Much of the Midwest is currently in a state of severe drought, stressing some wetland plants and wildlife and adding new challenges to the Wetlands Initiative's restoration work at Midewin National Tallgrass Prairie.
According to the National Oceanic and Atmospheric Administration (NOAA), this June and July were the hottest months on record in the U.S. in 118 years. Such extensive dry conditions also have not been seen in more than half a century. In Illinois, average precipitation this July was 1.5 inches, just one-third of the normal amount of rainfall.
Of course, drought is not an uncommon occurrence. Drought years and rainy years are part of the natural cycle. This process actually benefits ecosystems by maintaining the balance among species and allowing a more diverse range of species to survive. In drier years, more drought-tolerant species have the advantage in a landscape, while during wetter years, other species expand their range.
Tadpole remains after a marsh area dried up.
However, top climate scientists say it's very likely global warming has contributed to the record high temperatures of recent years, as well as the extreme 2012 drought. Climate change predictions indicate that droughts such as these will become more frequent and more severe in future years—potentially upsetting the balance of species and threatening ecosystems. This particular summer of drought may be foreshadowing the years to come.
The plant communities at Midewin National Tallgrass Prairie have been showing signs of stress as a result of the drought. Dry, cracked soil is visible in some areas of the Wetlands Initiative's restoration sites at Midewin. Some native vegetation appears to be dead, but these perennial plants have actually gone dormant for the season due to the extreme weather.
Wildlife has also noticeably changed their behavior patterns in response to the dry conditions. On TWI restoration sites, frogs have taken refuge in our tarps of water used to house young plants before they are introduced to their new wetland home. The lower, marshy areas are now a graveyard of tadpoles and crayfish shells. On the warmest days, the songbirds' voices fail to carry to the shade house where the field workers eat their lunches. Of course, no day is too warm for the ticks to be out.
The drought poses a challenge to TWI's restoration work itself, particularly establishing native plants from seeds and plugs (seedlings). With the very low rainfall this summer, the survival rate of young plants is significantly decreased. At Midewin, the field restoration crew has spent time hand-watering to help the newly installed plants get established. Staff ecologists are also working to get plugs delivered and put in the ground earlier in the season, so they can receive sufficient rainfall.
While it is possible that this would naturally be a drought year for Illinois, the science suggests climate change dynamics have played a role. Climate change has been progressing for some time now, and predictions are based on complex models and many years of scientific data. The data show that global temperatures are indeed rising and, as a result, our local climate trends are changing.
This means that the warmer weather that was once south of us may now be here. Consequences of this shift could be serious; continuing patterns of hotter weather could eliminate sensitive species locally. Wetlands house a multitude of rare plants and animals that are specially adapted to wet conditions and could be at risk for extinction if severe drought becomes more frequent.
According to scientists, more extreme weather patterns have been and will continue to be observed. Summer next year may not be quite as hot as this year is, or it may be even warmer; the point is that one year is just one data point on a graph. The general trend of the line shows the bigger picture of our climate, and that line is going up quickly.
The good news is that the Wetlands Initiative has incorporated strategies into our restoration work to help restored areas adapt to climate change. Taking into account the region's projected future climate, TWI ecologists source seed from more southern areas where possible, so that plants will be better adapted to hotter, drier conditions. As we remove manmade drainage systems, TWI seeks to recreate deeper-water habitats where drought-sensitive species like frogs can take refuge during dry periods. Finally, by restoring a diverse mix of wetland and prairie habitats on a large scale at Midewin, we can recreate landscapes that are more resilient to extreme weather like drought and more likely to persist long-term.
Learn more about projected local impacts of climate change and what you can do on the Chicago Wilderness website here.
Statistical information obtained from NOAA, the Intergovernmental Panel on Climate Change (IPCC), and the Illinois State Water Survey.
Nikki recently graduated with a Biology degree from Aurora University. She interned this summer with the Wetlands Initiative through the Associated Colleges of Illinois' Conservation and Green Jobs Internship Program.