نوع مقاله : مقاله پژوهشی
نویسندگان
1 گروه مهندسی محیط زیست، دانشکده منابع طبیعی و علوم زمین، دانشگاه شهرکرد، شهرکرد، ایران
2 دفتر موزه ملی تاریخ طبیعی و ذخایر ژنتیکی، سازمان حفاظت محیط زیست، تهران، ایران
3 پژوهشکده بیوتکنولوژی، دانشگاه شهرکرد، شهرکرد، ایران
4 گروه مهندسی طبیعت، دانشکدۀ منابع طبیعی و علوم زمین، دانشگاه شهرکرد، شهرکرد، ایران
چکیده
کلیدواژهها
عنوان مقاله [English]
نویسندگان [English]
Introduction: To effectively protect wildlife, it is crucial to understand ecological conditions and their relationship with habitats. Habitat suitability modeling is a valuable tool in this context. The brown bear (Ursus arctos), one of the most widely distributed terrestrial mammals, faces varying conservation statuses across different regions. In Iran, this species is classified as "endangered" due to habitat loss and reduction. Assessing potential high-suitability habitats is vital for the conservation of this species. This information helps managers make informed decisions regarding reintroduction, species translocation, and the development of protected areas, ultimately enhancing conditions for the preservation of this species by identifying key habitats.
Materials and Methods: The study area covers Kermanshah Province, spanning 24,361 square kilometers in the central Zagros mountain range. The dominant vegetation consists of Persian oak in a mountainous ecosystem. A total of 139 brown bear occurrence points were collected, with a minimum distance of 2.5 kilometers, through direct observations, camera trap images, identification of tracks and signs, verified reports, expert opinions, and ranger assessments. These points were validated and checked for spatial autocorrelation. Additionally, 13 environmental variables were selected based on previous studies and correlation analyses for habitat modeling. To model the geographic distribution, an ensemble modeling approach was applied using the Biomod2 package within the R environment.
Results and Discussion: The analysis indicates that the AUC and TSS metrics for the models were evaluated as good to excellent. The results from the ensemble approach of various models show that approximately 22.16% of the total area of Kermanshah Province (5,399.66 km²) is identified as suitable habitat for brown bears, with a probability of occurrence greater than 0.6. The optimal habitats for brown bears in Kermanshah Province are distributed at elevations ranging from 450 meters to over 3,000 meters, extending along the province’s mountain ranges in a northwest-southeast direction. The most significant contributing variables in the modeling process include total annual precipitation (22.26%), elevation (21.68%), slope (14.97%), and distance from forested areas (11.15%). Brown bears typically prefer habitats characterized by dense forests, rugged terrain, and minimal human disturbance, particularly at higher elevations where human access is limited. Habitats improve with increasing precipitation and elevation, with forests playing a crucial role as sources of food and shelter. Approximately 62% of bear occurrences were recorded in mountainous forests, 30% in grasslands and shrublands, and 8% in agricultural lands. Additionally, 7.67% of bear occurrences were identified within protected areas, although the majority of suitable habitats lie outside these zones. Livestock density was found to be the least significant factor influencing habitat selection.
Conclusion: The brown bear, as a species at the top of the food chain, plays a crucial role in the ecosystem, and its population and habitat decline can negatively impact biodiversity and ecosystem functions. Understanding suitable habitats and the factors influencing habitat selection is essential for the management and conservation of this species. The expanse of mountainous forests in Kermanshah Province is recognized as one of the most important brown bear habitats in western Iran. Therefore, it is recommended that, given the conservation status and ecological significance of the species under study, suitable brown bear habitats be incorporated into the protected area network.
کلیدواژهها [English]
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