Collaborative Research: P2C2--Does Liebig's Law Allow for Capturing More Signal from the Forest?

该项目旨在开发和应用树木生长模型，以加强对树木年轮宽度记录的气候信号（温度和湿度）的恢复。这种树木生长模型有可能改善大规模的气候重建，并将有助于了解和改善仪器和树木年轮气候重建之间的系统差异。生长模型基于李比希最小值定律，该定律描述了树木生长如何受到最大限制因素（例如阳光，养分，水分）的影响。研究人员将：1）对国际树轮数据库的4，213个树木年轮站点进行全面分析，以了解李比希定律如何影响林内变异性; 2）描述李比希定律在模型和观测背景下影响树木间气候信号分布的方式。该项目的目标是开发重建技术，用于在存在局部生长限制的情况下反演温度或降水的生长。这些重建技术有可能大大改善当地和区域气候变异的重建。潜在的更广泛影响包括使用树木生长和树木年轮替代物进行气候重建的新方法。将为旧金山弗朗西斯科州立大学（教育部指定的少数民族服务机构）一年级学生开设树木气候学实地班，目的是招收少数民族和经济困难的学生学习地球科学。该项目将支助两名研究生的教育和培训。研究人员将把这个项目的概念和结果纳入他们各自的课程和推广活动中。这个奖项反映了NSF的法定使命，并被认为是值得支持的，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。

This project aims to develop and apply a tree growth model in order to strengthen the recovery of climate signals (temperature and moisture) recorded in the width of tree-ring. This tree growth model has the potential to improve large-scale climate reconstructions and will be useful for understanding and ameliorating systematic differences between instrumental and tree-ring climate reconstructions. The growth model is based on the Liebig's law of the minimum which describes how tree growth is dictated by the most limiting factor (e.g. sunlight, nutrients, moisture). The researchers will: 1) conduct a comprehensive analysis of 4,213 tree-ring sites from the International Tree Ring Data Bank to understand how Liebig's Law influences within-stand variability; and 2) characterize the ways that Liebig's Law influences the distribution of climate signal across trees in both a model and observational context. The goal of this project is to develop reconstruction techniques for inverting growth for temperature or precipitation in the presence of local limitations on growth. These reconstruction techniques have the potential to result in substantially improved reconstructions of local and regional climate variability. The potential Broader Impacts include new methodologies to use tree growth and tree-ring proxies for climate reconstructions. A dendroclimatology field-based class to first-year students at San Francisco State University (a designated Minority Serving Institution by the Department of Education) will be developed, with the goal of recruiting minority and economically disadvantaged students to the Earth Sciences. The project will support the education and training of two graduate students. The researchers will incorporate concepts and results from this project in their respective classes and outreach activities.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.