Adil GÜNER, Vehbi ESER - optima

FACTORS AFFECTING NATURAL VEGETATION
OF EL-HAROUJ MOUNTAIN, CENTRAL PART OF LIBYAN DESERT
( SAHARA )
Y. M. EL-BARAS� 1 & M. W. BARRAN� 2
1 Botany dept.Faculty of Science, Gar-Younis UN. Benghazi Libya;yammab54@ Yahoo.com
2 Institute of Agricultural sciences El-Marj, Libya
El-Harouj mountain in the Libyan desert (coordinates 7:45 - 29:00 north and 17:00 - 18:30
east) south from sea coast at a distance of about 260km a special ecosystem relatively rich
when compared with the surrounding areas, however is characterized by poor and scarce
vegetation with low diversity,and low percentage plant cover, in some depressions and
valley beds,it varies between 15-40 % , where Acacia tortilis trees dominate , moreover
several species are met such as Tamarix aphylla, Pergularia tomentosa, Retama raetam,
Zygophyllum sp. and Panicum turgidum.
Some species grow on rocky heights as Anabasis articulata and Andrachne telephioides
,where they receive amounts of water mainly from fog and dew especially during nights
however these areas are home of interesting biota.
The salt marshes (Sabkha) are characterized by halophytic species, such as Nitraria retusa,
Zygophyllum sp., Tamarix sp. and Salsola sp.. However, the formation of these saline areas is
due to spilling of water and flooding of plains from high altitudes, or the shallow water
table.. Under these severe conditions as lack of drainage system and flooding of soil with
slightly saline artesian water rapidly increases its salinity.
The flora of this region is constituted of 64 species ( about 3% of total number of Libyan flora
) belonging to 55 genera and 21 families, with one endemic species Fagonia arabica var
membranacea. Zygophylaceae and Chenopodiaceae members are the most distributed species
on the study area constituting 14.1% each, Asteraceae 12.5%, Fabaceae, Poaceae and
Brassicaceae 7.8% and Boraginaceae 6.3 % .
Dry desert climate preveils on the study zone imposing a fragile ecosystem, with high
temperatures and little rainfall, aggravating human activities. The most important processes in
this area is agriculture, practiced mainly in the nearby oases, which resulted in the uprooting
of natural vegetation, and the depletion of groundwater, and increasing soil salinity, grazing
cause removal of the natural vegetation in depressions and valleys, but the most destructive
activity is oil exploration and extraction in the different concessions in the zone, resulting in
pollution, and solid waste disposal, and spilling of the waste water mixed with oil, which
causes soil pollution, in addition to trampling due to vehicles and machineries activities
around the oil wells and camps. Due to the above mentioned factors this area shuold be
designated as a protected areas.
Keywords: El-harouj, mountain, vegetation, Libyan desert
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