Evaluation of soil physiochemical properties and regeneration of Prosopis cineraria (L.) Druce stands in southern Iran

The objectives of this study were to evaluate the soil physiochemical properties and regeneration of Prosopis cineraria in Bushehr and Hormozgan provinces, and to determine the most important soil factors effecting P. cineraria distribution and regeneration establishment. For this purpose, we selected four natural pure sites including Chah Mobarak, Nakhl Ghanem, Amani, and Bahdeh in Bushehr and Hormozgan provinces. In each site, five 25*25 m plots were randomly selected and soil samples were taken in each plot in two depths of 0-5 and 6-25 cm. Also, all of the regeneration in each plot, were counted and categorized based on their height (seedlings, <10, 11–25, 26–50, 51–75, 76–100, 101–130, 131–200 and >200 cm height). Collected soil physiochemical data and regeneration classes were subjected to one-way ANOVA. Result indicated that the highest and lowest amount of soil calcium carbonate belonged to the Amani (57.28%) and Bahdeh (80.6 %) sites, respectively. However, no calcium carbonate was observed in Chah Mobarak and Nakhl Ghanem sites. The maximum and minimum soil electrical conductivity belonged to the Chah Mobarak (5.58 ds/m) and Bahdeh (1.28 ds/m) sites at the depth 0-5 cm, respectively. Furthermore, the highest amount of calcium carbonate were recorded in Bahdeh (77.7 %) and Amani (55.4 %) at the depth of 6-20 cm. Soil Organic matter (1.24 %) and nitrogen (0.12 %) were greater in Nakhl Ghanem compared to other sites. Results of regeneration indicated that there are significant differences among the studied sites. Furthermore, Nakhl Ghanem, Amani, Bahdeh, and Chah Mobarak had 3814, 1491, 2813, and 3088 regeneration per ha. No regeneration was recorded in Amani and Bahdeh for >200 cm height class. Based on the results, the most important soil factor effecting P. cineraria distribution are silt followed by sand, potassium and clay. Moreover, nitrogen is an essential soil element in P. cineraria regeneration establishment. However, calcium carbonate and electrical conductivity had negative effects on P. cineraria regeneration and should be considered in plantation plans.