长江口羽状锋海区浮游植物的生态研究

AN ECOLOGICAL STUDY ON PHYTOPLANKTON IN FRONTAL REGION OF CHANGJIANG ESTUARINE AREA

丰、枯水期的数量均值分别为２５０５．４×１０￣３个／米￣３（１９８８年８月）、３０３．５×１０￣３个／米￣３（１９８８年１２月）和１８９２２２．０×１０￣３个／米￣３（１９８９年８月），平面分布的斑块现象明显，丰、枯水期的数量密集区主要形成于表层盐度２５为中心的河口羽状锋锋面一带及其东侧海区。在影响研究海区浮游植物数量时间和空间分布的诸多因素中，长江径流量的变动是一个至关重要的因素。种类组成隶属于河口型的生态组成模式，河口沿岸低盐种是浮游植物群落的主要成份，决定着长江口浮游植物群落的性质。河口羽状锋海区存在着一个生物地球化学作用带，其位置的变动主要取决于锋面位置的变动。根据浮游植物数量密集区，ｐＨ和溶解氧的异常区的位置，可大致推断出长江口羽状锋的位置及其走向。

The mean values of phytoplankton during flood and dry periods are respec-tively 2505.4×10￣3 ind/m￣3(1988,8)、303.5×10￣3 ind/m￣3(1988,12)and 189222.0×10￣3 ind/m￣3(1989,8).The spot masses at horizontal plane become obvious.During there periods,high value region is mainly formed at front of estuarine area and its eastern,where thesurface salinity is about 25.In the different factors which exert an influence on time andspatial distribution of phytoplankton in studying area,the changjiang runoff fluctuation isan most important factor.The species composition belong to ecological composition modelof estuarine area.Low salinity species of estuarine coast are main part of phytoplanktoncommunities, which decides community feature.In eatuarine front area,there it exists abiogeographic chemical role zone.Its location variation is depended on the variation offrontal location.Accoarding to quantitative density zone and location of abnormal zone ofph and DO,the location and flow of estuarine front could be generly deduced.