Productivity of long-term grazing treatments in response to seasonal precipitation
Issue Date
1994-03-01Keywords
fluctuationssteppes
regression analysis
rain
biomass production
grazing intensity
semiarid zones
botanical composition
Colorado
forage
Metadata
Show full item recordCitation
Milchunas, D. G., Forwood, J. R., & Lauenroth, W. K. (1994). Productivity of long-term grazing treatments in response to seasonal precipitation. Journal of Range Management, 47(2), 133-139.Publisher
Society for Range ManagementJournal
Journal of Range ManagementDOI
10.2307/4002821Additional Links
https://rangelands.org/Abstract
Estimates of forage production for long-term ungrazed, lightly, moderately, and heavily grazed treatments (0, 20, 40, 60% removal of annual forage production) established in 1939 in shortgrass steppe communities were subjected to multiple regression analyses to assess long-term temporal trends resulting from grazing and short-term sensitivities to abiotic factors. Average production based upon all data from 1939-1990 was 75, 71, 68, and 57 g m-2 yr-1 for ungrazed, lightly, moderately, and heavily grazed treatments, respectively. Variability in forage production was explained mostly by cool-season precipitation, and magnitude of forage production was more sensitive to annual fluctuations in precipitation than to long-term grazing treatments. Production per unit increase of precipitation was greater for cool-season than warm-season precipitation, but only when cool-season precipitation was above average. This was attributed to differences in evaporative demand of the atmosphere resulting in different utilization-efficiencies of small and large rainfall events in the 2 seasons. Based upon a regression model constructed using data from 1939 through 1962, forage production was not affected by grazing to 20 to 35% removal. For pastures of average relative productivity, grazing at 60% level of consumption for 25 years resulted in a 3% decrease in forage production in wet years and a 12% decrease in dry years. Estimates of productivity after 50 years of heavy compared to light grazing treatment were -5 and -18% for wet and average y precipitation, respectively.Type
textArticle
Language
enISSN
0022-409Xae974a485f413a2113503eed53cd6c53
10.2307/4002821