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The Prediction Of Potential Suitable Distributions And Risk Assessment Of The Alien Invasive Plant Flaveria Bidentis(L.) In China

Posted on:2011-05-05Degree:MasterType:Thesis
Country:ChinaCandidate:X F CaoFull Text:PDF
GTID:2213330368484258Subject:Plant pathology
Abstract/Summary:PDF Full Text Request
Flaveria bidentis (L.) Kuntze, a Composite Flaveria specie, was a recently found alien plant in China. It might be a potential invasive species for its excessive strong reproductive and survival abilities. In this study, based on 32 ecogeographical factor variables of climate, topography and vegetation, we predicted the potential distribution of Flaveria bidentis in China using GARP, Maxent, ENFA, Bioclim and Domain five ecological niche models and we used the method of Receiver Operating Characteristic (ROC) curve analysis in assessing the accuracy of different Ecological Niche Models. Best simulation results obtained for risk analysis of domestic suitable range (P44) of the judge. According to quantitative analysis of PRA evaluation index system (five-level standard), it was Flaveria bidentis level of risk that was designated in China.This study includes:1. Using multiple sets of training data and verification data for model simulation and multiple ROC area under the curve (AUC) of statistical analysis and comparison, the high to low sequence in stability is Maxent> Domain> GARP> ENFA> Bioclim. The sequence of maximum AUC is Domain> Maxent> ENFA> GARP> Bioclim. The sequence of mean AUC is Maxent> Domain> ENFA> GARP> Bioclim. Evaluating these three aspects,we believe that the best model is Maxent.2. Maxent modelling is most suitable for Fleveria bidentis potential distribution analysis. Highly suitable areas of its forecast mainly in north and east part of China, including Hebei, central and southern Taiwan, Beijing, Tianjin, Shandong and northern and western Shandong, Henan, Anhui and Jiangsu provinces junction; edge over suitable areas include of the central and southern Hebei, Beijing, Tianjin, Shandong, Henan, Anhui, Jiangsu, Hubei, central, eastern Sichuan, and the central region of Yunnan.3. Using the Jackknife function of Maxent modeling, we believe that the most important five major ecogeographical factor variables of impacting Flaveria bidentis are annual mean temperature, temperature seasonality, precipitation of warmest quarter, altitude and mean precipitation of May. It's also the actual distribution of Flaveria bidentis consistent.4. According to PRA quantitative analysis evaluation index system, we obtained that the level of risk of Flaveria bidentis in China is the medium risk. Combined Flaveria bidentis suitable distribution in China, it indicated that it was not very invasive. With large breed in China's Hebei, it resulted in a significant impact on agricultural production. There may be missing the same biological niche competition for Flaveria bidentis in China's Hebei.
Keywords/Search Tags:Flaveria bidentis, Potential suitable distribution, Risk assessment, Maxent, Domain
PDF Full Text Request
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