Potential Distribution And Influenceing Factors Of Pedicularis Kansuensis In Alpine Grassland Of China

Climate change affects many ecosystems and biota worldwide,including the distribution of many species.Pedicularis kansuensis is a semi-parasitic poisonous plant,growing in the alpine meadows of 1800-4000 m above sea level,mostly in the colder regions of the northern temperate zone,including the arctic,eurasian and northwest north america,the western part of china to the north and west of Sichuan,and mainly in the altai mountain and bayinbrook area in Xinjiang.In recent years,it has spread rapidly on alpine grasslands,which seriously affects the balance of grassland ecosystem and the development of grassland animal husbandry,and causes serious harm to grassland ecological security.this paper takes into account the factors such as interspecific competition and diffusion barriers.using the maximum entropy algorithm(Max Ent)and Mig Clim model,we simulate the potential distribution pattern and area of P.kansuensis in Gansu,china in 2050 and 2070 under representative concentration pathway RCP 2.6and RCP 8.5 climate model,and analyze the key influencing factors of P.kansuensis distribution in Gansu.Based on the growth characteristics of plants,39 of the four types of environmental variables were originally selected,namely,bioclimatic variables,soil variables,topography and ultraviolet radiation.After correlation analysis and the accuracy of each of the bioclimatic variables in the study area,14 environmental variables were used in this paper.The accuracy of the model was verified by combining ROC curve(Receiver Operator Characteristic curve)and True Skill Statistic(TSS).The results showed that the prediction model of Gansu P.kansuensis showed excellent performance(AUC>0.9 and TSS>0.90).The results and conclusions are as follows:1)the current climate conditions,P.kansuensis is mainly distributed in Panzhihua,Aba Tibetan Autonomous Prefecture,Liangshan Yi Autonomous Prefecture and Ganzi Tibetan Autonomous Prefecture of Sichuan Province,Yunnan Province,Xigaze Region of Tibet Autonomous Region,Linzhi Region,Changdu Region,Gannan Tibetan Autonomous Prefecture and Longnan Region of Gansu Province,Yushu Tibetan Autonomous Prefecture of Qinghai Province and Guoluo Tibetan Autonomous Prefecture,Bayinbrook Prairie and Altay Prairie of Bayingorang Mongol Autonomous Prefecture of Xinjiang Uygur Autonomous Region.2)The four climate scenarios of 2050 and 2070 under the RCP 2.6 future climate model and 2050 and 2070 under the RCP 8.5 future climate model,the suitable habitat of P.kansuensis in Gansu generally shows a trend of migration from south to north.3)The important environmental variable affecting the distribution of P.kansuensis in Gansu were altitude(33.4%),annual temperature range(20.2%),annual precipitation(10.9%),precipitation in the warmest season(7.5%)and ultraviolet-B radiation season(6.9%),with a total contribution of 78.9%.4)Under RCP 2.6 future climate model,the occupied habitat will increase by0.04% by 2050 and to 0.51% by 2070.under RCP 8.5 future climate model,the average occupied habitat is expected to increase by 0.07% by 2050 and 0.53% by 2070.The growth of occupied habitats located in the southwest(Sichuan,Tibet and Yunnan)is relatively higher than that in the northwest(Gansu and Xinjiang).5)Through the comprehensive evaluation of the performance of the model by ROC curve method and real skill statistics method,the average value of both >0.9,indicating that the prediction results of the model are very good.Based on the feasibility,accuracy and rigor of species prediction in Max Ent and Mig Clim models,there is a significant improvement.In recent years,the rapid spread of P.kansuensis in Gansu on the grassland has caused huge losses to the grassland animal husbandry in China,seriously affected the ecological balance of the grassland,and predicted the potential geographical distribution of P.kansuensis in Gansu can provide a theoretical basis for the work of the relevant functional departments of the grassland.currently predicting the potential distribution of species in the future under future climate change scenarios,most researchers simply use from habitat suitability models to predict the change of distribution,ignoring the limiting conditions of species during diffusion.This paper synthesizes all kinds of environmental variables and scattered restriction conditions,and predicts the potential geographical distribution of P.kansuensis in Gansu Province to obtain its real niche,which is more instructive for production practice.