广西3种珍贵树种人工林土壤养分状况及酶活性比较

Comparison on soil nutrient status and enzyme activity in 3species of rare trees in Guangxi

【目的】分析广西3种珍贵树种人工林土壤养分及酶活性差异,为当地珍贵速生树种人工林的发展及合理利用提供理论依据。【方法】以相同立地条件下12年生的米老排、红推和黧蒴锥人工纯林为研究对象,测定并分析其土壤养分含量和酶活性。【结果】3种林地土壤有机质含量丰富,为31.9452.99 g/kg;全钾、全氮、全磷及速效养分含量为中等至极缺乏水平。黧蒴锥林综合土壤养分状况最好,红椎林次之米老排林较差。3种林地中米老排林土壤酶活性较高,红推林较低,不同土壤酶类型间活性大小均表现为蔗糖酶活性>过氧化氢酶活性>蛋白酶活性>脲酶活性。相关性分析结果表明,过氧化氢酶活性与水解氮含量、蔗糖酶活性与速效磷含量、蛋白酶活性与全磷含量呈显著正相关(p<0.05)。【结论】黧蒴锥人工林土壤养分状况最好,黧蒴锥的生长有利于改良土壤、恢复地力、防止土壤衰退和保持土壤肥力,可与其他针、阔叶树种混交,用于低效林改造。

[Objective]The differences in soil nutrient status and enzyme activity among 3 species of rare trees in Guangxi were analyzed,in order to provide theoretical basis for development and utilization of local rare fast-growing tree species.[Method]Taking 12-year-old pure plantations of Mytilaria laosensis,Castanpsis hystrix and Castanopsis fissa as research objects,the soil nutrient content and enzyme activity in the three plantations were determined and analyzed.[Result]Three plantations were rich in soil organic matter,and the content of organic matter was 31.94-52.99 g/kg.The contents of total potassium,total nitrogen,total phosphorus and available nutrient were in between medium level and very lacking level.C.fissa plantation had the highest soil nutrient contents,followed by C.hystrix plantation,and then M.laosensis plantation.M.laosensis plantation had the highest soil enzyme activity,followed by C.fissa plantation,and then C.hystrix plantation.The enzymes in soil were ranked according to their activities,as follows：invertase catalase protease urease.Correlation analysis showed that there were significantly positive correlations between catalase activity and hydrolyzable nitrogen content,between invertase activity and available phosphorus content,and between protease activity and total phosphorus content（P0.05）.[Conclusion]The soil nutrient status of C.fissa plantation is the best,the growth of C.fissa is beneficial to improve soil,recover land productivity fertility,prevent soil degradation and maintain soil fertility.Therefore C.fissa can be mixed with other needle-leaved tree and broad-leaved tree species,so as to transform lowefficiency forest.