CAREER: From Desert to Coastal Rainforest Soils- How do fungi transform minerals deployed across natural weathering gradients?

矿物风化破坏了维持地球上陆地生命的无机养分的供应。土壤微生物组，包括真菌群落，通过破坏，溶解和从矿物颗粒中提取营养物质来促进风化。真菌通过在土壤景观中散布探索性菌丝网络来寻找营养和水源。然而，确定真菌转化矿物质以提取岩石来源的营养物质的机制仍然具有挑战性，特别是在跨越不同气候，岩石类型和生态系统的天然土壤中。这项研究的目的是了解真菌如何与非生物环境相互作用，以启动矿物风化并在地球的关键地带形成土壤。该项目将利用高分辨率显微镜和质谱法的最新进展，以微米至纳米级分辨率研究真菌与矿物表面的相互作用。结果将展示新技术如何与综合关键区模型相结合，促进地球和环境科学的进步。鉴于土壤真菌在环境中无处不在的性质，该项目的研究结果将在土壤保护、农业活动和生物工程方面带来经济和社会效益。这项研究将与教育目标相结合，通过实施多样化，招募和留住社区大学生（地球）科学学术管道：土壤外展综合学习自我效能（土壤）桥。桥梁计划将通过分层指导，实地和实验室培训以及K-12外展活动为即将入学的大学生提供学术和社会资源。这项工作将探讨跨空间尺度的真菌-矿物相互作用，以回答与真菌对矿物转化的影响和对营养循环的贡献有关的未解决的问题。研究目标是：1）评估自然土壤的风化和覆盖生物气候景观的网袋中矿物基质的初期转化（沙漠到沿海雨林）和地形（山顶至排水）梯度，2）使用显微镜、质谱和对部署的矿物的元素分析，区分野外系统中的风化剂和真菌驱动的风化的初始阶段，和3）量化质量转移速率的矿物元素归一化矿物真菌接触面积确定从现场部署的矿物样品，随后放大使用土壤过程模型。 该研究将提供前所未有的洞察力，了解真菌如何应对气候，地形和养分的可用性，并将提供机制的见解，上调自然土壤的风化过程。该奖项反映了NSF的法定使命，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。

Mineral weathering replenishes the supply of inorganic nutrients that sustains terrestrial life on Earth. The soil microbiome, including fungal communities, contributes to weathering by disrupting, dissolving, and extracting nutrients from mineral grains. Fungi seek out nutrients and water sources by spreading networks of exploratory hyphae across a soil landscape. However, identifying the mechanisms used by fungi to transform minerals to extract rock-derived nutrients remains challenging, especially in natural soils that span different climates, rock types, and ecosystems. The goal of the research is to understand how fungi interact with abiotic environments to initiate mineral weathering and form soil in Earth’s critical zone. This project will utilize recent advances in high resolution microscopy and mass spectrometry to examine fungi interacting with mineral surfaces at micro-to nano-scale resolutions. The results will demonstrate how new technologies can promote the progress of the earth and environmental sciences in combination with an Integrated Critical Zone Model. The project findings will bring economic and societal benefits with respect to soil preservation, agricultural activity, and bio-engineering given the ubiquitous nature of soil fungi in the environment. This research will be integrated with the educational goal to diversify, recruit, and retain community college students in the (geo)sciences academic pipeline by implementing: Soils & Outreach for Integrated Learning & Self-Efficacy (SOILS) Bridge. The bridge program will enhance academic and social resources for incoming college students through tiered mentoring, training in the field and lab, and K-12 outreach. This work will probe into fungal-mineral interactions across spatial scales to answer unresolved questions related to fungal impact on mineral transformations and contributions to nutrient cycling. The research objectives are to: 1) Assess weathering of natural soils and incipient transformation of mineral substrates buried in mesh bags across landscapes that span bioclimatic (desert to coastal rainforest) and topographic (summit to drainage) gradients, 2) Differentiate weathering agents and the initial stages of fungal-driven weathering in field systems using microscopy, mass spectrometry, and elemental analyses of deployed minerals, and 3) Quantify mass transfer rates of mineral elements normalized to mineral-fungi contact areas determined from field-deployed mineral samples and subsequently upscaled using soil process models. The study will provide unprecedented insight into how fungi respond to climate, topography, and nutrient availability and will offer mechanistic insights into processes that upregulate weathering in natural soils.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.