钦江河口潮滩红树林群落空间分布

Mangrove community is a special ecosystem along tropical and subtropical estuaries. It has important values in attenuating large waves, promoting silting, and storing carbon. However, due to the global sea level rise and human disturbances, mangrove habitats have been destroyed with fragile community structures. Therefore, based on the UAV orthophoto image with field verification, historical remote sensing images, water salinity, and sediment samples in tidal flats along the Qinjiang estuary, the spatial distribution patterns of mangrove community in the tidal flat and associated influence factors of the Qinjiang estuary were analyzed. The results are as follows: (1) Tidal flats of the Qinjiang estuary mainly consist of A. corniculatum and S. apetala, where the “mangrove pure forest community” with A. corniculatum is an absolutely dominant species in this area. Meanwhile, gradually developed patterns from “mangrove pure forest community” in the estuarine tidal flats are found in the combination of “mangrove plant-semi-mangrove plant” and “mangrove plant-semi-mangrove plant-non-mangrove plant” in the tidal reach. (2) A. corniculatum is the frontier pioneer tree species of the seaward grown mangroves in the Qinjiang estuary. The forefront elevation of the A. corniculatum biennial seedling distribution is 0.11 m below local sea level, and the forefront elevation of A. corniculatum viviparous seedling distribution is 0.37 m below local sea level. Meanwhile, the distributed limit of the mangroves in the upstream of the Qinjiang Estuary is A. corniculatum, where the location of distribution limit in viviparous seedlings in that year is 10.18 km away from HS00 station. (3) The tidal water level and salinity of the Qinjiang estuary are the main driving factors for the distribution of mangrove communities, and the growth and development of mangrove plants were determined by the variations in grain size of sediments. These findings can provide theoretical and technical guidance for the present ecological restoration projects of mangrove communities in the mountainously tropical- estuaries of the world.