黄土丘陵区典型退耕恢复植被土壤生态化学计量特征  

Characteristics of soil ecological stoichiometry in typical fallow-restored vegetation in the loess hilly areas

作　　者：郭鑫 魏天兴 陈宇轩 沙国良 任康 于欢 GUO Xin;WEI Tianxing;CHEN Yuxuan;SHA Guoliang;REN Kang;YU Huan(College of Soil and Water Conservation/Key Laboratory of State Forestry Administration on Soil and Water Conservation and Desertification Combating/Ji County Station,Chinese National Ecosystem Research Network(CNERN),Beijing Forestry University,Beijing 100083,China)

机构地区：[1]北京林业大学水土保持学院/水土保持国家林业局重点实验室/山西吉县森林生态系统国家野外科学观测研究站,北京100083

出　　处：《干旱区地理》2022年第6期1899-1907,共9页Arid Land Geography

基　　金：“十三五”国家重点研发计划项目课题(2016YFC0501705);国家生态系统观测研究网络运行服务项目(2019-2020)资助。

摘　　要：为探究不同植被土壤碳(C)、氮(N)、磷(P)化学计量特征及其影响因素,以黄土丘陵区油松、刺槐、沙棘和草地4种典型退耕恢复植被0~100 cm土壤为研究对象,分析不同植被土壤有机碳(SOC)、全氮(STN)、全磷(STP)含量及其化学计量特征。结果表明:(1)不同恢复植被对土壤养分含量有显著影响,刺槐的SOC、STN最高,油松的SOC、STN最低,STP表现为草地>刺槐>油松>沙棘。(2)不同恢复植被土壤养分具有“表聚性”,随土层深度增加,SOC和STN含量呈下降趋势,而STP的变异性较弱。特别是刺槐的SOC和STN在60~100 cm呈增加趋势。(3)不同恢复植被土壤SOC:STN(C:N)、SOC:STP(C:P)差异不显著(P>0.05),刺槐的土壤STN:STP(N:P)显著高于其他植被类型(P<0.05),土壤C:N、C:P、N:P均低于全球及全国平均水平,研究区有机质的分解速率较快,P的有效性高,植被生长主要受N元素限制。(4)研究区土壤C:N、C:P和N:P主要受SOC和STN影响;土壤养分与土壤含水量(SWC)和土壤容重(BD)呈负相关,与土壤粉粒(slit)和黏粒(clay)含量呈正相关,STP对土壤细颗粒的响应强度大于SOC和STN。研究区土壤化学计量在不同退耕恢复植被间差异显著,其中刺槐的土壤养分含量较其他植被类型更好,可为该地区植被恢复工作进一步开展提供参考。The hilly and gully areas of China’s Loess Plateau are an arid and semi-arid region characterized by fragile ecosystems and harsh climates.A series of implemented ecological restoration projects,such as the“Grain for Green Project”,have greatly improved the local environments.To understand local nutrient cycling following vegetation restoration,it is important to study the content and ecological stoichiometry of soil carbon(C),nitrogen(N),and phosphorus(P)in different vegetation types and determine their driving factors.In our study,soil samples were collected in 0-100 cm layers from Pinus tabulaeformis,Robinia pseudoacacia,Hippophae rhamnoides,and grassland.The content and ecological stoichiometry of soil organic carbon(SOC),total nitrogen(STN),and total phosphorus(STP)were analyzed.The effects of soil water content(SWC),soil bulk density(BD),and soil texture on the stoichiometric characteristics were also analyzed.The results showed that:(1)Vegetation types had significant effects on the variations in soil nutrient contents.More specifically,Robinia pseudoacacia had the highest SOC and STN contents,whereas Pinus tabulaeformis had the lowest SOC and STN contents.STP content levels can be arranged in the following order:grassland>Robinia pseudoacacia>Pinus tabulaeformis>Hippophae rhamnoides.(2)Substantial soil nutrients accumulated on the soil surface among different vegetation types.With increasing soil depth,SOC and STN showed similar downward trends,whereas the variability of STP was comparatively weak.In particular,SOC and STN in Robinia pseudoacacia showed increases from 60-100 cm.(3)The variations in soil C:N and C:P among different vegetation types were not significant.Robinia pseudoacacia had significantly higher N:P than Pinus tabulaeformis,Hippophae rhamnoides,and grassland.In our study area,C:N,C:P and N:P were lower than global and national average levels,which indicated that the decomposition rate of organic matter in the soil was slow;the effectiveness of phosphorus was high,and vegetation gro

关 键 词：黄土丘陵区 退耕恢复植被 土壤养分 生态化学计量 土壤理化性质 

分 类 号：S153[农业科学—土壤学]