Nature Lab

Resource Science

Long-Term Patch-Burn Grazing Study

Applied on a rotating schedule, patch-burn grazing uses fire to stimulate plant growth, and cattle to influence how the plant community develops.

“Using this management,” explains MDC Grassland Ecologist Tom Thompson, “you’ll potentially have a shifting mosaic of habitat types. Short vegetation where the cattle have grazed, intermediate vegetation where they grazed the previous year, and tall vegetation in plots not recently grazed. And different wildlife species rely on each of those structural types.”

While initial studies on MDC prairies showed patch-burn grazing provided plant diversity similar to that on prairies managed with just patch burning and no grazing, the Missouri Prairie Foundation and other stakeholders voiced concerns about whether certain plant species might be negatively impacted by cattle over a longer period. To find answers, MDC launched a 15-year study on five prairies in 2015–2016 to assess how patch-burn grazing is influencing specific plant species and habitat structure.

Three times per growing season, researchers evaluate each study site. MDC staff look for 47 specific plant species, documenting them as present or absent. They also collect data on changes to vegetation structure. Outside contractors assess plant diversity and cover. The data is reviewed at five-year intervals to see what impacts patch-burn grazing is having.

“We aren’t going to know everything now,” says Thompson, “but our first five years of data show some plant responses that we’d like to evaluate further. We’ll be discussing these with internal and external stakeholders and determining changes to how we’re implementing patch-burn grazing, then seeing how those changes affect the plant community. We’re hoping within the 15 years to complete three to four cycles of patch-burn grazing so we can see its long-term effects.”

Patch-Burn Grazing at a Glance

Patch-burn grazing attempts to mimic natural processes that existed before European settlement. By burning different portions of prairie on a rotating schedule, a mosaic of different vegetative growth stages will result, providing short, intermediate, and tall growth that can serve the varying habitat needs of different species of birds, and potentially insects and other wildlife. Cattle (historically bison) tend to graze mostly in the recently burned portions to consume the nutritious grasses that emerge after the burns, while the areas burned in previous years get time to recover.