The response characteristics of grassland vegetation structure to grazing intensities with cows

By the controlled grazing experiment on the artificial grassland of Lolium perenne and Trifolium repense gracsland, the response characteristics of grassland vegetation structure to different grazing intensities with cows were quantitatively analyzed in this paper. The results showed that:(1) There were seasonal dynamics as double peaks for the grass biomass on the Lolium perenne and Trifolium repense under different grazing intensity, and the peak values became low with the increases of grazing intensity; (2) The residual height of grasses increased with the decline of grazing intensity (within the same grazing duration), and it implied that the successive regrowth of grassland vegetation favored the low stocking rate; (3) There were seasonal dynamics as three peaks for grass LAI (leaf area index), and the lower grazing intensity (P 3,P 4,P 5), the larger grass LAI; (4) Grazing could stimulate to the tilling of grass density, and grass density in any paddock reached their top during July to August; (5) Based on the analysis on the relationships between grazing intensity, and grassland vegetation parameters of RGR (relative growth index) and LAI increment, there was an optimum domain for grazing intensity or stocking rate. (P 2, P 3), and it can lay a foundation to determine the grazing capacity from grassland vegetation structure.