CHAMPAIGN, Ill., 10/11/19: Scorching summers are predicted for Illinois’ future, threatening already vulnerable plant species. University of Illinois scientists have presented a new way to prioritize restoration efforts, not necessarily focusing on the most precarious plants.
By mid- to late century, Illinois summer temperatures are expected to mimic those of a present-day summer in Texas and intense droughts and floods will become more common. A group of scientists at the Illinois Natural History Survey (INHS) evaluated the climate change vulnerability for all 331 of Illinois’ threatened and endangered plant species, making Illinois the first state to review every listed plant.
Findings showed that 88 percent of threatened and endangered plants are vulnerable to climate change, and 6 percent are extremely vulnerable. Habitat loss, barriers from land use change, seed dispersal ability, and sensitivity to changing temperatures and precipitation are the leading factors.
“A critical component is the barriers that prevent plant species from migrating to better adapt to changed climate,” said INHS botanist Greg Spyreas. “Far more habitats have been destroyed in Illinois than in other states, which makes more man-made barriers—cornfields, roads, and urban areas—in addition to natural barriers, such as the Illinois River, that constrain plants to isolated natural areas.”
Unlike animals, most plants cannot migrate long distances to offset the effects of climate change. In mountainous states, such as Colorado, plants need only move a short distance via seed dispersion to higher elevations to survive. In Illinois, however, seeds in Champaign may have to disperse to Chicago, for example, to find suitable habitat, Spyreas said.
Plants that thrive in particular conditions, known as habitat specialists, are most at risk. Many rare, endangered species fall into this category. These plants have very little to no chance of adapting to or surviving in a changing climate.
Assisted migration, or physically moving plants further north to where they are better suited to the environment, might be the only way to overcome the dispersal barriers. This science is still in its infancy, as researchers must take numerous factors into account to try to predict where or if assisted migration will be useful.
Perhaps the best approach, the scientists say, is not to target the most vulnerable of the 331 plants in the state, but instead to attempt to save those for whom Illinois constitutes the main portion of their total range— where Illinois has most of their populations in the world. Another priority are those plants for which the northern or central part of their range is Illinois.
“We are now in a crisis, and maybe this is the point when we need to do triage and prioritize the urgency of threatened and endangered plant species,” Spyreas said. “Instead of targeting our resources on trying to save the most vulnerable plants that have no chance of survival in Illinois because of climate change, we could focus on the ones that could survive.”
This controversial idea doesn’t mean that plant enthusiasts and environmentalists shouldn’t keep trying to restore all endangered plants, but that many factors should be considered when allocating limited financial resources to protect the large number of plants that can’t adapt to a warmer climate here.
“Although we want to protect as many organisms as we can, the reality is that with limited resources we cannot save everything,” said INHS plant ecologist Brenda Molano-Flores. “At some point we need to start making the difficult choices.”
Efforts must be directed to assist with preventing more plant species from reaching a similar fate by protecting and restoring more natural areas. Financial support is also needed to fill the knowledge gaps about rare plants’ natural history, ecology, and genetics to develop conservation and reintroduction programs.
In the short-term, Molano-Flores said she hopes that resource managers and conservation agencies will consider this prioritization method as part of their toolbox when making decisions regarding Illinois endangered plants.
This study was published in the journal Castanea with partial funding from the Illinois Department of Natural Resources.
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Media contact: Greg Spyreas, 217-300-4023, spyreas@illinois.edu; Brenda Molano-Flores, 217-265-8167, molano1@illinois.edu
Tricia Barker, Associate Director for Strategic Communications, 217-300-2327, tlbarker@illinois.edu
