杉木人工林不同发育阶段土壤肥力综合评价研究

Comprehensive evaluation of soil fertility in different developing stages of Chinese Fir Plantations

【目的】分析杉木人工林不同发育阶段土壤性质的变化,对各发育阶段的土壤肥力状况进行综合评价。【方法】以江西省大岗山区杉木人工林为研究对象,对幼龄林、中龄林、近熟林、成熟林、过熟林土壤主要物理化学性质和生物学性质进行测定,运用方差分析和相关分析法探讨不同发育阶段土壤性质的变化特点,并进一步运用主成分分析法对杉木人工林各发育阶段土壤肥力状况进行综合评价。【结果】(1)中龄林阶段土壤肥力状况表现出明显的恶化现象,但从近熟林阶段开始,随着林下环境的改善,土壤肥力状况出现明显恢复;(2)土壤纤维素酶、β-葡糖苷酶、蔗糖酶和多酚氧化酶活性与土壤理化性质密切相关,但淀粉酶活性的影响不明显;(3)土壤有机质、碱解氮、全氮、放线菌、真菌含量以及纤维素酶、β-葡糖苷酶和蔗糖酶活性等土壤因子是综合评价土壤肥力的重要指标。【结论】杉木人工林各发育阶段的土壤肥力,由高到低依次为过熟林>成熟林>近熟林>幼龄林>中龄林。

【Objective】 The recearch was conducted to analyze the soil properties variations and give comprehensive evaluation of soil fertility status in different developing stages.【Method】 Based on the determination of main soil physical,chemical and biological properties in the juvenile forest,medium forest,near-mature forest,mature forest and over-mature forest of Chinese fir plantations in Dagang mountain of Jiangxi Province,the variation characteristics of soil properties in different developing stages were explored by analysis of variance and correlation,soil fertility in different developing stages of Chinese fir plantations was further evaluated with principal component analysis.【Result】（1）The soil fertility was obviously deteriorated in the medium forest,but recovered in the near-mature forest with the environmental improvement of forest soil;（2）Close correlations were found between the activity of soil cellulose,β-glucosidase,sucrase and polyphenol oxidase and soil physical and chemical properties,but not for the activity of amylase;（3）Soil organic matter content,total and alkali-hydrolyzable nitrogen content,the number of actinomycetes and fungi,along with the activity of cellulase,β-glucosidase and sucrase,played important roles in the evaluation of soil fertility.【Conclusion】 The soil fertility levels in different developing stages of Chinese fir plantations are in the order of overmature forest〉mature forest 〉near-mature forest〉young forest〉medium forest.