不同林龄华北落叶松人工林林分生长与土壤养分的关系

为了给森林经营和资源保护提供科学依据,基于塞罕坝机械林场不同林龄(12a生幼龄林,27a生中龄林,40a生近熟林)华北落叶松人工林标准地的调查资料,采用Pearson相关分析对林分生长与土壤养分之间的关系进行探讨,结果表明:随着华北落叶松人工林林龄的增加,土壤pH值由5.76降到5.52,土壤酸性逐渐增强,速效磷含量变化范围为4.67~7.64mg/kg,与pH值变化一致,呈逐渐降低趋势;土壤有机质、全氮、速效钾以及全钾含量在中龄林中最高,分别为39.02g/kg、2.32g/kg、130.56mg/kg和17.6g/kg,近熟林次之,幼龄林最低。其中,全氮含量在各个林龄阶段差异显著(P0.05),全钾含量差异极显著(P0.01);土壤全磷含量和碱解氮含量随着华北落叶松人工林林龄的增加而增加,且在各个林龄阶段全磷含量差异显著(P0.05)、碱解氮含量差异极显著(P0.01)。总的来说,不同林龄华北落叶松土壤养分含量差异较大,幼龄林和中龄林对土壤养分的需求较高。

Study on relationship of soil nutrients and stand growth of Larix principis-rupprechtii plantations with different ages

In order to provide scientific basis for forest management and resource conservation,and based on the survey of Larix principis-rupprechtii plantations with different ages (a young-aged class,12 year-old stand;a middle-aged class,27 year-old stand;a near-mature class,40 year-old stand),the Pearson correlation analysis was applied to study the relationship between soil nutrients and stand growth in larch plantation plots.The results showed that with the increase of the stand age in Larix principis-rupprechtii plantations,the soil pH decreased from 5.76 to 5.52,showing the soil acidity is increased.The available P content ranged from 4.67 to 7.64 mg/kg,showing a trend of gradual decrease.The soil organic matter,total nitrogen,available potassium and total potassium content were the highest in middle-aged class,which were 39.02 g/kg,2.32 g/kg,130.56 mg/kg and 17.6 g/kg respectively,after which was the near-mature class,and the young stand had the lowest values.The total nitrogen content was significantly different at each age stage(P＜0.05),and the total potassium content was very significantly different (P＜ 0.01) among different ages.The content of total phosphorus and alkaline hydrolysable nitrogen of soils increased with the increase of age of Larix principis-rupprechtii plantation,and the total phosphorus content was significantly different at each stage (P＜ 0.05),while the content of alkaline hydrolysable nitrogen was very significant different (P＜0.01).In general,the soil nutrient content of Larix principis-rupprechtii in different ages is different,and the demand for soil nutrients is higher in young and middle-aged plants.