Potential Distribution Prediction Of Middle Flavor Style Flue-cured Tobacco Based On Ecological Niche Model

Flue-cured tobacco flavor is an important component of Chinese cigarettes style factors. The division of flue-cured tobacco based on flavor was put up by Chinese tobacco researchers in the1950s. The middle flavor style flue-cured tobacco has a large distribution area, in which ecological conditions vary significantly. It’s been considered that ecological conditions have important effects on the quality characteristics of tobacco, and form its unique flavor style.There is a necessary to make a thorough analysis for the known distribution of middle flavor style flue-cured tobacco. And the effects of ecological factors on the distribution should be analyzed as well. All these information will be useful to make a prediction of ecological suitability in a target area.In this paper, different ecological niche models were built by using already known distribution points of middle flavor style flue-cured tobacco, topographic factors, solar radiation factors and climatic factors. After comparison of all these models, an optimal model was selected and used to make the prediction of the potential distribution for middle flavor style flue-cured tobacco. The predicted result is mapped with a proper classification of suitability. And the impact of major factors on the predicted result is also studied.Specific content as well as the main conclusions are as follows:(1) The comparison among temperature, precipitation, solar radiation, topography and other factors in distribution areas for different flavor flue-cured tobacco show that there are significant differences between each kind. So it is OK to think that each different flavor flue-cured tobacco has its own the unique ecological niche. Based on these, ecological niche model could be employed to predict the potential distribution area for different flavor flue-cured tobacco.(2) By using different data sets, a variety of niche models were built. And the comparison show that the performance of Maxent and Domain prediction are better than SVM, ENFA, Bioclim and GARP. And the performance of Mahalanobis is the worst. Resort these models by descending order in accordance with the model prediction performance is:Maxent> Domain> SVM> GARP> ENFA> Bioclim> Mahalanobis. Meanwhile, in accordance with the stability of models, the sequence in descending order is resorted as follow:Maxent> Domain> GARP> SVM> ENFA> BIOCLIM> Mahalanobis.(3) As the number of sample points increases, the performance of all models are enhanced. But different model has different characteristics to respond the change. ENFA, BIOCLIM and SVM can be treated as one kind which vary significantly. And GARP, Domain, Maxent are on the other hand which change slightly.(4) After a comprehensive comparison, Maxent was chosen as the optimal model, and made the prediction of the suitable area for middle flavor style flue-cured tobacco. The suitability areas mainly distributed in most parts of Guizhou, southeast, northeast, and central of Chongqing, eastern Sichuan, western Hunan, western Hubei, southern Shaanxi, southeast of Gansu, south and central Shandong, southwest of Henan, central Jilin, and the southern Heilongjiang.(5)The analysis show that the solar radiation, precipitation, temperature have important effects on the distribution of middle flavor style flue-cured tobacco while the terrain factors’effect are relative smaller. Places with low solar radiation, high precipitation and warm temperature in early stage of tobacco growing usually have relative higher habitat suitability.