Estimating the Production and Long-Term Capacity of Grazing Using Precipitation Pattern in Steppe Rangelands of Abbas Abad, Taft

Extreme grazing is amongst the most important destructive factors in the country. Forage production is one of the most important factors influencing the grazing capacity and is influenced by climatic fluctuations. Predicting forage production using climatic data can be helpful in determiningthe long term grazing capacity in rangelands.The study was conducted to estimatethe production and long-term grazing capacity in the stepperangelands of Abbas Abad, Taft, in Yazd province. For so doing, first, the relationship between forage production and precipitation pattern was investigated using ten-year statistics (2004-2013). After estimating long-term production,long-term grazing capacity was determined using the available forage (the usual method) and the factors affecting the grazing capacity (metabolism energy). Regression models (simple and multiple, step wise) were used to findthe relationship between the annual forage production and the precipitation pattern. According to the results, previous rainfalls (the rainfall of the past year in addition to the rainfall of the growing season) and winter rainfalls, as independent variables, have the highest correlation with the total forage production in Abbas Abad region. 0.97 of the changes in total forage production can be estimated by previous and winter rainfalls. The results of determining capacity by means of the two common methods and metabolism energy indicated that,without considering effective factors, the estimated grazing capacity procedure, as the usual method, does not guarantee the sustainability of livestock production and utilization in rangelands.