杜鹃灌丛草地土壤容重与水分特征对不同休牧模式的响应  

Ecological responses of soil bulk density and water content to different non-grazing patterns in alpine rhododendron shrubland

作　　者：曹文侠[1] 徐长林[1] 张德罡[1] 师尚礼[1] 姚拓[1] 

机构地区：[1]甘肃农业大学草业学院草业生态系统教育部重点实验室,中-美草地畜牧业可持续发展研究中心,,甘肃兰州730070

出　　处：《草业学报》2011年第3期28-35,共8页Acta Prataculturae Sinica

基　　金：博士点基金(20106202120004);甘肃省自然基金(3ZS041-A25-049);现代农业产业技术体系资助

摘　　要：以土壤容重与土壤水分特征为主要指标,研究了祁连山高寒杜鹃灌丛草地对全生长季休牧(分枯草期重牧与枯草期轻牧)和传统夏季休牧(重牧)的响应。结果表明,随着土层深入,休牧杜鹃灌丛草地土壤呈容重增大、含水率减小、有机质含量降低的基本变化态势;休牧杜鹃灌丛土壤异质化明显,灌丛冠幅下土壤容重小于灌间土壤,土壤水分大于灌间;6月的土壤容重较8和10月的小,而土壤含水率高;高寒杜鹃灌丛草地土壤含水率与土壤容重间呈极显著的负相关关系,与土壤有机质间呈正相关关系;与传统夏季休牧相比,全生长季休牧的杜鹃灌丛草地灌间畜蹄践踏小径的宽度、深度和面积显著减少,土壤紧实度降低,土壤含水率升高,有效改善了土壤功能;枯草期的高强度放牧降低了全生长季休牧对杜鹃灌丛草地土壤状况的有效恢复;研究证实合理的休牧时期确定与利用强度控制是实现退化高寒杜鹃灌丛草地土壤功能修复的关键。The response of soil characteristics in rhododendron shrubland to different 2-year non-grazing patterns in the Qilian Mountains was studied using soil bulk density and soil moisture characteristics as the main indexes to evaluate herbivore trampling and degraded shrubland recovery.As shrubland soil depth deepened,the soil bulk density increased and soil water content and soil organic matter content reduced.The soils showed obvious heterogeneity;soil bulk density under shrub canopy was less than that under shrub space while soil water content was greater under shrub canopy.The soil bulk density in June was less than those in August and October but soil water content was greater;the soil bulk density showed a very significant negative correlation with soil water content and a positive correlation with soil organic matter.Compared with the traditional shorter summer grazing rest,the non-grazing pattern during the whole growing season had significantly less livestock trampling path features leading to an obvious reduction in soil compaction state,an increase in soil moisture,and an effective improvement of the soil water retaining function.High-intensity grazing in the grass plant withered period also affected the soil conditions for recovery of the rhododendron shrubland.These results confirmed that proper grazing intensity and rest periods should be the main approaches for restoration of degraded alpine rhododendron shrubland.

关 键 词：杜鹃灌丛草地 休牧 践踏 土壤容重 土壤水分 土壤有机质 

分 类 号：S812[农业科学—草业科学]