Vegetation, Fire, and Cattle: A Three-Part Examination of Grassland Restoration Efforts

Newswise — Burn, grow, graze, and repeat. This is a formula that integrates fire and grazing strategies to restore grass to rangelands in the southern plains of the United States. Throughout the world, woody plants are showing an increased presence in grasslands and savannas, reducing the amount of grasses to sustain livestock and altering wildlife habitat and biodiversity. In the U.S. Great Plains, honey mesquite has encroached upon native grasslands to impact cattle grazing strategies and necessitate development of plant control efforts.

Three companion articles in the May 2010 issue of Rangeland Ecology & Management discuss the results of grass restoration activities on U.S. southern Great Plains rangeland. The effects of fire and grazing on vegetation are examined in the first two articles and the third addresses livestock production.

Fire is a more economical way to reduce the encroachment of mesquite than mechanical or chemical methods. But fire needs fuel in the form of grasses to be effective. This requires that livestock grazing be deferred both to allow sufficient fuel to accumulate before using prescribed fire and to allow grasses to recover after burning.

Even then, fire does not kill mature mesquite plants, it only suppresses their growth, and repeated burning will be necessary. Within these articles, the authors evaluate rotational grazing strategies that allows fuel accumulation to carry a fire, recovery time for grasses, grass production to support cattle, and the capability to repeat the entire process.

Three grazing strategies, each using one herd and multiple paddocks, were compared on a Texas ranch from 1995 to 2001. All strategies used fire to control mesquite; one included chemical treatment as well. An untreated, continuously grazed strategy was used as a reference for the other management strategies. Twenty-five percent of the area was burned each year, with cattle stocked temporarily on the remaining unburned area. An eight-paddock system with use of fire was found to allow the greatest flexibility in managing the livestock, fire and growth periods. Rotational grazing and fire slowed the rate of mesquite cover increase, but did not reduce it.

The final article addresses cow–calf responses to these fire and grazing management strategies. The variables of conception rate, weaning weight, calf weight per hectare, and supplemental fed per cow were used to evaluate livestock performance. Although cattle in continuously grazed pastures fared significantly better in the first two years of the study, differences among strategies were minimal in the next five years. This suggests that both mangers and livestock required considerable time to adapt to the more intensive rotational grazing strategy.

Full text of the articles, “Integrated Grazing and Prescribed Fire Restoration Strategies in a Mesquite Savanna: I. Vegetation Responses, II. Fire Behavior and Mesquite Landscape Cover Responses, and III. Ranch-Scale Cow–Calf Production Responses,” Rangeland Ecology & Management, Volume 63, Issue 3, May 2010, are available at http://www2.allenpress.com/pdf/rama-63-3_275-285.pdf, http://www2.allenpress.com/pdf/rama-63-3_286-297.pdf, http://www2.allenpress.com/pdf/rama-63-3A_298-307.pdf.

About Rangeland Ecology & ManagementRangeland Ecology & Management is a peer-reviewed journal of the Society for Range Management that is published six times a year. The journal provides a forum for the presentation and discussion of research information, concepts, and philosophies pertaining to the function, management, and sustainable use of global rangeland resources. The journal is available online at www.srmjournals.org. To learn more about the society, please visit: http://www.rangelands.org/.