Study on nitrogen uptake and storage of benthic microalgae and its influencing factors in Daya Bay wetlands
In order to investigate the nitrogen absorption and storage capacity of benthic microalgae on surface sediments of different types of wetlands and its influencing factors,samples of benthic microalgae were collected from surface sediments of barren wetland(T1),estuarine wetland(T2)and mangrove wetland(T3)of Daya Bay in March and August 2017,and repeated freeze-thaw experiments were conducted.The results showed that the spatial and temporal distribution of the abundance of benthic microalgae varied significantly,and temperature,nutrients and sediment particle size were main factors affecting the growth and propagation of benthic microalgae in the Daya Bay coastal wetland.It was found that the nitrogen accumulation and storage capacity of benthic microalgae was stronger in dry season than in wet season,which was mainly due to excessive dryness and photostimulation caused by higher temperature and strong light.Excessive dryness and photostimulation could restrict the growth and reproduction of benthic microalgae.The abundant nutrients in estuary wetland promoted the growth and reproduction of benthic microalgae,resulting in the highest chlorophyll content and the maximum abundance of benthic microalgae in T2 Dan'ao river estuary wetland.The intracellular DIN content of benthic microalgae showed the spatial distribution characteristics of T2>T1>T3,which was consistent with the distribution characteristics of microalgae abundance(P<0.01),and the benthic microalgae had a strong accumulation capacity of NH4-N,accounting for about 90.4%of IC-DIN.Generally,IC-DIN of benthic microalgae accounted for 24.2%of the total sediment nitrogen pool,and about 20.0%of NH4-N,17.6%of NO3-N and 16.0%of NO2-N were stored in benthic microalgae cells.The nitrogen accumulation capacity of benthic microalgae in Daya Bay wetland was affected by nutrient load,and the higher the NH4-N load was,the stronger the nitrogen absorption and storage capacity of benthic microalgae was,which could effectively alleviate the nearshore eutrophication level.
万方数据
维普
