Understanding the vulnerability of forest ecosystems to climate change is critical for anticipating the potential of future forests to serve as “sinks” for anthropogenic CO2 emissions, to provide habitat for other species, and to regulate the hydrological cycle. The Kueppers lab group aims to understand how forests change in structure and distribution as a consequence of climate warming and related changes in hydroclimate. Our novel Alpine Treeline Warming Experiment investigated how warming affects tree recruitment within and above Rocky Mountain subalpine forests. Our tropical forest research on shifts in forest functional composition with precipitation variability is part of the Next Generation Ecosystem Experiments – Tropics project. In addition to field observations we also use demographic models of plant species and functional types to understand the pace and dynamics of forest change. Go to the Kueppers Lab Group website.