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1、第24卷第4期水土保持学报Vol.24No.42010年8月JournalofSoilandWaterConservationAug.,2010*不同土地利用方式下土壤抗冲性动态变化特征及其影响因素11,21杨玉梅,郑子成,李廷轩(1.四川农业大学资源环境学院,四川雅安625014;2.中国科学院山地灾害与地表过程重点实验室,四川成都610041)摘要:采用原状土冲刷槽法,以桉树人工林、茶园、撂荒地、枇杷园、杉木人工林土壤为研究对象,研究了土壤抗冲性动态变化特征及其影响因素。结果表明:土壤初始径流含沙量均较大,但随着冲刷时间的延长径流含沙量逐渐降低,并在3~
2、6min后逐渐趋于稳定;土壤抗冲性能随冲刷时间的延长呈波状变化,但总体上仍符合随冲刷时间延长,抗冲性增强的规律;土壤抗冲性能随冲刷时间的变化可用幂函数方程很好的拟合,其相关指数介于0.717~0.989;土壤抗冲性主要受容重、坡度、植物根系等因素的影响,其中<1mm须根是增强土壤抗冲性能的关键因子。<1mm须根根长、根表面积、根体积与土壤抗冲性强化值ANS呈显著或极显著正相关,其相关系数介于0.926~0.980。关键词:含沙量;土壤抗冲性;土地利用方式;植物根系中图分类号:S157.1文献标识码:A文章编号:1009-2242(2010)04-
3、0064-05SoilAnt-iscourabilityDynamicVariationCharacteristicsandItsInfluencingFactorsunderDifferentLandUseTypes11,2YANGYu-mei,ZHENGZ-icheng,LITing-xuan(1.CollegeofEnvironmentalandResourceScience,SichuanAgriculturalUniversity,Yaan625014;2.KeyLaboratoryofMountainHazardsandSurfaceProces
4、s,ChineseAcademyofSciences,Chengdu610041)Abstract:Onthebasisofundisturbedsoilsamplewashingmethod,soilant-iscourabilitydynamicvariationcharacteristicsanditsinfluencingfactorswerestudiedunderfivelandusetypesincludingChinesefirplanta-tion,eucalyptusplantation,loquatorchard,teaplantatio
5、nandabandonedland.Theresultsshowedthatthesedimentconcentrationofalllandusetypeswashighatthebeginning,thendecreasedgraduallyalongwiththescouringtimeafter3to6minutes.Soilant-iscourabilityassumedwavyvariationalongwithscouringtime.Anditalsoaccordedwiththelawthatant-iscourabilityincrease
6、dgraduallywithscouringtime.Thechangeregulationoftheindexofsoilant-iscourabilityalongwithscouringtimeobeyedthepowerfunction.Thefittingeffectwasgoodanditscorrelationindexliedbetween0.717~0.989.Soilbulkdensity,slopeandfibrousrootwerethemainfactorsofsoilant-iscourabilityunderdifferentla
7、ndusetypes.Inwhich,<1mmfibrousrootwasthekeyfactorenhancingsoilant-iscourability.Rootlength,surfaceareaandvolumeof<1mmfibrousrootweresignificantlypositivecorrelationtotheenhancementvalueofsoilant-iscourability.Theremarkablepositioncoefficientbetweenthemliedbetween0.926~0.980.Keywords
8、:sedimentconcentrat