ASWM's Hot Topics Webinar Series

Hot Topics WebinarsThe Association of Wetland Managers (ASWM) occasionally opens up its Members Webinars to non-members on special topics that are not specific to any of our other webinar series and that appeal to a broader audience than our membership. For this reason, the Association started a Special Topics Webinar Series that is available for anyone to participate in. Some of the topics in the past have included the Ramsar Convention and international projects, complex legal cases, environmental economics and more. These webinars are advertised through our website, newsletters, social media and emails. There is no specific day of the month when these webinars occur. For more information and/or to join our email list for notices about upcoming events, please contact Laura Burchill at .

If you haven’t used Go To Webinar before or you just need a refresher, please view our guide prior to the webinar here.  

Wetlands from the Nebraska Sandhills to Iowa’s Restored Ag Lands

Monday, September 21, 2020 - 1:00 pm-2:30 pm Eastern

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The U.S. EPA generously funds multiple wetland research and implementation projects each year, with each EPA Region awarding grants for specific activities in their respective areas. Two awardees from EPA Region 7 (which includes Nebraska, Iowa, Kansas and Missouri) will be sharing the results of their Enhanced State and Tribal Program (ESTP) grants: Steven Hall from the Iowa State University, and Andy Dzialowski from Oklahoma State. Bios and abstracts for both presentations can be found below.


  • Steven Hall, Assistant Professor, Department of Ecology, Evolution and Organismal Biology, Iowa State University
  • Andrew Dzialowski, Associate Professor, Department of Integrative Biology, Oklahoma State University


Most depressional wetlands in the Des Moines Lobe of Iowa are partially drained and managed for row crop production. These depressions typically have flashy hydroperiods and experience intermittent ponding throughout the growing season, often causing complete crop mortality, and their environmental impacts remain poorly understood. We found that cropped depressions were hotspots of nitrate leaching, yielding 40% higher nitrate (140 kg N ha-1 y-1) than cropped uplands, with higher methane emissions and similar nitrous oxide emissions as cropped uplands. In contrast, restored wetlands with consistently ponded conditions provided substantial net nitrate removal (1600 kg N ha-1 y-1) and similar nitrous oxide emissions as cropped depressions, albeit with greater methane emissions. In sum, cropped depressions are both poor croplands and poor wetlands under present management conditions. Improving the drainage characteristics of cropped depressions while establishing restored wetlands at catchment outlets merits consideration to optimize environmental and agronomic outcomes in these landscapes.


The Nebraska Sandhills is the largest grass-stabilized dune system in the Western Hemisphere. It contains thousands of wetlands and it has been identified as an ecosystem of major concern. Despite the ecological importance of the Sandhills, very little is known about the abiotic and biotic characteristics of the wetlands in this region. Therefore, we conducted an ecological assessment of Sandhill wetlands to establish baseline conditions, identify indicators that can be used in monitoring programs, and begin to identify reference conditions. We focused on macroinvertebrates because they respond to environmental change, affect wetland function, and provide important nutritional resources for waterbirds in the region. We also sampled permanent waterbodies in the Sandhills to document the impacts of invasive carp on macroinvertebrate communities and to compare macroinvertebrate communities between permanent lakes and wetlands in the region.

Steven HallBIOS 

Steven Hall is an Assistant Professor in the Department of Ecology, Evolution, and Organismal Biology at Iowa State University. His research program in biogeochemistry examines the impacts of soil processes on environmental services and impacts, particularly those related to water quality, soil fertility, and climate change.  

Andrew DzialowskiAndrew Dzialowski is an Associate Professor in the Department of Integrative Biology at Oklahoma State University (OSU). He received his PhD in Aquatic Ecology in 2003 from the University of Kansas. His research over the past 12 years at OSU has focused on invasive species, wetland ecology and bioassessment, water quality and reservoir management, and metacommunity ecology. 

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A Certificate of Participation to be used toward Continuing Education Credits will be available for this webinar. Free Certificates of Participation are a benefit of ASWM membership. Non-Members who request a certificate will be charged a processing fee of $25.00. You will have up to 60 days to retrieve your certificate. Certificates are not available for viewing recorded webinars. More Information can be found here.

To view Past ASWM's Hot Topics Webinar Series, click here.