荣成天鹅湖海草床及其邻近裸沙区浮游生物的时空变化特征

Spatial-temporal variation of characteristics of plankton in a seagrass bed and an adjacent area of bare sand in Swan Lake, Rongcheng, China

关键词:  海草床  浮游植物  浮游动物  群落结构  环境因子  天鹅湖

Key words:  Seagrass bed  Phytoplankton  Zooplankton  Community structure  Environmental factors  Swan Lake

摘要:

海草床是近海典型生态系统之一，为了解山东省荣成市天鹅湖鳗草(Zostera marina)海草床及其邻近裸沙区的浮游生物群落结构及时空变化特征，于2019年2月、5月、8月和11月，对天鹅湖鳗草海草床及其邻近裸沙区的浮游生物、海草床生态学特征及关键环境因子进行了周年调查，并应用典范对应分析(CCA)和冗余分析(RDA)探究了环境因子对浮游生物优势种的影响。结果显示，共发现浮游植物38种，隶属3门25属，其中，硅藻门(Bacilariophyta)种类最多(89.4%)，甲藻门(Dinophyta)次之(7.8%)；共发现浮游动物18种，幼虫3类，以甲壳动物(71.4%)为主；浮游生物种类数呈现显著的季节变化，且在11月达到最大值；海草床浮游植物和浮游动物的年平均丰度分别为5.4×104 cells/m3和1.6×104 ind./m3，是裸沙区浮游植物和浮游动物年平均丰度的1.4倍和1.5倍；典范对应分析和冗余分析显示，海草床浮游生物优势种主要与水温、海草床的植株密度及生物量显著相关，而裸沙区浮游生物优势种则主要与水温、pH值及氨氮含量等环境因子显著相关。结果表明，天鹅湖海草床相比裸沙区具有更丰富的浮游生物。本研究为深入了解海草床生态系统的结构和功能提供了基础数据。

Abstract:

Seagrass beds are a typical coastal ecosystem. To understand the temporal and spatial variation characteristics of the plankton community structure in a Zostera marina seagrass bed and an adjacent area of bare sand in Swan Lake, Rongcheng City, Shandong Province, an investigation of plankton diversity and abundance, ecological characteristics of the seagrass bed, and key environmental factors in the Z. marina seagrass bed and its adjacent bare sand area was conducted in February, May, August, and November in 2019. Canonical correspondence analysis (CCA) and redundancy analysis (RDA) were used to explore the influence of environmental factors on the diversity of plankton species. The results showed that there were 38 species of phytoplankton, belonging to 25 genera and three phyla, among which diatom species were the most abundant (89.4%), followed by dinoflagellates (7.8%). A total of 18 species of zooplankton and three species of larvae were identified (mainly crustaceans: 71.4%), and the number of plankton species was the highest in November. The annual average abundance of phytoplankton and zooplankton in the seagrass bed was 5.4×104 cells/m3 and 1.6×104 ind./m3, respectively, which were 1.4 times and 1.5 times higher than those in the bare sand area. The CCA and RDA analyses showed that the dominant plankton species in the seagrass bed were significantly correlated with water temperature, plant density, and biomass of seagrass beds, while the dominant plankton species in the bare sand area were mainly correlated with environmental factors such as water temperature, pH value, and ammonia nitrogen content. The results showed that the seagrass bed in Swan Lake supported a higher abundance and diversity of plankton compared with the bare sand area. This study provides baseline data for further elucidating the structure and function of the seagrass bed ecosystem.