不同林龄尾巨桉人工林根系-土壤C、N、P生态化学计量特征  

Soil-root Carbon,Nitrogen,and Phosphorus Stoichiometry of Eucalyptus urophylla×E.grandis Plantations at Different Ages

作　　者：竹万宽 许宇星 王志超 杜阿朋 ZHU Wankuan;XU Yuxing;WANG Zhichao;DU Apeng(China Eucalypt Research Centre,Zhanjiang 524022,Guangdong,China)

机构地区：[1]国家林业和草原局桉树研究开发中心,广东湛江524022

出　　处：《桉树科技》2020年第3期1-9,共9页Eucalypt Science & Technology

基　　金：广东省林业科技创新项目(2018KJCX014);广西创新驱动发展专项(桂科AA17204087-9);广东省自然科学基金(2020A1515011404);国家重点研发计划项目(2016YFD0600505,2016YFD0600504);广东湛江桉树林生态系统国家定位观测研究站运行项目(2020132008)。

摘　　要：分析不同林龄尾巨桉人工林根系-土壤C、N、P化学计量关系特征,以掌握土壤养分现状和变化规律对林木根系养分状况的影响。以2、6和9 a年生尾巨桉人工林为研究对象,测定根系及土壤C、N、P含量,分析二者生态化学计量关系特征及根系生态化学内稳性特征。结果表明:根系有机C和全N含量随林龄表现为先减后增趋势,全P含量9 a最小;土壤有机C随林龄先减后增,全P含量随林龄逐渐增大。根系C:N随林分生长而增大,C:P和N:P均为9 a最大;土壤元素化学计量比在林龄间未表现出差异性;根系N:P与其C:N、C:P存在极显著相关性,根系C:N与土壤C:N、C:P存在显著相关性。2 a和6 a的养分元素及其化学计量比均具有较强的内稳性特征,9 a根系C:P属于敏感型,具有一定可塑性。The stoichiometry of C,N and P between roots and soil in plantations of Eucalyptus urophylla×E.grandis at different ages were analyzed in order to understand variations of soil and root nutrients.This was done by examining soil and roots from plantations of E.urophylla×E.grandis at ages 2-,6-and 9-years.The results showed that contents of organic C and total N in roots decreased at first and then increased with plantation age,and that the content of total P was the lowest at age 9-years.Soil organic C decreased at first and then increased with plantation age,while total P content increased gradually with age.Root C:N ratios increased with plantation age and the ratios of both C:P and N:P were the highest at age 9-years.The stoichiometric ratio of soil elements showed no difference among plantation ages.There was a highly significant correlation between ratios of both N:P and C:N with C:P in the roots,and there was a significant correlation between root C:N and soil C:N with soil C:P.The nutrient elements and their stoichiometric ratios of 2-and 6-year-old plantations showed characteristics of internal stability,while the C:P value of 9-year-old plantations belonged to the sensitive type and has a certain plasticity.

关 键 词：化学计量特征 尾巨桉人工林 根系 土壤 

分 类 号：S718.516[农业科学—林学]