Plant-water relations in native shrubs of northeastern Mexico

Abstract

The aim of the current study was to establish how the xylem water potential (Ψ) in native shrubs such as Condalia hookeri, Cordia boissieri, Prosopis laevigata and Celtis pallida is influenced by soil water content, air temperature, relative humidity, and rainfall. Ψ was estimated at 15 days intervals between February 21 and June 30, 2017 in five different plants per species at 06:00 h and 14:00 h. During the wettest period, Ψ ranged from -0.67 (C. pallida) to -0.96 MPa (C. hookeri), in contrast, at the driest period, Ψ varied from -1.52 (P. laevigata) to -2.92 MPa (C. hookeri) at 06:00 h. At 14:00 h, C. pallida and C. hookeri achieved the highest (-1.07 MPa) and lowest (-3.10 MPa) Ψ values, respectively. Ψ at 06:00 h and rainfall were significantly and positively correlated with Ψ at 14:00 h; whereas the soil water content at different depths with Ψ values at 06:00 h was weak. P. laevigata and C. pallida maintained high values in Ψ at 06:00 h and 14:00 h under water stress conditions, so these species may be considered as drought tolerant species.