气候变化影响下长江上游松潘裸鲤和硬刺松潘裸鲤潜在栖息地变化预测研究OA

Gymnocypris potanini(GP)and G.p.firmispinatus(GPF),primarily inhabiting mountain riv-ers,are known as precious fishes in the production area and important cold-water economic fishes endem-ic to the upper Yangtze River basin(UYRB)in China.These two high-elevation,cold-water fish species are excellent models for understanding the adaptation of endemic genomes to climate change in the UYRB.However,the factors affecting their habitats and the alterations due to climate change and human activity are not yet clear.In this study,G.potanini and G.p.firmispinatus were selected for research,and we predicted the spatiotemporal changes in their habitat under future climate change scenarios,aiming to provide a critical reference for habitat assessment of endangered endemic fish species in the upper reaches of the Yangtze River.Species distribution models(SDMs)were constructed using four machine learning algorithms:Artificial Neural Networks(ANN),Classification Tree Analysis(CTA),Flexible Discriminant Analysis(FDA),and Maximum Entropy Modeling(MAXENT).After screening for covariance,impor-tance,and response curves,the mean diurnal range(BIO2),isothermality(BIO3),and temperature season-ality(BIO4)were selected as the key variables for SDMs from a pool of 19 climatic factors,7 human ac-tivity-related factors,and 4 natural geographic factors.These models were then calibrated using historical data(1970-2019)and subsequently applied to predict habitat changes under future SSP126 and SSP585 scenarios in 2050,2070,and 2090.Results show:(1)Model performance was excellent,with AUC(Area Under the ROC Curve)and TSS(True Skill Statistic)metrics of 0.981,0.912 for GP and 0.945,0.843 for GPF,respectively.(2)The GP habitats during the historical period(1970-2020)were primarily in the Minjiang River basin and Jialing River basin,while the GPF habitat was primarily in the Jinsha River ba-sin.The habitat quality of GP was higher than that of GPF,with 54.3%of primary habitat(suitability>0.8)for GP and 22.6%of primary habitat for GPF.(3)Under the SSP126 and SSP585 future scenarios across 2050,2070,and 2090,the eastern middle and lower Jinsha River is likely to become the new pri-mary habitat for GP,while new habitats for GPF will emerge in the southern upper Jinsha River and the middle-lower Jinsha River.Notably,habitat expansion under the SSP585 scenario is expected to be more extensive than under SSP126.Over the next century,no spatial overlap is anticipated between the habitats of GP and GPF.This study provides fundamental support for conserving the habitats of GP and GPF being altered by climate change and offers important insights for assessing the habitat of endangered endemic fish species in the upper Yangtze River under changing environmental conditions.