贡嘎山峨眉冷杉成熟林碳利用效率季节动态及其影响因子  

Season dynamics of carbon use efficiency and its influencing factors in the old-growth Abies fabri forest in Gongga Mountain, western Sichuan, China

作　　者：舒树淼 朱万泽[1] 冉飞[1] 孙守琴[1] 张元媛 SHU Shu-Miao;ZHU Wan-Ze;RAN Fei;SUN Shou-Qin;ZHANG Yuan-Yuan(Institute of Mountain Hazards and Environment,Chinese Academy of Sciences,Chengdu 610041,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院、水利部成都山地灾害与环境研究所,成都610041 [2]中国科学院大学,北京100049

出　　处：《植物生态学报》2020年第11期1127-1137,共11页Chinese Journal of Plant Ecology

基　　金：国家重点研发计划(2017YFC0505004);四川省环境治理与生态保护重大科技专项(2018SZDZX0031)。

摘　　要：碳利用效率(CUE)是植被生态系统的一个重要功能参数,反映了植被生态系统的固碳能力,适用于分析不同时间段内器官、个体和群落等不同层次的碳收支趋势,因而有助于对陆地生态系统碳功能的确定与预测,引起了广泛关注。该研究采用生物计量法,测定和计算了川西贡嘎山东坡峨眉冷杉(Abiesfabri)成熟林树木不同器官的呼吸与净生产力动态,分析了乔木层及其各器官CUE动态及主要影响因子,并估算了乔木层不同径级树木CUE。主要结果:(1)乔木层各器官月呼吸速率与温度呈正相关关系,以细根月呼吸速率为最大;不同径级树木年呼吸量无显著差异,以小径级树木树干的年呼吸量为最小。(2)乔木层细根和树干月净初级生产力(NPP)均随温度增加而增加,以细根月NPP为最大。小径级树木年NPP最大,其针叶年NPP也显著高于中径级和大径级树木。(3)林分乔木层及其各器官CUE大多集中在0.30–0.60之间,其中细根、树干CUE具有相似的月变化动态,均随温度的升高而上升。不同径级树木CUE及树干和针叶CUE均随树木个体的增大而明显下降。(4)气温和土壤温度与乔木层树干和细根CUE呈正相关关系,而降水量与针叶CUE呈负相关关系。细根CUE与树干CUE呈正相关关系,与针叶CUE呈负相关关系。峨眉冷杉成熟林乔木层CUE主要取决于树干和细根CUE。该研究证实了川西亚高山暗针叶成熟林仍具有较强的碳汇功能,在区域碳储存和森林生态系统碳循环中发挥着极其重要的作用。Aims Carbon use efficiency(CUE), an important function parameter, reflects the carbon sequestration capacity of forest ecosystems. It is useful in analyzing the temporal dynamics of carbon budgets at the organ, individual and community scales. It can help to determine and predict the carbon sink/source of terrestrial ecosystems, which is a matter of widespread concern. Methods Using the biometric method, we measured and calculated the respiration and net productivity dynamics of different fir organs from an old-growth Abies fabri forest on Gongga Mountain in the eastern Qinghai-Xizang Plateau, China. We studied the CUE dynamics of the tree layer and its organs and analyzed their influencing factors. We also estimated the CUE of whole trees of different diameters at breast-height(DBH) classes. Important findings(1) Monthly respiration rates in both the tree layer and its organs are positively related to temperature, and fine roots have the highest respiration rate of all. There is no significant difference in the annual respiration of whole trees with different DBH classes, and the small DBH trees(30–40 cm) have the minimum annual stem respiration.(2) The monthly net primary productivity(NPP) of the fine root and whole stem in the tree layer increases with temperature, with the fine root accounting for the largest proportion. The small trees have the greatest annual NPP, and their needle NPP is also significantly higher than that of the medium DBH(50– 60 cm) and large DBH(75–90 cm) trees.(3) The CUE of the tree layer and its organs are mostly among 0.30 to 0.60. The monthly changes in the CUE of both fine roots and stems are similar, and their CUE increases with temperature. The CUE of trees and their organs all decrease significantly with tree growth.(4) The CUE of both the stems and fine roots is positively related with the air and soil temperature, while precipitaion has a positive effect on needle CUE. Fine root CUE has negative and positive effects on stem CUE and needle CUE, respectively. The tree laye

关 键 词：碳利用效率 净初级生产力 呼吸碳消耗 峨眉冷杉成熟林 贡嘎山 

分 类 号：S718.5[农业科学—林学]