We examined the response of 11 functional traits of Cleistogenes squarrosa, including plant height and clump width, to the grazing of different intensity (no grazing; twice grazing in May and July; five grazing in the whole growing season). After five-year treatments, the number of reproductive branches, plant height, stem quality, specific leaf area and total leaf area were significantly reduced. Such reduction was significantly increased with the increases of grazing intensity. Under the treatments of grazing in May and July, the declines of each index were 61.7%, 21.5%, 33.3%, 21.6% and 26.7%, respectively; and the declines in the treatment of whole growing season grazing were 75.7%, 24.7%, 46.7%, 28.5% and 43.7%, respectively. The number of vegetative branches, number of leaf, total leaf area, stem quality, total leaf quality and clump width of the C. squarrosa had a synergistic relationship with aboveground biomass of the whole clump under different grazing intensities. The number of vegetative branches was significantly positively correlated with stem quality and total leaf quality. C. squarrosa had a dwarf-dense branching strategy to avoid grazing. The reduction of grazing intensity would be conducive to maintaining the stability of functional traits.
研究糙隐子草株高、丛幅等11个性状指标对不同强度放牧(不放牧;5、7月两次放牧;全生长季5次放牧)的响应。结果表明: 以不放牧为对照,经过连续5年的放牧处理,糙隐子草的生殖枝数、株高、茎质量、比叶面积和总叶面积显著降低,5、7月放牧处理各指标降幅分别为61.7%、21.5%、33.3%、21.6%、26.7%,全生长季放牧处理各指标降幅分别为75.7%、24.7%、46.7%、28.5%、43.7%,降幅随放牧强度的增加显著增强。在不同放牧强度下,糙隐子草的营养枝数、叶片数、总叶面积、茎质量、总叶质量、丛幅均与整丛地上生物量呈现协同变化关系,营养枝数与茎质量和总叶质量呈显著正相关。糙隐子草应对不同放牧强度干扰表现出矮小-密枝化的避牧响应策略,减轻放牧强度有利于维持其个体性状的稳定。.
Keywords: Cleistogenes squarrosa; functional trait; grazing intensity.