Most lakes in China are at eutrophic level, some of them have occurred seriously seasonal aglae bloom. Alga bloom occured mainly because of the interaction among external nutrient loading, internal nutrient release and environmental conditions. The fraction and concentration of nutrient in the sediment and overlying water, and changes of environmental conditions maybe the key limited factors to control the alga bloom, and these limited factors possiblly change with the seanson changes. But the previous studies are seldom to study the effects of nutrient seasonal release from sediment on the alga bloom succession. In order to found the key limited facors for the alga bloom in the different seasons and ascertain the relationship between the nutrient release from sediment and alga bloom, field investigation and laboratory simulated experiment were conducted. Firstly, possible key environmental factors, nutrient limited conditions and preponderant alge in the partical season are chosen by the means of field investigation; secondly, simulated experiments are conducted by using correspinding seasonal sediment, overlying water and preponderant alga to study the effect machanism of sediment seansonal changes on the alga succession and on the nutrient concentration in the porewater and overlying water, and at same time to find the key control factors in different seansons. This study is beneficial for the controlling technology and management of lake eutrophication.

Performing Organization Institute of Urban Environment, CAS
Sponsor National Nature Science Foundation of China (NNSFC)
Start Date 2006.10
End Date 2008.10