Akhdar Region Research Articles

Plant neighbourhood effects on insect herbivores associated with Junipers and Pistacia in Cyrenaica- Libya

This research set out to test whether there are neighbourhood effects on insect herbivory among the plants of the Al Jabal Al Akhdar region of Libya. Neighbouring plants in the locale of an individual plant might help or hinder it in the task of defence against insect herbivores, depending on their levels of defence (chemical or physical), and their interactions with potential herbivores. Such ‘neighbourhood effects’ are part of the complex network of species interactions that structure ecological communities. Having chosen to concentrate on the two main species of three study sites, Juniperus phoenicea and Pistacia atlantica, nine plots were mapped in detail and the insect herbivores sampled from focal plants, and then from all plants. Plant leaves of Juniperus and Pistacia were sampled for chemical analysis of their phenol content. Phenol levels were much higher in Pistacia (2308 ± 43 ppm, n = 45), than in Juniperus (1516 ± 43 ppm, n = 45), and there were effects of elevation as well, plants from middle elevation plots had the highest levels, while those from the lowest elevation at the coast had the lowest levels of tannins. The number of individual insects per plant was affected by the neighbourhood in both Pistacia No. individuals on the nearest conspecific (x2 = 5.22, df = 1, P = 0.022) and No. individuals on the nearest allospecific (x2 = 52.12, df = 1, P = 0.00) and Juniperus No. individuals on the nearest conspecific (x2 = 43.89, df = 1, P = <.001) and No. individuals on the nearest allospecific (x2 = 93.89, df = 1, P = <.001). There were clear effects of neighbouring plants on the density of insects of individual plants, in both Pistacia and Juniperus. From analysis result we found that the number of insect herbivores were a strongly affected by the local neighbourhood plant species, which attacked the focal shrubs (Juniperus sp and Pistacia sp) in the study sites, where the number of insect herbivores were not affected by the same neighbourhood (surroundings) plant species, however, the different neighbourhood plant species affected in each insect herbivores. There were no signs of any protective neighbourhood effects of tannin levels. Thus in the plant communities of Al Jabal Al Akhdar, associational avoidance appears to be the major mechanism of neighbourhood effects, rather than associational resistance.

Detecting NDVI & LST in the municipalities of Al Jabal Al Akhdar Region – Libya using remote sensing and GIS

Detecting NDVI & LST in the municipalities of Al Jabal Al Akhdar Region – Libya using remote sensing and GIS

The Ediacaran Hiyam Formation: A zoom through the diagenetic and structural complexity of the metamorphic Hi2 Member, Saih Hatat Dome, Oman Mountains

This is the first diagenetic study of the metamorphic upper Hiyam Member “Hi2” of the Saih Hatat Dome. Despite metamorphism, texture and paragenesis of the Hi2 Member are so well preserved that it is possible to unravel its diagenetic evolution. We applied lithological and structural field methods, transmission and cathodoluminescence microscopy to establish the paragenetic sequence and vein-forming deformation. Our work reveals a complex diagenetic and structural history, including several alternating dolomitization, calcite precipitation, silicification and fracturing events. Most of the replacive dolomite and silica are linked to early diagenesis under intertidal to sabkha and restricted marine as well as to terrestrial conditions. Evaporation of sea water concentrated Mg2+ and triggered extensive early dolomitization while silica-bearing fluids caused local silicification. Various generations of dolomite and calcite cements pervasively occluded macropores, micropores and veins. Late burial is reflected by pressure solution seams/stylolites, non-ferroan to weakly ferroan saddle-type dolomite cement and non-ferroan blocky and drusy calcite cement, filling veins and macropores. The various generations of calcite cements (e.g., in veins) are considered to have formed during burial or possibly meteoric conditions. The latter potentially resulted from tectonic uplift, while late dolomite cement displays hydrocarbon residues from coeval oil migration. A later minor oil migration event has also been recognized. Initial fracture/fissure formation is most likely related to folding during the Early Cambrian Angudan Orogeny (open NW-SE fractures) and to divergence during the Late Paleozoic Pangean/Neo-Tethys rifting (open NW-SE fractures). Metamorphism impacted the Hi2 Member, resulting in phyllite formation, phyllosilicate crystallization and ductile shearing. Metamorphism occurred during shallow Late Cretaceous subduction. Striking lithological similarities between the Hi2 Member and that of the upper Kharus Formation of the Jabal Akhdar region could indicate their lateral equivalence.

