干旱区生态环境知识资源中心(Arid): 放牧对草原土壤的影响

Arid

	放牧对草原土壤的影响
其他题名	The effects of grazing on grassland soils
	高英志; 韩兴国; 汪诗平
来源期刊	生态学报
ISSN	1000-0933
出版年	2004
卷号	24 期号:4 页码:790-797
中文摘要	介绍了放牧对草原土壤物理性质(容重、渗透率)、化学性质(有机质、N素)和微生物的影响.由于草原土壤系统本身的复杂性、滞后性和弹性,放牧对土壤性质的影响不尽相同.一般而言,随放牧强度的增大,动物践踏作用的增强,土壤孔隙分布的空间格局发生变化,土壤的总孔隙减少,特别是大孔隙(>50mum)和较大中等孔隙(9～50mum)减少,使土壤容重增加,土壤的渗透阻力加大,土壤的保水和持水能力下降.但在有机质含量很低的沙质土壤中,超载过牧,造成有机质含量降低,土壤的团粒结构减少,稳定性团聚体减少,土壤结构遭到破坏,使得土壤容重反而降低.土壤有机质和放牧之间存在复杂的相互关系,土壤有机质对放牧的响应受多种因素的影响,这些因素包括植被和土壤的初始状况;环境因素,特别是水分和温度;放牧历史(强度、频率、持续时间和动物类型).同时,土壤有机质含量低的土壤比含量高的土壤更易受放牧的影响,而使有机质发生变化.土壤微生物量碳是最具活性的土壤碳库,对环境的变化敏感,能较早地指示生态系统功能的变化.当考虑时间尺度时,高强度放牧对土壤肥力有负面的影响,短期内,由于加速了养分的循环效率,产生有利的影响,但长期无管理的超载放牧必然造成系统物质(资源)输入和输出的不平衡,最终导致草原生态系统退化,特别是在相对脆弱的干旱和半干旱生态区.为了保护草原的土壤资源,应改变只注重草原的经济功能(获取各种畜产品)的观念,而更应注重发挥草原的生态功能和社会功能,使草原得到修养生息.
英文摘要	The effects of grazing on physical properties (bulk density, water infiltration), chemical properties (soil organic matter, nitrogen) and soil microbes of grassland soils were reviewed based on published literature. The effects of grazing on soil properties were inconsistent, because of the complexity of the soil system, time lag after disturbance and resilience of soil system to perturbation. In general, because of the impact of animal trampling, there are changes in soil pore size distribution as well as total porosity with increasing stocking rate. The decrease in macropores (>50mum) and larger mesopores (9~50mum) could lead to higher bulk density, greater penetration resistance and a decreased soil water holding capacity. However, bulk density may decrease in sandy soil with lower organic matter content, because overgrazing causes soil organic matter to decrease, influences the stability of soil aggregates and results in collapsed soil structure. There exists a complex interaction between grazing and soil organic matter. Many factors determine the response of soil organic matter to livestock grazing. These factors include the initial conditions of vegetation and soil, environmental factors, especially moisture and temperature, and grazing history (intensity, frequency, duration, and type of animal). Soils with inherently low soil organic matter are more prone to change in response to grazing than soils high in organic matter. Microbial biomass is the most labile C and N pool in soil and can be used as a rapid and sensitive indicator of change in the soil management system. Grazing at high stocking rates may have opposing effects on soil fertility depending on the time-scale considered. In the short term, benefits may occur because of increased nutrient cycling efficiency. But, in the long term, overgrazing without management may cause a decline in soil fertility due to imbalanced nutrient input and output, which finally leads to the degradation of grassland, especially in the more fragile arid and semi-arid regions.
中文关键词	放牧 ; 草原生态系统 ; 土壤性质 ; 养分循环 ; 土壤微生物
英文关键词	grazing grassland ecosystems soil property nutrient cycling soil microbes
语种	中文
国家	中国
收录类别	CSCD
WOS类目	ECOLOGY
WOS研究方向	Environmental Sciences & Ecology
CSCD记录号	CSCD:1613994
来源机构	中国科学院植物研究所
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/205350
作者单位	中科院植物研究所, 植被数量生态学重点实验室, 北京 100093, 中国
推荐引用方式 GB/T 7714	高英志,韩兴国,汪诗平. 放牧对草原土壤的影响[J]. 中国科学院植物研究所,2004,24(4):790-797.
APA	高英志,韩兴国,&汪诗平.(2004).放牧对草原土壤的影响.生态学报,24(4),790-797.
MLA	高英志,et al."放牧对草原土壤的影响".生态学报 24.4(2004):790-797.