不同林龄杉木人工林根际与非根际土可溶性有机碳的差异  

Differences of Dissolved Organic Carbon in Rhizosphere and Bulk Soils of Chinese Fir Plantations at Different Stand Ages

作　　者：张雅婷 郑裕雄 杨智杰[1,2] 黄施楚 王海珍 余恒 钟羡芳 ZHANG Yating;ZHENG Yuxiong;YANG Zhijie;HUANG Shichu;WANG Haizhen;YU Heng;ZHONG Xianfang(0x09School of Geographical Sciences,Fujian Normal University,Fuzhou 350117,China;Sanming Forest Ecosystem National Observation and Research Station,Sanming 365000,Fujian,China;College of Natural Resources and Environment,Northwest A&F University,Yangling 712100,Shanxi,China)

机构地区：[1]福建师范大学地理科学学院,福州350117 [2]福建三明森林生态系统国家野外科学观测研究站,福建三明365000 [3]西北农林科技大学资源环境学院,陕西杨凌712100

出　　处：《亚热带资源与环境学报》2023年第1期48-55,共8页Journal of Subtropical Resources and Environment

基　　金：国家自然科学基金重大项目(32192433);福建省公益类科研院所专项(2022R1002001)。

摘　　要：土壤可溶性有机碳(Dissolved Organic Carbon,DOC)的主要来源根系分泌物与凋落物受不同林龄林木生产力差异的影响,但与其相关的研究仍较为缺乏。因不同浸提方法所提取DOC的来源不同,本研究通过热水(H_(DOC))、冷水(C_(DOC))和盐(S_(DOC))浸提方法所得结果,研究林龄对杉木人工林根际与非根际土壤DOC的影响差异。结果表明:(1)不同林龄根际土壤H_(DOC)与C_(DOC)均显著高于非根际土壤(P<0.05),S_(DOC)无显著差异。其中6 a根际土壤H_(DOC)和C_(DOC)分别是非根际土壤的198.7%和299.9%。(2)6 a根际土壤DOC含量均显著高于18 a与42 a(P<0.05),6 a根际土壤H_(DOC)是18 a和42 a的172.0%和132.8%;6 a根际土壤S_(DOC)与C_(DOC)分别比42 a高51.6%与57.0%。非根际土壤H_(DOC)与S_(DOC)含量随林龄增加而降低(P<0.05),其中6 a的非根际土壤H_(DOC)比18 a高36.2%,42 a的S_(DOC)比6 a低40.9%。(3)不同林龄根际与非根际土壤MBC存在显著差异(P<0.05),6 a根际土壤MBC显著高于18 a,42 a非根际土壤MBC显著低于其他林龄。综上所述,根际与非根际土壤DOC均具有随杉木林龄增加而降低的趋势。根际土壤与非根际土壤之间的差异主要受林木根系的影响,不同林龄根际土壤主要受根系分泌物、根系归还与土壤微生物生物量的影响,而非根际土壤主要受杉木速生特性与土壤微生物生物量的影响。The main sources of soil dissolved organic carbon(DOC)are root exudates and litter.The amount of root exudates and litter is affected by the differences in plantation productivity at different growth stages,but relevant research remains scarce.Due to the different sources of DOC extracted by the three extraction methods,the effect of stand age on the DOC of the rhizosphere and bulk soils of Chinese fir plantations was explored by using the results of hot water(H_(DOC)),cold water(C_(DOC))and salt(S_(DOC))extraction methods.The results showed that,(1)H_(DOC) and C_(DOC) in the rhizosphere soil at different stand ages were significantly higher than those in the bulk soil(P<0.05),while S_(DOC) had no significant difference(P>0.05).In 6-year Chinese fir plantations,H_(DOC) and C_(DOC) in the rhizosphere soil were 198.7%and 299.9%of those in the bulk soil,respectively.(2)The content of DOC in the rhizosphere soil of Chinese fir plantations of 6 years was significantly higher than that of 18 and 42 years(P<0.05).The 6-year Chinese fir plantations had the highest rhizosphere soil H_(DOC),which was 172.0%and 132.8%of that of 18-year and 42-year.The S_(DOC) of 6 a is 51.6%higher than that of 42 a,the C_(DOC) of 6 a was 57.0%higher than that of 42 a.The contents of H_(DOC) and S_(DOC) in the bulk soil decreased significantly with the increase of stand age(P<0.05).The H_(DOC) of 6 a was 36.2%higher than that of 18 a,and the S_(DOC) of 6 a was 40.9%higher than that of 42 a.(3)There were significant differences in MBC between rhizosphere soil and bulk soil of plantations at different stand ages(P<0.05).MBC of rhizosphere soil in 6-year was significantly higher than that 18 a,and MBC of bulk soil in 42-year was significantly lower than that in other stand ages.To sum up,although the sources of DOC in rhizosphere and bulk soils are different,they all tend to decrease with the increase of stand age.The difference between rhizosphere soil and bulk soil is mainly affected by forest root system.Rhizosphere soil is mainly affected b

关 键 词：可溶性有机碳 杉木人工林 林龄 根际与非根际 

分 类 号：S154.1[农业科学—土壤学]