American Journal of Environmental Sciences 1 (1): 46-49, 2005 ISSN 1553-345X © Science Publications, 2005 46 Vegetation Dynamics in the Tafileh Woodlands of Southern Jordan Saleh Al-Qura’n Department of Biology, Mu’tah University, P.O. Box 26, Karak, Jordan Abstract: Woodland vegetation in the Tafileh highlands of southern Jordan was investigated and quantitatively surveyed to determine the patterns of vegetation dynamics associated with altitude and topography. Three tree species (Juniperus phoenicea L. (evergreen needle-leaved woodland resistant to cold), Pistacia atlantica Desf. and Quercus aegilps L. (cold–deciduos broad-leaved woodland) and five shrubs (Colutea istria Miller, Gomphocarpus sinaicus R. Br., Thymelaea hirsute (L.) Endl., Crataegus aronia (L.) Bosc.ex DC and Daphne linearifolia Hart.) dominate the woody vegetation in the investigated area. Lower altitudes of southwest facing slopes demonstrate generally the higher plant densities than the higher altitudes of northeast facing slopes. Species segregation occurs on the basis of community ecological importance value depending on altitudes, slopes and human impact factor through grazing activities, wood gathering especially on plateau sites. Regeneration consequently negatively affected due to continuous reduction in species diversity and tree size distribution. Key words: Woodland, Vegetation, Phytogeography, Importance Value, Regeneration INTRODUCTION Jordan lies between longitudes 35° 40’ and 39° E and between latitudes 29° 30’ and 34° N in the transition region between zonobiome (with moist cold winters and dry hot summers) and the arid one. Jordan is of great interest in vegetation ecology because it is the meeting place of the Mediterranean, Irano-turanian and Saharo arabian regions or the Holarctic kingdom and the Nubo-sindian region of the palaeotropicl kingdom [1]. For this reason there are conspicuous changes in the vegetation and in the composition of the flora over relatively short distances (within 30 km on the western slopes of the border mountains). Tafileh mountain lies in the southern part of Jordan and has the highest highlands which supports the growing of forests and woodland vegetation, since of its unique climate and topography [2-4]. Although Tafileh mountain is dominated by the vegetation of the mediterranean phytogeographical element, but the presence of a mixture of other phytogeographical elemens is recorded within certain narrow slope strips especially which extended to the west towards the Jordan rift valley [5]. During the tertiary period, upheaval of mountains in the middle east brought about not only the physiographical segregation, but gave rise as well to climatic differentiation which serves to stimulate the diversity of plant species in highland areas [6]. In the investigated area, Juniperus phoenicea L., Pistacia atlantica Desf. and Quercus aegilops L. trees dominate the woodland vegetation where trees are festooned or sculptured with lichen species, while different fungus species are distributed on the ground below and it is speculated that the Tafileh mountains may have been the center of origin for these species from which it migrated to the lower peripheral regions south or west or even to the north [5, 7]. The study area is located 20 km south of Tafileh city in Al ata’ta mountain near Dana within Tafileh highlands at an elevation from 900-1500 m above the sea level. This area is dominated by sub humid and zonobiome conditions since it is influenced by the westerly and northerly fronts' currents associated with winter precipitation, so the cold snowy winter is the general climate. The mean annual precipitation is of 450 mm in winter while the spring months tend to be wetter with average precipitation about 150 mm. The mean summer temperature is 24°C while from 2-6°C is the average winter temperature. The mean evapotranspiration rates are 1300 mm/year. The ridges in the highlands are remnants of the lime stones and to a lesser extent with metamorphosed intrusive. Massive undifferentiated sand stones (so-called Nubian sand-stones of the Cambrian formation are dominant. Lime stones and dolomites, chalky marls and clays of the cenomanian and santonian-turonian [8, 9]. The soil parent material consists of metamorphic rocks with 6.5-7.0 pH, the soil texture ranges from loamy silt to silt clay to gravel clay. The first 15 cm often produces an average of 10% organic matter indicating the favorable climatic conditions for plant growth and development. It is clear for long period of time, inhabitants and residents have largely impacted adjacent woodlands by different ways and methods to get pasture, timber for fuels and building materials and implements which give a real evidence that these pressures influenced by the