基于光能利用率推导光合最适气温以改进生态系统生产力估算

doi:10.1093/jpe/rtag153

基于光能利用率推导光合最适气温以改进生态系统生产力估算

收稿日期:2025-11-28 接受日期:2026-06-13

Deriving optimal air temperature from light use efficiency to improve ecosystem productivity estimates

Suning Chen ^1,2, Mingchun Wu ^1,2, Peilin Wang ^1,2, Yaojie Liu ⁴, Linsheng Wu^1,2, Yongguang Zhang^1,2,3, Zhaoying Zhang^1,2*

¹ International Institute for Earth System Sciences, Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application, Nanjing University, Nanjing, Jiangsu 210023, China
² Jiangsu International Joint Carbon Neutrality Laboratory, Nanjing University, Nanjing, Jiangsu 210023, China
³ Frontiers Science Center for Critical Earth Material Cycling, Nanjing University, Nanjing, China
⁴ School of Geographical Sciences, Nanjing University of Information Science and Technology, Nanjing 210044, China

Received:2025-11-28 Accepted:2026-06-13
Supported by:
This research was supported by the National Natural Science Foundation of China (42522108, 42125105, 42471405, 42501489, 42201398), the Natural Science Foundation of Jiangsu Province (BK20240068), the Fundamental Research Funds for the Central Universities-Cemac “GeoX” Interdisciplinary Program (No. 2024300245), the Fundamental Research Funds for the Central Universities (0209-14380115) and the Young Elite Scientists Sponsorship Program by CAST (No. YESS20240694).

摘要/Abstract

摘要： 准确表征光合最适温度（T_opt）是精确预测陆地生态系统碳吸收的关键，传统的估算方法通常以总初级生产力（GPP）峰值对应的气温作为生态系统尺度的最适温度，但该方法会受到辐射、水分和物候同步变化的影响。本文提出一种具备生理学基础的最适温度计算方法，将T_opt定义为光能利用率（LUE）达到最大值时的对应气温，从而分离光合作用本身的内在温度响应特征。基于该方法，我们利用131个通量观测站点数据推导得到了光合最适温度（T_opt-LUE）。将植被光合模型（VPM）中原有按生物群系设定的固定参数T_opt替换T_opt-LUE后，GPP估算精度得到显著提升，模型决定系数R²达0.71，均方根误差（RMSE）为1.93 gC· m^-2· d^-1。而固定参数方案的R²仅为0.62，RMSE为2.84 gC· m^-2· d^-1。与基于增强型植被指数（EVI）的方法（RMSE=2.02 gC· m^-2· d^-1）和基于GPP峰值的方法（RMSE=2.06 gC· m^-2·d^-1）相比，本方法的RMSE分别降低了4.5%和6.3%。随后，我们利用气象数据和植被参数构建随机森林模型，生成了2001—2020年全球尺度动态光合最适温度数据集。结果显示，在全球约94%的植被覆盖区域，传统固定参数方法系统性高估了光合最适温度，平均偏差约为10℃。全球光合最适温度呈现出清晰的纬度梯度和生物群系分异特征，并与区域水热条件密切相关，为生态系统光合作用普遍存在热驯化现象提供了实证依据。过去二十年间，全球光合最适温度平均每年升高0.021±0.102℃，这一变化反映了生态系统对长期气候变化的热驯化响应，表明其适应过程具有可量化特征。将动态最适温度数据集引入VPM模型后，模型得到的碳吸收空间分布格局得到修正。热带地区原先显著的高估现象得到缓解（高估幅度约5 gC· m^-2· d^-1），同时改善了寒冷地区以及中国、印度、欧洲等区域的低估偏差。总体而言，本研究建立了一套具有机理基础的生态系统热驯化量化框架，为提升陆地碳循环模型中温度响应过程的模拟能力提供了新的方法支撑。

关键词: 光合最适温度, 光能利用率, 总初级生产力, 热驯化, 植被光合模型

Abstract: Accurately representing photosynthetic optimum temperature (T_opt) is essential for predicting terrestrial carbon uptake, yet conventional ecosystem-scale estimates based on peak gross primary productivity (GPP) are confounded by concurrent variations in radiation, moisture and phenology. Here, we develop a physiologically grounded approach that defines T_opt as the air temperature where light use efficiency (LUE) reaches its maximum, thereby isolating the intrinsic thermal response of photosynthesis. We derived efficiency-based T_opt (T_opt-LUE) from 131 flux observation sites. By replacing biome-based T_opt used in Vegetation Photosynthesis Model (VPM), we significantly improved GPP estimation (R² = 0.71, RMSE = 1.93 gC m^-2 d^-1) compared to the biome-based approach (R² = 0.62, RMSE = 2.84 gC m^-2 d^-1). We then used a Random Forest framework to generate global and time-varying T_opt-LUE fields (2001–2020). The results revealed that biome-based T_opt systematically overestimated T_opt-LUE across ~94% of global vegetated areas, with a mean bias of ~10°C. The global T_opt-LUE exhibit clear latitudinal gradients and biome‐specific contrasts, providing evidence for widespread thermal acclimation of ecosystem photosynthesis. This acclimation is reflected in a mean increase in T_opt-LUE of 0.021 ± 0.102 °C per year, underscoring a measurable response to long-term climate changes. When integrated into VPM, the dynamic T_opt-LUE fields reshape the spatial pattern of simulated carbon uptake, mitigating overestimation in tropical areas (~5 gC m^-2 d^-1) and enhancing underestimation in frigid areas and temperate regions including China, India and Europe. This study established a mechanistically grounded framework for quantifying ecosystem thermal acclimation, advancing the representation of temperature responses in terrestrial carbon cycle models.

Key words: Photosynthetic optimum temperature, Light use efficiency, Gross primary productivity, Thermal acclimation, Vegetation Photosynthesis Model

. 基于光能利用率推导光合最适气温以改进生态系统生产力估算[J]. Journal of Plant Ecology, DOI: 10.1093/jpe/rtag153.

Suning Chen, Mingchun Wu, Peilin Wang, Yaojie Liu, Linsheng Wu, Yongguang Zhang, Zhaoying Zhang. Deriving optimal air temperature from light use efficiency to improve ecosystem productivity estimates[J]. J Plant Ecol, DOI: 10.1093/jpe/rtag153.

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