粤港澳大湾区红树林时空分布演变及现存林龄遥感分析

红树林作为热带、亚热带以红树植物为主体的海岸带生态系统，是重要的海岸湿地类型之一。本文使用多源、多时相遥感数据，形成了1969-2020年粤港澳大湾区岸线、围填海、养殖区、红树林分布数据图集，并利用联合红树林识别指数(CMRI)对大湾区现存红树林进行时序分析得到红树林林龄数据集。结果表明，通过多源遥感数据解译得到现存红树林数据集，结合CMRI时序数据可以建立现存红树林变迁历史，进而有效估算红树林林龄。粤港澳大湾区红树林的时空分布发生了明显变迁，现存红树林面积约为3 316 hm²，大湾区内部各地区存量林龄差异较大，整体林龄均值为20 a。近50年间，岸线整体向海移动，岸线变迁、围填海和养殖区变化显著影响红树林面积、空间分布及林龄大小，人工种植是近20年红树林恢复的主因。

Analysis of spatial-temporal distribution evolution and age of existing mangrove forests in Guangdong-Hong Kong-Macao Greater Bay Area using remotely sensed data

Mangroves forests, as a coastal zone ecosystem dominated by mangrove plants in the tropics and subtropics, are one of the important coastal wetland types. In this paper, multi-source and multi-phase satellite data were used to form a data atlas of shoreline, reclamation, aquaculture area, mangrove distribution in the Guangdong-Hong Kong-Macao Greater Bay Area from 1969 to 2020, and the time series analysis of the evolution of mangroves in the Greater Bay Area was obtained by using the combine mangrove recognition index (CMRI). The results show that the existing mangrove forests data set can be obtained by interpreting the multi-source remote sensing data, and the CMRI time series data can establish the history of the existing mangrove forest change, and then effectively estimate the mangrove forest age. The temporal and spatial distribution of mangroves in the Guangdong-Hong Kong-Macao Greater Bay Area has undergone obvious changes, with the existing mangroves being about 3 316 hm2, and the existing forest age in various regions in the Greater Bay Area is quite different, and the overall average forest age is 20 a. In the past 50 years, the shoreline as a whole has moved towards the sea, and the changes in shoreline, reclamation, and breeding areas have significantly affected the area, spatial distribution, and age of mangroves. Artificial cultivation has been the main reason for the restoration of mangroves in the past 20 years.