Showcasing the multifaceted aspects of agricultural transformation: The example of mountain oases in Oman.

In the Anthropocene the consequences of land-use transformation on ecosystem services are of growing concern, particularly in fragile areas of mountain agriculture that often represent high nature-value farmland. This study uses a decadal repeated survey approach to analyse the effects of modernisation on oasis systems in the Jabal Al Akhdar region of northern Oman. This rugged mountain region at the north-eastern tip of the Arabian Peninsula experiences a growing influx of regional and international tourists since the opening of a modern highway 15 years ago. In 2007, at the onset of transformation processes, a survey was conducted with all households (HH) located in three major settlements along the 1000-m-altitude gradient of the Wadi Muaydin watershed. The survey was repeated in 2018, including all remaining HH of the three settlements. This longitudinal approach allowed studying the consequences of social-ecological transformation processes on crop and livestock husbandry, agricultural labour use, product marketing, and perception of the region's future by its local residents. Though the village inhabitants are aging and declining in numbers, they still adhere to agriculture, largely because of tradition and identity. Fallowing and abandoning farmland increased over the investigated time span but was paralleled by increased application of agrochemicals and animal manure on fields, purchase of roughage and concentrate feeds for small ruminants, concentration on cash crop and meat production for sale, and increased employment of migrant workers. These indicators of modernisation of oasis agriculture are accompanied by predominantly pessimistic views on future prospects of oasis farming. Commonly perceived problems are shortage of irrigation water and profound societal change. Against these challenges, value chain generation and direct marketing opportunities for local agricultural produce are seen as prerequisites to keep the high nature-value farmland of these mountain oases alive.

Response of Potential Indicators of Soil Quality to Land-Use and Land-Cover Change under a Mediterranean Climate in the Region of Al-Jabal Al-Akhdar, Libya

Conversion of native lands into agricultural use, coupled with poor land management practices, generally leads to changes in soil properties. Understanding the undesirable effects of land-use and land-cover (LULC) changes on soil properties is essential when planning for sustainable land management. This study was conducted in Al Jabal Al Akhdar region, Libya, to assess the effects of land-use and land-cover changes on soil quality inferred by analyzing the relative changes in 17 chemical, physical, and biological soil properties in the upper layer (0–20 cm) of disturbed and undisturbed soil systems. Soil samples were collected from 180 sampling sites with 60 from each of the three types of LULC prevalent in the study area: natural Mediterranean forests (NMF), rainfed agriculture (RA), and irrigated crops (IC). The soil properties of the two agricultural land uses were compared with soil properties under an adjacent natural forest, which served as a control to assess changes in soil quality resulting from the cultivation of deforested land. The results indicate significant reductions in most soil quality indicators under rainfed agriculture as compared to native forest land. Under irrigated agriculture, there were significant changes (p ≤ 0.05) in most of the soil quality indicators, generally, indicating a significant reduction in soil quality, except for improvement of nitrogen and phosphorus levels due to frequent fertilizer application. Our data support the notion that changes in land use and land cover, in the absence of sustainable management measures, induce deterioration of soil properties and ultimately may lead to land degradation and productivity decline.

Quality assessment of the surface and underground water in the region of Al Jabal Al Akhdar, Libya

