CAJ | 학술논문

在浅水湖泊中，沉积物易受到水流的扰动释放出原本沉降于其中的氮营养盐。沉水植物一方面能够减少水动力的作用，一方面又能够吸收沉积物中的和已经释放到上覆水中的氮营养盐供其生长同时改善水质。因此，研究沉水植物对沉积物中氮营养盐释放的影响具有很重要的实际意义。借助自主开发的生态水槽，研究苦草（Vallisneria spiraslis L.）在动、静水条件下对沉积物氮的释放的影响。实验装置包括四组水槽，两组动水槽中的一组只铺沉积物，另一组在沉积物上种植苦草，两组静水槽也如此设置。在40 d的实验周期内，我们在实验始末采集沉积物样品，在每一个采样时间点（0、1、3、6、12、20、30、40 d）采集水样，并测定沉积物中总氮含量，原水样中的总氮含量以及过滤水样中的总氮、氨氮、硝氮和亚硝氮的含量。研究结果表明：没有苦草的实验组0~1 cm沉积物层总氮下降幅度较大，有苦草的实验组表面0~1 cm沉积物层氮含量较高。苦草从根系周围沉积物中吸收氮，1~4 cm沉积物层的吸收量多于4~8 cm沉积物层。各水槽上覆水中总氮含量在第1天就有较大的增加，从0.09 mg·L-1分别升到0.60、0.50、0.379、0.36 mg·L-1在水动力影响下的增加更显著，后缓慢上升。动水槽中进入到上覆水的氮中80%以上是以溶解态氮形式存在，静水槽中这个比例高达90%以上。苦草对溶解态和颗粒态氮的去除率最高可达27.6%和84.3%。3种氮形态中硝态氮的含量比重较大，在动水条件下，苦草对氨氮，硝氮和亚硝氮的去除率最高可达30.0%、25.0%和60.0%。但苦草对水中氮形态的比例的影响并不明显。以上结果说明水动力条件明显促进沉积物中氮的释放，沉水植物苦草通过保护表层沉积物，吸收下层沉积物中氮，去除进入上覆水中的氮，特别是颗粒态氮和溶解态中的亚硝态氮来减少水环境中的氮含量。该研究旨在为沉水植物对湖泊沉积物营养盐释放量的影响估算及水环境质量评价提供科学依据。在淺水湖泊中，沉積物易受到水流的擾動釋放齣原本沉降于其中的氮營養鹽。沉水植物一方麵能夠減少水動力的作用，一方麵又能夠吸收沉積物中的和已經釋放到上覆水中的氮營養鹽供其生長同時改善水質。因此，研究沉水植物對沉積物中氮營養鹽釋放的影響具有很重要的實際意義。藉助自主開髮的生態水槽，研究苦草（Vallisneria spiraslis L.）在動、靜水條件下對沉積物氮的釋放的影響。實驗裝置包括四組水槽，兩組動水槽中的一組隻鋪沉積物，另一組在沉積物上種植苦草，兩組靜水槽也如此設置。在40 d的實驗週期內，我們在實驗始末採集沉積物樣品，在每一箇採樣時間點（0、1、3、6、12、20、30、40 d）採集水樣，併測定沉積物中總氮含量，原水樣中的總氮含量以及過濾水樣中的總氮、氨氮、硝氮和亞硝氮的含量。研究結果錶明：沒有苦草的實驗組0~1 cm沉積物層總氮下降幅度較大，有苦草的實驗組錶麵0~1 cm沉積物層氮含量較高。苦草從根繫週圍沉積物中吸收氮，1~4 cm沉積物層的吸收量多于4~8 cm沉積物層。各水槽上覆水中總氮含量在第1天就有較大的增加，從0.09 mg·L-1分彆升到0.60、0.50、0.379、0.36 mg·L-1在水動力影響下的增加更顯著，後緩慢上升。動水槽中進入到上覆水的氮中80%以上是以溶解態氮形式存在，靜水槽中這箇比例高達90%以上。苦草對溶解態和顆粒態氮的去除率最高可達27.6%和84.3%。3種氮形態中硝態氮的含量比重較大，在動水條件下，苦草對氨氮，硝氮和亞硝氮的去除率最高可達30.0%、25.0%和60.0%。但苦草對水中氮形態的比例的影響併不明顯。以上結果說明水動力條件明顯促進沉積物中氮的釋放，沉水植物苦草通過保護錶層沉積物，吸收下層沉積物中氮，去除進入上覆水中的氮，特彆是顆粒態氮和溶解態中的亞硝態氮來減少水環境中的氮含量。該研究旨在為沉水植物對湖泊沉積物營養鹽釋放量的影響估算及水環境質量評價提供科學依據。
재천수호박중，침적물역수도수류적우동석방출원본침강우기중적담영양염。침수식물일방면능구감소수동력적작용，일방면우능구흡수침적물중적화이경석방도상복수중적담영양염공기생장동시개선수질。인차，연구침수식물대침적물중담영양염석방적영향구유흔중요적실제의의。차조자주개발적생태수조，연구고초（Vallisneria spiraslis L.）재동、정수조건하대침적물담적석방적영향。실험장치포괄사조수조，량조동수조중적일조지포침적물，령일조재침적물상충식고초，량조정수조야여차설치。재40 d적실험주기내，아문재실험시말채집침적물양품，재매일개채양시간점（0、1、3、6、12、20、30、40 d）채집수양，병측정침적물중총담함량，원수양중적총담함량이급과려수양중적총담、안담、초담화아초담적함량。연구결과표명：몰유고초적실험조0~1 cm침적물층총담하강폭도교대，유고초적실험조표면0~1 cm침적물층담함량교고。고초종근계주위침적물중흡수담，1~4 cm침적물층적흡수량다우4~8 cm침적물층。각수조상복수중총담함량재제1천취유교대적증가，종0.09 mg·L-1분별승도0.60、0.50、0.379、0.36 mg·L-1재수동력영향하적증가경현저，후완만상승。동수조중진입도상복수적담중80%이상시이용해태담형식존재，정수조중저개비례고체90%이상。고초대용해태화과립태담적거제솔최고가체27.6%화84.3%。3충담형태중초태담적함량비중교대，재동수조건하，고초대안담，초담화아초담적거제솔최고가체30.0%、25.0%화60.0%。단고초대수중담형태적비례적영향병불명현。이상결과설명수동력조건명현촉진침적물중담적석방，침수식물고초통과보호표층침적물，흡수하층침적물중담，거제진입상복수중적담，특별시과립태담화용해태중적아초태담래감소수배경중적담함량。해연구지재위침수식물대호박침적물영양염석방량적영향고산급수배경질량평개제공과학의거。
