不同植被类型土壤水稳性团聚体及氮素的分布特征  

Distribution characteristics of soil water stable aggregates and nitrogen among different vegetation types

作　　者：张万宇 刘小娥[1] 洪建龙 张建鹏 ZHANG Wanyu;LIU Xiao’e;HONG Jianlong;ZHANG Jianpeng(College of Forestry,Gansu Agricultural University,Lanzhou,Gansu 730070,China)

机构地区：[1]甘肃农业大学林学院,甘肃兰州730070

出　　处：《森林与环境学报》2025年第2期136-146,共11页Journal of Forest and Environment

基　　金：甘肃农业大学科技创新基金-青年导师扶持基金项目“兰州市南北两山典型人工林土壤氮素矿化及酶活性响应机制研究”(GAU-QDFC-2022-17)。

摘　　要：以甘肃兴隆山5种天然植被类型(草地、灌丛、白桦林、青杄-白桦混交林、青杄林)3个土层(0~20、20~40、40~60 cm)土壤为对象,研究土壤团聚体稳定性及水稳性团聚体氮的变化特征,并采用相关性分析、多元回归分析揭示土壤水稳性团聚体全氮含量与土壤水稳性团聚体平均重量直径(MWD),以及MWD与土壤氮素的关系。结果表明:5种植被类型的土壤水稳性团聚体均以水稳性大团聚体(粒径>0.25 mm)为主,表现为青杄林>灌丛>草地>青杄-白桦混交林>白桦林。草地、白桦林、青杄-白桦混交林土壤水稳性团聚体MWD随着土层的加深逐渐减小,而灌丛和青杄林则先增大后减小。5种植被类型土壤水稳性团聚体MWD表现为青杄林>草地>白桦林>灌丛>青杄-白桦混交林。5种植被类型土壤水稳性团聚体全氮含量表现为青杄-白桦混交林>青杄林>白桦林>草地>灌丛。土壤水稳性团聚体全氮贡献率均以水稳性大团聚体为主。土壤水稳性团聚体MWD与水稳性大团聚体全氮含量呈正相关关系,与粒径≤0.25 mm的土壤水稳性团聚体全氮含量无相关关系,且土壤水稳性团聚体MWD与土壤氮素均有不同程度的相关性。土壤水稳性团聚体越稳定其固氮能力越强,同时氮素的积累可促进水稳性大团聚体的形成。该地区青杄林土壤的稳定性最好,有利于碳氮的积累。Soil samples of three layers(0-20,20-40,40-60 cm)of five natural vegetation types(grassland,shrubland,Betula platyphylla forest,Picea wilsonii-Betula platyphylla forest,and Picea wilsonii forest)in Xinglong Mountain,Gansu Province were collected,and the variation characteristics of soil aggregate stability and nitrogen in water-stable aggregates were studied.Correlation analysis and multivariate regression analysis were performed to reveal the relationship between the nitrogen content and the mean weight diameter(MWD)of soil water-stable aggregates,as well as between MWD and soil nitrogen.The results showed that the soil samples of the five vegetation types mainly had large water-stable aggregates(particle size>0.25 mm),which followed the order of Picea wilsonii forest>shrubland>grassland>Picea wilsonii-Betula platyphylla forest>Betula platyphylla forest.The MWD of soil water-stable aggregates in grassland,Betula platyphylla forest,and Picea wilsonii-Betula platyphylla forest gradually decreased with the deepening of the soil layer,while that in shrubland and Picea wilsonii forest first increased and then decreased.Among different vegetation types,the MWD of soil water-stable aggregates was in the order of Picea wilsonii forest>grassland>Betula platyphylla forest>shrubland>Picea wilsonii-Betula platyphylla forest.The total nitrogen content in soil water-stable aggregates of the five vegetation types was in the order of Picea wilsonii-Betula platyphylla forest>Picea wilsonii forest>Betula platyphylla forest>grassland>shrubland.The total nitrogen in soil water-stable aggregates was mainly contributed by large water-stable aggregates.The MWD of soil water-stable aggregates had a positive correlation with the total nitrogen content in large water-stable aggregates,while it had no correlation with the total nitrogen content in soil water-stable aggregates with a particle size≤0.25 mm.Moreover,the MWD of soil water-stable aggregates was correlated with soil nitrogen to varying degrees.The soil water-stable aggregates

关 键 词：土壤团聚体 土壤氮素 稳定性 植被类型 兴隆山 甘肃 

分 类 号：S714[农业科学—林学]