مقايسه پوشش گياهي زير و خارج تاج گونه كهور آمريكايي Prosopis juliflora (SW.) DC در استان هرمزگان

Comparison of vegetation cover under canopy cover and open area of Prosopis juliflora (SW.)DC in Hormozgan province

Prosopis juliflora is a thorny, large-crowned, evergreen tree with deep as well as lateral root system, belongs to Mi-mosaceae family. It is a fast growing species. The green leaves of the species are not palatable for the animals. Introduction of Prosopis juliflora to Iran such as other none native species, has not been carried out, according to a written program. Prosopis juliflora is called under different Persian names in cultivated areas at coastal southern Iran especially Hormozgan province. Lack of real ecological information about this species and potential of native vegetation and because of easy establishment of Prosopis juliflora, its high resistance to environmental condition and its ready environment adaptation have gained it good acceptance for forestation programs particularly in sand dune stabilization without pay attention to some influence of Prosopis juliflora on natural vegetation and agricultural lands. Generally, the characteristics of drought hardiness and good performance of Prosopis juliflora in different ecological regions of south of Iran make it a prime candidate for use in forestation programs aimed at fodder production, as well as for provision of wind breaks and shading. Prosopis juliflora regeneration occurs naturally and can be seen growing on river banks, alluvial soils and barren lands where animal graze freely. Animal feeds on fallen pods and then disseminate the seeds encapsulated in their dropping. After the rain, seeds start to germinate and, if conditions are favorable, they become seedlings and later trees. This research work has the objective of determining of effect of Prosopis juliflora on annual vegetation under canopy cover in Hormozgan province were carried out on three different sites namely Bandar Abbas, Minab and Sirik, with purpose of devising future strategies for utilization Prosopis juliflora in future forestation programs. The results showed that percent cover of annual vegetation including grasses, forbs and total of percent cover under canopy and open area in years when rainfall is high, have significant difference but in years with low rainfall there is not significant difference between percent cover under canopy and open area in all sites.