Understanding the structure and function of the tissues that transport water and sugars in plants—xylem and phloem—is essential for predicting and managing the future of both agricultural and natural ecosystems and how they respond to stress. Yet, there are large gaps in current knowledge about how these tissues are organized, how they interact, and how they respond during drought. This project will test hypotheses for how the coordinated anatomy and physiology of leaf carbon and water transport determines the growth, drought resilience, and geographic distribution of plant species, for a wide range of species of herbs, shrubs, and trees from across the US. By combining measurements of xylem and phloem function with state-of-the-art mechanistic models at different scales (leaf, whole plant and ecosystem), the project team will generate fundamental discoveries and resolve how the leaf carbon and water transport systems contribute to whole plant and ecosystem function. This project will benefit the American public more broadly by creating unprecedented databases for leaf structure and function and plant responses to drought, by training undergraduate students in methods of research, data analysis, and writing, and—in collaboration with artists—by developing workshops to transform scientific research into creative public engagement, combining lectures, demonstrations, and hands-on activities, including creation of visual pieces and augmented- and virtual-reality experiences. Further, the project will include outreach to the grape and wine industry, highlighting new discoveries, as the interaction between sugar and water transport in grapevine leaves strongly influences grapevine stress responses and wine quality. The goal of this research is a mechanistic understanding of the variation in leaf xylem and phloem traits and their coordination and dynamics during drought, and implications at tissue, organ, plant and ecosystem levels. First, the project will break new gr