Effect of irrigation water salinity on the growth of trees for revegetation in the United Arab Emirates

Abstract

In the United Arab Emirates (UAE), 4 local tree species, Prosopis cineraria, Acacia tortilis, Zizyphus spinachristi and Salvadora persica, are mainly used for afforestaion. Salt tolerance was in the order of S. persica > P. cineraria ≥ Z. spina-christi > A. tortilis. The growth (height, basal diameter and area of canopy) of 4 tree species and EC of irrigation water and saturation extract of soil (SES) in the afforestation areas in UAE were investigated. EC values of irrigation water were between 0.67 and 15.80 dSm-1, and exceeded 10 dSm-1 in more than 50% of the areas. EC values of SES were increased with increasing EC of irrigation water and ranged from 1.78 to 31.96 dSm-1. A. tortilis tended to be planted in the areas with lower salinity water and S. persica with higher salinity water. From the comparison between the growth of trees on high salinity soil (EC of SES was above 10 dSm-1) and low salinity soil (EC of SES was below 10 dSm-1), salinity stress obviously decreased the growth of A. tortilis, but slightly that of P. cineraria and Z. spina-christi.