Groundwater Use and Salinity Dynamics at Forested Sites of Temperate South America

南美洲温带森林地区地下水利用和盐度动态

• 批准号: 0717191
• 负责人: Robert Jackson
• 金额: $ 41.5万
• 依托单位: Duke University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-09-01 至 2011-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0717191&HistoricalAwards=false
• 关键词: Groundwater; Use; Salinity; Dynamics; Forested

This research examines environmental and hydrological consequences of land use change in South America with the goal of understanding how conversion of grasslands to plantation forests affects groundwater, soil salinity and nutrient availability. The research 1) compares paired native grasslands and plantations in Argentina and Uruguay for their growth and water use, 2) initiates measurements of groundwater and stream chemistry at 19 paired grassland and forested watersheds, and 3) develops a framework for predicting increases in aboveground productivity and water use with forestry based partly on groundwater characteristics, including the depth to ground water, the salinity of the water, and the tolerance of different tree species to that salinity. An additional goal is to understand how different tree species alter the chemistry and hydrology of ecosystems, particularly through their ability to use groundwater at different depths and of different salinities.The activities outlined in this proposal provide several benefits to society. One is a model of salinization that bears directly on drinking-water quality in the region, since forests are being extensively planted into grasslands that overlay shallow fresh water, the primary source of renewable drinking water. The research will provide information on the environmental costs and benefits of conversion of grassland to forests as a means of sequestering carbon from the atmosphere. Another benefit is information that leads to more sustainable forestry practices, including a more complete accounting of approaches for biological carbon sequestration. The project includes significant contributions from high-school students and undergraduates and provides them with an early introduction to science research.

这项研究探讨了南美洲土地利用变化的环境和水文后果，目的是了解草地向种植园林的转化如何影响地下水、土壤盐分和养分供应。该研究1）比较了阿根廷和乌拉圭成对的天然草地和种植园的生长和用水情况，2）在19对草地和森林流域开始测量地下水和河流化学，3）开发了一个框架，用于预测地上生产力和林业用水量的增加，部分基于地下水特征，包括地下水的深度，水的盐度，以及不同树种对盐度的耐受性。 另一个目标是了解不同树种如何改变生态系统的化学和水文，特别是通过它们利用不同深度和不同盐度的地下水的能力。一个是直接影响该区域饮用水质量的盐碱化模式，因为森林被广泛种植在覆盖浅淡水的草原上，而浅淡水是可再生饮用水的主要来源。这项研究将提供关于将草地转变为森林作为从大气中吸收碳的一种手段的环境成本和效益的信息。 另一个好处是提供信息，导致更可持续的林业做法，包括更完整地说明生物碳固存的方法。 该项目包括高中生和本科生的重要贡献，并为他们提供了科学研究的早期介绍。