摘要
选取太湖贡湖湾水陆交错带内的黄菖蒲、双穗雀稗、李氏禾、黄花水龙及香菇草这5种植物,长江下游常见沙壤土、水陆交错带新生底质两种土壤,模拟扰动条件下5种水生植物对底质氮磷释放的抑制.结果表明,植物对底质总磷释放具有显著的抑制作用,双穗雀稗、香菇草、黄菖蒲可以将上覆水总磷浓度控制在0.02 mg·L^(-1),李氏禾、黄花水龙控制在0.03mg·L^(-1);李氏禾、黄花水龙试验组总磷释放率控制在0.1 d-1,双穗雀稗、香菇草、黄菖蒲试验组控制在0.05 d-1.植物生长增加了底质氮的赋存,带来底质氮释放的增加,而黄菖蒲、双穗雀稗则可以将底质总氮释放速率控制在0.02 d-1,上覆水总氮浓度控制在0.4 mg·L^(-1).植物须根根长密度、根重密度、根表面积密度成为抑制底质氮磷释放的主要因素,须根穿插增加底质中粒径≤50μm的颗粒物,从而减少了水体扰动造成的底质上扬;同时须根在生长过程增加底质总氮含量,吸收底质中的磷.5种水陆交错带植物正是通过上述两种机制抑制底质中氮磷的释放,其中黄菖蒲、双穗雀稗因为其发达的根系,抑制氮磷物质释放的效果最佳,其次为李氏禾、香菇草,黄花水龙对底质氮磷释放的抑制作用在5种植物中最小.
The article researched the effect of Iris pseudacorus L. ,Paspalum distichum L. ,Leersia hexandra Swartz,Ludwigia peploides and Hydrocotyle υulgaris on the nitrogen and phosphorus repression in sandy soil from lower reaches of Yangtze River and clay from stored littoral zone. The result indicated that plants had a significant inhibitory effect on total phosphorus release from sediment, with concentration in overlaying water below 0. 02 mg·L^ - 1 in Paspalum distichum L. , Hydrocotyle vulgaris, Iris pseudacorus group, below 0. 03 mg·L ^- 1 in Leersia hexandra Swartz, Ludwigia peploides group; with release rate below 0. 1 d^ - 1 in Leersia hexandra Swartz and Ludwigia peploides group, below 0. 05 d ^- 1 in Paspalum distichum L. , Hydrocotyle υulgaris, Iris pseudacorus group. While the plants were proved to aggravate total nitrogen release by accumulating in sediment, with concentration in overlaying water below 0. 4 mg·L ^- 1 in Paspalum distichum and Iris pseudacorus L. group; with release rate below 0. 02 mg·L ^- 1 . Root weight density, root length density, root surface area density were major factors, which increased the proportion of particles in sediment with diameter of below 50 μm, therefore decreased sediment resuspension against hydraulic disturbance; the root system also enriched total nitrogen in sediment and absorbed phosphorus from sediment. These five kinds of plants in terrestrial - aquatic transverse actually repressed nitrogen and phosphorus release from sediment in two ways mentioned above, Paspalum distichum L. and Iris pseudacorus L. possessed the best effect due to their developed root system , followed by Leersia hexandra Swartz and Hydrocotyle υulgaris, and Ludwigia peploides had the least effect.
出处
《环境科学》
EI
CAS
CSCD
北大核心
2017年第2期589-599,共11页
Environmental Science
基金
国家水体污染控制与治理科技重大专项(2013ZX07101-014-04,2014ZX07510-001-01)
关键词
水陆交错带植物
底质粒径
底质氮磷
须根根系
littoral-zone plants
sediment diameter
nitrogen and phosphorus in sediment
root system