Surface and groundwater are the main sources of water supply in Libya. This study aims to assess the water quality index for drinking and irrigation purposes. 15 surfaces and 47 groundwater samples are collected in an area where lies in Al Jabal Al Akhdar region, northeast Libya. Water quality parameters such as temperature (T), pH levels, EC, TDS, TH, TAK, major cations ( Ca2+, Mg2+, Na+, K+ and NH4+) and major anions (Cl-, PO43-, HCO3-, NO3-, SO42- and NO2-) were measured. Water quality indices including SAR, % Na, RSC, PI, MH, Kelly’s Ratio and PS were also computed. Main water types were classified based on Piper trilinear diagram. The results revealed a basic pH level for surface water with a maximum level of 7.88. In addition, it is also exhibited a basic pH level for groundwater in the wet season and changed from acidic to basic in the dry season with a maximum level of 8.1. This indicates high-level concentrations of bicarbonate in water samples as measured. It observed that the ratio between TDS and EC increased with the decrease of pH levels, which indicates more releasing inorganic matter. Calcium and sodium are the dominant cations while Bicarbonate and sulfate are the dominant anions in water samples. Based on the U.S salinity, the Wilcox, and the Doneen classifications, the obtained results revealed that the surface water is suitable for drinking and irrigation purposes. Meanwhile, the groundwater is classified between excellent and doubtful except for some samples that were classified as unfit for irrigation purposes. Furthermore and based on the Piper diagram, the water types are classified as calcium sulfate, sodium chloride and as calcium bicarbonate. The water statuses categorization, based on the computational method of water quality index for drinking and irrigation agree with that concluded by US salinity, the Wilcox, and the Doneen diagram.

Impact of Edaphic Factors on Vegetation Composition in Al-Jabal Al-Akhdar, Libya

AL JABAL Al Akhdar region is a typical mountainous ecosystem, North East Libya characterized by unique environment in the Middle East. The aim of this study was to examine the spatial pattern of vegetation composition and its relationship with environmental variables in Al Jabal Al Akhdar. Vegetation sampling was carried out using 63 stands on studied seven wadis, distributed at Al Jabal Al Akhdar. The results showed that the study area is the home of 91 species, belonging to 85 genera and 44 families. Twelve of the recorded species are endemic and endangered plants. Application of TWINSPAN program and (DCA) resulted in identification of seven vegetational groups (from A to G) at cut level three of the TWINSPAN classification. Using Canonical Correspondence Analysis (CCA) against the soil variables revealed that the most important correlation of environmental variables with species distribution in Al Jabal Al Akhdar are chloride content, pH value, silt content and major cations (Na+ , Ca+2, Mg+2 and K+).

Terrace agriculture in a mountainous arid environment – A study of soil quality and regolith provenance: Jabal Akhdar (Oman)

In the Sultanate of Oman remnants of deteriorating terrace agricultural systems offer important insights into long-term human adaptation in the arid tropics. Irrigation and terrace agriculture in the mountainous Jabal Akhdar region reveal historic agricultural practices in a rugged, high elevation context. The present study examines soil quality and regolith provenance in abandoned agricultural soil terraces. Three soil profiles in each of the Villages of Hadash and Wijma were excavated and analyzed. Physical, chemical and mineralogical analyses were conducted for all soil horizons. In addition, six other soils, 3 possible soil parent rocks (regolith) and soil’s bedrock were collected. Soil ages were constrained by 14C assays and stable isotope, (13C and 18O) on the bulk carbonates in the calcrete (caliche). The results demonstrate that both sites display poor soil quality with very low average total organic carbon (TOC) (6.2–5.0 g kg−1) and mean weight diameter (MWD; 0.27–0.48 mm), with low water stable aggregate content (<42%). All the geochemical, mineralogical and the thin section analyses show that the soils exhibit unique characteristics that differ from those of other sediments (possible parent regolith) and soils in the vicinity. The finding of ostracod shells in the soil terraces in both areas and 14C dating of calcrete (10.193 ± 30–13.887 ± 40 a BP) indicate that regolith was human-transported to terraces to create soil. The 14C ages of the bulk carbonates match well with a dry period of high calcite precipitation contemporaneous to the Younger Dryas. The Hadash and Wijma soil terraces are located ~45 km away from each other, but still display significant similarities in terms of regolith provenance and soil development and were likely filled with regolith from the same source. These results offer new perspective on agricultural terrace development and oasis agriculture in a rugged, high-elevation, arid environment.

