Abstract

FILIO-HERNANDEZ, E. et al. Seasonal water relations in four native plants from northeastern Mexico. Revista bio ciencias [online]. 2019, vol.6, e605.  Epub Oct 02, 2020. ISSN 2007-3380.  https://doi.org/10.15741/revbio.06.e605.

In the life of plants, water deficit is frequent, because availability of water is the first limiting factor of plant growth and yield. The present study related soil water content and evaporative demand components (air temperature, relative humidity and vapor pressure deficit) and precipitation with water potential in trees and shrubs of native species from northeastern Mexico: Prosopis laevigata (Fabaceae), Cordia boissieri (Boraginaceae), Helietta parvifolia (Rutaceae), and Karwinskia humboldtiana (Rhamnaceae). Water potentials were determined between August and October 2016 at 15 days-intervals at predawn and midday. Maximum and minimum seasonal predawn values ranged from -1.29 MPa (C. boissieri) to -5.10 MPa (H. parvifolia). At midday, it varied from -1.53 MPa (P. laevigata) to -4.0 MPa (K. humboldtiana). Water potentials at predawn and midday showed significant correlations with soil water content. In contrast, a negative relationship was observed with air temperature and vapor pressure deficit. On a diurnal basis, the species showed a typical pattern of variation in diurnal water potential, where it decreased from maximum values at predawn and reached minimum values at noon. This pattern was associated to evaporative demand components such as vapor pressure deficit, relative humidity, and temperature. Under low soil water availability, P. laevigata appeared to be the most drought tolerant species, since it showed less water stress compared to the remaining species.

Keywords : Prosopis laevigata; evaporative demand components; water deficit; water potential; drought.