基于森林冠层高度和异速生长方程的中国红树林地上生物量估算

Estimation of Mangrove Aboveground Biomass in China Using Forest Canopy Height through an Allometric Equation

红树林是一种高效率的滨海蓝碳生态系统,准确估算红树林地上生物量对研究碳循环和气候变化十分重要,获取中国红树林地上生物量将具有现实意义和应用价值。遥感技术便捷高效、观测范围广,能够服务于大尺度的生态系统监测。文章使用基于GEDI星载激光雷达反演的森林冠层高度数据和基于异速生长原理构建的红树林“树高-生物量”异速生长方程,估算2019年中国红树林地上生物量,进而分析其数量、空间分布特征及主要影响因素。结果显示,2019年中国红树林地上生物量总量和均值分别约为1974827 t和73.0 t/hm^(2);红树林分布的各省份(地区)的地上生物量均值在53.3~92.1 t/hm^(2),其中海南省的红树林地上生物量均值最高,达到92.1 t/hm^(2);中国红树林地上生物量的累积和分布受纬度和人为因素的影响。研究结果能够为后续红树林生态系统碳储量的核算提供数据基础和技术参考,也将有助于中国沿海红树林生态恢复和保护措施的制定,以及控制碳排政策的出台实施。

Mangroves,which have extremely high primary productivity,are efficient coastal blue carbon ecosystems.Aboveground biomass(AGB)is an important component of vegetation carbon pools.Thus,accurate estimation of mangrove AGB is critical for studying carbon cycle and climate change.While the practical significance and application of information obtained on mangrove AGB in China is apparent,studies of this nature in China at a national scale have rarely been reported.Remote sensing technology is convenient,efficient,has a wide observational range,and can be used for large-scale ecosystem monitoring.Canopy height is a structural parameter that is positively correlated with the AGB of vegetation.The Global Ecosystem Dynamics Investigation(GEDI)spaceborne Light Detection and Ranging(LiDAR)satellite,launched in recent years,is able to obtain vegetation canopy height.This study employed forest canopy height derived from GEDI satellitebased LiDAR and an allometric equation based on the allometric theory to estimate mangrove AGB in China in 2019,and the quantitative and spatial distribution of mangrove biomass and their main influencing factors were analyzed.The results showed that the total and mean AGB of mangroves in China in 2019 were about 1,974,827 t and 73.0 t/hm^(2),respectively.Guangdong-Hong Kong-Macao area showed the largest total mangrove AGB,reaching 843,836 t.The mean values of AGB in each province(region)with mangrove ecosystems nationwide ranged from 53.3 to 92.1 t/hm^(2),of which the largest was found in Hainan Province,reaching 92.1 t/hm^(2).In Hainan,Taiwan,and Fujian provinces,mean mangrove AGB was higher than the national mean.Considering nature reserves,the mean AGBs of mangroves in Neilingdingdao-Futian and Mai Po mangrove nature reserves in Shenzhen Bay in the Guangdong-Hong Kong-Macao area and Dongzhaigang mangrove nature reserve in Hainan province were relatively high,with values greater than 110 t/hm^(2).The accumulation and distribution of mangrove AGB in China are affected by latitude and anthropogenic factors.This study provides a comprehensive analysis of mangrove AGB in China based on remote sensing and an allometric equation and can provide a database and technical reference for estimating carbon storage in mangrove ecosystems.It will also contribute to the implementation of ecological restoration and protection measures for coastal mangroves,as well as carbon emission control in China.