Final Report: Evaluating the Influence of Plants on Hydrologic Cycling: Quantifying and Validating the Role of Plant Processes and Stomatal Conductance

Summary

This project, funded by the U.S. Department of Energy from September 2020 to September 2024, investigated the influence of plant processes on global hydrologic cycling and climate models. Researchers quantified how leaf, organism, and community-level plant processes, particularly stomatal conductance and leaf area changes, contribute to uncertainties in predicting precipitation, evapotranspiration, and runoff under increasing CO2. Key findings from 12 publications include an observed 22.9% increase in net photosynthesis and a 32.1% decrease in stomatal conductance over the past century (1901-2014), and that global mean land surface temperature can vary by 2.2°C due to land parameter uncertainties. The study also revealed that assumptions about plant water use strategy modify the total global photosynthetic response to elevated 2x preindustrial CO2 by 6.4% to 9.6%, highlighting the need for improved plant process representation in climate models.

Key Facts

Source Document

https://example-government.gov/policy-document-link