Trees contribute to the carbon, water and nutrient cycles in forested systems and impact the weathering engine that shapes landscapes and soils.  On the other hand, the water, soils and landscapes also affect trees, sometimes determining species or size distributions and other characteristics of forests. To understand the influence of trees in shaping the critical zone requires a multi-disciplinary approach. This workshop will host 20 to 25 people from ecology, physiology, hydrology, geochemistry, soil science, and geology who will spend 2.5 days outlining a research agenda to understand the tree-landscape interface.  The goal of the workshop is to produce a Vision Paper describing the research agenda for the next five years and to show how this agenda can be addressed at CZOs and other similar settings. A sub-team of authors will emerge from the broad group as determined by effort and interest.