plants Article Environmental and Management Effects on Demographic Processes in the U.S. Threatened Platanthera leucophaea (Nutt.) Lindl. (Orchidaceae) Timothy J. Bell 1,†, Marlin L. Bowles 2,†, Lawrence W. Zettler 3,* , Catherine A. Pollack 4 and James E. Ibberson 3 1 Department of Biological Sciences, Chicago State University, 9501 S King Dr., Chicago, IL 60628, USA;
[email protected] 2 The Morton Arboretum, 4100 IL 53, Lisle, IL 60532, USA;
[email protected] 3 Department of Biology, Illinois College, 1101 W College Ave, Jacksonville, IL 62650, USA;
[email protected] 4 U.S. Fish and Wildlife Service, 230 South Dearborn St., Suite 2938, Chicago, IL 60604, USA;
[email protected] * Correspondence:
[email protected] † Retired. Abstract: Populations of the U.S. threatened orchid, Platanthera leucophaea, are restricted to frag- mented grassland and wetland habitats. We address the long-term (1998–2020) interactive effects of habitat (upland prairie vs. wetland), fire management (burned vs. unburned) and climatic variation, as well as pollination crossing effects, on population demography in 42 populations. Our analysis revealed the consistent interactive effects of habitat, dormant season burning, and climatic variation Citation: Bell, T.J.; Bowles, M.L.; on flowering, reproduction, and survival. Burning increased flowering and population size under Zettler, L.W.; Pollack, C.A.; normal or greater than normal precipitation but may have a negative effect during drought years Ibberson, J.E. Environmental and apparently if soil moisture stress reduces flowering and increases mortality. Trends in the number Management Effects on Demographic of flowering plants in populations also correspond to precipitation cycles. As with flowering and Processes in the U.S.