Grazing for Conservation

A stock trailer stops at Talbot Conservation Area. The manager opens the gate, and the driver unloads 30 head of cattle into a field of green grass. That’s right — cattle. On a Missouri Department of Conservation grassland area.

The value of grazing for conservation may not be clear at first glance. Some people equate grazing with environmental problems, and examples of poorly managed grazing abound. Nevertheless, well-managed grazing creates cycles of disturbance and regrowth that can dramatically improve grassland habitat, and it may be essential to the healthy function of the grassland community as a whole. This is why the Department of Conservation partners with livestock producers to graze some areas that it owns or manages. It’s also why the Department has launched a long-term study to explore the effects of conservation grazing on native grassland communities.

Conservation Grazing Mimics Natural Processes

Missouri’s fertile soils and humid climate support prolific plant growth. Grasslands, whether introduced or native, that aren’t managed periodically with fire, grazing, or some mechanical means become too thick and tall for use by most wildlife within just a few short years. Think about how tired you feel after hunting or hiking through thick, tall grass for a few hours. Now imagine trying to navigate a sea of tall grass as a thumb-sized quail chick, box turtle, or crawfish frog.

Historically, fire and grazing kept prairies free of tall trees and created a shifting mosaic of diverse habitat patches across the landscape. Bison and elk no longer roam Missouri’s grasslands, but managers can use cattle to sculpt the habitat into short, tall, dense, and sparse patches that comprise a thriving grassland community. Managers must focus and refocus grazing season-to-season and year-to-year in order to move these habitat patches across the landscape. They frequently use prescribed fire to focus grazing intensity. This approach, called patch-burn grazing, relies on the animals’ preference for grazing fresh regrowth on recently burned sites. The result mimics the historic impact of native grazers on a much smaller scale. Managers also use temporary electric fences to concentrate grazing disturbance on overgrown sites. Regardless of the method, the aim is to shift grazing intensity across the landscape over time to avoid grazing the same area in the same manner year after year.

Matt Hill manages Wah’Kon-Tah Prairie as well as a number of other grasslands in and around St. Clair County. He says, “Of all the practices we depend on — prescribed fire, mowing, haying, spraying, and grazing — only the combination of fire and grazing meets our goal of providing diverse vegetative composition within a management unit because of its ability to provide a mosaic of varying height and thickness.”

Matt emphasizes that bare ground with clumpy grasses and scattered wildflowers is perfect foraging habitat for turtles, young birds, and many small mammals. “We also use grazing to help control invasive plants,” he says. “For instance, we use cattle to graze tall fescue short so that herbicide application is more effective in the fall. Grazing accomplishes the site preparation that would otherwise require many staff hours, hundreds of gallons of diesel fuel, and wear and tear on tractors and mowers.”

Temporary Impact Fades Quickly, Increases Habitat Diversity

Not all plants and animals thrive under the same conditions. Conservation grazing creates patchy grasslands that provide homes for a greater variety of wildlife than grasslands managed as a single, uniform unit. So, in any given year, some parts of a grassland should remain ungrazed while other patches are grazed short, and still others are regrowing after past grazing. These regrowth areas host an array of annual and biennial plants that provide wildlife food in the form of seeds, nectar, pollen, and insects. Such patches are often under-represented in today’s grasslands, yet they may be among the most beneficial to wildlife. Under conservation grazing, the grasses and other perennial plants regrow and evidence of grazing fades.

Grazing Plans are Specific and Adaptive

Before stocking cattle on an area, managers prepare written grazing plans that define the location and timing of prescribed burns, the location of temporary fences, the type and number of grazing animals to be stocked, and the duration of grazing needed to accomplish habitat objectives. These plans are site-specific and adaptive. They vary from site to site and change for each site over time. This approach is responsive to changing grassland conditions and is preferable to simplistic cookie-cutter plans that can cause grasslands to become increasingly uniform.

Conservation grazing is implemented to benefit grasslands and restore cycles of disturbance and regrowth that strengthen the natural community. Managers choose the number of cattle stocked and the duration of grazing on Department areas to meet specific habitat objectives, not livestock performance or economic considerations. Once the livestock have accomplished their grassland management work, they are returned to privately owned land in time for some regrowth to occur before winter.

Conservation Grazing Benefits Wildlife

Managers and ecologists still have much to learn about how grazing affects individual species, but available data and theory suggest that grazing benefits grasslands and a wide range of wildlife species that depend on them. Managers consider results from Missouri-based grazing studies, as well as relevant results of research conducted in nearby states, when deciding how to implement conservation grazing.

Invertebrates

The sheer diversity of insects and arthropods is mindboggling. As a result, there is no easy way to broadly categorize insect response to grazing or other management.

A study conducted near Stillwater, Oklahoma, found that grassland patches managed with fire and grazing produce about 50 percent more invertebrates, by weight, than do grasslands managed to be more uniform in appearance. Patchy pastures also held a wider variety of invertebrates than did the more uniform pastures. Managing habitat that meets the needs of a broad range of invertebrates can mean similar benefits to other members of the food web, including humans. This is because many of these invertebrates help pollinate crops that feed us.

Other studies have found that prior land use, such as tillage or the use of herbicide, can have lasting consequences that outweigh the effects of current management. A study in the Grand River Grasslands of northwest Missouri found that land-use history had a stronger influence on butterfly, ant, and leaf beetle community composition than current fire and grazing management. Efforts to conserve native insect communities may need to begin with native plant restoration.

