南海北部及台湾海峡夏季自养与异养区域的分布

Abstract

采用黑白瓶方法,在2012年夏季测定了台湾海峡及南海北部16个站位群落总的初级生产力(grOSS PrIMAry PrOduCTIOn,gPP)和群落呼吸(COMMunITy rESPIrATIOn,Cr),总的初级生产力gPP水柱积分平均值为106.6±7.51MMOl O2 M–2·d–1(MEAn±SE,以下同),群落呼吸Cr平均为131.1±5.95MMOl O2 M–2·d–1,净群落生产力(nET COMMunITy PrOduCTIOn,nPP)变化范围为-179.0~377.6MMOl O2 M–2·d–1(中值为-40.4MMOl O2 M–2·d–1)。受上升流的影响,琼东海域呈现明显的自养状态。在珠江口,由于珠江冲淡水的流入,该区域也呈现自养状态。相反,台湾海峡近岸以及粤东近岸均为异养区域。由此可见,异养区域的群落呼吸并不是完全由本地初级生产力决定,有机碳在空间上的输送对海洋浮游生物群落新陈代谢的影响可能极为重要。

We investigated the metabolic states of plankton communities in the Taiwan Strait and the northern South China Sea by measuring gross primary productivity(GPP),community respiration(CR) and bacterial production(BP) at 16 stations in these areas.GPP averaged 106.6 mmol O2 m-2·d-1 with a standard error of 7.51 mmol O2 m-2·d-1.CR averaged 131.1 mmol O2 m-2·d-1with a standard error of 5.95 mmol O2 m-2·d-1.Net community productivity varied from-179.0 to 377.6 mmol O2 m-2·d-1with a median value of -40.4 mmol O2 m-2·d-1.Our results showed that the area affected by Qiongdong upwelling was autotrophic.In the areas affected by the Pearl River discharge,the plankton community was also autotrophic.By contrast,other areas including the Taiwan Strait nearshore waters and the South China Sea open waters were heterotrophic.Therefore,community respiration was not entirely determined by the local primary productivity in the study areas.Our results suggest that the spatial transport of organic carbon plays an important role in determining the metabolic state of the plankton community.