Experimental study on the ecological efficiencies of plankton communities

本研究旨在确定水生环境中浮游生物通过食物链结构转化的生态效率。本研究中使用的大部分微生物都是从湖泊环境中分离出来的，并在培养条件下成功维持。本研究还揭示了紫外线辐射对湖泊生态系统中溶解有机物的影响，从而影响细菌的代谢。建立了湖泊水体中溶解性有机碳（DOC）的测定方法。用紫外辐射的水下衰减对几个湖泊的DOC垂直剖面进行了阐述和讨论。研究了湖泊浮游原生动物的季节变化，估算了其对细菌的掠食率和浮游动物的掠食性损失。成功地分离和培养了几种细菌、原生动物、轮虫和浮游甲壳类动物。本研究表明，湖水中浮游植物排出的有机物转化为细菌细胞有机物的生态效率为40-48%。对水生环境中的氮及其细菌代谢进行了研究和综述。

The present study was conducted to determine the ecological efficiencies of conversion through food chain structure of planktonic organisms in aquatic environments. Most of the microorganisms used in this study were isolated from lake environment and successfully mainteined in culture conditions. This study also revealed effects of ultraviolet radiation on the dissolved organic matter which affect bacterial metabolism in lake ecosystems.1.A method was established for determination of dissolved organic carbon (DOC) in lake water. Vertical profile of DOC in several lakes was elucidated and dicussed with underwater attenuation of ultraviolet radiation.2.Seasonal change of protozoan plankton in a lake was studied and their grazing rate of bacteria, as well as their predatory loss by zooplankton were estimated.3.Several strains of bacteria, protozoa, rotifers, and crustacean plankters were isolated and cultivated successfully.4.This study demonstrated that the ecological efficiency is 40-48% from phytoplankton excreted organic matter to bacterial cellular organic matter in lake water.5.Nitrogen in aquatic anvironment and the related bacterial metabolisms were considered and summarized.