March 10, 2016

Research project focuses on state’s wetlands

by Tim Crosby

CARBONDALE, Ill. – Wetlands aren’t always that wet. So a researcher at Southern Illinois University Carbondale is trying to create models that would predict when wetlands in Illinois will become saturated with water. 

Michael Eichholz, associate professor of zoology in the College of Science, will use ground surveys and radar imaging in an effort to improve wetland protection and restoration efforts in the state. Doctoral student John O’Connell and a team of field and lab technicians will assist Eichholz, who works with the Cooperative Wildlife Research Laboratory at SIU. 

The work is part of a larger, overall research project begun last year that is looking at improving the quality of wetland management to help increase productivity for wildlife. 

Wetlands that are too dry, silted-in or invaded by exotic species are of little use to waterfowl, which use wetlands to promote migration and as breeding grounds. Researchers are trying to ascertain what proportion of existing wetlands are not inundated by water, as well as the quality of resources produced by wetlands that are inundated during biologically important times of the annual cycle. 

The study, they hope, will provide data necessary to modify wetland habitat management objectives to account for non-producing wetlands. 

Eichholz just this month received a $10,000 seed grant from the Illinois Water Resources Center to pursue further research. IWRC officials awarded money to several institutions, including SIU. 

“The results of these diverse and innovative projects will help break down key barriers to understanding and protecting Illinois’ water resources and aquatic habitats,” said Brian Miller, IWRC director. “We are very pleased to continue our support of research with real significance for the state and the region.” 

Eichholz said the team is focused on finding a method to estimate the proportion of wetlands that are inundated during times of the year that are important biologically to certain bird populations. Whether the wetlands are saturated can impact the birds’ migrations and breeding periods, he said. 

Variations in the amount of water in wetlands is a good thing, helping make them the most productive habitat in the ecosystem. The same variations, however, can also limit resources available to the creatures that live there. At times, wildlife need more water, and at times, less. The natural ebb and flow makes it difficult for scientists and habitat managers to set accurate goals when restoring a wetland. 

Scientists have accurate estimates of the overall acreage of wetlands, but they lack the means to estimate how much of that acreage is inundated – and therefore a resource for wildlife – at any given time, Eichholz said. 

Examples include migratory waterfowl, which are likely most dependent on inundated wetlands in the mid-migration regions of the country during spring migration, from about mid-February to mid-April. Marsh birds and wading birds need inundated wetlands for breeding season, May through July in the Midwest, while migratory shorebirds require it for the autumn migration during July–September. 

“This project aims to develop models to estimate wetland inundation for the entire state of Illinois,” Eichholz said. “Two different approaches are being used to reach these ends.” 

In the first approach, the team will visit random wetland sites to look at seasonal changes in inundation and will then scale those findings up and plug them into the National Wetlands Inventory database. The database is known to contain errors, and the team will attempt to identify those, as well. 

The surveys will provide an estimate of total wetland inundation in the state specific to the type of wetland surveyed, Eichholz said. The survey approach is part of the larger project begun last year, in collaboration with the Illinois Natural History Survey, which includes assessing the quality of the resources available in inundated areas. To determine that, researchers will look at factors such as vegetation sampling and stress indicators. 

The second approach will use satellite-based radar imagery that can penetrate the forest canopy to detect inundation on a larger scale. Researchers will then use the results from that analysis to model inundation patterns in the state. 

In addition to O’Connell, four other SIU students will participate the study. They are Micah Miller, a graduate student in zoology; Harley Copple, a senior in zoology; along with Shawn Caldwell and Travis Preston, both seniors in geography. 

Eichholz said the study could provide valuable information. 

“If successful, not only could this study be used to develop more accurate wetland protection and restoration goals, (but) archived data could be used to estimate future annual variation in wetland availability,” he said. “Further, because archived data would be available for analysis, correlations could be conducted with past inundation estimates and vital rates of wetland dependent organisms to help better explain how wetland availability influences population dynamics and distribution of these organisms.” 

The Upper Mississippi River Great Lakes Region Joint Venture, part of the U.S. Fish and Wildlife Service, and the Illinois Department of Natural Resources Federal Aid Grant W-184, also are supporting the project.