浅耕对西藏高原退化草甸土壤和植物群落特征的影响  

Effects of shallow plowing on soil and plant community of degraded alpine meadow in Tibetan plateau

作　　者：宗宁[1,2] 石培礼[1] 蒋婧[2,3] 宋明华[3] 孟丰收[1,2] 熊定鹏[1,2] 张宪洲[1] 沈振西[1] 

机构地区：[1]中国科学院地理科学与资源研究所生态系统网络观测与模拟重点实验室拉萨高原生态试验站,北京100101 [2]中国科学院大学,北京100049 [3]中国科学院地理科学与资源研究所生态系统网络观测与模拟重点实验室,北京100101

出　　处：《草业科学》2014年第1期8-14,共7页Pratacultural Science

基　　金：国家重点基础研究发展计划(2010CB833502);国家重点基础研究发展计划(2010CB951704);中国科学院战略性先导科技专项(XDA05060700)

摘　　要：草地管理对植被和土壤会产生重要的影响。为探讨浅耕措施对高寒草甸的影响,对西藏高原当雄县典型退化高寒草甸浅耕处理地块的土壤理化性质和植物群落变化进行调查。结果显示,浅耕实施12年后,草地土壤性质得到改善,表层土壤含水量提高35%,而土壤容重降低了28%。0-10和10-20cm土壤可利用无机氮含量分别显著提高了3.2倍和1.7倍。同时,植物群落组成也发生了改变,植被盖度显著增加,杂草类物种丰富度显著降低,可食性丛生类禾草植物重要值显著升高,成为优势物种,草地生产力提高。试验结果表明,在退化高寒草甸适度浅耕有利于改善退化高寒草甸的水分、养分状况,提高可食性牧草的生产力,但从物种多样性保护和群落稳定性维持角度来看仍存在一定的风险。Rangeland management plays important role in soil and vegetation. In order to understand the effects of shallow plowing on degraded alpine meadow, pair-comparison survey was conducted to quantify soil feature and community variation in Damxung county, Tibet Autonomous Region, China. Compared with degraded alpine meadow, soil water content and nutrient increased after 12-year shallow plowing practice with soil water content increased by 35% and bulk soil density decreased by 38.7%. Mineral nitrogen contents of soil increased by 3.2 and 1.7 times at depth of 0―10 cm and 10―20 cm, respectively. Furthermore, shallow plowing practice facilitated vegetation recovery in degraded alpine meadow. Coverage of alpine meadow vegetation significantly increased with the richness and dominance of weeds declined. The species composition changed with dominance of grass in terms of coverage and important value. The above- and under-ground biomass after shallow plowing significantly increased. It indicates that moderate shallow plowing practice can facilitate soil carbon and nitrogen accumulation and vegetation restoration in the degraded alpine meadow. However, it has risk to decrease species richness and community stability.

关 键 词：高寒草甸 浅耕 植物群落特征 植物生产力 

分 类 号：S812.29[农业科学—草业科学] Q948.15[农业科学—畜牧学]