Tropentag, September 11 - 13, 2024, Vienna "Explore opportunities... for managing natural resources and a better life for all"

Modelling of the climate change impacts on the Iranian riverine fish species diversity as a hot spot area

¹Shahid Beheshti University, Environmental Sciences Research Institute, Dept. of Biodiversity and Ecosystem Management, Iran
²Shahid Beheshti University, The Center for Remote Sensing and Geographic Information System Research, Iran
³CSIRO Environment, Australia
⁴Oregon State University, Dept. of Fisheries, Wildlife, and Conservation Sci., United States
⁵Shahid Bahonar University of Kerman, Dept. of Biology, Iran
⁶BOKU University, Austria

Abstract

Iran is one of the world’s biodiversity hot-spots. However, most of riverine fish species in this country are currently under threat from numerous human activities. In this context, climate change acts as an additional threat compromising biodiversity and freshwater ecosystem function and potentially disturbing the ecological services they provide. In this study, we predicted potential relative probability of 132 fish species under two climate change scenarios (RCP 4.5 and RCP 8.5) in river habitats of Iran in the 2050s and the 2080s by MaxEnt model. Seven environmental variables (maximum width, elevation, river slope, the basins occupied by the target species, average annual precipitation, annual mean temperature, and the temperature difference between the coldest and hottest months of the year) were used for modelling. Also, AUC (Area Under the Curve) index was used to evaluate the modelling performance.

The results of this study showed that under optimistic (RCP 4.5) and pessimistic (RCP 8.5) scenarios in the 2050s and the 2080s, species will show different outcomes to their habitat range such as “reduction”, “expansion”, “reduction and expansion”, as well as “no change”. Thus, 37 species had a "reduction" response in all scenarios. 14 species had only "expansion" reaction, 58 species had "reduction and expansion ", 6 species had "no change" and 17 species had a combination of reactions in the scenarios. Comparing the maps of estimating the species richness in different climatic scenarios with the current condition and observing the difference in the presence of species, we found that the greatest decrease in species richness is predicted under the RCP 8.5 scenario in 2080 in the Caspian Basin, especially its western regions.

With the warming climate, the distribution range of some species in the country will expand, some will be limited and some will probably remain constant. In other words, the country's biodiversity will certainly change. Therefore, this study will provide valuable information to managers and decision makers to prevent possible damage by taking appropriate measures and prioritisation.

Keywords: Biodiversity conservation, climate heating impacts, Iran, MaxEnt, species distribution modelling

Contact Address: Hossein Mostafavi, Shahid Beheshti University, Environmental Sciences Research Institute, Dept. of Biodiversity and Ecosystem Management, Tehran, Iran, e-mail: hmostafaviwgmail.com