1. THE STUDY SITES The study was conducted in Begasheka and Debreikidan watersheds, Tigray, northern Ethiopia (Fig. 2) Life forms Life forms 19 woody plant species were identified and the life form composition is indicated in table 1 Table 1 Life forms (from Debrekidan watershed) indicating regeneration status of four dominate species DSH vs Biomass CONCLUSION From this reach it was possible to draw the following two major conclusions: The enclosures in both sites haven given a considerable amount of biomass production & regeneration capacity which can offer some socio-economic benefit in addition to the environmental service to the community Though, the regeneration pattern of most species in the enclosures is expanding type, some species like Senna sengueana, Mytenus senegalnesis, & Olea africana formed distorted type of natural regeneration curve, which is an indicator of interference. The potentials of enclosures in increasing woody biomass & regeneration (A case study of Begasheka and Debrekidan watersheds, Tigray, northernEthiopia) The potentials of enclosures in increasing woody biomass & regeneration (A case study of Begasheka and Debrekidan watersheds, Tigray, northern Ethiopia) Ermias Aynekulu 1* Emiru Birhane 1 and Nigussu Begashaw 1 1 Faculty of Dryland Agriculture and Natural Resources, Mekelle University, P.O.Box 231, Mekelle, Ethiopia * Corresponding author: e-mail: ermias8@yahoo.comermias8@yahoo.com Fax: +251 344 409304 Fig. 2 The study sites: Debrekidan (right-top) and Begasheka (right-bottom) on the map of Tigray METHODS The procedures followed in the study is summarized in Fig. 3 Watersheds delineated using GPS Random plots generated using excel Plot centers navigated using GPS Inventory made on each plot Fresh & oven-dried wt. of samples taken based on diameter class Regeneration & diversity of species analyzed Biomass & regeneration in the enclosures Fig. 3 Schematic diagram depicting the major process of the study Fig. 4 Biomass field data collection (top and bottom) Plant name Number of seedlings Number of saplings Number of trees Becium grandifoliume23852 Dodonea Angstofolia576417 Euclea shcimpri228530 Acacia saligna103210 All species39924389 RESULTSSummery Biomass produced in the Begasheka and Debre-kidan were 6.86 ton/ha and 3.8 ton/ha respectively. 745 individuals representing 30 species & 731 individuals representing 19 species were found in Begasheka & Debre-kidan respectively. Fig. 5 The structural composition of the all species was found to be healthy in both Debrekidan (left) and Begasheka (right) watersheds Fig. 6 Diameter at Stump Height (DSH) poorly explain the variability in biomass (example from Debrekidan watershed) From the two watersheds, 45 plots with a radius of 5.6 m were used in this study and laid down randomly in the enclosures. Height, diameter at stump height (DSH), diameter at breast height (DBH), Crown diameter, number, identity and life forms were recorded. Single tree-sampling method, destructive, was used to estimate the above ground woody biomass of each species. Sample trees were cut, dried in oven to estimate their moisture content and biomass.INTRODUCTION General: Area closure development is one of the most commonly practiced strategies to restore degraded dryland environments in most part of Northern Ethiopia. However, Performance of closures are not well studied, High scarcity of fuel wood in the area, competes with protection Unwise utilization of resource developed after rehabilitation Therefore, it was necessary to study the impact of area enclosures on enhancing woody biomass accumulation, & regeneration pattern in order to determine future development of enclosures. Fig. 1 Impact of enclousre in vegetation cover in Begasheka watershed: Unclosed & degraded area (left) and enclousre (about 10 years) showing restoration of vegetation (right).Objective: General General Investigate the role of enclosures in rehabilitating degraded drylands that would ultimately offer viable promises for both environmental & socio-economic benefits to the society.Specific Estimate the biomass accumulated in the enclosures in the study area Assess regeneration of species in the enclosures