黔东南丘陵山地5种林分类型土壤有机碳与理化性质间的关系OA北大核心CSTPCD

[Objective]The aim of this study is to explore the relationship between soil organic carbon content and soil physicochemical factors of different forest types in southeastern Guizhou Province,China.[Methods]The pure Pinus massoniana forest,pure Cunninghamia lanceolata forest,coniferous mixed forest,broad-leaved mixed forest,and coniferous broad-leaved mixed forest were selected in Tianzhu State owned Forest Farm.The standard plot survey method was used to set up sample plots for five types of forests.Five point sampling method was used to collect soil samples from 0-20 cm,20-40 cm,and 40-60 cm layers of each forest,and soil organic total carbon,soil pH,soil moisture content,soil bulk density,and soil gravel content were measured for each forest type,nitrogen,phosphorus,potassium and other physical and chemical indicators.Person correlation analysis between soil organic carbon and soil physical and chemical properties were conducted.[Results](1)The total organic carbon content of soil pure Pinus massoniana fores ranged from 22.25 to 42.08 g/kg,pure Cunninghamia lanceolata forest ranged from 30.12 to 50.33 g/kg,coniferous mixed fores ranged from 22.93 to 48.17 g/kg,broad-leaved mixed forest ranged from 24.01 to 67.68 g/kg,and soil coniferous broad-leaved mixed forest ranged from 32.99 to 92.36 g/kg.Overall,coniferous broad-leaved mixed forest soil had the highest organic carbon content,and all forest types exhibited surface enrichment characteristics.(2)The pure Pinus massoniana forest was positively correlated with soil total nitrogen and hydrolyzed nitrogen,while the pure Chinese fir forest was negatively correlated with soil total nitrogen and hydrolyzed nitrogen.The mixed coniferous forest was negatively correlated with soil pH,soil moisture,total nitrogen,and total potassium content.The broad-leaved forest was positively correlated with soil pH and total potassium content,while the mixed coniferous and broad-leaved forest was positively correlated with soil moisture,total nitrogen,total phosphorus,and total potassium content.(3)The organic carbon content of pure Pinus massoniana fores soil was mainly affected by the content of hydrolyzed nitrogen,pure Cunninghamia lanceolata forest and coniferous mixed fores were mainly affected by the content of total nitrogen,broad-leaved mixed forest was mainly affected by the soil pH,coniferous broad-leaved mixed forest was the main factor of soil moisture,total phosphorus,hydrolyzed nitrogen,and total nitrogen,and the degree of influence is manifested by the order:water content＞total phosphorus＞hydrolyzed nitrogen＞total nitrogen.[Conclusion]The content of soil organic carbon is significantly influenced by forest type and soil physicochemical properties,and constructing a mixed forest with needle and broad-leaved trees is more conducive to the accumulation of soil organic carbon.