction and fragmentation, and the spread of invasive species. Understanding the habitat requirements of T&E species is vital to their conservation, as it informs management decisions. Trifolium reflexum L. (Fabaceae), also known as buffalo clover, is state threatened in Illinois and North Carolina and state endangered in Kentucky and Ohio. T. reflexum historically occurred across much of eastern North America along bison paths, where trampling would scarify seeds and reduce interspecific competition. The primary habitats in which T. reflexum historically occurred were tallgrass prairie, oak savanna, and dry open woods, all of which experienced natural fire disturbance. With the near elimination of wild bison populations and fire suppression across eastern North America, T. reflexum habitat has been reduced and degraded. However, the species persists in high quality open woods and along trails such as rights-of-way and mountain bike paths. Populations of T. reflexum within Illinois offer an excellent opportunity to research the species in all three habitats where it occurs, as well as at the edge and center of its north-south geographic distribution. Additionally, the growth rates of populations within the state range from positive to negative, offering a unique opportunity to identify environmental variables related to T. reflexum fitness. In an attempt to determine the optimal habitat for T. reflexum restoration in Illinois, we visited extant and extirpated populations during spring and summer 2022. Through measuring microsite environmental variables and vegetation composition, as well as functional traits of T. reflexum related to growth and reproduction, we aimed to determine how T. reflexum fitness was impacted by its environment. Extant populations exhibited greater soil temperatures and photosynthetic active radiation than extirpated populations, and vegetation composition differed between populations and microsites. Shorter T. reflexum individuals exhibited higher rates of reproduction, though fitness was variable between populations. Implications of this research will include management recommendations for extant populations as well as for identifying possible sites for reintroduction.