Managing Invasive Plants: Concepts, Principles, and Practices link

U.S. Fish & Wildlife Service
America's National Wildlife Refuge System

MANAGING INVASIVE PLANTS: Concepts, Principles, and Practices

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Management Methods: Prescribed Grazing

Left to right: Photo of cattle grazing in a pasture, bison standing among invasive plants, two sheep in a pasture, and goat browsing shrubs.
 Photo credits: USDA ARS (left to right) S Bauer, J Dykinga, P Rech, S Bauer


Prescribed grazing is the application of domestic livestock grazing at a specified season and intensity to accomplish specific vegetation management goals. While traditional grazing practices are often blamed for promoting plant invasions, prescriptive grazing can be used to control invasive plant populations and enhance desirable vegetation conditions.

Prescribed grazing is a relatively new addition to the invasive plant management toolbox, and information related to the impacts of grazing on various invasive plants and plant communities is limited.

Prescribed grazing should be used sensibly, with careful consideration of its compatibility with the habitat, land management goals, infestation characteristics, livestock needs, and resources available to implement the program successfully.

In this module, you will become familiar with

  • different roles of grazing in natural, domesticated, and prescribed grazing systems
  • effects of grazing on biological communities and the environment
  • general principles for developing grazing prescriptions
  • examples of how grazing prescriptions can be integrated into invasive plant management

Natural Grazing Systems

Photo of pronghorn antelope
Grazing by wild ungulates plays an important ecological role in some plant communities. Photo credit: D Menke/USFWS

Grasslands and wild ungulates such as bison (Bison bison), elk (Cervus elaphus), and pronghorn antelope (Antilocapra americana) have coexisted for tens of millions of years, occupying once widespread "grazing ecosystems" (Frank et al. 1998). These animals play an important role in maintaining species composition and functional character of natural grazing systems.

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Domesticated Grazing Systems

Today, most grazing ecosystems of prehistory have been converted to pasture and rangelands to accommodate domesticated livestock grazing and other human activities (Frank et al. 1998, Freilich et al. 2003). Although sustainable vegetation management is necessary to maintain a viable forage base, traditional livestock grazing is inherently managed for the benefit of livestock production. While growing numbers of ranchers manage domestic herds to mimic natural grazing patterns, human-managed grazing systems inevitably stray from natural regimes in how and where they are implemented (Freilich et al. 2003).

General Characteristics of Natural versus Domesticated Grazing Systems
NATURAL Grazing Systems DOMESTICATED Grazing Systems
  • A variety of native ungulates graze a variety of plants.
  • Grazing events are short duration and occur over large areas (i.e., migratory bison).
  • Density of grazing ungulates is determined by natural population controls.
  • Plant communities are tolerant to frequent grazing.
  • Usually a single, introduced ungulate species grazes a few types of plants.
  • Grazing events are often season-long and sedentary.
  • Density of grazing ungulates is determined by human controls (stocking rates).
  • Plant communities may or may not be tolerant to frequent grazing.

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Prescribed Grazing Systems

Grazing Systems
Diagram showing how prescribed grazing systems incorporate aspects of natural and domesticated grazing systems.
Prescribed grazing systems incorporate aspects of both natural and domesticated grazing systems.

Prescribed grazing is the application of livestock grazing to accomplish specific vegetation management goals (Frost and Launchbaugh 2003). Grazing prescriptions incorporate attributes of historic grazing regimes and address some of the challenges and issues of domestic grazing systems to create effective and ecologically beneficial results. While traditional grazing management aims to manage the land to benefit livestock production, prescribed grazing manages livestock to benefit the land.

Prescribed grazing systems

  • typically employ domestic sheep, goats, and cattle; may also use horses, pigs, geese, or domesticated native ungulates
  • carefully manipulate seasonal timing with grazing intensity and the behaviors of livestock to produce predictable plant community response
  • can be designed to accomplish a variety of management, conservation, or restoration objectives

Although livestock grazing is often blamed for promoting plant invasions, it can also enhance desirable plant communities and help control invasive plant populations.