نوع مقاله : مقاله پژوهشی
نویسندگان
1 گروه تنوع زیستی و مدیریت اکوسیستم ها، پژوهشکده علوم محیطی، دانشگاه شهید بهشتی، تهران، ایران
2 گروه علوم محیط زیست، انستیتو تکنولوژی فدرال زوریخ، دانشگاه زوریخ ( ETH Zurich ) ، سوئیس
چکیده
کلیدواژهها
عنوان مقاله [English]
نویسندگان [English]
Introduction:
Carnivores have always been exposed to threatening processes because of their placement at the top of the food pyramid. Nowadays, approximately 65% of carnivores are listed as Critically Endangered or Vulnerable in the IUCN Red List of threatened species. On a global scale, in order Carnivora, the Hyaenidae family is the smallest with only four species. Hyaena hyaena is the only member of the Hyaenidae faimly in Iran, which is listed as “Near Threatened” (NT) in the IUCN Red List. The current study aimed to model the species distribution of the striped hyaena (Hyaena hyaena), which has a wide distribution in Iran.
Materials and methods:
Using nineteen layers of climatic variables, the correlations between those variables were analyzed and then highly correlated variables were excluded from the modeling process. Finally, eight species distribution models from the sdm package (GLM, GAM, BRT, SVM, RF, MARS, CART, and FDA) in R software were used. Given that the output of species distribution models are often uncertain, which is an undeniable fact, one possible solution to estimate the difference between projections and reduce the uncertainty, is the use of ensemble prediction system instead of using a single modeling method. Therefore, after determining the potential habitats of the Hyaena hyaena with those eight mentioned models and by using the ensemble prediction system, the best regions for the distribution of this species in Iran were estimated.
Results and discussion:
The results of this study showed that annual mean temperature, seasonal precipitation and precipitation of the warmest season have the most influence on the distribution of Hyaena hyaena. In general, FDA, GAM, BRT, CART and GLM models are fairly reliable, the MARS model is very reliable, and SVM and RF models are completely reliable. The results showed that the GLM, GAM, BRT, MARS, CART, RF models demonstrate that the suitable areas for Hyaena hyaena are generally the central regions of Iran, while the SVM and FDA models predicted the southern margin of the Caspian sea to make the best regions for the distribution of this species.
Conclusion:
The difference in the predictions that each model makes confirms the uncertainty between models. Therefore, the necessity of using Ensemble method is revealed. The results of the Ensemble model showed that the most suitable regions for the Hyaena hyaena species distribution are semi-arid and central steppe regions of Iran.
کلیدواژهها [English]