Collaborative Research: 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，在我们对森林特征的波动以及它们如何在时间和空间上变化的理解上存在很大差距。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NSF国家生态观测网(NEON)提供的前所未有的机会来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属性(特征)。该项目将通过澄清影响森林生长和水分利用的植物特征如何在给定地点和整个美国大陆随环境变化来解决关键差距。研究人员还将使用最先进的模型来提供一种新的能力来预测森林功能，从小树丛水平一直到大陆规模。然后，他们将利用这些信息开发一种新的理论，以提高生态学家预测森林生态系统对环境变化反应的能力。该项目将与学生培训和地方研讨会的更广泛影响相结合，以便在我们的机构内和霓虹灯站点附近以及全球研究和教育界以外的地方向当地研究和教育界传播科学及其可获得性。该项目将提供对特性在确定整个大陆10个森林霓虹灯站点通量方面的作用的机械性理解，并提供一个新的范式来提高从标准到美国大陆的通量。我们的总体假设是，物种的特性强烈地调节了生态系统对气候的反应与碳和水循环有关的时间和空间尺度的变化。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着环境和气候的变化而变化？对于霓虹灯地点的物种，我们将测量对水运输、气体交换和资源经济具有关键影响的特性，测试特性与气候因素的关系，并将这些关系应用于绘制美国大陆森林的特性图。(2)气候和特征如何影响森林水分利用和生产力？我们将把特征数据同化到机械化的陆地生态系统模型中，以量化预测的冠层通量对多个时间尺度上站点内部和跨站点特征多样性的敏感性。(3)气候、干扰和物种组成的变化将如何影响冠层通量？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，以及这些影响如何根据林区内和林区之间的特征多样性而变化。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势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.