Prediction And Risk Analysis Of Potential Adaptation Zones Of Invasive Pest Of Red Palm Weevil In Jiangxi Province

With global warming,human activities expanding,demands of urban town greening construction increasing,as well as more and more alien tree(such as the tropical species of the palm tree)planting,the spread of invasive pests(Rhynchophorus ferrugineus feeding on palm tree species)was driven widely and rapidly.So it is necessary to predict these invasive pests' potential distribution and risk before a successful invasion.Former studies on risk analysis and distribution prediction in Rhynchophorus ferrugineus are mainly taking the national scale,then it is difficult to provide specific refered materials for the introduction of local prevention and control programs.In recent years,R.ferrugineus invaded Jiangxi Province and brought dangerous breakouts in several cities.Thus,it is urgent to uncover the risk,suitability,and potential distribution of R.ferrugineus in other cities or places of Jiangxi.This study took the entire province of Jiangxias a local case researchof R.ferrugineus.It collected high-resolution climate,terrain raster data and other environmental variable dataand then formed models to predict the risk and scopes which are suitable to R.ferrugineus.These results could play an important role in introducing and implementing a specific plan of pest prevention and control,aiming to protect the local ecosystem and forestry resources and avoid big loss in economy.This study was dedicated to answer: how is the invasion risk of R.ferrugineus,which areas are more suitable for its habitat requirements,and which areas could face higher risk? We used PRA method to evaluate risk through calculating R value.After collecting a large amount of occurrence data of R.ferrugineus and high-resolution raster data of environmental factors we used GARP and MaxEnt soft to predict the distribution of the pest and uncover the risk areas in Jiangxi Province.Additionally,in order to obtain the maximum distribution zone of the potential habitat of R.ferrugineus in Jiangxi province,climate data correlated with terrain variables(elevation,slope etc.)and two developmental indexes(Developmental zeros and Effective accumulative temperature of generations,as limited factors for R.ferrugineus)were produced throughout the study area,and then,with these variables,but without considering host resources and occurrence points data,a model was build to predict the distribution of suitable habitat for the pest in Jiangxi.Main research findings are as follows:(1)PRA risk analysis show: R.ferrugineus belongs to high risk invasive pest in Jiangxi.Its risk R value is 2.20;the value of spread and colonization risk is 2.05,and the risk management difficulty risk value is 2.33.Therefore,in order to reduce risks and reduce harm losses,the local government needs to be vigilant and promptly issue and implement a prevention and control plan for the R.ferrugineus.(2)The prediction results based on two niche models of GARP and MaxEnt show that: most areas in Jiangxi province are the high or moderate risk areas of the R.ferrugineus,especially adjacent the areas where the risk has happened,and the south-central Jiangxi where mean annual temperature is high.Risk free areas are mainly concentrated in mountain areas with high altitude and low temperature.Therefore,the prevention and control of R.ferrugineus in Jiangxi should be arranged in these areas in advance so that reducing the spreading risk in Jiangxi.(3)Analysis of climatic topographic factors show that bio01(annual average temperature),bio06(lowest temperature in the coldest month),bio09(average temperature in the lowest season),and bio11(average temperature in the coldest quarter)have strong influence on happening of R.ferrugineus while slope,exposure,isothermality etc,have less influence.(4)Comparing the two ecological niche models GARP and MaxEnt,it founds that the prediction results of the two models are quite different.The GARP model predicted that most regions of Jiangxi Province were highly suitable risk range while MaxEnt model predicted that most regions of Jiangxi Province were moderately suitable risk range,which is consistent with simulated results conducted by the predecessors who used both for species prediction.Namely,GARP predicts that the range of risk areas is relatively large while the MaxEnt predicts range of risk areas is relatively narrow.Therefore,it can be inferred that the MaxEnt result may be more susceptible to the number of known occurrence points and their distribution locations,while the GARP results are more likely to be dominated by factors such as altitude and low temperature.Therefore,improving the accuracy of MaxEnt's prediction depends on the accuracy and numbers of known occurrence places while GARP results are more susceptible to factors such as altitude and low temperature.Therefore,improving the accuracy of the MaxEnt prediction depends on the accuracy and completeness of the known occurrence places of the species;if GARP can provide more accurate and higher resolution environmental data,it can improve its prediction ability.(5)Based on the prediction of fitness model constructed,the results show that most of the areas in Jiangxi Province are high or highly suitable habitats for R.ferrugineus,especially in the northern Jiangxi Plain and the Jitai Basin of central Jiangxi,and hilly land of southern Jiangxi.However,a few unsuitable habitats are mainly distributed in high altitude mountainous regions such as Lushan,Jiulingshan,Wugongshan,Wuyishan,Jinggangshan and Wanyangshan.