SGER: The Role of Plants in the Weathering of Silicate Rocks

这项探索性研究小额赠款（SGER）涉及通过双重方法对植物在风化中的作用进行初步研究；对夏威夷岛和圣海伦斯山的实地研究，以及实验室分析。夏威夷为研究风化提供了一个独特的机会，因为这里有：(1)可以追溯到4000多年前的玄武岩；(2)在恒定的基岩岩性和恒定的小气候的小区域内，有各种各样的植物，从地衣和藻类到发育良好的雨林；(3)可以接触到目前正在同一地区研究植物生态学的生物学家的专业知识。我们计划测量年轻流风化皮的厚度、矿物学和化学成分，并确定在存在和不存在特定生物群的情况下风化的化学成分相对速率。地球化学碳循环模型及其对显生宙大气CO的影响（Berner, 1990）揭示了更多了解陆地植物如何影响化学风化的重要性。这既包括植物对硅酸盐风化吸收CO速率的影响，也包括植物介导的风化对大气CO变化的反馈响应。

This Small Grant for Exploratory Research (SGER) involves preliminary study of the role of plants in weathering by a two-fold approach; a field study on the island of Hawaii and on Mt. St. Helens, and laboratory analyses. Hawaii offers a unique opportunity to study weathering because here there are: (1) dated basalts ranging back to more than 4000 years (2) a wide range of plant life, from lichens and algae to well developed rainforest, within small regions of constant bedrock lithology and constant microclimate and (3) access to the expertise of biologists who are presently studying plant ecology in the same area. We plan to measure the thickness and mineralogical and chemical composition of weathering rinds on young flows and to determine the chemical composition relative rates of weathering in the presence and absence of specific biota. Modeling of the geochemical carbon cycle and its effect on atmospheric CO over Phanerozoic time (Berner, 1990) has revealed the importance of knowing more about how land plants affect chemical weathering. This includes both the effect of plants on the rate of uptake of CO by silicate weathering and the feedback response of plant-mediated weathering to changes in atmospheric CO .