Study on Flow, Sediment and Nutrients, Primary Production in Gravel rivers for Restoration of Ecosystem

砾石河流量、泥沙、养分、初级生产力研究以恢复生态系统

基本信息

批准号：
14205070
负责人：
IKEDA Synsuke
金额：
$ 36.44万
依托单位：
TOKYO INSTITUTE OF TECHNOLOGY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (A)
财政年份：
2002
资助国家：
日本
起止时间：
2002 至 2004
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-14205070/
关键词：
Gravel rivers Nutrients transport Primary production Periphyton Sediment transport pollution load in watershed Plants on flood plain 土砂流出流れ栄養塩有機物洪水粒度分布一次生産

项目摘要

1.Laboratory experiments were performed to know the characteristics of growth, detachment and interspecific competition of filamentous and non-filamentous periphyton, in which the primary production rates, the respiration rates and the detachment rates of each kind of periphyton were measured by using various methods. The results of the experiments show that there are no significant differences of the primary production rates and the respiration rates between filamentous and non-filamentous periphyton. The detachment rate of periphyton is found to increase with friction velocity, and the detachment rate of filamentous periphyton takes smaller value than that of non-filamentous periphyton.2.The field observations were performed to understand the characteristics of growth and nutrient uptake of Phragmites japonica on flood plain in a gravel river, in which the temporal variation of plant biomass, the content of nutrients of vegetation and the concentrations of nutrients in the groundwater were measured. The result of the field observations show that the growth of the vegetation was restricted by the groundwater level in the present observation site. The hydroponics experiment of the riparian vegetation was conducted to understand the nutrition uptake due to photosynthesis. The results of the experiment show that the nitrogen uptake of the vegetation was closely associated with the amount of respiration of the roots of the vegetation.3.Field observation on the supply of sediment and nutrients from Nagura river basin, Ishigaki Island, was studied. They were estimated by measuring water velocity, depth, turbidity, concentrations of carbon, nitrogen and phosphrous. It was found that heavy rains yield nutrients mainly in particulate type. However, sugar cane field yields dissolved nutrients gradually after the rain. The timing of flood and tide is an important factor to control the discharge of sediment and nutrients to the tidal area such as lagoon and river mouth.

1.通过实验室实验了解丝状和非丝状附生生物的生长、脱落和种间竞争特征，采用多种方法测定各类附生生物的初级生产力、呼吸速率和脱落率。实验结果表明，丝状和非丝状附生生物的初级生产力和呼吸速率没有显着差异。发现附生生物的脱离率随着摩擦速度的增加而增大，且丝状附生生物的脱离率比非丝状附生生物的值要小。2、通过田间观测，了解芦苇的生长和养分吸收特性。在砾石河漫滩上测量了植物生物量、植被养分含量和地下水养分浓度的时间变化。现场观测结果表明，目前观测点的植被生长受到地下水位的限制。对河岸植被进行水培实验，以了解光合作用对营养的吸收。实验结果表明,植被氮素吸收量与植被根系呼吸量密切相关。3.对石垣岛名仓河流域沉积物和养分供给进行了现场观测研究。它们是通过测量水流速度、深度、浊度、碳、氮和磷的浓度来估计的。研究发现，大雨产生的养分主要以颗粒形式存在。然而，雨后甘蔗地逐渐释放出溶解的养分。洪水和潮汐的时机是控制泥沙和营养物质向泻湖、河口等潮汐区排放的重要因素。