西南喀斯特地区不同林龄华山松人工林根际土壤化学计量特征与根际效应  

Rhizosphere effect and stoichiometric characteristics of rhizosphere soil in Pinus armandii plantations at different stand ages in karst region of southwest China

作　　者：何斌 虞应乾 李望军 邹顺 白晓龙 薛晓辉 HE Bin;YU Yingqian;LI Wangjun;ZOU Shun;BAI Xiaolong;XUE Xiaohui(Guizhou Province Key Laboratory of Ecological Protection and Restoration of Typical Plateau Wetlands,Guizhou University of Engineering Science,Bijie 551700,Guizhou,China;College of Ecological Engineering,Guizhou University of Engineering Science,Bijie 551700,Guizhou,China;Management Center for the Prevention and Control of Rocky Desertification of Bijie City,Bijie 551700,Guizhou,China)

机构地区：[1]贵州工程应用技术学院贵州省典型高原湿地生态保护与修复重点实验室,贵州毕节551700 [2]贵州工程应用技术学院生态工程学院,贵州毕节551700 [3]毕节市防治石漠化管理中心,贵州毕节551700

出　　处：《中南林业科技大学学报》2023年第11期109-119,共11页Journal of Central South University of Forestry & Technology

基　　金：贵州省科技计划项目(黔科合基础-ZK[2021]一般231号);贵州省教育厅青年人才成长项目(黔教合KY字[2022]120和123号);毕节市科学技术项目(毕科合重大专项字[2021]1号);贵州省典型高原湿地生态保护与修复重点实验室开放基金项目(毕科联合字贵工程[2021]8号);贵州省重点学科“生态学”项目(ZDXK[2013]11号)。

摘　　要：【目的】为了解华山松对西南喀斯特环境的适应策略和养分循环机制,本研究探讨华山松根际土壤化学计量特征和根际效应对林龄的响应,为西南喀斯特地区人工林抚育管理提供科学依据。【方法】采用时空互代的方法,在贵州省毕节地区选取4个林龄(10、16、22和47 a)的华山松人工林作为研究对象,运用生态化学计量学方法,分析各林龄下根际土壤养分含量和根际效应,以及p H值和C、N、P化学计量特征。【结果】随林龄增加,根际土壤TC、TN、SOC含量先降低后升高,TP、TK、AN和AK逐渐升高,AP逐渐下降,TC_(a)和p H值先升高后降低。C∶N和C∶P比随林龄增加先降低后升高,N∶P比波动性变化。不同林龄华山松土壤养分的根际效应不同,幼龄林(10 a)和中龄林(16 a)对土壤养分的根际效应均为正效应,而近熟林(22 a)和成熟林(47 a)对土壤养分的根际效应显著降低,TN、AN、TP和TK在22 a时均表现为负效应;p H值无明显根际效应。根际土壤SOC与TN、TP和AN呈显著正相关,与TC_(a)呈显著负相关;p H值与SOC和TN呈显著负相关,与TC_(a)呈显著正相关;TK和TC_(a)含量与C∶N、C∶P、N∶P之间存在着显著负相关性。【结论】本研究结果表明,华山松根际土壤C、N、P、K和C_(a)含量均处于较高水平,具有较强的“自肥”作用;幼林龄阶段根际土壤的C∶N和C∶P显著高于其他阶段,华山松生长可能受到N和P限制;林龄对华山松根际土壤有效养分的富集效应大于全量养分。【Objective】To estimate the adaptation strategies and nutrient cycling mechanism of Pinus armandii to the poor soil nutrients in karst area in Southwest China,and to explore the response of stoichiometric characteristics of rhizosphere soil and rhizosphere effects to stand ages,so as to provide the scientific basis for cultivation and management of plantations in this area.【Method】Using the method of spatiotemporal alternation,four forest ages(10,16,22 and 47 a)of P.armandii plantations were selected in Bijie,Guizhou province.The nutrient contents,pH value,rhizosphere effect and C:N:P ratios of rhizosphere soil of P.armandii were studied at different stand ages.【Result】The contents of TC,TN,SOC,C:N and C:P ratio in rhizosphere soil decreased initially with the increasing plantation age,but increased thereafter.The contents of TP,TK,AN and AK increased gradually with the increase of stand age;while the contents of AP decreased gradually.With the increase of forest age,the contents of TC_(a) and the pH value increased firstly and then decreased.The ratios of C:N and C:P firstly decreased and then increased with the increase of forest age,and the ratio of N:P fluctuated.The rhizosphere effects of soil nutrients were different at different ages.The rhizosphere effects of young(10 a)and middle-aged(16 a)forests on soil nutrients were positive,while the rhizosphere effects of mature(22 a)and mature(47 a)forests on soil nutrients were significantly decreased,and TN,AN,TP and TK were negative at 22 a.pH had no obvious rhizosphere effect.Correlation analysis showed that the contents of SOC was positively correlated with the contents of TN,TP and AN,and negatively correlated with the contents of TC_(a).The pH value was negatively correlated with the contents of SOC and TN,and positively correlated with the contents of TC_(a).The contents of TK and TC_(a) were negatively correlated with C:N,C:P and N:P.【Conclusion】The results of this study showed that the contents of C,N,P,K and C_(a) in rhizosphere soil of P

关 键 词：华山松人工林 林龄 土壤养分含量 C∶N∶P比 根际效应 

分 类 号：S791.241[农业科学—林木遗传育种]