喀斯特山地不同退化植被下烟管荚蒾氮同位素组成的季节变化  

Seasonal Variation of Nitrogen Isotopic Composition in the Leaves of Viburnum utile from Different Degraded Karst Plant Communities

作　　者：罗绪强 张桂玲[2,3] 杨鸿雁[1] 邓家彬 刘兴 阮英慧 廖晶晶 LUO Xu-qiang;ZHANG Gui-ling;YANG Hong-yan;DENG Jia-bin;LIU Xing;RUAN Ying-hui;LIAO Jing-jing(School of Geography and Resources,Guizhou Education University,Guiyang 550018,China;Karst Ecosystem Observation Research Station in Puding,Chinese Academy of Sciences,Puding 562100,China;School of Chemistry and Materials Science,Guizhou Education University,Guiyang 550018,China)

机构地区：[1]贵州师范学院地理与资源学院,贵阳550018 [2]中国科学院普定喀斯特生态系统观测研究站,普定562100 [3]贵州师范学院化学与材料学院,贵阳550018

出　　处：《科学技术与工程》2020年第11期4243-4249,共7页Science Technology and Engineering

基　　金：国家自然科学基金(41563007);贵州省优秀青年科技人才培养对象专项资金(黔科合人字[2015]21号);贵州省优秀科技教育人才省长资金(黔省专合字[2012]80号);贵州省高层次创新型人才资金(黔人领发[2015]3号)。

摘　　要：为探讨喀斯特灌木丛优势树种烟管荚蒾(Viburnum utile)叶片稳定氮同位素组成的季节变异特征及其影响因素,以喀斯特高原贵州省清镇市王家寨峰丛洼地小流域为例,选取流域内稀疏灌草丛、草灌丛、灌丛3种植被类型下的常绿树种烟管荚蒾为具体研究对象,分别在4月(生长初期)、7月(生长旺盛期)、9月(生长晚期)和12月(生长停滞期)对其叶片稳定氮同位素组成和N、P、K、Ca、Mg、Fe、Mn、Cu、Zn元素含量进行测定分析。结果表明:研究区烟管荚蒾叶片的δ^15N在不同群落间和不同坡位间均无显著差异(P>0.05),群落间的变化趋势为灌丛<稀疏灌草丛<草灌丛,坡位间的变化趋势为中坡<下坡<上坡,变化范围为-3.28‰^-0.59‰,平均值为-2.22‰;烟管荚蒾叶片δ^15N值在不同群落中均表现出9月最负而12月最正的特征,变化趋势均为9月<7月<12月,但仅在草灌丛群落中的7月与12月间和9月与12月间有显著差异(P<0.05),在其他群落中各月份间的差异均不显著(P>0.05),同一生长期内不同群落间、不同坡位间的差异也不显著;研究区植被类型、坡位和季节对烟管荚蒾叶片δ^15N的交互影响均不显著,说明烟管荚蒾对生境恶劣的喀斯特环境具有特殊的适应能力;烟管荚蒾叶片的δ^15N与Fe、Mn含量密切相关,同时受N、P、K、Fe、Mn、Cu、Zn元素化学计量比的影响,说明其叶片δ^15N值的变化主要受自身氮生理代谢过程的控制;研究区9月温暖湿润和12月干旱寒冷的气候特征可能是导致烟管荚蒾叶片δ^15N在9月最负和12月最正的主要原因。To investigate the seasonal variation and the corresponding factors on stable nitrogen isotope compositions of the leaves of Viburnum utile, a dominant species of shrubbery in Karst areas, the nitrogen stable isotope compositions and the contents of N, P, K, Ca, Mg, Fe, Mn, Cu, and Zn of the leaves samples of V. utile, collected from four growth phases, i.e., the initial growth phase(April), vigorous growth phase(July), late growth phase(September) and lag phase(December) of sparse vegetation, shrub grassland, and shrubs in Wangjiazhai, a small watershed of the Karst plateau located in Qingzhen City, Guizhou Province, were determined and analyzed. Results indicate that the δ^15N values of the leaves sampled in both multi-communities and different slope locations ranged from-3.28‰ to-0.59‰ in average of-2.22‰, which was indistinctive(P>0.05). Particularly, the variation in multi-communities was in an order of shrubs < sparse vegetation < shrub grassland, and that in different slopes was middle slope < downhill slope < uphill slope. The δ^15N value of leaves sampled from all the communities presented the most negative one in September and the most positive one in December with a similar variation trend of September < July < December. Moreover, the seasonal variation of δ^15N values was significant(P < 0.05) only in shrub grassland that produced between July and December and between September and December but indistinctive(P > 0.05) in the other communities and in the same growth phase of all communities and slope positions. Communities, slope positions, and seasons showed indistinctive influence on the δ^15N values of V. utile, indicating that the V. utile can well adapt to the harsh environment in karst areas. The δ^15N values of the leaves were highly related to Fe and Mn contents and influenced by the stoichiometric ratio of N, P, K, Fe, Mn, Cu and Zn, demonstrating that the variation of the δ^15N values was dominated by the metabolic process of nitrogen. Therefore, the diverse climate, being warm an

关 键 词：稳定性氮同位素比率 季节变化 烟管荚蒾 喀斯特退化植物群落 元素化学计量比 

分 类 号：Q948.112[生物学—植物学] X142[环境科学与工程—环境科学]