Extended Data Fig. 1: Relationship of W to sample year.
From: Diminishing CO2-driven gains in water-use efficiency of global forests

For all 422 tree-ring isotope series containing data from the period 1851–2015, W was calculated using Equation 3.
From: Diminishing CO2-driven gains in water-use efficiency of global forests

For all 422 tree-ring isotope series containing data from the period 1851–2015, W was calculated using Equation 3.