the effect of soil physico-chemical properties on gum arabica (acacia arabica, wild var. nilotica) vegetative characteristics (a case study at kosar 3, flood water spreading station, in tangestan, bushehr province)

rehabilitation of arid and semi-arid regions by tolerant native plant cover is a primary concern to create a sustainable balanced ecosystem. thus, the existing plant species of the region should be recognized together with a comprehensive survey and study of the environmental factors such as climate and soil conditions which affect the establishment of these plant species. this paper attempts to examine the effects of soil physico-chemical properties on some distinctive vegetative characteristics of gum arabic (acacia arabica wild var. nilotica), in tangestan flood water spreading experimental station at bushehr province. a cluster sampling scheme was designed and applied. each cluster consists 4 square sample plots, each 1600 square meter (40×40 meters). the vegetative characteristics (collar diameter, tree height, crown diameter at two major directions) were measured and recorded carefully. at the center of each cluster, soil samples were collected at 0-20 and 20-45 cm depths to evaluate major soil characteristics such as soil acidity, electrical conductivity, nitrogen, phosphorus and potassium content and sand, clay and silt percent. for the analysis of variance, the factorial experimental in completely randomized design was used. the comparison of means was done using duncan's new multiple range tests. the results suggest a significant difference at one percent statistical error level between the mean collar diameters of upland and downland subdivision basins, where, downland exhibits more favorable condition. the canonical correlation analysis suggests a significant correlation at one percent statistical error level between vegetative characteristics of gum arabic and some distinctive soil properties, i.e., the finer soil texture results a better condition for crown canopy development.