摘要
通过对黑麦草 -三叶草人工草地进行受控放牧实验 ,定量研究了草地植被结构对不同放牧强度 (放牧率 )条件下的反应特征变化 .结果表明 :(1 )黑麦草 -三叶草人工草地的禾草生物量季节动态 ,在不同放牧强度下基本上均呈明显的“双峰型”变化 ,而且随放牧强度的增大 ,峰值逐渐降低 ;(2 )草群中禾草的留茬高度 (相同放牧时间 ) ,随放牧强度减小而升高 ,说明放牧强度的降低有利于草地植被的后期再生 ;(3)草地禾草的叶面积指数 (LAI)在放牧条件下呈“三峰型”变化 ,低放牧强度下 ,禾草的叶面积指数较大 ;(4 )放牧有利于草地禾草的分蘖 ,使草群植物密度提高 ,7至 8月份各小区的植物密度达到最高 .从草地植被结构的综合性参数———相对生长速率 (γRGR)与叶面积增量 (LAIincrement)对放牧强度的响应分析还表明 ,梯度放牧实验中存在一个最适放牧强度 (或放牧率 )范围 ,可由此提供确定草地最适放牧率的植被结构基础 .
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.
出处
《东北师大学报（自然科学版）》
CAS
CSCD
北大核心
2001年第3期73-79,共7页
Journal of Northeast Normal University(Natural Science Edition)
基金
国家自然科学基金资助项目 (3 0 0 70 5 45 )
教育部科技重点资助项目 (0 0 0 43 )
