A Baby Boom for Rare Legumes

A new study by partners from the Missouri Botanical Garden and Washington University concludes that populations of rare plants should be aggressively increased now, before the effects of climate change become more severe.

Of all the effects brought on plants by a changing climate, drought is among the most potentially damaging. While much of the media attention related to drought focuses on its impact on agriculture, drought can also significantly affect natural systems, including populations of rare plants. “Native species that occur in grasslands and woodlands of the Midwest are adapted to fluctuations in climate, but they may not be able to cope with extreme climatic events associated with rapid climate change,” explains Matthew Albrecht, Associate Scientist of Conservation Biology at the Garden’s Center for Conservation and Sustainable Development (CCSD).

With droughts expected to increase in quantity and severity as climate change intensifies, Albrecht and his research partners, Holly Bernardo of the Washington University Biology Department and Tiffany Knight of the Martin Luther University Institute of Biology, wanted to determine whether the management of endangered plant species could be enhanced to withstand the anticipated effects of a warmer, dryer future.

Astragalus bibullatus (Pyne’s ground-plum). Photo by Matthew Albrecht.

To answer that question, the team set up a study of Astragalus bibullatus (Pyne’s ground-plum), a Federally endangered legume endemic to limestone cedar glades in Tennessee. “Over the past seven years, we have been monitoring the few remaining Pyne’s ground-plum populations to understand the response of plants to ongoing management efforts in cedar glades to reduce woody vegetation, which increases sunlight that plants need to flower and set seed. Coincidentally, the monitoring and management overlapped with a major drought year (2012) that markedly reduced survival and flowering. We then used this data in mathematical simulations to understand what might happen to the species if in the future droughts doubled in frequency over the next 50 years, as climate change scenarios predict.”

Based on our study, we found that populations of rare plants should be managed for the largest increases in size possible now, before the effects of climate change become severe.
-Matthew Albrecht, Associate Scientist of Conservation Biology

A recently published report of their findings concludes that there are steps we can take now to help fortify endangered plant populations for the coming changes, but the work will not be easy.

“Populations of rare plants should be managed for the largest increases in size possible now, before the effects of climate change become severe,” Albrecht explains. “And in the long run, management efforts need to become more risk-averse. One way to do that is by creating more variability in habitat structure at the landscape scale, which will decrease the chances that a single severe drought will devastate all the individuals of geographically restricted rare species. But of course, one of the best ways to decrease the negative impact of climate change on rare plants, is to support regional, national and global initiatives to reduce carbon emissions in order to reduce the severity of climate change overall.”

Learn more about Albrecht’s study in this audio slideshow


John Dedeke
Senior Digital Media Editor


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