不同土地利用方式对桂西南岩溶山地土壤酶活性的影响

Effects of different land-use types on soil enzyme activityin karst mountain areas of Southwest Guangxi

以桂西南典型喀斯特地区不同土地利用方式(裸地、农田、荒草地、灌丛和次生林)为对象,研究不同土地利用方式下土壤酶活性的变化规律。结果表明:土地利用方式对土壤酶活性影响显著,除蔗糖酶外,脲酶、蛋白酶、淀粉酶、碱性磷酸酶、酸性磷酸酶、过氧化氢酶、多酚氧化酶和纤维素酶总体变化规律相似,次生林土壤酶活性显著高于其它土地利用方式,其次是灌丛和农田,荒草地较低,裸地酶活性最低;总体上相同土地利用方式下湿季酶活性高于干季。相关性分析表明土壤脲酶、蛋白酶、淀粉酶、碱性磷酸酶、纤维素酶和多酚氧化酶等相互之间关系密切,并与土壤主要养分含量呈显著相关性,是土壤质量评价的一个参考指标。不同土地利用方式下土壤微环境、植被构成等因素导致了土壤酶活性的差异性。为实现桂西南岩溶山地生态系统的健康发展,在目前人为干扰不可避免的情况下,该区域应尽量选择以林地恢复为主的土地利用方式。

Five kinds of land use types with the same altitude at a typical rocky desertification mountainous region of Pingguo County in Guangxi were chosen to investigate the changes in soil enzyme activity under different land use in karst mountain areas of Southwest Guangxi.Five kinds of land use included secondary forest （SF）,bushwood （B）, waste grassland （WG）,waste land （WL）and cropland （C）.The results showed that different land use types signifi-cantly influenced the enzyme activity.Soil urease,proteinase,amylase,alkaline phosphatase,acid phosphatase,peroxi-dase,polyphenol oxidase and cellulose behaved the same change besides of invertase.The rate order of soil enzyme ac-tivity was SF〉B〉C〉WG〉WL relatively.With an exception of polyphenol oxidase,soil enzymes with the same land use at wet season were higher than that in dry season on the whole.Correlation analysis showed a significant re-lation among soil urease,proteinase,amylase,alkaline phosphatase,cellulose,polyphenol oxidase and so on,which also related soil nutrition content with indicators,therefore,soil enzyme could be useful for reflecting soil quality.The sig-nificant difference was observed in different land use types owing to special factors such as framing soil micro-environ-ment and plant species composition.Now,human interference was inevitable in this region,in order to realize the healthy development in typical rocky desertification mountainous region of Pingguo County in Guangxi,the soil en-zyme changes should be taken into consideration,the land use types with rare disturbance and woodland restoration mode of land use should be chosen as far as possible.