The Incremental Assessment, Mixture Effect, Soil of Eucalyptus Camaldolensis (Dehn) and Prosopis Juliflora (Sw.) D.C.Plantations in Laleh Forest Park of Dezful

Knowing the qualitative and quantitative characteristics of plantation is principal of forest management. Laleh Natural Park in DEZFOUL, with a total area of 9.31 hectares, is located 11 km far from Dezful. The 23-year old stands in the studied park were Eucalyptus and Prosopis. In order to study the number of trees, according to the small levels of the studied stands (pure Eucalyptus 1.9 hectare and mixed with Prosopis 1.7 hectare), the full calipering inventory method was selected and the certain characteristics such as diameter at the breast height and height of all trees. According to the results, the average number of trees in the pure Eucalyptus stand is equal to 110.5 trees per hectare, the average diameter at breast height of stand is 25.22 cm and the average total height is 12.10 m. Also, the average number of species in the mixed Eucalyptus and Prosopis stand is 70.6 trees per hectare, the average diameter at breast height is 27.32 cm and the average total height is 9.57 m. In order to study the effect of Eucalyptus and Prosopis on the soil of the area, 50 soil samples were taken at 2 depth of 0-10 and 10-20 cm from pure and mixed stands and some soil characteristics including texture, moisture and acidity were studies. Soil texture of both stands in this study was loam. There was no significant difference between the two populations in terms of total relative humidity. In terms of acidity, there was a significant difference between two soil depths of 0-10 and 10-20 cm soil in the pure stand which was higher at depth of 10-20 cm.