In shallow lakes, the nitrogen will release from sediments to the water column when the sediment got disturbed. Submerged plants can not only reduce the hydrodynamic force, but also absorb nitrogen from sediment to improve the water quality in the lake. Therefore, it is very important to study the impact of submerged plants on the hydrodynamic process and the release of nitrogen from the sediment. In this paper, the impacts of Vallisneria spiraslis L. on the release of nitrogen from the sediment under static and dynamical conditions were studied in flumes. The sediments were paved along the bottom of the flumes. Two static conditions and two dynamical conditions with or without planting Vallisneria spiraslis L. in the flume were designed to generate different turbulence on the sediment surface. The sediment samples were taken in the first and last day during the 40 day long experimental period for determining total nitrogen concentration only. The water samples were taken at eight different days, such as 0, 1, 3, 6, 12, 20, 30, 40 d for determining dissolve nitrogen, ammonia, nitrate and nitrite in filtered water. The results showed that the total nitrogen in the surface layer (0~1 cm) of the sediment without Vallisneria spiraslis L. were smaller than that with Vallisneria spiraslis L. The plants absorbed more nitrogen from the middle layer (1~4 cm) of sediment than from the deep layer (4~8 cm). The total nitrogen in the water column dramatically increased since the first day from 0.09 mg·L-1 to 0.60, 0.50, 0.379, 0.36 mg·L-1 respectively, and dynamical condition enlarged this increment. Dissolved nitrogen in the water column took 80%of total nitrogen in hydrodynamic conditions and 90% in static ones. The Vallisneria spiraslis L. reduced both dissolved and particular nitrogen by 27.6%and 84.3%, respectively. The nitrate took a large proportion of total nitrogen in overlying water. The Vallisneria spiraslis L. reduced ammonia, nitrate and nitrite in the water under hydrodynamic condition by 30.0%, 25.0% and 60.0%, respectively. The proportion of tree kinds of nitrogen in overlying water changed few with the impact of Vallisneria spiraslis L. Results indicated that the hydrodynamic force enhanced the release of nitrogen from sediment dramatically. The Vallisneria spiraslis L. protected the surface sediment from being disturbed by hydrodynamic forces and absorbed nitrogen from deep layer of sediment and water column, especially decreased particular nitrogen and dissolved nitrite. The results of this study could provide scientific tools for estimating the impact of submerged plants on the release of nitrogen from sediment and the Water Environmental Quality Assessment.