鼎湖山森林演替序列植物-土壤碳氮同位素特征
熊鑫;张慧玲;吴建平;褚国伟;周国逸;张德强
【期刊名称】《植物生态学报》 【年(卷),期】2016(040)006
【摘要】植物群落对水分利用和养分利用的优化策略,土壤碳周转和氮循环过程对演替变化如何响应,森林土壤有机碳积累机制等都是森林生态学需要解决的关键问题.然而,这些生态学过程的变化在短时间内通过传统的研究手段难以被精确观测,碳氮同位素(13C、15N)技术的应用或许能提供更多有价值的信息.该文通过对鼎湖山森林演替序列代表性群落——马尾松(Pinus massoniana)针叶林(PF)、针阔叶混交林(MF)和季风常绿阔叶林(BF)植物-土壤碳氮同位素自然丰度的测定,分析了叶片稳定碳同位素比率(δ13C)和稳定氮同位素比率(δ15N)与其叶片元素含量的关系,以及叶片-凋落物-土壤δ13C、δ15N在演替水平和垂直方向上的变化特征.结果显示:1)主要优势树种叶片δ13C与其C:N极显著正相关(p＜0.01),凋落物和各层土壤δ13C均表现为PF＞MF＞ BF,沿演替方向逐渐降低;2)叶片δ15N与叶片N含量正相关(p=0.05),凋落物和表层土壤(0-10 cm) δ15N沿演替方向逐渐增大;3)不同演替阶段土壤δ13C、δ15N均沿垂直剖面呈现增大的趋势.结果表明:南亚热带地区植物群落的发展并不一定受水分利用和氮素利用的补偿制约;δ13C自然丰度法的应用有助于森林土壤有机碳积累机制,尤其有助于成熟森林土壤“碳汇”机制的阐释;植物-土壤δ15N值可作为评估土壤氮素有效性和生态系统“氮饱和”状态的潜在指标.%Aims The optimal patterns of plant community for water use and nutrient utilization,the responses of soil carbon and nitrogen tumover processes to forest
succession,and the mechanisms of soil organic carbon accumulation,are three critical issues in forest ecosystem study.It is difficult to accurately detect these ecological processes with conventional methodologies in the short term,yet the application of 13C and 15N natural abundance technique
may
yield
important
information
about
these
processes.Methods This study was conducted in Dinghushan Biosphere Reserve.We investigated the natural isotopic abundance of both 13C and 15N of plant-soil continuum along a successional gradient from Pinus massoniana forest (PF) to coniferous and broad-leaved mixed forest (MF),and monsoon evergreen broad-leaved forest (BF).We also analyzed the correlations of foliar stable carbon isotope ratio (δ13C) and stable nitrogen isotope ratio (δ15N) with foliar elemental contents and the variations of soil δ13C and δ15N along soil profiles at different successional stages.Important findings A significant positive correlation between foliar δ13C and foliar C:N was observed.In both litter and soil,the δ13C values tended to decrease along the forest succession,with the order as PF ＞ MF ＞ BF.Foliar δ15N was positively correlated with foliar N content.The δ15N values of litter and upper soil (0-10 cm) increased with successional status.Both soil δ13C and δ15N values increased with increasing soil depth at all three forests.Our results imply that 1) trade-off between water use efficiency and nitrogen use efficiency did not necessarily exist in subtropical forests of China;2) the
application of isotopic technique could assist understanding of the mechanisms
of
soil
carbon
accumulation
in
subtropical
forests,especially in old-grow forests;3) the 15N natural abundance of plant-soil continuum could be a potential indicator of soil nitrogen availability and ecosystem nitrogen saturation status. 【总页数】10页(533-542)
【关键词】稳定碳同位素比率;稳定氮同位素比率;演替;森林;鼎湖山 【作者】熊鑫;张慧玲;吴建平;褚国伟;周国逸;张德强
【作者单位】中国科学院华南植物园,广州510650;中国科学院大学,北京100049;中国科学院华南植物园,广州510650;中国科学院大学,北京100049;中国科学院华南植物园,广州510650;中国科学院大学,北京100049;中国科学院华南植物园,广州510650;中国科学院华南植物园,广州510650;中国科学院华南植物园,广州510650 【正文语种】中文 【中图分类】 【文献来源】
https://www.zhangqiaokeyan.com/academic-journal-cn_chinese-journal-plant-ecology_thesis/0201255519224.html 【相关文献】
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鼎湖山森林演替序列植物-土壤碳氮同位素特征
