黄土丘陵区林分密度对人工刺槐林土壤理化性质及酶活性影响  

Effects of Stand Density on Soil Physicochemical Properties and Enzyme Activities in Robinia seudoacacia Plantations in the Loess Hilly-Gully Region

作　　者：刘少华 赵敏 王亚娟 孙亚荣 陈云明 Liu Shaohua;Zhao Min;Wang Yajuan;Sun Yarong;Chen Yunming(State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau,Northwest A&F University,Yangling,Shaanxi 712100,China;Institute of Soil and Water Conservation,Chinese Academy of Sciences and Ministry of Water Resources,Yangling,Shaanxi 712100,China)

机构地区：[1]西北农林科技大学水土保持研究所黄土高原土壤侵蚀与旱地农业国家重点实验室,陕西杨陵712100 [2]中国科学院水利部水土保持研究所,陕西杨陵712100

出　　处：《水土保持研究》2024年第5期123-129,138,共8页Research of Soil and Water Conservation

基　　金：国家自然科学基金项目“抚育间伐调控黄土丘陵区刺槐人工林水分养分机理研究”(41771556)。

摘　　要：[目的]探讨陕北黄土丘陵沟壑区刺槐人工林土壤理化性质及土壤酶活性随林分密度的变化趋势以及土壤理化性质和土壤酶活性的关系,以期明确改善该区刺槐人工林土壤质量的适宜林分密度,阐明影响土壤养分可利用性的主导环境因子,为该地区刺槐人工林高质量发展的修复模式提供理论依据。[方法]以位于黄土丘陵沟壑区的陕西省延安市安塞区县南沟流域的刺槐(Robinia pseudoacacia)人工林为研究对象,分析了高(1500株/hm^(2))、中(1200株/hm^(2))、低(900株/hm^(2))3种林分密度之间土壤理化性质和土壤酶活性的差异,利用冗余分析探讨了土壤酶活性与土壤理化性质的关系。[结果](1)中密度土壤含水率、有机碳、全氮、有效磷和硝态氮含量均显著高于低、高密度;(2)土壤β-葡萄糖苷酶、纤维素酶、蔗糖酶、多酚氧化酶、过氧化氢酶、脲酶、亮氨酸氨基肽酶和N-乙酰氨基葡萄糖苷酶活性均随林分密度增大呈先降低后升高趋势,在1200株/hm^(2)时最低;(3)Pearson相关性分析结果表明与土壤碳、氮、磷循环相关的酶活性与对应的养分含量呈显著负相关关系;(4)冗余分析结果显示:土壤有机碳、全氮和全磷对土壤酶活性的解释度显著,分别解释了土壤酶活性变异的59.8%(p<0.01),20.8%(p<0.01)和9.5%(p<0.05),土壤有机碳含量是影响土壤酶活性的主要因子。[结论]中等密度(1200株/hm^(2))有利于提高刺槐林土壤养分、水分含量,是一种适宜的刺槐林营林措施,同时应注重土壤有机碳含量变化,以期及时采取林分密度调控措施,从而改善土壤酶活性,进而提高土壤养分水平,促进刺槐林质量提升。[Objective] The aims of this study are to determine the appropriate stand density,and to provide the reference for implementing effective restoration practices for improving soil quality of Robinia pseudoacacia plantation in the hilly and gully region of the Loess Plateau in China by analyzing the response of soil physicochemical properties and enzyme activities to stand density changes and the relationship between soil physicochemical properties and enzyme activities.[Methods] R.pseudoacacia plantations of three stand density classes—low density(900 trees/hm^(2)),medium density(1 200 trees/hm^(2)),and high density(1 500 trees/hm^(2)) density—were sampled in the Xiannangou watershed of Ansai County in loess hilly-gully region of northern Shaanxi Province,China.We analyzed the effects of stand density on soil physicochemical properties,enzyme activities,and determined the relationship between soil physicochemical properties and enzyme activities by redundancy analysis.[Results](1) Compared to low-and high-density plantations,medium density plantations significantly increased soil water content,soil organic carbon,soil total nitrogen,soil available phosphorus,and soil nitrate nitrogen.(2) With the increasing in stand density,the soil enzyme activities,including β-glucosidase,cellulase,invertase,polyphenoloxidase,catalase,urease,leucine aminopeptidase,and N-acetyl-β-glucosaminidase decreased first and then increased,and were the lowest at medium density plantations.(3) Pearson analysis showed that soil enzyme activities related to carbon,nitrogen,and phosphorus cycle negatively were correlated with the content of the corresponding resource.(4) Results of redundancy analysis showed that soil organic carbon,total nitrogen,and total phosphorus had significant effects on soil enzyme activities.Soil organic carbon,total nitrogen,and total phosphorus explained 59.8%(p<0.01),20.8%(p<0.01),and 9.5%(p<0.05) of the variation of soil enzyme activities,respectively.[Conclusion] Medium density(1 200 trees/hm^(2)) can help

关 键 词：刺槐人工林 林分密度 土壤理化性质 土壤酶活性 

分 类 号：S714.2[农业科学—林学]