海拔梯度和原生林转换对北热带山地土壤有机碳密度的影响  

Effects of Altitudinal Gradient and Primary Forest Conversion on Soil Organic Carbon Density in the Northern Tropical Mountains

作　　者：王平[1] 俞筱押 丁智强 谭小爱 华红莲[1] 李玉辉[1] WANG Ping;YU Xiao-ya;DING Zhi-qiang;TAN Xiao-ai;HUA Hong-lian;LI Yu-hui(Department of Geography,Yunnan Normal University,Kunming 651500,China;School of tourism and resource environment,Qiannan normal university for nationalities,Duyun 558000,China;School of Geographical Sciences,Fujian Normal University,Fuzhou 350007,China)

机构地区：[1]云南师范大学地理学部,云南昆明650500 [2]黔南民族师范学院旅游与资源环境学院,贵州都匀558000 [3]福建师范大学地理科学学院,福建福州350007

出　　处：《土壤通报》2024年第2期391-400,共10页Chinese Journal of Soil Science

基　　金：中央财政林业改革发展资金项目(530600200000000025798);国家自然基金项目(41861030)资助。

摘　　要：[目的]探究北热带土壤有机碳密度(SOCD)对海拔梯度和原生林转换的响应特征及内在机制。[方法]以中国红河蝴蝶谷地区海拔105~3012 m的山地和原生热带雨林转换而来的香蕉和橡胶种植园为研究对象,研究0~40cm土壤有机碳(SOC)在海拔梯度和原生林转换后的变化情况,并用最小角回归(Least Angle Regression,LARS)、偏相关和皮尔森相关分析探究气候和土壤理化因子的耦合驱动作用。[结果](1)海拔与SOC呈显著正相关,从低海拔的砖红壤带到高海拔的棕壤带,SOC储量增加了452.1%(0~40 cm土层),该变化主要受土壤容重(BD)、酸碱度(pH)、全磷(TP)、速效氮(AN)和年平均气温(MAT)的驱动,偏相关分析表明MAT对SOCD的作用不随土壤理化因子而改变,但土壤理化因子对SOCD的作用却受MAT的控制。(2)低地原生林转换为橡胶和香蕉种植园后SOC储量分别损失了49.7%和43.5%,SOCD损失与土壤BD增加和C/N减小有关,二者反映了原生林转换后凋落物归还减少和侵蚀加强两个重要的生态过程。[结论]北热带山地土壤碳密度极易受到年均气温的影响,而低海拔土壤碳密度主要受人类活动干扰的调控,未来对土壤碳密度的评估除考虑垂直梯度分异外,还应考虑原生林转换为种植园导致的土壤有机碳损失。[Objective]The paper aimed to approach the response and mechanism of soil organic carbon density(SOCD)to mountain elevational gradients and lowland native forest conversion.[Method]The effects of altitudinal gradients and forest conversion on SOCD(0~40 cm)were investigated in the Butterfly Valley tropical rainforest of southwestern China.Meanwhile,the driving role of climatic and soil physicochemical factors were further explored based on LARS regression,Partial and Pearson correlation analyses.[Result]①Altitudinal gradients had a significant positive correlation with SOC,and SOCD was increased by 452.1%from the laterite zone at a low altitude to the brown earth zone at a high elevation in the 0 to 40 cm soil layers,which the variation was mainly driven by BD,pH,TP,AN and MAT.Partial correlation analysis showed that the effect of MAT on SOC did not vary with soil physicochemical factors,but the effect of soil physicochemical factors on SOCD was controlled by MAT.②The conversions of lowland native forests to rubber and banana plantations resulted in SOCD losses of 49.7%and 43.5%.The loss of SOC was associated with an increase in soil BD and a decrease in C/N.both of them reflects two important ecological processes,the reduction of litter return and the intensification of erosion,following the conversion of native forests.[Conclusion]The SOCD in the northern tropical alpine elevation zone were highly susceptible to MAT factors,while the SOCD dynamics at the lower elevations probably were subject to a combination of human disturbance.Future assessments of SOCD in tropical soils should take into account the loss of SOC due to conversion of native forests to plantations and the altitudinal gradient differentiation.

关 键 词：土壤有机碳密度 海拔梯度 热带雨林 原生林转换 热带种植园 

分 类 号：S153.6[农业科学—土壤学]