Instrinsic water use efficiency of Ponderosa Pine of the southwestern U.S.

Tree rings were collected from 17 populations of ponderosa pine forests across the southwestern U.S. Carbon isotope of early wood and latewood were then analyzed for each annual ring, from 1960-2017. Intrinsic water-use efficiency (A/gs) chronologies were calculated with adjusted latewood chronologies as used in Strange et al. (2023) Global Change Biology. Details regarding the process of calculating adjusted latewood chronologies can be found in the methods section of Strange et al. (2023) Global Change Biology.