Effects of daily nitrogen and phosphorus input on planktonic community metabolism in a semi-enclosed bay by mesocosm experiment  

作　　者：Chenhui Xiang Yao Li Zhixin Ke Gang Li Yadong Huang Xinying Su Liangmin Huang Xinyu Song 

机构地区：[1]Key Laboratory of Tropical Marine Bio-resources and Ecology,South China Sea Institute of Oceanology,Chinese Academy of Sciences,Guangzhou 510301,China [2]Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou),Guangzhou 510301,China [3]University of Chinese Academy of Sciences,Beijing 100049,China [4]Nansha Marine Ecological and Environmental Research Station,South China Sea Institute of Oceanology,Chinese Academy of Sciences,Guangzhou 510301,China [5]Innovation Academy of South China Sea Ecology and Environmental Engineering,Chinese Academy of Sciences,Guangzhou 510301,China

出　　处：《Acta Oceanologica Sinica》2022年第8期99-110,共12页海洋学报（英文版）

基　　金：the National Natural Science Foundation of China under contract No.41890853;the Fund of Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou)under contract No.GML2019ZD0404;the Science&Technology Basic Resources Investigation Program of China under contract No.2018FY100105;the Fund of Innovation Academy of South China Sea Ecology and Environmental Engineering,Chinese Academy of Sciences under contract No.ISEE2018ZD02;the National Key Basic Research Program of China(973 Program)under contract No.2015CB452904;the Development Project of China under contract Nos2017YFC0506302 and 2016YFC0502805。

摘　　要：Planktonic metabolism plays an important role in affecting the energy transportation and carbon cycle of the marine ecosystem.However,its regulation mechanism remains unclear under the continuously exogenous nutrient inputs in nearshore waters.In this study,a mesocosm experiment was conducted in a semi-enclosed bay,the Daya Bay,to explore the responses of plankton metabolic balance and community structure to a concentration gradient of daily nitrogen and phosphorus inputs.The results showed that nutrient enrichments promoted phytoplankton biomass,total primary production,and community respiration,and the promoting effect enhanced alongwith the increase of nutrient concentration.However,the net community production fluctuated more violently between autotrophic and heterotrophic with the increase of nutrient inputs and tended to be more heterotrophic from the 5 th day to the 10 th day of the experiment.In addition,the daily flux of nitrogen and phosphorus,2μmol/(L·d)and 0.066μmol/(L·d),respectively,could be regarded as a potential threshold for ecosystem stability and health,since most of the ecological characteristics related to plankton structure and function have undergone significant changes when the nutrient level is higher than that.In the nearshore enclosed or semi-enclosed waters,nutrient from continuous terrigenous input is likely to be concentrated and exceed this level,indicating the ecological risks due to the metabolic unbalance and the deterioration of plankton community structure.

关 键 词：primary production community respiration community metabolism continuous nutrient input mesocosm experiment Daya Bay 

分 类 号：Q178[生物学—水生生物学]