Page 50 - 《广西植物》2025年第8期
P. 50
1 4 1 6 广 西 植 物 45 卷
( 1. College of Life Sciencesꎬ Guangxi Normal Universityꎬ Guilin 541006ꎬ Guangxiꎬ Chinaꎻ 2. Guangxi Key Laboratory of Plant Conservation and
Restoration Ecology in Karst Terrainꎬ Guangxi Institute of Botanyꎬ Guangxi Zhuang Autonomous Region and Chinese Academy of Sciencesꎬ Guilin
541006ꎬ Guangxiꎬ Chinaꎻ 3. Guangxi Guilin Urban Ecosystem National Observation and Research Stationꎬ National Forestry and Grassland
Administrationꎬ Guilin 541006ꎬ Guangxiꎬ Chinaꎻ 4. Guangxi Zhuang Autonomous Region Forestry Research Instituteꎬ Nanning 530002ꎬ
Chinaꎻ 5. Nanning Eucalypt Plantation Ecosystem Observation and Research Station of Guangxiꎬ Nanning 530002ꎬ China )
Abstract: Estimating gross primary productivity (GPP) of vegetation is essential for exploring the flow and storage of
carbon in terrestrial ecosystems and helps to explain the factors influencing global climate change. Remote sensing GPP
models are important tools for simulating GPP at regional and global scales. In order to clarify the applicability of two
remote sensing GPP modelsꎬ TG and VIꎬ to two typical forests in the central subtropics as well as the simulation effects
of different model parameter calibration methodsꎬ the present study was conducted to calibrate the sensitive parameters of
the TG and VI models based on the ground ̄based meteorological data and MODIS data using flux ̄tower measured GPP at
both annual and seasonal scalesꎬ and then the GPPs of the regenerated evergreen broad ̄leaved forest and eucalyptus
plantation in the central subtropics were simulatedꎬ and the simulation accuracies of the TG and VI models in these two
ecosystems were compared and analyzed. The results were as follows: (1) The simulation accuracy of the models was
improved after parameter calibrationꎬ especially in the case of seasonal calibrationꎬ the simulation accuracy was
significantly better than that of the year ̄round calibration. (2) The correlation between the input parameters of the TG
2
and VI models and the measured GPP of the two ecosystems was high (R > 0.70ꎬP< 0.001). (3) The correlation
between the simulated and measured GPPs of the TG model was higher than that of the VI modelꎬ and the simulation
error of the TG model was the smallest in the regenerated evergreen broad ̄leaved forest ecosystem (ïRE ï< 2%). In
conclusionꎬ both models have the potential to be applied in two typical forests in the central subtropicsꎬ and the
simulation effect of the TG model is better than that of the VI model.
Key words: gross primary productivity (GPP)ꎬ remote sensingꎬ eddy covariance methodꎬ land surface temperatureꎬ
enhanced vegetation index
陆地生态系统作为净碳汇在全球碳循环中发 的空间分辨率有限ꎬ只能估算站点尺度的 GPPꎮ
挥着重要作用ꎬ抵消了过去几十年人类活动所排 当前基于涡度相关法的碳通量地面观测站点ꎬ远
放的 10% ~ 60% 的 CO ( Heimann & Reichsteinꎬ 未达 到 区 域 或 更 大 尺 度 GPP 估 算 研 究 的 要 求
2
2008ꎻ Friedlingstein et al.ꎬ 2020)ꎮ 植物通过光合 (Griebel et al.ꎬ 2016)ꎮ
作用在单位时间内固定的有机碳量被称为生态系 卫星遥感技术可以实现区域乃至全球的观测
统 的 总 初 级 生 产 力 ( gross primary productivityꎬ 覆盖能力ꎬ提供较大时空尺度的数据产品ꎬ但其观
GPP)ꎬ而光合作用是生态系统中主要的固碳途径 测精度不及涡度相关法( 张晓娟等ꎬ2022)ꎮ 因此ꎬ
(方精云等ꎬ2001)ꎮ GPP 决定了进入陆地生态系 将遥感资料和通量塔观测数据相结合ꎬ可以发展
统的初始能量和物质ꎬ是陆地生态系统碳循环中 陆地 GPP 估算模型ꎬ弥补涡度相关法和遥感技术
的重要通量ꎮ 准确测定和估算 GPPꎬ是理解碳收 分别在空间尺度和观测精度上的缺陷( Liu et al.ꎬ
支、气候变化及生态系统服务的基础ꎬ对于促进我 2014)ꎮ 以遥感数据为主的 GPP 模型减少了对地
们对全球碳循环的理解及预测气候反馈至关重要 面气象数据的依赖ꎬ更加适用于下垫面复杂、地势
(Zhu et al.ꎬ 2024)ꎮ 涡度相关法( eddy covariance 多变 的 区 域 ( Tian et al.ꎬ 1999ꎻ Sjöström et al.ꎬ
method)在生态系统尺度上为测量 GPP 提供了一 2013ꎻ Verma et al.ꎬ 2014)ꎮ Sims 等(2008)提出的
种可靠的间接方法( Beer et al.ꎬ 2010ꎻ于贵瑞等ꎬ TG 模型(temperature and greenness model)ꎬ利用归
2014)ꎮ 目前ꎬ基于涡度相关法的测量结果已被广 一 化 处 理 后 的 增 强 型 植 被 指 数 ( enhanced
泛应用于生态系统碳循环研究ꎬ并被视为生态系 vegetation indexꎬ EVI) 和 地 表 温 度 ( land surface
统尺度的碳通量真值ꎬ用于对其他测量方法的结 temperatureꎬ LST) 模拟北美地区的常绿阔叶林和
果进行验证(朴世龙等ꎬ2022)ꎮ 但是ꎬ涡度相关法 针叶林的总初级生产力ꎮ Wu 等(2010) 提出了 VI

