Abstract Detail

Ecology

Bernardo, Holly [1], Albrecht, Matthew [2], Knight, Tiffany [3].

Climate change alters the optimal management strategy of an endangered plant.

Many of our globally rare and endemic plant species live in habitats that are maintained by frequent disturbances. To preserve and restore these populations, demographic models are often used to quantify the optimal disturbance frequency of the habitat. There is recent concern that climate change will alter optimal management strategies, since drought might decrease the benefit of a recently disturbed habitat to these endemic species. We ask whether disturbance and drought interactively affect population dynamics and optimal management of Astragalus bibullatus, a Federally endangered legume endemic to Tennessee glades. First, we determined the independent and interactive effects of drought and management (via woody canopy cover) on plant vital rates. Then we used matrix population models to determine their effects on A. bibullatus’ probability of extinction, time to extinction and future population size. Under current drought frequencies, A. bibullatus’ probability of extinction was minimized with the most frequent management, since open habitats promote recruitment of new individuals. However, as drought frequency increases, the probability of extinction was minimized with less frequent management, since canopy cover protected adult individuals from death during drought events. Combining these results, we recommend managing disturbance-dependent habitats by: 1) creating microhabitat mosaics within sites to provide opportunities for increased reproduction and recruitment (open microhabitats) and to promote adult plant survival (closed microhabitats), and 2) varying management interval across the landscape to decrease species-wide risk by preventing a single drought from severely impacting all sites. Our study it the first demographic model to quantify how climate change influences optimal management, but the results should be applicable to edaphic plant species in other ecosystems.

1 - Washington University in Saint Louis, Biology and Biomedical Sciences, 1 Brookings Dr., Biology Department, Saint Louis, MO, 63130, USA
2 - Missouri Botanical Garden, P.O. Box 299, St. Louis, MO, 63166, USA
3 - Martin-Luther-University, Institute of Biology / Geobotany and Botanical Garden, Am Kirchtor 1, Halle, Salle, 06108, Germany

Keywords:
Plant-climate interactions
drought
disturbance
habitat management
endangered species
conservation
population viability.

Presentation Type: Oral Paper
Session: 14, Ecology Section: Plant Functional Traits and Responses
Location: 201/Savannah International Trade and Convention Center
Date: Monday, August 1st, 2016
Time: 2:45 PM
Number: 14004
Abstract ID:54
Candidate for Awards:Ecological Section Best Graduate Student Paper