مدلسازی اثرات تغییرات اقلیمی بر توزیع جغرافیایی جنس trametes در ایران

شواهد اثرات منفی تغییرات اقلیمی بر تنوع زیستی در حال افزایش است که نشان می دهد تغییرات اقلیمی یک تهدید عمده برای تنوع زیستی کره زمین است. مطالعات صورت گرفته نشان داده که تنوع زیستی ایران تحت تاثیر اثرات منفی تغییرات اقلیمی قرار خواهد گرفت اما اثرات تغییرات اقلیمی بر قارچ ها ناشناخته مانده است. در مطالعه حاضر نحوه اثرگذاری تغییرات اقلیمی بر توزیع قارچ های جنس trametes در شمال ایران مورد بررسی قرار گرفته و مهمترین عوامل اقلیمی موثر بر توزیع این جنس تعیین شده است. برای سنجش اثرات تغییرات اقلیمی از رویکرد تجمیعی (ensemble approach) و با در نظر گرفتن مدل های خطی تعمیم یافته (glm)، مدل های سازشی تعمیم یافته (gam)، مکسنت (maxent) و جنگل تصادفی (rf) استفاده شد. نتایج حاصل نشان داد بارش در خشک ترین ماه سال و تغییرات فصلی بارش مهمترین عوامل موثر بر توزیع قارچ های جنس trametes در شمال ایران هستند. بر اساس نتایج مدل های تغییر اقلیم این قارچ ها تا 60 درصد از زیستگاه های مطلوب خود را از دست خواهند داد. زیستگاه های مطلوب پایدار این جنس که در مطالعه حاضر شناسایی شدند اولویت بالایی برای حفاظت این گروه از قارچ ها تحت شرایط اقلیمی در حال تغییر دارند.

modeling the impacts of climate change on geographic distribution of the genus trametes

introductionevidence for the negative impacts of climate change on biodiversity is mounting, showing that climate change is one of the greatest threats to global biodiversity (chen et al., 2011; dubey and shine,2011; hannah, 2015; terribile et al., 2018; archis et al., 2018). climatechange can affect the diversity and composition of species within bothterrestrial and aquatic ecosystems (diaz et al., 2003; dijkstra et al., 2011; ruiz-labourdette et al., 2013;hannah, 2015; liu et al., 2018). it is predicted that some species will become more dominant while others will decline or disappear (hannah, 2015). while the negative impact of climate change is well documented on some taxonomic groups like vertebrates and plants species (hannah, 2015) little is known about the negative impacts of climate change on fungi and macro fungi(shrestha et al., 2014; burgess et al., 2017; gao et al., 2019; hao et al.,2020). macro fungi are important components of ecosystems and play important roles in nutrient cycling, decomposition, symbiosis, and food sources for many animals and humans. however, climate change can have negative impacts on macro fungi, such as altering their distribution and diversity thus, it is necessary to investigate potential impacts of climate change on them (cao et al., 2021). recent studies have shown that climate change will have negative impacts on iran’s biodiversity (yousefi et al., 2019).  however, little is known about the potential impacts of climate change on the diverse taxonomic groups in the country particularly macro fungi (yousefi et al., 2019). thus, the aim of this study is to predict the impact of climate change on distribution of the genus trametes in north of iran. materials and methodsdistribution records of the genus trametes were collected during our fieldwork from 2000 to 2022 in iran. current and future climate data (annual mean temperature (bio1), mean diurnal range (mean of monthly (max temp - min temp)) (bio2), isothermality (bio3), temperature seasonality (standard deviation) (bio4), annual precipitation (bio12), precipitation of driest month (bio14), precipitation seasonality (coefficient of variation) (bio15)) were obtained from chelsa high resolution climatologies version 2.1 (kargeret al., 2017). for future climate we considered following five cmip6 (the coupled model intercomparison project phase 6) global circulation models (gcms): gfdl-esm4, ipsl-cm6a-lr, mpi-esm1-2-hr, mr-esm2-0, ukesm1-0-ll. we applied an ensemble approach, using four distribution modeling methods (generalized linear models (mccullagh nelder 1989), generalized additive models (hastie tibshirani 1990), maximum entropy modelling (phillips et al. 2006) and random forest (breiman 2001)) to predict the impacts of climate change on distribution pattern of the genus. we also identified the most important climatic predictor of the genus distribution (phillips et al. 2006). in this study auc and tss were used to assess the performance of the model. results discussion according to the auc and tss the model performed well (auc=0.942 and tss=0.811). the model showed that under current climate the genus has 36,456km2 suitable habitats but the genus suitable habitats will decrease to 14,749 km2. we found that the genus will lose 60% of its suitable habitat under the climate change (2070 ssp585). our results are in line with previous studies that have shown that fungi species will lose their suitable habitats under future climate change. for instance, gua et al. (2017) have shown that tricholoma matsutake will lose considerable proportions of its suitable habitat due to climate change. however, it is predicted that some species like ophiocordyceps sinensis will expand their range under the changing climate (shrestha and bawa, 2014). results also showed that precipitation of driest month and precipitation seasonality are the most important predictors of the genus distribution.