Mapping hydroscapes' along the iso- to anisohydric continuum of stomatal regulation of plant water status

The concept of iso- vs. anisohydry has been used to describe the stringency of stomatal regulation of plant water potential (). However, metrics that accurately and consistently quantify species' operating ranges along a continuum of iso- to anisohydry have been elusive. Additionally, most approaches to quantifying iso/anisohydry require labour-intensive measurements during prolonged drought. We evaluated new and previously developed metrics of stringency of stomatal regulation of during soil drying in eight woody species and determined whether easily-determined leaf pressure-volume traits could serve as proxies for their degree of iso- vs. anisohydry. Two metrics of stringency of stomatal control of , (1) a hydroscape' incorporating the landscape of over which stomata control , and (2) the slope of the daily range of as pre-dawn declined, were strongly correlated with each other and with the leaf osmotic potential at full and zero turgor derived from pressure-volume curves.