黑龙江省3种林分类型土壤养分特征与肥力评价OA

The aims of the study are to explore the soil nutrient characteristics and fertility status under different forest types,clarify effective measures for improving soil physical and chemical properties and optimizing nutrient cycling processes,expound the influence mechanism of forest structure and tree species composition on soil fertility formation and evolution,and provide scientific references for resource utilization planning in the sustainable development of the forestry industry in Heilongjiang Province.Three different forest types,including Larix gmelinii pure forest,Larix gmelinii-Juglans mandshurica mixed forest,and Juglans mandshurica pure forest,were selected as the research objects.Soils in the 0-10,10-20 and 20-30 cm soil layers were sampled and measured.The physical and chemical properties of the soil were quantitatively analyzed,and single-factor analysis of variance and comprehensive soil fertility evaluation methods were used for analysis.The results showed that:(1)with the increase of soil depth,soil bulk density increased,while natural water content,saturated water content,and capillary water content showed decreasing trends,but the degree of change varied under different forest types;(2)forest types had significant effects on some soil chemical properties.The physical and chemical index values of Larix gmelinii pure forest were lower than those of Juglans mandshurica pure forest and Larix gmelinii-Juglans mandshurica mixed forest;(3)principal component analysis was used to evaluate the soil fertility of different forest types,and the results showed that the soil fertility order was:Larix gmelinii-Juglans mandshurica mixed forest＞Juglans mandshurica pure forest＞Larix gmelinii pure forest.It was recommended to consider near-natural forest cultivation in the management of existing forest stands,timely carry out understory replanting and renewal,create coniferous-broadleaved mixed forests,construct multi-layered and uneven-aged mixed forest structures,and improve soil quality through litter return and microorganism-driven nutrient transformation processes to enhance the fertility of coniferous forest land in this area.