Soils drive convergence in the regulation of vascular tension in land plants

This article examines why diverse land plants regulate water transport within a surprisingly narrow range of leaf vascular tension. Based on a meta-analysis of 19 species and a theoretical model of soil water extraction, the authors show that stomatal regulation of transpiration is activated around a common threshold of 1,3 ± 0,6 MPa. The study suggests that soil physical constraints help explain universal patterns in plant water relations and the limits of water extraction under drying conditions.