植物生态学报 ›› 2019, Vol. 43 ›› Issue (12): 1048-1060.DOI: 10.17521/cjpe.2019.0221

• 研究论文 • 上一篇    下一篇

青藏高原东缘主要针叶树种叶片碳氮磷化学计量分布格局及其驱动因素

蔡琴1,2,丁俊祥1,2,张子良1,胡君1,2,汪其同1,2,尹明珍1,2,刘庆1,尹华军1,*()   

  1. 1 中国科学院成都生物研究所, 中国科学院山地生态恢复与生物资源利用重点实验室, 生态恢复与生物多样性保育四川省重点实验室, 成都 610041
    2 中国科学院大学, 北京 100049
  • 收稿日期:2019-09-27 接受日期:2019-12-05 出版日期:2019-12-20 发布日期:2020-01-26
  • 通讯作者: 尹华军 ORCID:0000-0001-9202-8286
  • 基金资助:
    第二次青藏高原综合科学考察研究专题(2019QZKK0301)(STEP2019QZKK0301);中国科学院前沿科学重点研究项目(QYZDB-SSW-SMC023);国家自然科学基金(31872700);国家自然科学基金(31700387);四川省重点研发项目(18ZDYF1821)

Distribution patterns and driving factors of leaf C, N and P stoichiometry of coniferous species on the eastern Qinghai-Xizang Plateau, China

CAI Qin1,2,DING Jun-Xiang1,2,ZHANG Zi-Liang1,HU Jun1,2,WANG Qi-Tong1,2,YIN Ming-Zhen1,2,LIU Qing1,YIN Hua-Jun1,*()   

  1. 1 Chengdu Institute of Biology, Chinese Academy of Sciences, Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization of Chinese Academy of Sciences, and Ecological Restoration and Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu 610041, China
    2 University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2019-09-27 Accepted:2019-12-05 Online:2019-12-20 Published:2020-01-26
  • Contact: YIN Hua-Jun ORCID:0000-0001-9202-8286
  • Supported by:
    Supported by the Second Qinghai-Xizang Plateau Scientific Expedition and Research Program(STEP2019QZKK0301);Frontier Science Key Research Programs of Chinese Academy of Science(QYZDB-SSW-SMC023);National Natural Science Foundation of China(31872700);National Natural Science Foundation of China(31700387);Key Research Programs of Sichuan Province(18ZDYF1821)

摘要:

理解植物叶片化学计量特征及其驱动因素对认识植物种群分布规律及预测植物对环境变化响应具有重要意义。该研究采集了青藏高原东缘针叶林84个样点共29种主要针叶树种叶片, 探讨该区域常绿针叶树种叶片碳(C)、氮(N)、磷(P)化学计量特征和分布格局及其驱动因素。结果表明: (1)在科和属水平上, 不同针叶树种叶片C、N含量和C:N差异显著; 叶片N:P < 14, 表明该区域针叶树种主要受N限制。(2)叶片N、P含量在环境梯度上表现出一致的分布规律: 均呈现出随纬度和海拔增加而显著降低, 随年平均气温(MAT)和年降水量(MAP)增加而显著增加的趋势; 而叶片C含量与纬度、海拔、MATMAP均未表现出显著相关性。(3)叶片C:N、C:P呈现出与N、P含量变化相反的分布格局: 均随纬度和海拔增加而显著增加, 随MATMAP增加而显著降低; 而叶片N:P与海拔、MATMAP均无显著相关性。(4)进一步分析表明, 叶片C、N、P含量及其化学计量比的主要驱动因素不尽相同。具体而言: 土壤特性是叶片C含量和N:P变异的主要驱动因子, 而叶片N、P含量和C:N、C:P的变异主要由气候因素决定。总之, 该区域针叶树种叶片化学计量沿环境梯度的变异规律有力地支持了温度生物地球化学假说, 在一定程度上丰富了对环境变化下植物叶片化学计量分布格局及其驱动机制的认识。

关键词: 叶片化学计量, 分布格局, 驱动因素, 青藏高原东缘, 亚高山针叶林

Abstract:

Aims The leaf stoichiometry and potential driving factors play a vital role in understanding the distribution patterns of plant community and predicting the plant responses to environmental changes. In this study, we aimed to investigate the spatial distribution patterns and driving factors of leaf carbon (C), nitrogen (N) and phosphorus (P) stoichiometry of coniferous species on the eastern Qinghai-Xizang Plateau, China.
Methods We collected leaf and soil samples from 29 coniferous tree species at 84 sampling sites on the eastern Qinghai-Xizang Plateau. Linear fitting was used to analyze the variation patterns of leaf stoichiometry along geographical and climatic gradients. Partial redundancy analysis was used to characterize the relative contributions of climate and soil factors to leaf stoichiometry variation patterns.
Important findings (1) At the level of family and genus, C and N concentrations as well as C:N of leaves were significantly different across distinct conifer species. The leaf N:P was less than 14, indicating that conifer species in the study region were mainly N-limited. (2) Leaf N and P concentrations showed a consistent distribution pattern along environmental gradients. Specifically, N and P concentrations of leaves were significantly decreased with elevated latitude and altitude, while remarkably increased with the increase of mean annual temperature (MAT) and mean annual precipitation (MAP). In comparison, leaf C concentration had no significant correlation with latitude, altitude, MAT or MAP. (3) The leaf C:N and C:P showed an opposite distribution pattern with leaf N and P concentrations, which significantly increased with elevated latitude and altitude, while markedly declined with the increase of MAT and MAP. Leaf N:P had no significant correlation with altitude, MAT or MAP. (4) The main driving factors of leaf C, N, P concentrations and their stoichiometric characteristics were different. Specifically, soil properties were the main driving factors accounting for the variations of leaf C concentration and N:P. The variations of leaf N and P concentrations as well as ratios of C:N and C:P were primarily explained by climatic factors. Collectively, variations of leaf stoichiometry of coniferous species along environmental gradients in the study region provided a compelling support for the Temperature Biogeochemistry Hypothesis. These findings largely improved the understanding of the distribution patterns and driving mechanism of leaf stoichiometry under changing environments.

Key words: leaf stoichiometry, distribution pattern, driving factor, the eastern Qinghai-Xizang Plateau, subalpine coniferous species