荒漠草原4种常见植物群落土壤酶活性比较

Comparative Studies on Soil Enzymic Activities of Four Kinds of Common Plant Communities in Desert Steppe

该研究以宁夏盐池县沙边子地区4种常见的植物群落苦豆子（Sophora alopecuroides）、芨芨草（Achnatherum splendens）、油蒿（Artermisia ordosica）和盐爪爪（Kalidium foliatum）为研究对象,通过对群落组成和土壤基本理化性质的研究,以及对脲酶、过氧化氢酶、磷酸酶、蔗糖酶4种常见土壤酶活性的检测,分析了荒漠草原不同植物群落的土壤微环境。结果表明：（1）不同植物群落物种组成不同,且在研究区禾本科、菊科、藜科植物出现的频率相对较高。（2）不同植物群落土壤理化性质存在差异。苦豆子群落土壤容重较低,土壤全氮含量相对较高;芨芨草群落土壤pH明显较高,土壤有机碳含量相对较高;油蒿群落土壤水分含量较低,土壤全磷含量较低;盐爪爪群落土壤盐分含量显著高于其它植物群落。（3）不同植物群落土壤酶活性存在差异,其中芨芨草和油蒿群落的表层土（0~10cm）的土壤脲酶活性较高;油蒿和盐爪爪群落的土壤过氧化氢酶随着土层加深酶活性反而有升高趋势;苦豆子和芨芨草群落的土壤磷酸酶活性较高,盐爪爪群落各土层间磷酸酶活性无显著差异;4种群落土壤蔗糖酶活性普遍较低,且各土层间差异也不大。（4）不同植物群落的同种土壤酶活性间相关性不同。研究认为,根据不同植物群落特征及土壤特性,尤其是不同植物群落间土壤酶活性的相关性,可预测荒漠草原地区植物群落演替趋势,通过适度的人为调控,可使群落向进展方向演替。

In this paper,Sophora alopecuroides,Achnatherum splendens,Artermisia ordosica and Kalidium foliatumare 4kinds of common plant communities growing in Yanchi County of Ningxia Province.They were taken as examples to study the soil microenvironment of different plant communities in desert steppe.After the study of community composition,the basic physical and chemical properties of the soil,we measured urease,catalase,phosphatase,sucrase.The results showed that：（1）the species composition of the different plant communities were various,and the frequency of occurrences of Gramineae,Compositae,Chenopodiaceae were relatively high in survey region.（2）There were differences on soil physical and chemical properties in the 4kinds of plant communities.For example,the soil bulk density was less in S.alopecuroides community and the total nitrogen was relatively higher,the pH and organic carbon content of soilwere significantly higher than others in A.splendens community.The soil moisture content and total phosphorus were lower in A.ordosicacommunity and the salt content was higher markedly in K.foliatumcommunity.（3）There were differences of soil enzyme activity among 4kinds of plant communities.The urease activity of A.splendens and A.ordosicacommunities topsoil soil（0-10cm）was higher;soil catalase of A.ordosicaand K.foliatumcommunities increased as soil deepening;soil phosphatase activity of S.alopecuroides and A.splendens communities were higher and soil phosphatase activity of K.foliatumcommunity was no significant difference in various soil layer（P0.01）;soil sucrase activity of 4kinds of communities was generally low,and the little difference between the soil layer.（4）The correlation of the same soil enzyme activity was different among various plant communities.In conclusion,the different plant community characteristics and soil traits,especially the correlations of soil enzyme activities among different plant communities,can predict the succession of plant communities in desert steppe,and can be used as ways of vegetation restoration of desert steppe on the other hand.That is,moderate artificial disturb can raise soil enzyme activity,then increase biomass,which make desert steppe onto positive succession.