Terrestrial systems in the northern high latitudes have exhibited extensive changes in response to warming climate over the past decades. Changes in plant productivity and transpiration, animal phenology and behaviors, disturbances in landscape surficial and belowground processes have been projected to impact regional hydroclimate and carbon budgets through atmosphere - vegetation - cryosphere interactions. This session solicits contributions of observational and modeling studies to advance our understanding of relevant processes. Topics of interest include but are not limited to dynamics of vegetation structure, form, and productivity, water, energy, and carbon cycles, vegetation-animal feedbacks, and hydroclimate impacts on runoff processes, earth-surface erosion, and subsurface freeze-thaw processes. Theoretical analyses and model simulations using in-situ or remote sensing observations at various spatial and temporal scales are also encouraged.