Intrinsic water-use efficiency (W
i
) reconstructions using tree rings often disregard developmental changes in W
i
as trees age. Here, the authors compare W
i
across varying tree sizes at a fixed CO2 level and show that ignoring developmental changes impacts conclusions on trees’ W
i
responses to CO2 or climate.
- R. J. W. Brienen
- E. Gloor
- M. Timonen
