SDSU Extension, in partnership with a variety of non-government, state, and federal agencies, has recently released a public report on the status of native plant communities in Eastern South Dakota.
Visit Open Prairie to access the study’s data, GIS layers, Geodatabases, report, charts, and maps.
The report is based on a comprehensive look at the Eastern South Dakota landscape that incorporated the use of field and tract-level historic Farm Service Agency (FSA) cropland history, coupled with high resolution aerial photographs provided through the USDA National Agriculture Imagery Program (NAIP). Most other land use analysis relies on interpretation of satellite imagery and other National Agriculture Statistics Service (NASS) data to estimate current or recent land use, and while those interpretations can help define large-scale trends in land use, they cannot provide a cumulative or comprehensive assessment of the sum-total of all historic land cropping and other land conversion.
Evaluating Native Grasslands & Woodlands
Land Evaluation: The SDSU Extension project required staff technicians to evaluate all historic land use data on a section-by-section basis. In total, technicians evaluated approximately 22.6 million acres, or about 35,000 square miles of land in the 44 counties east of the Missouri River.
Native Lands: Surprisingly, the term ‘native’ can have several interpretations, with some persons assuming a former crop field planted to native grasses should be qualified as native. However, the SDSU Extension study relied on an ecological definition of the term, quantifying lands as potentially native only if there was no evidence of historic soil disturbance from farming, development, or other human causes. If historic soil disturbance was confirmed, those acres were removed. For example, a gravel pit, cattle feedlot, golf course, or small town would all be removed, as would a grass hayfield, CRP, or other habitat on a previously farmed field, regardless of how long ago the farming occurred.
Purpose: The intent of this analysis was to set a benchmark for the status of truly native grasslands and woodlands. These lands are an incredible asset to South Dakota’s agricultural and natural resources heritage and the industries that rely on them, including but not limited to grazing, hunting, tourism, and recreation. In addition, the importance of these lands to wildlife, water, and soil quality cannot be overstated. Reports by both conservation and agricultural groups have recognized major losses of grasslands converted to row-crop agriculture in recent years. None of these reports however can define exactly how much of that conversion impacted native grasslands in relation to other grass cover types like CRP, hayfields, or tame pastures. The new SDSU Extension data will set a comparative benchmark that has been lacking in previous reports, allowing future analysis to determine actual rates of loss of native grasslands. Understanding this critical component of South Dakota’s grassland communities is critically important as native grasslands, once converted, can never be truly restored to their full suite of ecological functions.
Total Acres: Overall, the study identified 5,488,025 acres of Eastern South Dakota land that is still potentially native, representing about 24% of the entire Eastern South Dakota landscape. About 200,000 of these acres may have had a tillage history, but there was not enough historical evidence for a clear determination. Conversely, nearly 73% of Eastern South Dakota land has been manipulated from its native state at some point. About 15 million acres, or close to 66%, of Eastern South Dakota land has a recorded tillage history, with an additional approximately 7% of the land having been disturbed for other human uses. The remaining 3% was determined to be comprised of large water bodies over 40 acres in size.
Grasslands & Woodlands: Of the approximately 5.5 million acres of native lands remaining in Eastern South Dakota, over 5.4 million acres are native grasslands, with about 100,000 acres categorized as woodlands. Because of the sensitive nature of these native plant communities, SDSU Extension also gathered information on the overall level of permanent protection afforded to these lands under various types of conservation ownerships or programs.
Protection & Conservation: Overall, when the total of fee title ownership and permanent protections, such as conservation easements, were assessed, it was determined that only 962,734 acres of native lands (about 17.5%) had any type of permanent protection from future conversion to cropland or other uses. In total, the amount of land in Eastern South Dakota that is both native and under some level of permanent protection, represents only 4.3% of the 22.6 million-acre Eastern South Dakota landscape.
Current and historic management of native grasslands is the primary factor in how those lands function for private and public goods and services. Well-managed native grasslands provide superior grazing and recreational opportunities, in addition to public services associated with air, water, and soil quality. Wildlife habitat is also a critical component, and well managed native grasslands are key resources for declining grassland-obligate birds, mammals, reptiles, pollinator plants, and insects.
Conversely, poorly managed native habitats subject to intensive continuous grazing, overapplication of chemicals or fertilizers, or general neglect, do not often provide the long-term ecological stability or profit potential that well-managed tracts do.
Native Habitat Quality
In this study, SDSU Extension was not able to determine the overall quality of the remaining tracts of native habitats. It is believed however that most remaining tracts, if subject to improved management, would likely provide improved return on investments to landowners and the public, through improved grazing systems, reduced chemical costs and other inputs, improved water retention and productivity, and improved wildlife habitat.