Research Sheds Light on Regional Impacts to Playas

PLJV routinely states that there are approximately 80,000 playas found throughout the region—but recognizes that many are partially or no longer functional because of modifications from agricultural activities and other economic developments. Estimates of numbers of playas modified and differences among regions have been largely speculative. However, two recent papers have shed light on the amount of playa modifications and accumulated sediments.

“We are excited about these findings,” says PLJV Conservation Science Director Anne Bartuszevige. “The information will help us update our planning and better understand the ability of our landscape to support migrating waterfowl.”

In Physical Loss and Modification of Southern Great Plains Playas (Journal of Environmental Management 112:275-283), Lacrecia Johnson and her coauthors sought to estimate the number of playas that have been modified through cultivation, hydrologic impacts (pits, berms, etc), and loss through accumulated sediments. They determined that only 2% of playas in the Southern High Plains had no wetland or watershed modifications. In addition, they estimate that 17% of playas have been completely filled with sediments such that there is no longer a visible depression. Finally, they estimate that smaller playas are being lost from the landscape faster than larger playas.

While Johnson focused in the Southern High Plains, Dale Daniel and his coauthors investigated the amount of accumulated sediments in playas throughout the western Great Plains and the differences between native grassland, CRP and cropland playas. In Land Use and Conservation Reserve Program Effects on the Persistence of Playa Wetlands in the High Plains (Environmental Science and Technology doi: 10.1021/es404883s), the authors document differences in amount of accumulated sediments in the north, central and southern playa areas. Sediments were greater in the southern playas; these playas had lost about half of their total volume to accumulated sediments. As expected, accumulated sediments were greater in cropland playas than in playas in CRP, and grassland playas had the lowest amount of accumulated sediments.

According to Bartuszevige, this research is valuable to understanding the dynamics of playas and the impacts that have been occurring for decades. “With this information, PLJV can produce better and higher quality decision support tools for playa conservation, and hopefully turn the tide of playa loss.”

For more information about Physical Loss and Modification of Southern Great Plains Playas, contact Dave Haukos at dhaukos@ksu.edu. Contact Dale Daniel at dale.daniel@okstate.edu to discuss Land Use and Conservation Reserve Program Effects on the Persistence of Playa Wetlands in the High Plains.

Posted: May 6, 2014