Quantitative estimation of complex phosphate - solubilization by immobilized or free Azospirillum Lipoferum (H3) as vital vaccine in Pikovskaya broth (PVK) medium

Azospirillum species were collected from the rhizosphere and free soil of different plants in Al-Jabal El- Akhdar region. The isolates were identified according to biochemical activities. Isolate (H3) which showed the higher solubilization efficiency (SE) on Pikovskaya medium (PVK) containing insoluble phosphate (inorganic phosphate) Ca3(po4)2 Isolate (H3) was identified as Azospirillum lipoferum (H3), which used as an inoculum as free cell suspension or as alginate formulation. Phosphate solubilization was measured by A.lipoferum (H3) as free or alginate immobilized cells in (PVK) liquid medium and recording the pH of the medium at the same time. The results showed in the phosphorus content by immobilized bacteria in liquid (PVK) broth medium from 2nd day of incubation (2.48 µg/ ml) to 10th day (3.70 µg/ ml) and the free bacteria from 2nd day (8.81 µg/ ml) to 10th day (4.49 µg/ ml). pH of the liquid (PVK) broth medium was recorded from 2nd day to 10th day after incubation which decreased by immobilized A.lipoferum (H3) from 7.00 pH to 4.47 on the 10th day and by the free A.lipoferum (H3) to 6.00, which improved the production of organic acids from sugars which was response of decreasing the pH of the medium. This present study contribute to make agriculture more productive with less harm to the environment and for developing countries where the use of fertilizers is costly, and to encourage of using the biofertilizers ‘plant growth promoting rhizobacteria’ (PGPR) instead of the chemical fertilizers to enhance the plant growth which is the main goal to increase the food production in a healthy way.

Monitoring of Land Degradation and Desertification in the South of Jabal Al Akhdar Mountain in North East Libya

Over the last few decades, global warming and human activities have led to changes and deterioration in natural vegetation across the world. Land degradation in arid, semi-arid areas led to the emergence of desertification especially areas that are located along the desert margins. The Al Jabal Al Akhdar Mountains (The green Mountain) in the north east Libya is one of those areas that have experienced changes in vegetation cover. This region has environmental and economic importance in providing habitat for wildlife and services for local communities and cities in the Libyan Desert. This research will investigate natural vegetation dynamics in the Al Jabal Al Akhdar region using remote sensing techniques in an attempt to monitoring the desertification over the last 42 years to determine the factors that have caused this problem. The overall aim of this paper was to evaluate the factors which have affected vegetation cover change in the Al Jabal Al Akhdar region over the last 42 years.

GIS-Based Groundwater Information System (GWIS) of Al Waseetah area: Case study

Since groundwater is the main water resource in Libya, groundwater information system (GWIS) is required as a decision support system (DSS) where it promises great potential for effective management and assessment of groundwater resources, and enhances the sustainability and efficient use of groundwater resources. This paper discusses the requirements and the design approach for the preparation of GWIS using geographic information system (GIS) techniques, where Al Waseetah area in Al Jabal Al Akhdar region was selected as a case study because of the availability of the hydrogeological data. The system structure and characteristics were defined and designed to store and manipulate the groundwater data, where 155 groundwater wells data were used to test and implement the GWIS system, in addition to remote sensing data as well as previous geological and hydrogeological studies. A series of maps and the hydrogeological map were produced and used to evaluate and interpret the groundwater system in Al Waseetah area.

Effect of Management System on Serum Copper Level and Haematology of Jabal Akhdar Breed Goats in two Sites in Al Jabal Al Akhdar Region of Oman

ABSTRACT: Blood samples were collected from randomly selected healthy Jabal Akhdar breed goats reared in two sites in the Jabal Akhdar region of Oman. Seven males and 65 female goats, age range 2 months to 4 years, raised in Shnoot Al-Dar village were kept under a semi-intensive system (SIS) and 2 males and 18 females, age range 4 months to 5 years, raised in Al-Ala'lana village and kept the under free range system (FRS) were studied. Serum Cu and haematological values were measured. There were no significant (p&gt;0.05) effects of age, sex or serum copper levels on the haematology of goats, so data was pooled and only the effects of the management system on serum Cu and haematology were analysed. There were highly significant (p&lt;0.001) differences between the two systems in all parameters studied. FRS goats were higher than SIS goats in mean values (± SE) of serum Cu (mg/l) 0.60 ± 0.07 vs 0.48 ± 0.33, red blood cells (RBC) (X1012/L) value 15.03 ± 0.42 vs 14.97 ± 0.25, mean cell volume (MCV) (fl) 21 ± 21 vs 19.57 ± 0.19, and haematocrit (HCT) (%) value 31.84 ± 0.59 vs 29.6 ± 0.35. SIS values were higher than FRS in haemoglobin (Hb) (g/dl) 9.34 ± 0.16 vs 9.26 ± 0.27, mean cell haemoglobin (MCH) (pg) 6.21 ± 0.05 vs 6.16 ± 0.08 and mean cell haemoglobin concentration (MCHC) (g/dl) 31.96 ± 0.38 vs 29.05 ± 0.64. Therefore, it is evident that the management system can affect the serum copper levels and haematology of the Jabal Akhdar breed of goats in the Jabal Akhdar region of Oman.