Birds

Grassland birds are the most rapidly declining bird group in North America. Proper grazing can maintain heavy cover needed for nesting and protection from the weather while creating areas of short grass interspersed with taller wildflowers needed for brood-rearing. More importantly, grazing can provide these patches within easy walking distance for newly hatched chicks. Greater prairie-chickens, upland sandpipers, bobwhite quail, and others benefit from the variety and arrangement of habitat patches that conservative grazing creates.

Reptiles and Amphibians

More study is needed to understand how grazing affects reptiles and amphibians. However, findings from a study on Osage Prairie Conservation Area near Nevada support the idea that these animals use the diverse habitat patch types created with fire and grazing.

Small Mammals

An Oklahoma study found that different kinds of small mammals select habitat based on the amount of plant litter covering the ground. For example, hispid cotton rats, prairie voles, and harvest mice chose patches with the most litter. Hispid pocket mice tend to favor areas with a medium amount of plant litter, and deer mice are more abundant in areas with little plant litter. Grasslands that provide patches with varying amounts of litter meet the needs of a wider diversity of rodents, thereby providing a more diverse food base to their predators.

Grazing Diversifies Grass Plantings

Many grasslands on conservation areas were managed as crop fields or fescue pastures by previous landowners. Department staff have planted some of these fields to diverse mixes of grasses and wildflowers harvested from local native prairies. On others, they established commercially available native grass cultivars and legumes. Increasingly, public land managers agree that many of these grasslands are out of balance because grasses have out-competed broadleaved plants to an extent that diminishes habitat benefits. Conservation grazing is proving to be an effective, cost-efficient means of temporarily suppressing dominant grasses and creating a more open habitat structure so a wider variety of plants — and animals — can thrive.

A prime example of the benefits of grazing may be found at the Robert E. Talbot Conservation Area in Lawrence County. One of the older plantings there had become “grassed-in,” with limited plant diversity and a problem with the invasive exotic plant sericea lespedeza. Patch-burn grazing was implemented in 2011. Since then, grassland bird diversity has increased and bobwhites now regularly choose the site to nest and rear their chicks. In fact, radio telemetry has shown that quail prefer grazed areas over all other available habitats on the area. Grass dominance has decreased, and native wildflower diversity has increased. Sericea lespedeza has become a less-serious problem because grazing promotes more effective control of this weed with less herbicide. Essentially, the reintroduction of the natural processes of fire and grazing helped transform what had become a stagnant planting into a more vigorous and complex plant community that requires less staff time and money to maintain.

Conservation Grazing on Native Prairie

Grasslands on some Department-owned areas are native prairies, which, by definition, have never been plowed. These diverse prairies are exceptionally rare communities — less than one-half of 1 percent of Missouri’s historic native prairie remains. These special places provide a glimpse of what one-third of Missouri may have looked like before European settlement.

Grasses can also grow to dominate native prairie. Many types of wildlife benefit when prairie is carefully grazed. Grazing also gives plants that may have labored under the shadow of tall grasses renewed access to sunlight, and may aid in the germination of some seeds. Native prairie evolved under the complementary processes of fire and grazing, so it makes sense that it remains resilient to some level of grazing today.

More information about how grazing may affect long-lived perennial plants is needed. There is evidence to suggest that some prairie plants may decline under grazing management that fails to provide a sufficient rest period from grazing. However, no studies have focused on how populations of individual species change under conservation grazing management, which does include periods of rest.

An initial Department study of the plant community on five patch-burn grazed prairies showed no detectable shift in plant composition after a three-year grazing rotation. A longer-term study aimed at learning how some prairie plant species’ populations change under patch-burn grazing is underway. In addition to shedding light on changes in prairie plant diversity, this study will also provide a better understanding of how grazing changes the vegetation structure among habitat patches. Although slated to run through 2029, Department scientists and land managers will review incoming data from these studies at five-year intervals to guide decisions about where and how to implement grazing.

Value of a Long-Term Perspective

Some visitors to our areas don’t find recently grazed areas particularly pretty — they can look a bit thin and scruffy in the short-term. But you can’t fairly judge a grassland’s health by the look of a recently grazed patch any more than you can judge a wetland’s health as floodwaters begin to recede. When viewed from a long-term perspective, we can begin to see the temporary impacts of grazing as a natural phase in the life cycle of a healthy grassland community. Be sure to visit the Department’s grazed grasslands often to witness these changes first-hand and take in the area’s beauty as it is remade again and again.

Why Cattle Instead of Bison?

Some people ask why we graze with cattle instead of bison. There are subtle differences in the habits of bison and cattle: bison eat slightly more grass than cattle. They also spend less time in shade and travel farther from water. However, these differences are minimal on Missouri’s relatively small grasslands. Managing bison would require more elaborate fencing, year-round staff time, and would complicate public-use opportunities. Privately owned cattle are removed from Department areas at the end of the planned grazing season, which provides more flexibility in grazing management than if bison were present year-round.

Conservation Grazing Help is Available

The Department works with farmers and landowners across the state to help them improve wildlife habitat via well-planned prescribed fire and grazing management. The intent is to help them support wildlife and conserve natural resources while maintaining or even improving grazing enterprise profitability. See Page 3 for regional office phone numbers.