不同坡位轻木人工林土壤养分含量及其化学计量特征  

Soil Nutrient Content and Stoichiometric Characteristics of Ochroma pyramidale Plantations in Different Slope Positions

作　　者：刘元玺 杜官本 赵志娟 孙建丽 肖建冬 王文兵 刘有军 王新华 吴俊文 Liu Yuanxi;Du Guanben;Zhao Zhijuan;Sun Jianli;Xiao Jiandong;Wang Wenbing;Liu Youjun;Wang Xinhua;Wu Junwen(College of Forestry,Southwest Forestry University,Kunming 650224,China;School of Material Science and Engineering,Southwest Forestry University,Kunming 650224,China;Mengla County Mengxing Farm Liability Co.,Ltd.,Mengla 666303,China)

机构地区：[1]西南林业大学林学院,云南昆明650224 [2]西南林业大学材料科学与工程学院,云南昆明650224 [3]勐腊县勐醒农场责任有限公司,云南勐腊666303

出　　处：《山东农业科学》2024年第5期116-125,共10页Shandong Agricultural Sciences

基　　金：国家自然科学基金项目(32071688)。

摘　　要：碳(C)、氮(N)和磷(P)通常用于评估土壤质量。为了解云南西双版纳地区不同坡位轻木人工林生长土壤C、N和P含量及其化学计量特征差异,本研究通过野外调查采样与室内分析相结合的方法,以2年生轻木人工林为研究对象,分析比较上坡位和下坡位轻木人工林中土壤C、N和P的化学计量特征及其对轻木生长的影响。测定指标包括土壤有机碳(SOC)、总氮(TN)、总磷(TP)、碱解氮(AN)和有效磷(AP)含量,并评估两个坡位中SOC/TN、SOC/TP、TN/TP和AN/AP值的差异。结果表明:①下坡位轻木树高和胸径较上坡位分别显著增加23.39%和49.43%。②随着土层深度的增加,土壤SOC、TN、TP、AN和AP含量总体呈降低趋势;在3个不同深度的土层中AP含量均表现为下坡位显著高于上坡位,在20~40 cm土层中AN含量也表现出下坡位显著高于上坡位。③40~60 cm土层土壤各养分含量显著低于0~20 cm土层(上坡位TP除外),在0~60 cm 3个不同深度的土层中,AN/AP值均表现为上坡位显著高于下坡位;20~40 cm和40~60 cm土层中,SOC/TP值均表现为下坡位显著高于上坡位。④相关分析和主成分分析结果表明,在上坡位中,主要由SOC/TP、AN/AP和SOC/TN值反映土壤肥力情况;在下坡位中,主要由AP、AN和SOC含量反映土壤养分情况。综上,下坡位轻木的生长状况显著优于上坡位,土壤SOC、AP和AN含量对轻木的生长起关键性作用,也反映了TP、TN与AP、AN的转化情况;AN/AP值反映土壤中养分的可利用效率,对轻木的生长有直接相关作用,可作为当地评估林地养分是否缺失的信号。Carbon(C),nitrogen(N)and phosphorus(P)are commonly used to assess soil quality.To understand the differences in soil C,N and P contents and their stoichiometric characteristics under Ochroma pyramidale grown in different slope positions in Xishuangbanna region,this study took biennial plantations of O.pyramidale as subjects,the stoichiometric characteristics of soil C,N and P and their effects on growth of O.pyramidale were analyzed and compared between upper and lower slopes based on field sampling and inves-tigation and laboratory analysis.The contents of soil organic carbon(SOC),total nitrogen(TN),total phos-phorus(TP),alkaline nitrogen(AN)and available phosphorus(AP)were determined,and the differences in the ratios of SOC/TN,SOC/TP,TN/TP and AN/AP between the two slopes were assessed.The results were as follows.①Compared with the lower slope position,the tree height and diameter at breast height of O.pyramidale at the upper slope position increased by 23.39%and 49.43%,respectively.②Decreasing tends were found in contents of soil SOC,TN,TP,AN and AP with increasing of soil depth,among which,AP content in all the three soil layers and AN content in 20~40-cm soil layer were significantly higher in the lower slope position than that in the upper slope position.③All the soil nutrient contents except for TP in the upper slope position in 40~60-cm soil layer were significantly lower than those in 0~20-cm layer;the AN/AP ratio in all the three soil layers was significantly higher in the upper slope position compared with the lower slope position;the SOC/TP ratio in the 20~40-cm and 40~60-cm soil layers were significantly higher in the lower slope position than that of the upper slope position.④Through correlation and principal component analyses,the soil fertility in the upper slope position was mainly reflected by the SOC/TP,AN/AP and SOC/TN ratios,and the soil nutrient situation in the lower slope position was mainly reflected by the AP,AN and SOC con-tents.In summary,the growth of O.pyramidale in the lower

关 键 词：坡位 轻木 生长 土壤养分 化学计量比 

分 类 号：S714.2[农业科学—林学]