Abstract. Chedad AW, Hammou MA, Chelghoum H, Chedad A, Amara OO, El Bouhissi M, Dahmani W, Sadine SE. 2022. Diversity and distribution pattern of scorpions from the Ouarsenis massif of Tissemsilt, North-West Algeria. Biodiversitas 23: 2444-2450. Ecological barriers such as mountains are important factors leading to fragmentation of the range of different species and the important cause of vicariance events. Ouarsenis massif (Tissemsilt, North-West Algeria) is an important protected Park. This paper presents a preliminary study of scorpion diversity and assesses this biodiversity change in this Mountain range along a gradient of many ecological descriptors, including elevation, vegetation cover, slope, and soil types. During 2020 and 2021, we sampled 179 specimens of scorpions by direct hunting from the eight biotopes in Ouarsenis massif. Only adult individuals were used for identification after being killed and kept in 70% alcohol. Based on morphological criteria, we identified eight species distributed in two genera and two families. The family Buthidae was represented by five species with the highest relative abundance (RA) was Buthus tunetanus (RA: 47.49%). Furthermore, the family Scorpionidae was represented by three species with the highest RA was Scorpio maurus (RA: 25.14%). The Shannon index (H’: 2.71 bits) indicated that Ouarsenis massif region had a high level of scorpion diversity and the value of evenness (E: 0.90) reflected the high equilibrium between the effectiveness of sampled species. The main determinant descriptor of scorpion distribution was the elevation and soil types, while the vegetation cover could be considered an ancillary factor.

This is the first regional study aimed at understanding the diversity of the fauna nesting in the populations of Atlas Pistachio in Algeria. Fieldwork which lasted 6 years, consisted of mixed sampling (stratified then subjective) accompanied by surveys of the surrounding population in order to find the vertebrate species sought. A total of 160 species have been identified in all the study area (Tiaret region). There are 160 species of birds (46 migratory species and 66 sedentary species); 21 species of mammals; 5 species of freshwater fish; 17 species of reptiles and 5 species of amphibians. The present study revealed to us the existence of an exceptional fauna diversity in this area with some new data on the distribution of some species, especially birds and mammals. For the forest of Atlas Pistachio, there are less than all the study area, because of the location of the 4th forests, with two of them in the north of Tiaret region (mountains of Tagdemt and Guertoufa) and the the others forests in the south, in the steppe ecosystem (Rechaiga and Rosfa). Our study reveals that the most species and the diversity of fauna are located in the north (Tagdempt and Rosfa) with 47 species of birds of an total of 57 species that we mentioned in all the 4th forests of the Atlas Pistachio, 8 of the total of 12 species of mammals, 9 of the total of 13 reptiles and only one species of amphibians with is Sclerophrys mauritanica. We can say also that only two species have a direct relation with this tree, we talk about Sturnus vulgaris and Mus musculus, wich prefer the fruits and seeds of this tree; that Sturnus vulgaris with is a wintering migrant birds, and his migration come over the period of fruting of this endemic and important tree. For the mouse (Mus musculus), as all the rodentodia species, they prefer the seeds, that they collect into their hole. We can say at last, that the Tiaret region is very important biotope, for all the vertebrate species, for his heterogeneity ecosystems, and their location with consist of an migratory halt for many birds, also the nesting birds wicth come every year for the reproduction.