秦岭山地松栎林土壤理化性质耦合关系  

Coupling relationship between physical and chemical properties of soil within pine-oak mixed forest in Qinling mountains

作　　者：吴昊[1,2] 董思谨 王文浩 WU Hao;DONG Sijin;WANG Wenhao(College of Life Science,Xinyang Normal University,Xinyang 464000,Henan,China;College of Forestry,Northwest A&F University,Yangling 712100,Shaanxi,China)

机构地区：[1]信阳师范学院生命科学学院,河南信阳464000 [2]西北农林科技大学林学院,陕西杨凌712100

出　　处：《中南林业科技大学学报》2020年第10期117-126,共10页Journal of Central South University of Forestry & Technology

基　　金：国家自然科学基金项目(31070570);信阳师范学院“南湖学者奖励计划”青年项目(2018B051)。

摘　　要：【目的】土壤是森林生态系统的重要组分之一,林地土壤理化性质及其耦合关系对森林生态系统的发育过程、空间格局和生态功能具有重要影响。针对秦岭油松-锐齿槲栎混交林土壤物理性质与其养分含量及元素化学计量特征的关系进行研究,旨在筛选出对林地土壤养分元素含量及其化学计量比起主导作用的土壤物理性质指标,揭示养分元素沿土壤物理性质梯度的变化趋势,以期为秦岭森林生态系统功能维护及可持续经营提供参考依据。【方法】在研究区设置15块调查样地进行土壤样品采集,分别测定非毛管孔隙度、毛管孔隙度、总孔隙度、容重、最大持水量和毛管持水量等6项物理性质指标,以及总有机碳(C)、总氮(N)、总磷(P)、总钾(K)、速效N、速效P和速效K等7项化学养分指标,并计算其生态化学计量比,运用单因素回归分析和典范对应分析(CCA)等方法研究林地土壤的理化性质耦合关系。【结果】非毛管孔隙度、总孔隙度与林地土壤"物理性质-化学养分"CCA排序轴及"物理性质-化学计量比"CCA排序轴的相关系数均达到显著水平。土壤总P含量随非毛管孔隙度及总孔隙度的增加而显著上升;C:P和N:P均随非毛管孔隙度的上升而显著下降,P:K随非毛管孔隙度的上升显著增加;随着总孔隙度上升,N:P显著下降而P:K显著增加。此外,速效P含量随土壤容重增加而呈现明显的"先上升后下降"单峰变化趋势。C:N位于CCA排序图的中心位置,且与各物理性质指标之间无显著性回归关系,表现出较强的化学计量内稳性。【结论】秦岭松栎林土壤物理特性对其化学性质产生了显著影响,起主导作用的物理指标依次为非毛管孔隙度、总孔隙度和容重,土壤持水量对该区土壤化学性质的影响力较弱。同时,在林区内毛管孔隙度及总孔隙度较高的区域应注意人工添加N肥,以缓解N元素的限制性作【Objective】Soil is one of the important components of forest ecosystems.The physical and chemical properties of forest soil and their coupling relationships have important influences on the development process,spatial pattern and ecological function of forest ecosystems.Here,we examined the relationships between soil physical properties,nutrient contents and element stoichiometry of pinus tabulaeformis-Quercus aliena var.acuteserrata mixed forest in Qinling mountains,supposed to select the dominant soil physical property index that determining its nutrient elements and stoichiometric characteristics,and to reveal the variation trends of nutrient elements along the gradient of soil physical properties,for providing reference for the function maintenance and sustainable management of forest ecosystems in Qinling mountains.【Method】15 sampling plots were set in the study areas to collect the soil samples,and then measured their six soil physical properties containing non-capillary porosity,capillary porosity,total porosity,bulk density,maximum water capacity and capillary moisture capacity,as well as measured their six nutrient element indices containing total organic carbon(C),total nitrogen(N),total phosphorus(P),total potassium(K),available N,available P and available K and their ecological stoichiometric ratio,respectively.We then used the methods of single factor regression model analysis and canonical correspondence analysis(CCA)to study the coupling relationships between physical and chemical properties of these forest soils.【Result】The correlation coefficients of non-capillary porosity and total porosity with CCA ordination axis in‘physical properties-chemical nutrients’and‘physical propertiesstoichiometric ratio’all reached a significant level.The soil total P content significantly increased with the increase of non-capillary porosity and total porosity.Both C:P and N:P significantly decreased with the increase of non-capillary porosity,while P:K significantly increased with the increase

关 键 词：非毛管孔隙度 总孔隙度 土壤容重 生态化学计量 松栎混交林 秦岭 

分 类 号：S714.2[农业科学—林学] X171.1[环境科学与工程—环境科学]