Linked from
The 21 pages that link to Water-use efficiency, each with the reason it gives.
TranspirationRelated: Plants balance carbon uptake against water lost through transpiration.
StomataRelated: Stomatal regulation sets a trade-off between carbon uptake and water loss.
C3 carbon fixationRelated: C3 plants balance carbon uptake against water loss through stomata.
Water consumptionRelated: Reducing water consumed per unit of output is a common management goal.
EcophysiologyRelated: It connects plant gas exchange to drought response and carbon gain.