Man made ecosystems of dry lands are key habitats due to their ecological characteristics to survey biodiversity. This study investigated bird diversity in three oases of the Northern Algerian Sahara (i.e., Biskra in 2006, Oued Souf in 2008 and Ouargla in 2009), by using the spot-mapping method. Bird density "D" (pairs/10 ha), species richness "S" (number species), diversity (Shannon index) "H'" (in bits), and evenness "E" varied from one oasis to another (Biskra: D = 98.5, S = 47, H' = 4.49, E = 0.81; Oued Souf: D = 96, S = 33, H' = 3.9, E = 0.77; Ouargla: D = 91.5, S = 44, H' = 4.39, E = 0.80). Differences in bird diversity between the monitored palm groves are due to the ecological characteristics of each environment. Documented literature outlined close taxonomic similarities between bird assemblages of the study area with many Northern Saharan oases. The Hybrid Sparrow Passer domesticus x Passer. hispaniolensis and some Columbidae species including Columba livia, Streptopelia turtur, Streptopelia senegalensis, and Streptopelia decaocto were the abundant species throughout surveyed oases in which they represented more than half (55.6%) of the sum of species densities (D = 286 pairs/10 ha). These synthropic species have known a huge expansion of their distribution range throughout Algerian oases. The correspondence analysis allowed the aggregation of both families and species into oasis they belong to. One-way ANOVA was tested to analyse variations of both family and species densities between studied oases. The ANOVA revealed there was no significant variation either in family densities (p = 0.937) or in bird densities (p = 0.622) between the surveyed oases because of the small size of bird populations.

The diet of the Short-eared Owl Asio flammeus was analysed in an arid environment in Hassi El Gara located in the southeast of El Golea (Ghardaia, Algeria). The diet was determined by analysing 138 pellets. Our data showed that the diet was dominated by mammals (Chiroptera and Rodentia). Based on relative biomass, birds were the main prey species. Mammals were the second most important prey. Mammals were the major food item throughout the seasons and their contribution to the diet ranged from 50.7% in spring to 73.6% in summer. Birds were the second numerous prey with 8.1% in summer and 29.6% in spring. The dominant prey species was Myotis sp., making up 37.8%. It was followed by Gerbillus nanus (5.4%), Columba livia (4.3%) and Bufo mauritanicus (4.1%).

pre ´sent travail porte sur l'e ´tude du re ´gime alimentaire de la Chouette effraie dans deux re ´gions steppiques (M'Sila et Djelfa) situe ´es sur les hautes plaines de l'Alge ´rie a `travers l'analyse des pelotes de rejetions collecte ´es dans six stations. L'analyse de 706 pelotes issues des diffe ´rentes stations a permis de recenser 1380 items de proies repre ´sente ´s par sept classes, 12 ordres, 32 familles et 76 espe `ces proies. Les mammife `res sont les plus consomme ´s, avec des taux variant entre 59,1 % et 90,0 %, dont la dominance est attribue ´e aux rongeurs (abondance relative, AR > 58 %). Ces derniers constituent les proies les plus profitables en biomasse (61,4 % B 99,2 %). La proie la plus consomme ´e est Meriones shawii, avec des taux variant entre 31,9 % et 76,6 %. Ge ´ne ´ralement, Tyto alba pre ´sente un re ´gime alimentaire diversifie ´dans la plupart des stations (0,69 E 0,76), mise a `part la station d'Ain El-Hadjel ou `elle se caracte ´rise par un re ´gime tre `s peu varie ´(E = 0,35) avec une forte consommation de la Me ´rione de Shaw (AR = 76,6 %).ß 2014 Acade ´mie des sciences. Publie ´par Elsevier Masson SAS. Tous droits re ´serve ´s.

Abstract. Rached-Kanouni M, Kara K, Khammar H, Ababsa L. 2020. Floristic diversity and demographic structure of the Sidi R'Ghies forest, north-eastern of Algeria. Biodiversitas 21: 875-881. In Algeria, the degradation of the ecosystems induces a loss of biodiversity and an increase in the adverse effects of climate change and anthropogenic actions, especially at the level of the ecosystems of semi-arid zones. This study aims to determine the floristic composition and demographic structures of different stands within the Sidi R'Ghies forest, north-east of Algeria. Data were collected using floristic surveys, diameter measurements at 1.30 m and total height for trees in four plots with size for each plot of 1000 m2. The diversity indices have been calculated on the basis of specific frequencies. The analysis revealed a low floristic richness with 6 woody species belonging to 5 families with the most dominant are the Cupressaceae and Fagaceae (29%). The low density of woody trees (97.78 individuals/ha) was found in Plot 1 and the high density of 205.56 individuals/ha was found in Plot 4. The diametric structure adjusts to the Weibull distribution and shows a predominance of young individuals. The distribution of trees in height classes shows a single distribution with an asymmetric curve. This positive distribution reveals a predominance of individuals with a height between 2 and 8 m (sapling to mature stage). This work, which provides an overview of the state of the floristic diversity of the Sidi R’Ghies forest, allows taking appropriate measures to safeguard our plant resources.

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