权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

The effect of forest, wet land and pasture land on the solute dynamics in terrestrial to lake ecosystem.

森林、湿地和牧场对陆地到湖泊生态系统溶质动态的影响。

基本信息

批准号：
13460060
负责人：
SHIBATA Hideaki
金额：
$ 9.6万
依托单位：
Hokkaido University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2001
资助国家：
日本
起止时间：
2001 至 2003
项目状态：
已结题

项目摘要

To clarify the effect of vegetation and land-use on biogeochemical processes in combined watershed including the forest, wet land and agricultural land, analysis of land-use characteristics, vegetation pattern, solute chemistry and dynamics in stream and lake were investigated in the Shimarinai Rake watershed located in northern Hokkaido Japan. Terrestrial vegetation pattern in the watershed was affected the soil moisture condition which closely related to the topographic features. The wetland and swamp forest distributed in the lower slope and riparian area played a significant role on the formation of the stream chemistry, The seepage from the wet land has higher dissolved organic carbon and nitrogen which produced from the decomposed organic matters in the soil. On the other hand, nitrate in the groundwater and stream water in the riparian wet land significantly decreased than that in the other area, suggesting that the immobilization and/or denitrification were important mechanisms for net nitrogen sink in the wet land. Larger amount of nutrient (N and P) was released from the pasture land to stream and lake ecosystem. The annual nutrient flux from pasture to the stream and lake was remarkably greater than that from forest and wetland ecosystem in the whole watershed. Our analysis using integrated monitoring of biogeochemical processes, census of vegetation pattern and processes and GIS analysis for the synthesis could proposed the new tool to assess the ecosystem function and processes in the larger combined watershed.

为了阐明植被和土地利用对森林、湿地和农田复合流域生态地球化学过程的影响，对日本北海道北方岛津内Rake流域的土地利用特征、植被格局、河流和湖泊溶质化学和动力学进行了分析。流域内的陆地植被格局受土壤水分状况的影响，而土壤水分状况又与地形特征密切相关。分布在低坡和河岸带的湿地和沼泽森林对河流化学的形成起着重要的作用，湿地渗漏水中含有较高的溶解性有机碳和氮，这些有机碳和氮是土壤中有机质分解产生的。河岸带湿地地下水和河水中硝酸盐含量显著低于其他地区，表明固定化和反硝化作用是湿地氮素净汇的重要机制。大量的养分（N和P）从草地释放到河流和湖泊生态系统。在整个流域内，草地向河流和湖泊的营养盐通量明显大于森林和湿地。综合运用生态地球化学过程监测、植被格局与过程普查和GIS分析等方法，为更大规模的流域生态系统功能与过程评价提供了新的工具。