黄土高原马栏林区不同森林类型的土壤肥力研究

Study on soil fertility of forest type in Malan Forest Region on the Loess Plateau

用灰色关联分析法对黄土高原马栏林区主要森林类型优势层生长状况与土壤养分因子的关联性进行分析,并对土壤肥力进行评价。结果表明腐殖质层和有机质是影响森林乔木层生长的主导土壤因子,其次是全氮和碱解氮,然后依次为速效钾、速效磷、全磷、pH值。土壤肥力的综合评价排序总体结果显示,辽东栎占优势的林型肥力最高,油松林、山杨占优势的混交林居中,辽东栎+白桦混交林较差,而白桦占优势的混交林最差。人工油松林对土壤有一定的改良作用;而多数混交林的土壤肥力高于以其中某一树种占优势的林型,但以辽东栎为优势种的林型比辽东栎混交林土壤肥力高,且辽东栎的重要值百分数越大,其土壤肥力越高。

Based on the grey relational analysis method,the relationship between the growth of trees and soil nutrient factors were analyzed,and the properties of soil nutrient in main forest types of Malan Forest Region were evaluated on the Loess Plateau in this paper. The soil nutrient factors affecting the growing of the trees could be lined as humus〉 organic matter〉 total nitrogen〉 available nitrogen〉 available kalium〉 available phosphate〉total phosphate〉pH. The arrangement of comprehensive evaluation of soil fertility indicated collectively that the soil fertility of Quercus liaotungensis dominated forest was the best, Pinus tabulaeformis forest and Populus davidiana dominated mixed forest were in the middle, Q. liaotungensis ＋B. platyphylla mixed forest was worse, especially Betula platyphylla dominated forest was the worst. The artificial P. tabulaeformis forest had improved soil fertility to some extent. The soil fertility of great majority mixed forest was higher than that of the forest types which dominant species was each of the main species of the mixed forest. While soil fertility of forest dominated by Q. liaotungensis showed higher than that of Q. liaotungensis mixed forest, and the bigger the important value of Q. liaotungensis,the better the soil fertility.