Collaborative Research: Investigation of Fe and Mo Isotope Fractionation During Weathering

共同研究风化系统科学联盟：临界区生物地球化学的两家工作室世界土壤资源对人类社会的重要性可能仅次于水。土壤带内过程的速率和机制对整个地球系统的事件有重大影响；例如，这些过程有助于养分循环并中和流域中的酸性降水。尽管土壤资源很重要，但对土壤形成率的估计是基于未经证实的稳态假设，而且差异很大。然而，所有的估计都同意一个共同点：目前对土壤侵蚀率的估计比平均土壤形成速度的估计高出一到三个数量级，考虑到土壤对社会的重要性，这是一个令人不安的结论。这一建议的科学价值在于解决了一个更好的系统跟踪和传播有关风化和土壤形成的信息的明显需要。我们提出的倡议将调查以下问题：地球的风化引擎如何将岩石转化为土壤，以滋养生态系统，塑造陆地景观，并控制大气二氧化碳？答案需要在一系列时空尺度上耦合物理、化学和生物过程，并涉及各种科学和工程学科。传统上，陆地低温地球化学家和土壤化学家曾在小型、单PI或双PI项目中工作。很少有跨规模和跨学科的大型多PI项目是从这个社区开发出来的。相比之下，在其他科学社区中，已经开发了大型项目，将科学家组织成协调一致的多所大学团队。例如，IRIS和COSEE在激发地震学和海洋学界的热情和兴趣方面取得了极大的成功。我们提出了一种新的范式，即风化系统科学联盟(WSSC)，以在陆地低温地球化学家和土壤化学家/生物学家之间建立这种多PI的风化科学和环境生物地球化学方法。为了为拟议的WSSC奠定基础，我们正在申请两个研讨会的资金，一个是2006年在费城举行的第18届世界土壤科学大会的研讨会，届时将有顶尖科学家参加，他们将讨论有关临界区的研究前沿和需求，以及一名数据库专家。WSSC目前的设想包括四个组成部分：1)一套用于数据收集的“节点”站点；2)一个“骨干”土壤站点网络，将对各种深度的一套标准风化参数进行调查；3)为仪器和样本节点站点和骨干站点以及协调的数据管理和样本存储系统提供技术支持；4)通过各种社区建设办法将这些努力结合起来。这一资金申请的更广泛影响包括：1)提高对风化科学和环境生物地球化学领域当前问题多样性的了解；2)提高美国科学家对国外正在进行的风化倡议的了解；3)制定一项协调计划，以量化不同环境下的风化速率；4)制定一项计划，使风化科学领域的数据收集标准化；5)制定一项计划，存储和传播全世界风化现场的数据，供整个自然科学界使用；以及6)组织科学界调查与人类社会和自然生态系统密切相关的风化科学的基本问题。

Collaborative Research Towards a Weathering System Science Consortium: TwoWorkshops on Biogeochemistry of the Critical ZoneThe world's soil resource is probably second only to water in terms of its importance to human society. The rates and mechanisms of processes within the soil zone have a significant impact on events throughout Earth's systems; for example, these processes contribute to nutrient cycling and neutralize acidic precipitation in watersheds. Despite the importance of the soil resource, estimates of soil formation rates are based upon unproven assumptions of steady state and vary widely. However, all estimates agree on a common point: the current estimates of soil erosion rates are one to three orders of magnitude greater than estimates of average soil formation rates, a disturbing conclusion considering the importance of soils to society.The scientific merit of this proposal lies in addressing a clear need for a better system tracking and disseminating information regarding weathering and soil formation. Our proposed initiative will investigate the following question: How does Earth's weathering engine transform rock into soil to nourish ecosystems, shape terrestrial landscapes, and control atmospheric carbon dioxide? The answer requires coupling physical, chemical, and biological processes over a range of spatial and temporal scales and involves a variety of scientific and engineering disciplines.Traditionally, terrestrial low-temperature geochemists and soil chemists have worked in small, single or double PI projects. Very few large, multi-PI projects that cross scales and disciplines have developed from within this community. In contrast, among other scientific communities, large programs have developed to organize scientists into coordinated multi-university teams. For example, IRIS and COSEE have been extremely successful in generating enthusiasm and interest in the seismology and oceanography communities. We propose a new paradigm, a Weathering System Science Consortium (WSSC), to forge this type of multi-PI approach to weathering science and environmental biogeochemistry among terrestrial low-temperature geochemists and soil chemists/biologists. To lay the groundwork for the proposed WSSC, we are requesting funding for two workshops, a symposium at the 18th World Congress of Soil Science in 2006 in Philadelphia that will feature leading scientists who will discuss research frontiers and needs concerning the critical zone, and a database specialist. The current vision for WSSC incorporates four components: 1) a set of "node" sites for data collection; 2) a network of "backbone" soil sites that will be investigated for a standard set of weathering parameters over a range of depths; 3) technical support for instrument and sample node sites and backbone sites and coordinated data management and sample storage systems; and 4) the integration of these efforts through a variety of community-building approaches. The broader impacts of this funding request include the following: 1) improved understanding of the current diversity of questions within the fields of weathering science and environmental biogeochemistry; 2) improved understanding by US scientists of weathering initiatives occurring abroad; 3) development of a coordinated plan to quantify weathering rates in diverse settings; 4) development of a plan to standardize data gathering in the field of weathering science; 5) development of a plan to store and disseminate data from weathering sites worldwide for use by the entire natural sciences community; and 6) organization of the scientific community to investigate fundamental questions in weathering science with great relevance to human society and natural ecosystems.