Seasonal ecophysiological responses and behavior of phillyrea latifoliaspecie to climate change in Tunisia

Résumé

Abstract Background As part of global climate change, variation in precipitation in arid ecosystems is leading to plant adaptation in water-use strategies; significant interspecific differences in ecophysiological response will change the plant behavior. The mainaim of this study was to investigate the ecophysiological responses of Phillyrea latifolia species to seasonal drought stress. Measurements were conducted between March and December 2018. The parameters studied were the Leaf Water Potential (ψ leaf ), Net photosynthesis (Pn), stomatal conductance (gs) and leaf transpiration (Tr), maximum efficiency of PSII photochemistry (Fv/ Fm), and Hydraulic conductivity. Main results The results showed that all measured parameters varied significantly with the season(P <.0001). The results of ψ leaf showed the highest average in summer (−2.99±0.08 MPa). Likewise, the highest values of the maximal photochemical efficiency of PSII (Fv/Fm) were observed in summer (0.83±0.06). However, the highest values of Pn (3.62±0.41 µmol m -2 s -1 )and Tr (0.3±0.028 µmol m -2 s -1 ) were noted in autumn. The Initial Hydraulic Conductivity ( K in ) value was in spring (1.34 -04 ±110 -5 mmol s -1 m -2 MPa -1 ) and autumn (1.1810 -04 ±2.3010 -6 mmol s -1 m -2 MPa -1 ) and the Maximal Hydraulic Conductivity ( K max ) was the highest during the spring season (3.4510 -04 ±2.7010 -11 mmol s -1 m -2 MPa -1 ). The results of the Stomatal Conductance (gs)were showed that the lowest values were recorded in summer (0.19±0.04 MPa). The percentage of loss conductivity (PLC) reached 66%. During the spring season, the soil had a decreasing moisture profile as it moved to the depths and varied from 15.23±5.48% at 20cm to 6.26±2.46% at 80 cm. Conclusions The best physiological performances of Phillyrea latifolia reported in spring and autumn may be attributed to favorable environmental conditions. The answers depend not only on the specie but also on the climates in which they grow.

Citer ce document

Accès au document

Ce document est hébergé sur son dépôt institutionnel d'origine.

Auteur(s)

Statistiques

Consultations : 1

Téléchargements : 0