高寒嵩草草甸植物群落对牧场主“控制放牧”分异的响应与适应  

Response and Adaptation of Plant Community in Alpine Kobresia Meadow to Different Grazing Intensities

作　　者：林丽[1,2] 李本措 樊博 兰玉婷 司梦可 LIN Li;LI Ben-cuo;FAN Bo;LAN Yu-ting;SI Meng-ke(Northwest Institute of Plateau Biology,Chinese Academy of Sciences,Xining 810008,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院西北高原生物研究所,青海西宁810008 [2]中国科学院大学,北京100049

出　　处：《中国草地学报》2022年第9期19-30,共12页Chinese Journal of Grassland

基　　金：青海省科技厅应用基础研究项目(2020-ZJ-720)。

摘　　要：选择相同地理和气候单元下高寒嵩草草甸不同家庭牧场为研究对象,对植物群落构件特征进行连续3年的定位监测,发现:同最低放牧强度牧场相比,随放牧强度增高,(1)地上生物量显著降低;土壤表层活根量波动性降低,而死根量先降低后增高;(2)禾本科生态位宽度降低24.2%~32.7%,而莎草科先增高后降低;(3)禾本科同其他功能群生态位重叠度或增高或不变,而莎草科同其他功能群生态位重叠度先增高后降低;(4)植物群落多样性和均匀度降低,优势度增高;(5)在轻度或适度放牧强度下牧场以禾本科为建群种,而在较高放牧强度下以莎草科为建群种。综上,植物群落构件特征可以对放牧干扰产生自适应调节,长期区别化放牧改变了植物群落的生产能力,调节了各功能群在系统中的生态位,重塑了群落总体组织结构,是形成相同地理和气候单元下,以家庭牧场围栏为界限的植物群落特征分异的主控因子。而受到草地生态系统构件特征对干扰应答分异的影响,在较大的空间尺度下,高寒嵩草草甸在放牧强度改变后植物群落演替的方向还有待于进一步研究。This study monitored plant community components’characteristics for three straight years by selecting four alpine Kobresia meadows pastures in the same geographical and climatic area,belonging to different herds.The results showed that:with the increase of grazing intensity,(1)The biomass of aboveground plants was significantly reduced.(2)The biomass of living roots decreased,while the biomass of dead roots first decreased and then increased.(3)Gramineae plant functional groups(PFG)niche breadth was decreased by 24.2%~32.7%,while Cyperaceae PFG first increased by 104.7%and then decreased by 85.8%~89.2%.(4)The plant community diversity and evenness decreased while the dominance increased.(5)Gramineae was the dominant species in the alpine meadow under low or light grazing intensities,whereas Cyperaceae was the dominant species in the alpine meadow under moderate or higher grazing intensities.It can be concluded that the long-term different grazing intensities affected the construction and yield in the plant communities and reestablished the ecological niche of components in plant communities,which led to a variation in the component and construction of the plant communities under the same geographical and climatic area.Its self-adaptive adjustment changed the plant community’s characteristics to different grazing disturbances.The feature of the alpine grazing meadow,divided into different households,was mainly controlled by herders of the pasture,and the“controlled grazing”was the main driving factor in explaining the differentiation between plant communities separated by fences under the same geographical and climatic area.However,due to the different ability of resistance and resilience of the components in plant communities to overgrazing,we should put a great effort into exploring whether it is a universal rule in the alpine meadow succession process.

关 键 词：放牧 植物群落演替 植物群落特征 生态位 生态系统稳定性 

分 类 号：S812[农业科学—草业科学]