氮添加对海南热带山地雨林固碳关键过程的影响——以优势植物厚壳桂和白颜树的光合为例  

Effects of nitrogen addition on the key carbon sequestration process in a tropical montane rainforest in Hainan Province of southern China:a case study of photosynthesis of dominant trees Cryptocarya chinensis and Gironniera subaequalis

作　　者：田地 林权虹 赵常提 朱瑞德 马素辉 俞庆水 吉成均[2] 沈海花 Tian Di;Lin Quanhong;Zhao Changti;Zhu Ruide;Ma Suhui;Yu Qingshui;Ji Chengjun;Shen Haihua(School of Forestry,Key Laboratory for Silviculture and Conservation of Ministry of Education,Beijing Forestry University,Beijing 100083,China;Institute of Ecology,College of Urban and Environmental Sciences,Key Laboratory for Earth Surface Processes of Ministry of Education,Peking University,Beijing 100871,China;Institute of Botany,Chinese Academy of Sciences,Beijing 100093,China)

机构地区：[1]北京林业大学林学院,森林培育与保护教育部重点实验室,北京100083 [2]北京大学城市与环境学院,地表过程分析与模拟教育部重点实验室,北京100871 [3]中国科学院植物研究所,北京100093

出　　处：《北京林业大学学报》2022年第10期93-101,共9页Journal of Beijing Forestry University

基　　金：中央高校基本科研业务费专项(PTYX202252);国家自然科学基金项目(32271680、31800397)。

摘　　要：【目的】植物光合作用是森林生态系统固碳的关键生理过程。探究氮沉降对热带森林生态系统中优势乔木叶属性和光合参数的影响,将为揭示热带树木对外源氮输入的响应过程、评估氮沉降背景下森林固碳潜力变化奠定基础。【方法】以海南尖峰岭热带山地雨林中的优势乔木树种厚壳桂和白颜树为研究对象,通过9年的氮添加试验,分析3种氮添加水平对优势树种重要叶属性和光合参数的影响。【结果】叶属性和光合参数在物种间呈现明显差异。对于植物叶属性,氮添加显著增加了厚壳桂的比叶面积与2个树种叶片中的氮磷比,但降低了叶绿素含量,并在一定程度上改变了叶片养分含量。对于植物光合,氮添加有促进蒸腾速率和气孔导度的趋势,但未显著影响光合作用参数(净光合速率、胞间CO_(2)浓度、最大羧化速率和最大电子传递速率)。【结论】总体上,9年氮添加尚未显著改变海南热带山地雨林中2个优势树种的光合作用过程。在大量野外监测的基础上,从植物叶功能属性−光合作用之间的耦合关系的角度,揭示热带树木对氮添加的响应机制,是下一步研究的重点方向。[Objective]Plant photosynthesis is a key physiological process for carbon sequestration in forest ecosystems.Here,we studied the effects of nitrogen deposition on leaf traits and photosynthetic parameters of dominant tree species in tropical forest ecosystems,aiming to lay a foundation for revealing the response process of tropical trees to exogenous nitrogen inputs and assessing the change of forest carbon sequestration potential in the context of nitrogen deposition.[Method]A nitrogen addition experiment was conducted for nine years to analyze the effects of three nitrogen addition levels on important leaf traits and photosynthetic parameters of two dominant tree species(i.e.,Cryptocarya chinensis and Gironniera subaequalis)in the tropical montane rainforest of Jianfengling,Hainan Province of southern China.[Result]Leaf traits and photosynthetic parameters showed significant differences between species.For plant leaf traits,nitrogen addition significantly increased specific leaf area of C.chinensis and nitrogen to phosphorus ratio of both species,decreased chlorophyll content,and altered leaf nutrient content to some extent.For plant photosynthesis,nitrogen addition tended to promote transpiration rate and stomatal conductance,but did not significantly affect photosynthetic parameters(including net photosynthetic rate,intercellular CO_(2) concentration,maximum carboxylation rate,and maximum electron transport rate).[Conclusion]Overall,9 years of nitrogen addition has not yet significantly altered leaf photosynthetic process of two dominant tree species in Hainan tropical montane rainforest.Based on extensive field monitoring,revealing the response mechanisms of tropical trees to nitrogen addition from the perspective of leaf functional traits-photosynthesis coupling is the next step of our research focus.

关 键 词：氮沉降 热带山地雨林 叶片 功能属性 光合 

分 类 号：S718.5[农业科学—林学]