تأثير الزحف العمراني على الغطاء النباتي في المنصورة وسطية– الجبل الأخضر– ليبيا- 2009-2021

Abstract

This study was conducted to investigate the effect of urban areas on the composition and type of vegetation cover. Close sites were chosen in this study to overcome differences in location, climate and topography in Al Jabal Al-Akhdar region .Study sites were selected in the region extending from Mansura in the east to Settia in the west, taking into account that the study sites are on the same latitude, and that there is no difference in topography and elevation between them to ensure consistency between sites .Biodiversity indicators (abundance - plant composition - similarity coefficient - homogeneity coefficient) were calculated in the study sites. Twelve plant species of trees and shrubs were found in all study sites, and Juniperus phoenicea L. and Pistacia lentiscus Pass. were the highest prevalent. The distribution and homogeneity of plants were different from one site to another, as the Juniperus phoenicea L. was the most homogeneous in three study sites, while Pistacia lentiscus Pass. and the Cistus incanus L. were homogeneous, each of them in one site separately. Average vegetation coverage, loss rates of vegetation cover, and number of plant individuals lost per hectare were calculated for all plant species under study in the five locations. The results have found a significant loss of plant species covering the study sites, and the highest percentage of decline was for Juniperus phoenicea L, Pistacia lentiscus pass. and Ceratonia siliqua L, while the Rhammus alaternus L., Saureja thymbra L., Phlomis floccose D.Don, Cistus incanus L., Marrubium volgare L. and Sarcopoterium spinksum L. showed a decrease, but at a lower rate.