A dynamic model of litter interception that can be applied to the management of semi-arid meadow steppe with prohibition of grazing

Abstract

As a common measure for grassland restoration, the fence for prohibition of grazing is usually applied to the steppe in northern China. A study in Hulunbuir grassland showed the average litter mass in the steppes that enclosed for ten years can reach 70-550g/m2. The excessive accumulation of litter caused by long-term grazing prohibition can intercept more precipitation, which will reduce the water available to grassland plants and hinder the further recovery of plant communities. Therefore, the establishment of a reasonable litter interception model can help estimating the interception of steppes with different litter accumulation and provide some theoretical support for the formulation of fencing policies. Based on the model of litter interception rate change, we established a dynamic interception model of litter: I=Im(1−e−kt) (t: time;I: dynamic interception; Im: maximum interception; k: exponential coefficient of litter interception). After testing by an indoor simulated rainfall experiment, we found that this model has high accuracy (R2:0.908 – 0.992). The litter mass (LM) determines the maximum interception, and the rainfall intensity (RI) determines the speed of interception which reaches its maximum value. After the conversion of coefficients, we established a prediction model of litter interception based on LM and RI: I=(0.003LM+0.44)[1−e−(0.33RI+3.76)t],R2=0.86,P<0.001. The easily obtainable characteristics of LM and RI data make this model easy to apply.