短花针茅荒漠草原土壤颗粒多重分形及理化性质对放牧强度的响应  

Multi-fractal characteristics of soil particles and soil physicochemical properties in responses to grazing intensity in desert steppe

作　　者：潘嘉琛 董智[1] 李红丽[1] 闫影影 陈艺文 李永强[2] PAN Jiachen;DONG Zhi;LI Hongli;YAN Yingying;CHEN Yiwen;LI Yongqiang(College of Forestry,Shandong Agricultural University,Taishan Forestry Ecosystem Research Station,Tai'an 271018;College of Resources and Environment,Shandong Agricultural University,Tai'an 2171018,China)

机构地区：[1]山东农业大学林学院,泰山森林生态站,泰安271018 [2]山东农业大学资源与环境学院,泰安271018

出　　处：《干旱区资源与环境》2021年第8期93-99,共7页Journal of Arid Land Resources and Environment

基　　金：国家自然科学基金(31870708,51879155);国家重点研发计划(2016YFC0500504)资助。

摘　　要：放牧是草原生态系统退化的重要驱动力,为揭示放牧强度对荒漠草原土壤理化性质的影响,本文以四子王旗重度(HG)、中度(MG)、轻度(LG)和封育禁牧(CK)4种放牧强度下短花针茅荒漠草原0~40cm土壤为研究对象,探讨土壤多重分形特征及理化性质对放牧强度的响应。结果表明:4种放牧处理不同土层多重分形谱图并不完全重合,0~10 cm土层颗粒细化及分散程度(谱形)除CK外均正响应于放牧强度变化;土壤颗粒分布范围(谱宽)表现为MG>LG>HG>CK,各土层粒径分布谱形最大的土层并不严格对应于谱宽最广的土层;放牧强度间不同土层容重及含水量的变化均呈HG>MG>LG>CK(P<0.05),而孔隙度变化则与之相反;不同放牧处理的w(有机C)、w(速效N)、w(速效P)变化规律相同,均呈LG最大,HG最小,且均随土层深度的增加而降低。土壤理化性质均在LG时有所提升,轻度放牧有助于遏制荒漠草原的土壤退化。Grazing is an important driving force for the degradation of steppe ecosystem.In order to reveal the effects of grazing intensity on soil physicochemical properties of desert steppe,0-40 cm soil data of desert steppe that under the heavy grazing(HG),medium grazing(MG),light grazing(LG),and no grazing(CK)were taken to discuss the responses of multi-fractal characteristics of soil particles and physicochemical properties to grazing intensity changes.The results showed that spectrums of soil multi-fractal at different soil layers of 4 kinds of grazing intensity are not coinciding.Fine particle contents and dispersion degree of 0-10 cm layer positively respond to the increasing of grazing intensity except CK;response of particle distribution range to grazing ranks as MG>LG>HG>CK.Response of soil particle distribution status of various soil layer to 4 kinds of grazing intensity are not the same,summit value of dispersion degree and distribution range are not at the same soil layer.Responses of soil bulk density and moisture of various soil layers to grazing intensity changes all rank as HG>MG>LG>CK(P<0.05),but that of porosity changes are negative to increasing of grazing intensity,which rank as HG<MG>LG<CK.Responses of contents of soil organic carbon,available N,and available P of different layers to grazing intensity changes show similar regularity,the contents show maximum value at LG and minimum value at HG,and these contents in 4 kinds of grazing intensity are decreasing with soil layer increasing.Soil physicochemical properties are all promoted significantly at LG,light grazing retards soil degradation of desert steppe.

关 键 词：放牧强度 土壤理化性质 多重分形 荒漠草原 

分 类 号：S812[农业科学—草业科学]