Houda Khedir, Abdallah Aouadi, Sihem Seddik,
Volume 10, Issue 4 (12-2024)
Abstract
Lotic systems are rapidly changing due to anthropogenic impacts, making it crucial to note the diversity and abundance of Odonates for effective conservation of these running waters. Our study aimed to assess and compare the Odonate communities in two adjacent rivers, Medjerda and Cheref, in Souk Ahras, northeastern Algeria collected during the period from January 2022 to August 2023. In total, 27 species belonging to 7 families and 17 genera were recorded, with three rare species in Numidia, and three Maghrebian endemic species, including Gomphus lucasii (Selys, 1850) listed as “Vulnerable” in the IUCN Mediterranean Red List. Coenagrion mercuriale (Charpentier, 1840), a locally endangered species, was abundantly present in the Medjerda River. Additionally, the presence of the desert species Trithemis kirbyi (Selys, 1891) in Medjerda confirms their northward expansion within Algeria. The Libellulidae were the most dominant family with 11 species. Our findings revealed no significant differences in terms of biodiversity indices (Richness, Simpson, Shannon, & Pielou's evenness) between the two rivers. However, significant dissimilarities were observed in Odonate assemblages likely due to habitat and environmental variations. Many factors, such as water pumping, overgrazing, untreated wastewater, and riverbank development, which influence Odonate species, were observed in the two rivers. Consequently, an urgent conservation plan should be put in place to preserve water resources and biodiversity in the region. This study highlights the need for continued monitoring and conservation efforts, especially for rare and threatened species in the face of increasing anthropogenic pressures on these aquatic ecosystems.
Salima Zereg, Aicha Mouane, Abdallah Aouadi,
Volume 11, Issue 1 (3-2025)
Abstract
The study investigated the spatial and seasonal variations in arthropod diversity using different trapping methods within two types of cedar forests (dead and healthy) in Belezma National Park, located in Batna. The field survey was carried out from January 2017 to December 2018, employing three sampling techniques: Barber pots, coloured traps, and suspended traps. A total of 108 species belonging to four classes, 13 orders, and 66 families were recorded. Representing 95.4% of the total species richness, insects were the predominant class, with 46 species. Within this class, Hymenoptera had the highest incidence (46.01%), followed by Diptera (23.6%). The Shannon-Weaver index exceeded 3 across stations, seasons, and sampling methods, indicating high diversity. Additionally, Equitability values surpassed 70% across all observations. PERMANOVA analysis revealed significant differences in composition between the different stations, seasons, and sampling methods. This research highlighted several key factors influencing arthropod diversity, including the condition of the habitat (dead vs. healthy cedar forests), seasonal variations, and the effectiveness of various sampling techniques.
