底土碳氮磷比值及其环境因子沿海拔变化——以湘东大围山为例  

Soil C,N,and P Ratios and Their Environmental Controls along Elevation Gradients of Subsoil:A Case Study of Mt.Daweishan of Eastern Hunan Province,China

作　　者：黄得志 盛浩[1] 尹泽润 薛毅 田宇 HUANG Dezhi;SHENG Hao;YIN Zerun;XUE Yi;TIAN Yu(College of Resources&Environment,Hunan Agricultural University,Changsha 410128,China)

机构地区：[1]湖南农业大学资源环境学院,长沙410128

出　　处：《山地学报》2021年第5期621-630,共10页Mountain Research

基　　金：国家自然科学基金(41571234);湖南省教育厅优秀青年项目(15B110)。

摘　　要：深入理解山地表土和底土有机碳(SOC)、全氮(TN)、全磷(TP)含量及其元素化学计量比与环境因子沿海拔带的关系,可揭示山地土壤养分产生空间变异的限制因子。目前,研究的对象多为表土和整个土壤剖面,对于底土的相关研究较少,且没有综合考虑海拔、植被、坡度和坡向对碳氮磷比值的影响。本研究选取湘东典型花岗岩大围山为研究对象,野外沿垂直带设置20个调查样地,结合实验分析土壤SOC、TN和TP含量,探索土壤C、N、P化学计量比值与环境因子的关系。结果表明:(1)土壤剖面上SOC、TN和TP含量均与海拔呈显著正相关,且土壤SOC、TN和TP含量两两均呈显著正相关,揭示了土壤C、N、P元素存在耦合关系。(2)表土C∶N、C∶P和N∶P分别为12.3~97.8、30.6~367.3和0.5~16.9,表土C∶N∶P平均值72∶3.8∶1,明显高于底土平均值(18∶1.4∶1)。(3)环境因子中的地形(海拔、坡向)和土壤理化性质(阳离子交换量和土壤质地)是影响垂直带土壤C、N、P化学计量比的主要因子。本研究有助于认识土壤元素生物地球化学循环特征,并为科学保育山地土壤生态系统提供参考。It is quite necessary to investigate the relationship between soil organic carbon(SOC),total nitrogen(TN),total phosphorus(TP)in mountain subsoil due to little concerns to be paid to the subject yet.At present,the topsoil and the soil profile were researched,mostly.There are few related studies on subsoil,and the effects of altitude,vegetation,slope and aspect on the ratio were not comprehensively considered.Understanding the stoichiometric ratio variations with environmental factors along elevation gradients in mountains can reveal the influencing factors of spatial variation to soil nutrients.In this study,Mt.Daweishan of eastern Hunan province in China was targeted as a case study and 20 sample plots were allocated along elevation gradients in the field.The SOC,TN,and TP contents of the samples were measured to interpret the relationship between the stoichiometric ratios of soil C,N,and P,and their environmental factors.The findings are those:(1)SOC,TN,and TP contents in soil profiles were significantly positively correlated with elevation.And SOC,TN,and TP contents were significantly positively correlated with each other,indicating the coupling of C,N,and P in subsoils.(2)The ratios of C∶N,C∶P,and N∶P ranged from 12.3 to 97.8,30.6 to 367.3,and 0.5 to 16.9,respectively,and C∶N∶P average ratio was 72∶3.8∶1 in topsoil,which much higher than those in subsoils(18∶1.4∶1).(3)The topography(elevation and slope aspect)and soil physicochemical properties(CEC and soil texture)were the main factors for the stoichiometric ratios of soil C,N,and P element in Mt.Daweishan.This study is helpful to understand the biogeochemical cycle characteristics of soil elements and provide reference for scientific conservation of mountain soil ecosystems.

关 键 词：土壤养分 底土 化学计量比 环境因子 大围山 

分 类 号：S153.6[农业科学—土壤学]