Age Structure and Current Status of Aleppo Pine ( Pinus Halepensis ) Trees on the Western Side of Sidi Alhumry Pine Plantation in Aljabal Al-Akhdar Region

Aleppo pine trees have been extensively planted in many areas in Aljabal Al- Akhdar region for ecological and recreational purposes. The objectives of this study were to investigate the age structure and current status of Pinus halepensis. Miller trees on the western side of Sidi Alhumry plantation. More than 70 pine trees were sampled to estimate the year of establishment, parameters for dbh and tree-height were noted for every sampled tree in the study design. The oldest pine tree found on the site was established in 1962 while the youngest tree found was established in 1984. Our results indicated a gap of over 20 years between pine trees on the study area which suggests either a long afforestation process or an effective regeneration during the first 2 decades. Average dbh and height for pine trees were typical for similar pine stands in the area with an overall dbh average of 29cm and tree-height of 10m. However, thinning would be advisable to ensure better growth and high yield for pine trees on the site.

Heavy mineral beach placers of the Ordovician Amdeh Formation (Member 4, Wadi Qahza, Saih Hatat, eastern Oman Mountains): Where is the main source area?

We studied an excellently exposed section of the slightly metamorphic siliciclastic Amdeh Formation. The section is near the base of the Amdeh Member 4 (Am4). Am4 is of Early to Mid-Ordovician age and 1677 m thick. Two lensoid placers were examined for their mineral composition (X-ray diffraction, transmitted and reflected light microscopy), geochemistry (X-ray fluorescence), in-situ gamma-ray emissions and the sedimentary structures of the host rocks. The placers were deposited in a beach environment as indicated by sedimentary structures in the associated quartzites, such as parallel lamination, parting lineations and sand volcanoes and as indicated by the compositional and textural maturity of the host rock and the placers. Placer deposition may have been favored by rising sea-levels. Overall, the dark placers contain the following heavy minerals: anatase (up to 35–40%) > ilmenite > zircon > hematite (a few %) > and apatite (<1%, may be present in trace amounts as indicated by low phosphorous contents in XRF analysis). The presence of monazite is indicated in our study by LREEs plus yttrium. Due to the high amounts of ilmenite and anatase, the placers' titanium contents are high (up to 20.5 wt%). In both placers, the concentrations of the light rare earth elements (LREEs) lanthanum, cerium, praseodymium and neodymium plus yttrium (geochemically affine to HREEs) are noteworthy (between ∼3000 and 7000 ppm). The source rocks can be expected in metamorphic and acidic plutonic rocks in the basement of Oman, which may have shed detritus from exposed basin flanks, but other potential source areas lay to the north and south of the basin. A source area with pre-enriched quartz in sandstone to explain the massive quartz influx would also be possible. The coastal/shallow shelf facies of Am4 shows very little bathymetric variability despite its thickness, which requires rapid and continuous subsidence. We attribute basin subsidence to rifting, withdrawal (and subrosion?) of salt in the subsurface (Ara Formation) due to sediment loading and possibly to gravity-driven subsidence due to the presence of dense ophiolite units below the Ara Salt. The absence of the Amdeh Formation in the west (Jabal Akhdar Dome) may be explained by rift shoulder uplift. While the Amdeh Formation accumulated in the rift basin, the Jabal Akhdar region occupied parts of the northwestern rift shoulder.

