摘要
[目的]华北落叶松是内蒙古苏木山主要栽植树种,华北落叶松在苏木山栽植初期长势良好,近年来随着华北落叶松林龄的增加,不同林分密度华北落叶松长势产生差异,本文旨在对苏木山不同林分密度华北落叶松人工林土壤养分特征进行研究.[方法]本文以内蒙古苏木山林场林分密度500～600株·hm-2、900～1 000株·hm-2、1 300～1 400 株·hm-2、1 800～2 000 株·hm-2 的 40 a生华北落叶松人工林为研究对象,分析华北落叶松人工林不同林分密度对林下土壤养分的影响,及各土壤养分之间的关系.[结果]各密度华北落叶松人工林在0～30 cm土层中,土壤有机质、全氮、速效钾随土层深度的增加而减小.本文研究的土壤养分含量各因子之间存在显著相关性,其中有机质、全氮、碱解氮、速效磷、速效钾含量与土壤pH值呈显著负相关;全氮、碱解氮、速效磷、速效钾与土壤有机质呈极显著相关,全钾与有机质呈显著负相关.[结论]在所研究的林分密度中,密度为900～1 000株·hm-2 时,0～30 cm土层土壤的有机质、全氮、速效磷、速效钾含量相对较高,pH值较低,即苏木山 40 a生华北落叶松人工林林分密度为 900～1 000 株·hm-2 时,土壤养分含量较高,利于林木生长,为最佳经营密度.
Abstract
[Objective]Larix principis-rupprechtii is the main planting tree species in Sumu mountain,Inner Mongolia.In the early stages of planting,Larix principis-rupprechtii has shown good growth.In recent years,with the increase of Larix principis-rupprechtii forest age,there have been differences in growth among different forest densities of Larix principis-rupprechtii.It is necessary to study the soil nutrient characteristics of different forest densities of Larix principis-rupprechtii artificial forests in Sumu mountain.[Method]This article takes 40 year old Larix principis-rupprechtii plantations with stand densities of 500-600 plants·hm-2,900-1 000 plants·hm-2,1 300-1 400 plants·hm-2,and 1 800-2 000 plants·hm-2 at Sumu mountain Forest Farm in Inner Mongolia as the research objects,and analyzes the impact of different stand densities on soil nutrients under Larix principis-rupprechtii plantations,as well as the relationship between soil nutrients.[Result]The results showed that in the 0-30 cm soil layer,the soil organic matter,total nitrogen,and available potassium decreased with the increase of soil depth in the artificial forest of Larix principis-rupprechtii at different densities.There is a significant correlation between various factors of soil nutrient content studied in this article,among which organic matter,total nitrogen,alkaline nitrogen,available phosphorus,and available potassium are significantly negatively correlated with soil pH value.Total nitrogen,alkali hydrolyzed nitrogen,available phosphorus,and available potassium showed extremely significant correlations with soil organic matter,while total potassium showed a significant negative correlation with organic matter.[Conclusion]In the studied forest density,when the density is 900-1 000 plants·hm-2,the soil organic matter,total nitrogen,available phosphorus,and available potassium content in the 0-30 cm soil layer is relatively high,and the pH value is low.That is,when the density of the 40 year old Larix principis-rupprechtii artificial forest in Sumu mountain is 900-1 000 plants·hm-2,the soil nutrient content is high,which is conducive to tree growth and is the optimal management density.
基金项目
内蒙古自治区关键技术攻关计划项目(2021GG0032)
NETL
NSTL
万方数据