Forest hydraulic trait composition regulates regional scale terrestrial carbon cycling

Abstract:

Terrestrial ecosystems currently sequester ~25% of human carbon emissions annually, yet rapid changes in water availability have the potential to disrupt their resilience and role as a carbon sink. Tree hydraulic traits and local forest trait diversity have been shown to be critical for representing the underlying mechanisms governing forest productivity and mortality during periods of water limitation. Here, we leverage novel high-resolution maps of community weighted hydraulic traits and trait diversity based on species’ composition and abundance derived from >160,000 ground-based permanent plots across the contiguous U.S. combined with satellite remote sensing data of vegetation water content and productivity. We examine the sensitivity of regional scale carbon cycling to drought and relate ecosystem responses to community weight trait means and local trait diversity. Overall, these results link individual plant physiological responses to community weighted metrics and show that regional scale carbon cycling is sensitive to ecosystem-level metrics of drought vulnerability.