Screening the insecticidal effect of thirty plant extracts from Jabel Akhdar region northeast Libya against adults of confused flour beetle, Tribolium confusum du Val (Coleoptera: Tenebrionidae) using contact toxicity bioassay and fumigation toxicity bioa

At the last forty years the world directing to replaceing the conventional pesticides by economic alternatives are more safty for health and suitable for different cases, the plant extracts (Green Pesticides) were in the front of these alternatives, in this study, thirty plant extracts were isolated from ten plant they are endemic in Jabel Akhdar region northeast Libya using three different solvents (hexane, ethanol and water). The efficacy of these extracts against the confused flour beetle, Tribolium confusum were evaluated by two methods for bioassay a contact toxicity bioassay (C.T.B.) on filter paper and fumigation toxicity bioassay (F.T.B.). The results showed that, ethanol extracts were the best comparing with others two solvents and the ethanol extracts of Caper, Thyme, Nerium and Nabq were more effective than others in the both bioassays methods, when the ethanol extracts of Rosmary was grate effective by (C.T.B.) with 100% mortality whereas it give only 50% mortality by (F.T.B.). However everyone who ethanol extract of Harmel, and ethanol extract of Juniper showed high efficacy by 100% mortality for each one with (F.T.B.) bioassay, while they give only 73.33% and 50% mortality with (C.T.B.) for each one respectively.

A late Pleistocene refugium in Mediterranean North Africa? Palaeoenvironmental reconstruction from stable isotope analyses of land snail shells (Haua Fteah, Libya)

The late Pleistocene to Holocene archaeological record of North Africa is key to understanding the emergence of anatomically modern humans into West Asia and Europe, and the broadening of subsistence strategies in the shift from hunter-gatherer to pastoral-agricultural lifeways. Some contend that these developments were modulated by major shifts in climate and environment. Evaluation of this hypothesis requires the pairing of local and regional climate records with well-dated archaeological sequences. The Haua Fteah archaeological site in the Gebel Akhdar region of Libya provides a key site to test this hypothesis as the cave contains one of the longest and most complete sequences of human occupation in North Africa as well as abundant material for palaeoenvironmental reconstruction. This study uses stable isotope analyses (δ18O and δ13C) of the terrestrial mollusc Helix melanostoma to construct a palaeoenvironmental framework for interpreting North African human-environment interactions from the Upper Palaeolithic to the Neolithic (∼30,000 to 5000 years ago).The land snail stable isotope records from Haua Fteah suggests that cool arid conditions in the cave peaked during marine isotope stage (MIS) 2. This stage was, however, only marginally drier than previous and subsequent stages and coincided with an increase in occupation density in the cave. This suggests that the Gebel Akhdar may have served as an environmental refugium from the more extreme aridity in the surrounding Sahara and arid coastal plains for Late Stone Age (LSA) populations in North Africa. Conditions became progressively wetter towards the Holocene. However, generally wetter conditions were interrupted by two arid episodes at c. 8.0 ka and 7.3 ka that appear to coincide with regional changes reflected elsewhere in the Mediterranean basin.

A Preliminary Documentation of the Coral Reefs from Libya

Corals studies in Libya are very limited, although they play an important role in the oil exploration as they form excellent reservoirs of coral reef buildups at some oil fields of Sirt Basin (e.g. Intisar “Idris” and Sahabi Fields). Both fields are produced from Paleocene coral reefs. Meanwhile, in Cyrenaica, corals are of less importance as they are not reported in subsurface tertiary rocks, which probably in the environmental settings of these sediments out of the core of reef as occurred in the surface. Meanwhile, corals are reported from older (Jurassic) subsurface successions as in Concession NC-152, but the cementation diagenesis leads to blocking and destroying the porosity. This study presents the first surface documentation work of eight scleractinian coral species from the exposed sediments in northern Libya, where sixtaxa is reported from Al Jabal al Akhdar region, these include a) an association of huge colonies of Caulastrea sp. and Stylophora sp., from the Middle Eocene Darnah Formation at West Darnah road cut section. Theco-existence of the fastCaulastrea sp. with the slow Stylophora sp. is due to the competition strategy; b) Antiguastrea sp. which is reported from the Oligocene Algal Limestone of Al Bayda Formation at Daryanah-Abyar Roadcut section; c) Cyphastrea sp. andAleveopora sp. from Oligo-Miocene Al Faidiyah Formation at Al Fatayah cement quarry and d) Tarbellastraea sp. From Middle Miocene Benghazi Formation at Benghazi Cement Quarry. In addition, two species Astraeaopora sp. and Actinacis paroraiare reported from the Upper Miocene sediments of formation “M” in As Sahabi area.

