Primary Research On Pest Risk Analysis Of Alien Invaseive Species Erwinia Amylovora

This thesis is mainly about the pest risk analysis on fire blight(a disease caused by an alien invasive species Erwinia Amylovora)in assist of the technique of Geographical Information System and about the foundation of an multiple index analysis system for alien invasive species.Fire blight was first observed in 1978 in New York. With the expansion of the world trade, it has spread into many countries all over the world. Up to now, the disease has its distribution in more than 40 countries all together. China puts it in the first-class quarantine list to prevent its invasion into our country. The disease which is caused by Erwinia amylovora causes disastrous consequences especially to pear, apple, hawthorn and quince.In the thesis, meteorological database of China was built up including the mean temperature and precipitation of the 730 weather stations. By database software the meteorological data(in the form of *.dat )of different weather stations are transformed into that can be recognized by the GIS software(*.dbf), and the data are arranged in the order of year. The distributions of the main affected host in china are also built up by the showing, searching and other relative functions provided by the GIS software.Fire blight is very extensive and serious in many European countries, so there are many researches about the epidemiology of the disease. In the thesis, by references of these researches, the factors for the disease to prevail are selected, and the effectiveness of the factors is confirmed in the European and northern African areas.The meteorological data are imported into the GIS software-ARCINFO and by its function of interpolation, the thesis depicts the distribution of the temperature and precipitation in china during the flowering period of the apple and pear which are the main host, and finally find out the potential suitable areas for the disease in China. The factors are: temperature is 15.6℃or more, the precipitation is 2mm or more. China was divided into four kinds of risk areas of the disease, that are high risk areas, middle risk areas, low risk areas and almost no risk areas. The thesis also analyzed the economic losses of pear production in China in 2003. It has been found out that the risk areas are almost the main producing areas of apple and pear which are of great economic importance in China, so if the invasive pathogen invade in China successfully, it will cause tremendous losses of our pear and apple production.The thesis also established a multiple index analysis system for alien invasive species, and analyzed the risk of the fire blight caused by the invasive species Erwinia Amylovora comprehensively using said system in aspects of economic, environmental losses and social effects and so on.