南麂列岛夏季浮游植物群落演替特征及影响因子研究OA北大核心CSCDCSTPCD

This study systematically analyzed the structural characteristics of the phytoplankton community and their environmental drivers in the waters of the Nanji Islands during the summer months from 2013 to 2018.A total of 116 species belonging to 55 genera and 5 phyla were identified,with Bacillariophyta and Dinophyta being the dominant groups.As a representative dominant diatom species,Skeletonema costatum prevailed in most years.Ni-trogen and phosphorus nutrients played a key regulatory role in the phytoplankton community succession.High nitrogen and low phosphorus conditions favored the growth of dinoflagellates.In 2014,under such conditions,di-noflagellate abundance accounted for 54.44%of the total community proportion,whereas,in 2017,the relatively low nitrogen and high phosphorus conditions provided a suitable environment for the occurrence of a Skeletonema costatum red tide.Extreme climate events substantially influenced the community structure:El Niño/La Niña events altered the water temperature and nutrient concentrations,which resulted in noticeable changes in the abundance ratios of diatoms to dinoflagellates as well as shifts in the dominant species.These results indicate that the evolution of the summer phytoplankton community structure in the Nanji Islands from 2013 to 2018 was jointly driven by the red tide events,El Niño/La Niña events,and terrestrial inputs.Furthermore,dissolved oxygen,suspended solids,and nitrogen-phosphorus nutrients were identified as the key environmental factors that influence phytoplankton abundance and composition.This study provides data support and scientific references for the ecological protection and sustainable development of the Nanji Islands'marine environment.