Quantitative Assessment of Stakeholder Perceptions for Tourism Development

Tourism development has both positive and negative impacts on an economy. Various studies have attempted to capture these impacts using sophisticated quantitative modelling tools such as input–output models or computable general equilibrium models. Other studies have been designed to understand the perceptions of stakeholders. These studies are essentially descriptive and have not applied modelling approaches to capture the perceptions systematically. In this paper, a relatively new modelling approach, the analytic hierarchy process (AHP), is used to capture systematically the subjective perceptions of stakeholders about tourism development in the Jebel Akhdar region of the Sultanate of Oman. The results show that respondents generally prefer a huge increase in tourism activity in the region, although they also anticipate some negative impacts.

Geographic patterns in the distribution of Palearctic songbirds

AbstractA database was created of digitized equal area distribution maps of 3,036 phylogenetic species of Palearctic songbirds. Biogeographic patterns are reported for two data sets: (1) including all passeriform bird species reported as breeding within the boundaries of our study map, (2) passeriform species restricted in their distribution to our study region, thus excluding the partly extra-limital taxa. With respect to the data set excluding partly extra-limital taxa, the average range size is 238 grid cells (grid cell area: 4,062 km2). Analysis of the geographic distribution of species richness for the full data set showed several hotspot regions, mostly located in mountainous areas. The index of range-size rarity identified similar hotspot regions as that for species richness, albeit that the range-size rarity de-emphasized the central Siberian hotspot. Range-size rarity hotspots that are not evident on the measure of species richness concern a great number of islands. Much more prominent on the index of range-size rarity are the Atlas Mountains of northern Africa, the Jabal al Akhdar region in NE Libya, and the eastern border of the Mediterranean. Restricting the analysis of geographic variation to the 25% of the species with smallest ranges resulted in a greatly simplified pattern of hotspots.

Seismicity of the Northwestern Region of Libya: An Example of Continental Seismicity

Libya is situated on the Mediterranean foreland of the African Shield; its seismicity and tectonics reflect the geological history of the north African craton. Libya is not considered a highly active seismic region (Gutenberg and Richter 1965). However, several earthquakes of magnitude > 6.0 have occurred in Libya during the past century. A number of authors have investigated the seismicity and seismotectonics of Libya (Seiberg 1932; Minami 1963; Gordan and Engdahl 1963; Campbell 1968; Goodchild 1968; Kebeasy 1980; Westway 1990; Suleiman and Doser 1994; Al-Heety and Eshwehdi 2004). These investigations show that seismic activity in Libya is documented back to A.D. 262 and A.D. 365, when two large events destroyed the ancient city of Cyrene. Most of the seismic activity is concentrated on the coast of the northwestern part of Libya in the Al Jabal Al Akhdar region. The seismicity of this coastal region extends to the north as far as Greece. Another active seismic zone is concentrated along the eastern margin of the NW-SE trending Hun Graben. The region offshore of Tripoli is active as well. The southern part of Libya appears to be largely aseismic. In previous investigations of seismicity in Libya, all data were collected from international sources such as the National Earthquake Information Center (NEIC), the International Seismological Centre (ISC), the European-Mediterranean Seismological Centre (EMSC), and the bulletins of the national networks ( e.g. , those in southern Europe, Egypt, Tunisia, and others). Until very recently, there has been no national seismic network; the Libyan Seismological Network began operation in early 2006. This study represents the first attempt to study the seismicity of Libya using records of a local seismic station, Gharyan station. (Gharyan station data are available from the office of the Libyan Seismological Observatory and are available …