Historical drought effects on rangelands in northwest Oklahoma

Authors: Gunter, Stacey; HOGAN, ROB - Texas Agrilife Extension

Submitted to: Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 11/10/2011
Publication Date: 11/14/2011
Citation: Gunter, S.A., Hogan, R. 2011. Historical drought effects on rangelands in northwest Oklahoma. Proceedings of the Drought Grazing Management Serminar, November 14-15, 2011, Beaver, Boise City and Goodwell, OK. p. 10-20.

Interpretive Summary: Droughts are common to the Great Plains and these weather events are the most costly natural hazard affecting the United States. Most of the monetary losses are associated with lost crop production, but losses to public water supplies, recreation and tourism, and ecological services are not accounted for in this estimate. One of the ecological services of rangelands on the Great Plains is to produce forages for livestock production. When drought occurs, forage production is decreased and livestock production is compromised. Cattle can make body weight gains even on overgrazed rangelands for the first few years. Many times, supplementation can be used to mask the shortage of forage by substituting nutrients for lost forage production. The combination of supplementation and overgrazing can be profitable in years with near-normal rainfall totals. But during severe droughts, supplementation is inadequate to replace the missing nutrients as forage production declines. Overgrazing increases grass mortality and reduces the vegetative cover, thus increasing wind and water erosion of these sandy soils. During droughts, decreaser species of grasses disappear from the plant community and increaser species (less desirable grasses) become relatively more abundant. Proper stocking during drought years can decrease grass mortality and conserve the vegetative cover that prevents erosion. Once the rainfall returns to normal, forage production by these rangelands quickly increase and, likewise, cattle production quickly follows. For the first couple of years during recovery, forbs (weedy species) will be disproportionately high but will return to appropriate levels in the near future without herbicide intervention. Decreaser species of grasses (desirable grasses) return to the plant communities in 2 to 4 years if rangelands are properly stocked. If overgrazing is continued during the recovery period, the plant community will not return to a satisfactory range condition.

Technical Abstract: Droughts are common to the Great Plains and these weather events are the most costly natural hazard affecting the United States. Most of the monetary losses are associated with lost crop production, but losses to public water supplies, recreation and tourism, and ecological services are not accounted for in this estimate. One of the ecological services of rangelands on the Great Plains is to produce forages for livestock production. When drought occurs, forage production is decreased and livestock production is compromised. Cattle can make body weight gains even on overgrazed rangelands for the first few years. Many times, supplementation can be used to mask the shortage of forage by substituting nutrients for lost forage production. The combination of supplementation and overgrazing can be profitable in years with near-normal rainfall totals. But during severe droughts, supplementation is inadequate to replace the missing nutrients as forage production declines. Overgrazing increases grass mortality and reduces the vegetative cover, thus increasing wind and water erosion of these sandy soils. During droughts, decreaser species of grasses disappear from the plant community and increaser species (less desirable grasses) become relatively more abundant. Proper stocking during drought years can decrease grass mortality and conserve the vegetative cover that prevents erosion. Once the rainfall returns to normal, forage production by these rangelands quickly increase and, likewise, cattle production quickly follows. For the first couple of years during recovery, forbs (weedy species) will be disproportionately high but will return to appropriate levels in the near future without herbicide intervention. Decreaser species of grasses (desirable grasses) return to the plant communities in 2 to 4 years if rangelands are properly stocked. If overgrazing is continued during the recovery period, the plant community will not return to a satisfactory range condition.