摘要
轮叶黑藻(Hydrilla verticillata)是我国浅水湖泊常见的沉水植物,经常用于湖泊生态修复工程.然而在生态修复中后期,轮叶黑藻又往往会过度繁殖,影响其他湖泊功能的发挥.镧改性膨润土(锁磷剂)可以有效地降低沉积物中生物可利用磷含量,近年来被用于控制湖泊沉积物磷释放,其对轮叶黑藻生长和形态的影响还有待阐明.本研究在2种不同上覆水营养盐浓度条件下,设置添加和不添加锁磷剂2种处理,探究沉积物添加锁磷剂对轮叶黑藻生长及形态特征的影响.结果表明:1)沉积物添加锁磷剂之后,铁锰结合态磷、有机磷、铝结合态磷等生物可利用磷浓度显著降低,而生物不可用磷,如钙结合态磷浓度显著升高;2)沉积物添加锁磷剂显著降低了轮叶黑藻的生物量和生长率.添加锁磷剂的处理组植物的株高、地上部分生物量均明显低于无锁磷剂组;相反,添加锁磷剂显著增加了植物的根长和地下部分生物量,进而提高了植物的根冠比;3)锁磷剂对轮叶黑藻生长的影响程度与水体营养盐浓度有关,在低营养盐浓度水体中锁磷剂对植物生长和形态特征的影响更为显著.本研究表明,锁磷剂的添加能降低沉积物中生物可利用磷浓度,抑制轮叶黑藻的生长,同时这种影响程度与在水体营养盐浓度有关.
Hydrilla verticillata is a common submerged plant in shallow lakes in China,and is often used as a pioneer species in lake ecological restoration projects.However,the Hydrilla verticillata tends to overgrowth,forming a canopy which affects other functions of lakes.Lanthanum-modified bentonite(Phoslock^■)can effectively reduce the bioavailable phosphorus content in sediments.In recent years,it has been used to control phosphorus release from lake sediments.Its impact on the growth and morphology of Hydrilla verticillata remains to be clarified.In this study,two treatments with and without Phoslock^■in the sediments were set up to investigate the effects of Phoslock^■on the growth and morphological characteristics of Hydrilla verticillata under two different water nutrient concentrations.The results show that:1)After adding Phoslock^■to the sediments,the bioavailable phosphorus concentration,such as Fe/Mn combined phosphorus(BD-P),organic phosphorus(Org-P),Aluminum-bound phosphorus(Al-P),is significantly reduced,while the non-bioavailable phosphorus concentration,such as Calcium-bound phosphorus(Ca-P),is significantly increased.2)The addition of Phoslock^■in the sediments significantly reduced the biomass and growth rate of the Hydrilla verticillata.The plant height and aboveground biomass of Phoslock^■group were significantly lower than those without Phoslock^■;on the contrary,the addition of Phoslock^■significantly increased the root length of the plant and the underground biomass,and increased the plant’s root-shoot ratio.3)The effect of Phoslock^■on the growth of Hydrilla verticillata is related to the concentration of nutrients in the water,and the effect of Phoslock^■on plant growth and morphological characteristics is more significant in low-nutrient water.Overall,this study shows that the addition of Phoslock^■can effectively reduce the concentration of bioavailable phosphorus in sediments and inhibit the growth of Hydrilla verticillata,and this effect is more significant when the concentration of nutrients in the water is reduced.
作者
符亦舒
何虎
何宏业
马路生
苏雅玲
刘正文
Fu Yishu;He Hu;He Hongye;Ma Lusheng;Su Yaling;Liu Zhengwen(Department of Ecology and Institute of Hydrobiology,Jinan University,Guangzhou 510632,P.R.China;Nanjing Institute of Geography and Limnology,Chinese Academy of Sciences,Nanjing 210008,P.R.China)
出处
《湖泊科学》
EI
CAS
CSCD
北大核心
2021年第2期388-396,共9页
Journal of Lake Sciences
基金
国家自然科学基金项目(41471086)
中国科学院南京地理与湖泊研究所“一三五”项目(NIGLAS2017GH01)联合资助。
关键词
水体营养盐
沉积物
轮叶黑藻
镧改性膨润土(锁磷剂)
生态恢复
Water nutrient
sediment
Hydrilla verticillata
lanthanum-modified bentonite(Phoslock^■)
ecological restoration
