不同林龄杉木林地土壤特性分析

Soil Properties' Analysis under Different Ages of Chinese Firs

测定了1年、10年、18年、32年的杉木林地土壤微生物数量、化学性质、酶活性。结果表明:随着杉木林龄的增长,土壤pH降低,有机质含量增加,土壤中细菌、真菌、氨化细菌、微生物总量呈现"低-高-低"的趋势,放线菌数量变化未表现出明显趋势;水解氮、有效磷、有效钾从幼龄林到中龄林含量有所增加,中龄林以后降低,到成熟林时达到最低;蛋白酶、脲酶、过氧化氢酶、蔗糖酶的活性从幼龄林到中龄林逐渐增强,而在中龄林之后开始下降。随着土层深度的增加,土壤中各种微生物数量、土壤pH、有机质含量、水解氮、速效磷、速效钾以及各种酶的活性均有所降低且趋势较明显。

The soil microorganism quantities,chemical properties and enzyme activity in 1-year,10-year,18-year and 32-year Chinese Firs were determined.The results indicated that along with the age growth of Chinese Firs,pH values of soils decreased,organic matter increased,bacteria,fungi,ammonifying bacteria and microorganism amount exhibited a trend of ＂low-high-low＂,actinomycete＇s number did not show an obvious trend;hydrolysable nitrogen,available phosphorus,available potassium contents increased from young forest to middle-age forest,and reduced after middle-age forest,and reached minimum at the mature stage;activities of protease,urease,hydrogen peroxidase,invertase increased from young forest to middle-age forest,and reduced after middle-age forest.With soil depth increasing,all kinds of microbe quantity,pH values of soils,organic matter,hydrolysable nitrogen,available phosphorus,available potassium and all kinds of enzyme activities of soil decreased with an obvious trend.