RESUMEN
The marginal populations of the Sahara blue-eyed pond turtle, Mauremys leprosa saharica (Testudines: Geoemydidae) in the pre-Saharan area in the Lower Draa Valley, are faced to extreme environmental conditions of arid climate and anthropogenic activities including overuse of water and land salinization. In this study, we investigated a small isolated population of the blue-eyed pond turtle at Sidi El Mehdaoui Oasis, Lower Draa Valley, to determine its population structure and morphometric characteristics. Water salinity was about 24% of seawater and dissolved oxygen concentration was less than 3 mg l-1 (sub-hypoxia). The average body size of adults (carapace length) was much lower in comparison to other Moroccan populations. Among adult individuals, the mean carapace lengths were 103 ± 21 mm and 104.4 ± 35 mm for males and females, respectively. The corresponding mean body mass were 173 ± 92.4 g and 135 ± 52 g. There were no significant differences between sexes for size or weight. The studied population is small, with a predominance of adults (75%). A significant sexual size dimorphism was found. In fact, the Sexual Dimorphism Index for size had the lowest level ever described for the species possibly because of the low productivity of this marginal isolated habitat. The increased drought and salinization are major threats to the long-term persistence of the vulnerable populations of the Saharan blue-eyed pond turtle and their habitats. Therefore, conservation measures of these populations through the protection of their habitats are very urgent.
Asunto(s)
Tortugas , África del Norte , Animales , Tamaño Corporal , Ecosistema , Femenino , MarruecosRESUMEN
Water is essential to human societies and a prerequisite for flourishing nature, especially in arid regions. Yet, climate change and socio-economic developments are expected to exacerbate current and future stresses on water resources, demanding innovative approaches to balance water needs for society and nature conservation. In this study, we use the IPBES conceptual framework to combine ecological and socio-economic insights and analyse the connections between people and nature in the water scarce Draa River Basin, southern Morocco. We study the diversity of desert benthic macroinvertebrates as one component of nature using DNA barcoding and their potential to serve as bioindicators of human impact by relating species occurrences to environmental parameters. Furthermore, based on 87 interviews with farmers and key institutional stakeholders, we investigate how farmers perceive water related changes and how water is managed in the basin. Regarding benthic macroinvertebrates, 41 families were identified, 475 DNA barcodes generated and assigned to 118 putative species (Barcode Index Numbers) of which 60 were first records. This indicates a lack of reference sequences for known, but also a potentially high number of undescribed species. Environmental parameters, which are partly influenced by human activities, such as aquatic stages, salinity and intermittency, were the most important variables explaining invertebrate richness and community composition in generalized linear models. We further describe farmers' perceptions of decreasing water quality and quantity. Farmers generally believe that they are able to cope with water related changes, although perceptions are regionally differentiated with farmers downstream being less optimistic. With growing concerns, water policies currently focus on increasing water supply and less on reducing water demands. Based on these findings, the usefulness of the IPBES framework for understanding social-ecological system dynamics is reflected, and recommendations for future freshwater management and research are derived.
Asunto(s)
Ecosistema , Ríos , Animales , Conservación de los Recursos Naturales , Humanos , Marruecos , Recursos HídricosRESUMEN
Food habits of the Moroccan dorcas gazelle, Gazella dorcas massaesyla, previously investigated in the 1980s using microhistological fecal analysis, in the M'Sabih Talaa Reserve, west central Morocco, were re-evaluated over three seasons (spring, summer and autumn 2009) using the trnL approach to determine the diet composition and its seasonal variation from fecal samples. Taxonomic identification was carried out using the identification originating from the database built from EMBL and the list of plant species within the reserve. The total taxonomic richness in the reserve was 130 instead of 171 species in the 1980s. The diet composition revealed to be much more diversified (71 plant taxa belonging to 57 genus and 29 families) than it was 22 years ago (29 identified taxa). Thirty-four taxa were newly identified in the diet while 13 reported in 1986-87 were not found. Moroccan dorcas gazelle showed a high preference to Acacia gummifera, Anagallis arvensis, Glebionis coronaria, Cladanthus arabicus, Diplotaxis tenuisiliqua, Erodium salzmannii, Limonium thouini, Lotus arenarius and Zizyphus lotus. Seasonal variations occurred in both number (40-41 taxa in spring-summer and 49 taxa in autumn vs. respectively 23-22 and 26 in 1986-1987) and taxonomic type of eaten plant taxa. This dietary diversification could be attributed either to the difference in methods of analysis, trnL approach having a higher taxonomic resolution, or a potential change in nutritional quality of plants over time.