Observations and simulations of the terrestrial carbon and water budget are fundamental to understanding biosphere-atmosphere interactions under a changing climate. A wide range of processes, covering various spatial and temporal scales, influence the response of terrestrial carbon fluxes (NEE, GPP, TER, fires, methane, lateral export) to changes in land and atmospheric moisture availability. The vegetation and soils also contribute to regulating land-atmosphere moisture fluxes (evapotranspiration, precipitation), which in turn feeds back to the water cycle and the climate system. Observations or modeling assumptions made at different spatial and temporal resolutions also pose new challenges in terms of scaling and uncertainty quantification.

This session aims to synthesize our current understanding and identify knowledge gaps and transferability across scales, We encourage contributions exploring carbon-water interactions from multiple perspectives (remote-sensing, experimental, modelling) and covering all types of biomes (boreal, temperate and tropical forests, grasslands, wetlands, …). Contributions might include for example: 1) disentangling the impact of co-varying drought-driven changes to soil moisture, vapour pressure deficit, or temperature on land carbon fluxes, 2) using in-situ or satellite observations to evaluate or improve the representation of water-carbon interactions and biological processes in models, 3) developing and implementing new representations of plant and ecosystem responses to land and atmospheric moisture stress (e.g. through plant hydraulics, optimality approaches, etc.) and 4) scaling carbon- water interactions from the leaf-level to the global scale and bridging the gap between data streams taken at different temporal and spatial scales (e.g. using modeling, theoretical or statistical approaches).

Solicited speaker: Alexandra Konings, Stanford University