Response of Submerged Macrophyte and Filamentous Green Algae to Nitrogen and Phosphorus Loads

HU Junjie; XUE Liyang; PANG Weijie; YAN Chunlan; PEI Guofeng

doi:10.19672/j.cnki.1003-6504.0661.23.338

Abstract：In this study,Vallisneria denseserrulata Makino and Rhizoclonium hieroglyphicam Kütz were used as the research objects to explore the effect of internal-exogenous nutrient load on the growth of submerged macrophyte and filamentous green algae.A treatment system of"sediments-Vallisneria denseserrulata Makino-Rhizoclonium hieroglyphicam Kütz"un-der laboratory conditions,the physicochemical factors,sediments nutrient content,and the growth characteristics of Vallis-neria denseserrulata Makino and Rhizoclonium hieroglyphicam Kütz were determined under different nutrient loads.The study found that non-persistent input of exogenous nutrients was able to cause a transient increase of TN and TP concentra-tions in the water,and continuous release of nutrients from sediments was the fundamental cause for maintaining N and P con-centrations in water.In water with TN and TP concentrations not exceeding 14.39 and 3.93 mg/L,respectively,increasing bio-mass of Vallisneria denseserrulata Makino was in the form of increased plant height(15％～25％higher than control group)and decreased total tillers(12％～43％lower than control group).Exogenous nutrient promoted the growth of Rhizoclonium hi-eroglyphicam Kütz(the biomass increased by 65％from the control).N load(TN concentration＞10 mg/L)affected the growth position of Rhizoclonium hieroglyphicam Kütz in water,and the accumulated biomass of Rhizoclonium hieroglyphicam Kutz hindered the use of light by Vallisneria denseserrulata Makino.