Collaborative Proposal: MRA: Scaling from Traits to Forest Ecosystem Fluxes and Responses to Climate Change, from Stand to Continent

了解森林碳和水的变化，即“生态系统的呼吸”，对于评估森林的功能及其面临的压力，以及预测和管理地球环境至关重要。然而，我们对森林特征波动以及它们如何随时间和空间变化的理解存在很大差距。这些差距阻碍了我们预测不同森林如何应对环境变化的能力。该项目利用美国国家科学基金会国家生态观测站网络（NEON）提供的前所未有的机会，确定森林对气候不稳定的反应如何取决于森林中植物物种的性质（特征）。该项目将通过澄清影响森林生长和水分利用的植物性状如何随给定地点和美国大陆的环境而变化，来解决关键的空白。研究人员还将使用最先进的模型，提供一种新的能力，从小簇树木一直到大陆尺度预测森林功能。然后，他们将利用这些信息发展一种新的理论，以提高生态学家预测森林生态系统对环境变化的反应的能力。该项目将对学生培训和当地研讨会产生更广泛的影响，以便将科学及其可及性传达给我们机构内和NEON站点附近的当地研究和教育社区，以及全球研究和教育社区。该项目将提供特征在确定整个大陆10个森林NEON站点的通量中的作用的机制理解，并提供从林分到美国大陆的高通量的新范例。我们的总体假设是，物种特征在与碳和水循环相关的生态系统对气候响应的时空尺度变化中起着强烈的调节作用。我们将回答三个关键问题：(1)美国大陆森林的功能特征如何随环境和气候而变化？对于NEON站点的物种，我们将测量对水运，气体交换和资源经济有重要影响的特征，测试特征与气候因素的关系，并应用这些关系来绘制美国大陆森林的特征。(2)气候和特征如何影响森林水分利用和生产力？我们将把性状数据同化到陆地生态系统机制模型中，以量化在多个时间尺度上预测的冠层通量对站点内和站点间性状多样性的敏感性。(3)气候、干扰和物种组成的变化如何影响冠层通量？使用参数化模型，我们将测试气候和干扰对生态系统通量的影响，以及这些变化如何取决于森林站点内部和跨站点的性状多样性。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Knowledge of changes in forest carbon and water, the “breathing of the ecosystem”, is critical to assess how forests function and the stresses they face, and to predict and manage the Earth environment. However, there are large gaps in our understanding of fluctuations in forest characteristics, and in how they vary in time and space. These gaps hinder our ability to predict how different forests respond to environmental change. This project utilizes an unprecedented opportunity provided by the NSF National Ecological Observatory Network(NEON) to determine how forest response to climate instability depends on the properties (traits) of the plant species in the forest. This project will address critical gaps by clarifying how plant traits that influence forest growth and water use vary with the environment at given sites and across the continental U.S. Researchers will also use state-of-the-art models to provide a new ability to predict forest function from the level of small clusters of trees all the way to the continental scale. They will then use this information to develop a new theory to enhance the ability of ecologists to predict forest ecosystem responses to environmental change. This project will be integrated with broader impacts in student training, and local workshops to communicate the science and its accessibility to the local research and education communities within our institutions and in the proximity of NEON sites, and beyond, to the global research and education communities.This project will provide a mechanistic understanding of the role of traits in determining fluxes for 10 forested NEON sites across the continent and a new paradigm to upscale fluxes from stand to the continental US. Our overarching hypothesis is that species’ traits strongly mediate the temporal and spatial scales of variation in ecosystem responses to climate in relation to carbon and water cycles. We will answer three key questions: (1) How do functional traits vary with environment and climate across forests of the continental USA? For species of NEON sites we will measure traits with crucial influence on water transport, gas exchange and resource economics, test the relationships of traits to climatic factors, and apply these relationships to map traits across forests of the continental USA. (2) How do climate and traits influence forest water use and productivity? We will assimilate the trait data into mechanistic terrestrial ecosystem models to quantify the sensitivity of predicted canopy fluxes to trait diversity within and across sites at multiple time scales. (3) How will shifts in climate, disturbance and species composition influence canopy fluxes? Using parameterized models, we will test the influence of climate and disturbances on ecosystem fluxes, and how these vary depending on trait diversity within and across forest sites.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.