浅水湖泊沉积物生源要素与浮游藻类和沉水植物的关系OA北大核心CSTPCD

In this study,we explored the effects of biogenic substances in sediments on phytoplankton and submerged macrophytes in shallow lakes in the middle and lower reaches of the Yangtze River basin.The study was based on summer investigations of water quality,biogenic substances in sediments and sub-merged macrophytes in 11 shallow lakes from 2003 to 2020(Baoan Lake during the summers of 2003-2012,2020;Hongxing,Honghu,Nanhu,Qingling,Sanliqi and Zhangdu Lakes in the summer of 2003;Di-anshan,Gehu,Wuchang and Yangcheng Lakes in the summer of 2004).The relationship between sedi-ment nutrient content and algal or macrophyte dominance was analyzed using univariate linear regression.Results show that:(1)The total phosphorus content in sediment(TPSed)was highest in algal-dominated lakes(0.71±0.21)g/kg and lowest in macrophyte-dominated lakes(0.52±0.13)g/kg.Total nitrogen con-tent(TNSed)and total organic carbon content(TOCSed)in sediment were highest in macrophyte-dominated lakes[TNSed:(4.64±3.57)g/kg;TOCSed:(55.89±50.28)g/kg]and lowest in intermediate lakes[TNSed:(1.86±1.26)g/kg;TOCSed:(20.00±12.13)g/kg].(2)Regression analysis shows that phytoplankton chlo-rophyll-a content(Chl-a)increased and submerged macrophytes biomass(BMac)decreased significantly at high TPSed(P<0.05).However,TNSed and TOCSed had little effect on Chl-a and BMac(P>0.17).(3)TPSed thresholds for the disappearance of submerged macrophytes in summer was 0.87-0.98 g/kg in the lakes of the middle and lower reaches of the Yangtze River basin.Our results demonstrate that TPSed is a better predictor of Chl-a and BMac than TNSed and TOCSed in shallow lakes of the middle and lower reaches of the Yangtze River basin.More quantitative analysis of these relationships will provide a scientific basis for assessing sediment pollution in shallow lakes and determining sediment conditions necessary for re-storing and maintaining the submerged macrophyte community.