陆地生态系统年总初级生产力时空二维变异的生物地理学机制研究

The global pattern and dynamics of annual gross primary productivity (AGPP) in terrestrial ecosystems is comprehensively represented by its two dimensional variability, which is comprised by the interannual variability and the geospatial variability of AGPP. Investigating the causes, variations, shaping mechanisms, quantitatively expressions, and their interactions is a frontier area of biogeographical research, which also serves as a basis for assessing the global pattern and dynamics of terrestrial ecosystem productivity and carbon sequestration function. Long-term network observations provides a data basis for investigating the biogeographical mechanisms of AGPP two dimensional variability in terrestrial ecosystems. Based on the community photosynthetic capacity theory and the community light use efficiency theory, we employed the integrating analysis on the interaction among environmental factors, ecosystem properties, and the spatial-temporal variability of AGPP, which primarily aims to reveal the ecophysiological mechanism controlling the AGPP interannual variation, the biogeographical mechanisms dominating the AGPP geospatial variability, and the dual effects of ecophysiology and biogeography on the AGPP two-dimensional variability. The ecological comprehensive information mechanism model is thus developed, which aimed to assess the spatial pattern and the dynamics of AGPP in China and globally. Our results would provide the scientific knowledge, model, and data basis for assessing the global productivity and carbon sequestration function in terrestrial ecosystems.

陆地生态系统年总初级生产力（AGPP）的全球格局和动态变化是其年际变异与地理空间变异构成的二维变异的综合体现，研究AGPP二维变异的成因、变异规律、形成机制、定量表达及相互作用关系，是评估陆地生产力和固碳功能全球格局及动态变化的基础，也是生物地理学科学研究的前沿领域。长期联网观测数据的积累，为开展生态系统AGPP二维变异的生物地理学机制研究提供了数据保障。本研究以群落光合能力理论及群落光能利用率理论为依据，采用整合分析环境要素-生态系统属性-植被AGPP时空格局相互关系的技术途径，重点揭示控制AGPP年际变异的生理生态学机制，地理空间变异的生物地理学机制，以及控制AGPP二维变异的生理生态学与生物地理学双重作用机制，研发定量评估AGPP二维变异的全信息生态学机制模型，评估中国及全球AGPP的动态变化和空间格局，为评估陆地生态系统生产力、固碳功能提供科学知识、模型工具和基础数据。

基于FLUXNET和ChinaFLUX的联网观测，获取了北半球陆地生态系统105个站点867个站点年的GPP观测数据，在此基础上，分析了年总初级生产力AGPP的时空变异特征及其对气候要素时空变化的响应差异。基于群落光合能力理论，提取了各站点年的GPP季节变化属性参数，并探讨了三个GPP季节变化属性参数的时空变异特征和影响因素，及其对年总初级生产力时空变异的影响；基于光能利用率理论，提取了各站点年的光能利用率参数，并探讨了两个光能利用率参数的时空变异特征和影响因素，及其对年总初级生产力时空变异的影响。最后，基于“气候要素-生态系统属性-生态系统年总初级生产力”的理论关系，揭示了控制AGPP年际变化的生态学机制和地理空间变异的生物地理学机制，阐明了AGPP时空二维变异的生态学与生物地理学双重作用机制，并基于该机制对生态系统AGPP进行了初步评估，为AGPP的时空变异提供了新的研究视角。项目资助发表学术论文8篇，其中第一标注SCI论文1篇，第二标注SCI论文3篇，完成预期目标。