Tick-borne relapsing fever (TBRF) is caused by Borrelia species transmitted to humans by infected Ornithodoros sp. ticks. The disease has been rarely described in North Africa, and in Tunisia the local transmission of TBRF seems to have disappeared or is undiagnosed. A longitudinal study was conducted in 14 sites located in four different bioclimatic zones of Tunisia to assess both the distribu...

abstract alluvial fans are the most striking phenomena o fluvial geomorphology . these forms are found in frount of mountains and pediments of arid and semiarid zones . alluvial fans are affected by climate changes and tectonics . occurring of tectonic events lead to reaction of alluvial fans . some of these reactions appear on dissection of alluvial fans and displacement of depocenters on allu...

the aim of this study is assessing and mapping landslide susceptibility in watershed of semiarid mountain areas. saeedabad-chai watershd is located on the northwest of iran and the north of sahand mountain. this study is using bivariate statistical analysis (bsa), weights-of-evidence (woe),gis. the results of this assessment show that causative factors as slope (∑wæ’= + 3.965), landuse(∑wæ’...

carbonates are among the most common soil constituents in arid and semiarid zones. they exhibit many significant differences in their chemical and mineralogical, suite, origin, physical and micromorphological properties and consequently in their activities in soil. the differences cause different properties of calcareous soils. six profiles of aridisols and inceptisols with carbonate accumulati...

States of ecological maturity and temporal trends of drylands in Morocco, Algeria and Tunisia north of 28 ̋N are reported for 1998–2008. The input data were Normalized Difference Vegetation Index databases and corresponding climate fields, at a spatial resolution of 1 km and a temporal resolution of one month. States convey opposing dynamics of human exploitation and ecological succession. They ...

Today, the stems of edible Opuntia are consumed as vegetables, cattle food, and processed in addition to being used for raw materials cosmetics medical supplies various countries, including Mediterranean, South America, Middle East, North Africa Asia, showing their wide adaptability climate zones ranging from arid, semiarid temperate zones. In a time when global warming population growth requir...

Current research has determined that traits involved in reproductive strategies and processes of seed dynamics should be studied together, and under varying environments, in order to clarify their roles in the ecology of plant communities. Here, we analyzed reproductive traits (allocation to reproduction, efficiency of seed production, and seed size) at the community level and their relationshi...

[1] Significant variations in interannual and decadal recharge rates are likely in alluvial basins of the semiarid southwestern United States on the basis of decadal variations in climate and precipitation and correlation of El Niño with high rates of winter precipitation and streamflow. A better understanding of the magnitude of recharge variations in semiarid and arid regions would reduce wat...

Problems associated with the application of monthly rainfallrunoff models to arid and semiarid areas for water resource estimation purposes are discussed with respect to the representation of hydrological processes and the model rainfall input. The problems are illustrated using a specific monthly model applied to catchments within the semiarid to arid parts of southern Africa. Some model impro...

Some endemic shrubs in arid and semiarid ecosystems are in danger of extinction, and yet they can play useful roles in maintaining or restoring these ecosystems, thus practical efforts are needed to conserve them. The shrubs Amygdalus pedunculata Pall., Amygdalus mongolica (Maxim.) Ricker and Ammopiptanthus mongolicus (Maxim. ex Kom.) Cheng f. are endemic species in arid and semiarid regions of...