Distribution Pattern And The Effect Factors Of Invasive Animal Species In Guangxi Province, China

Alien Invasive Species (AIS)means those species appeared beyond the historical growing area, erupting as lack of natural enemy or other factors and giving a certain extent of hazards to local ecosystem.Nowadays, AIS’invading speed of Guangxi province continues to accelerate,it is important to introduce new technology to assist the research while the traditional method has limited effect. This paper use geographic information technique to analysis the relationship between distribution mode of Invasive Animals (IA) and factors of human activity and nature in Guangxi province.Human activity factor (HAF) has a significant impact on IA’s spreading efficiency, while nature factor (NF) decides whether it can survive or not. In recent years, environmental pollution caused by human activities also has some influence on IA’s probability of survival.The invasion of IA of all counties in Guangxi province was quite serious.Investigation showed there were67kinds of IA amounting to50%of whole China’s134, including9classes24orders and45families,while insecta had the largest proportion of59.7%.The number of IA in all85country were more than30with an average of34.22,while Hepu county and Dongxing county had reached a peak of47kinds.The overall results showed a distribution of a high number of invasive species in north and south and a lower number in central region, formed a transmeridional "corridor" formed by low quantity. According to density, all most areas are similar (20species/km2*10000), Heshan, Dongxing and Pingxiang three counties have reached the top three with94.29,79.66,56.92(species/km2*10000) respectively.30species have been found in all85counties in the investigation, which means that the invasion situation is very serious.According to the statistics of Guangxi Statistics Department in2011, we extracted8economic factors as human activity factor, including Administrative Region Land Area(sq.km), Population at the Year-end, Gross Domestic Product(10000Yuan),Per Capital GDP(10OOOYuan), Financial Revenue(10000Yuan),Total Sown Area of Major Farm Crops (hectare), Gross output of Grain (ton), Length of Domestic Ways (km).Length of Domestic Ways=Length of Domestic Highways+Length of Domestic Railways. This paper acquired the distribution data of five types of landforms, including woodland, wasteland, residential area, water and cloud (excluded by natural factor) by using Google Map13th remote sensing graph, then divided according to administrative area location of each county.Based on the species composition of IA, all the85counties have been clustered into4parts, including Hepu, Hechi, Linggui and Guigang, each cluster showing obvious regionality. After principal component analysis(PCA) on8environmental factor, we obtained F1-F3three principal components, then make linear regression using F1-F3as independent variables to structure multi-variable regression equation (MVRE) with IA quantity and density as dependent variable.Fl-F3have entered MVRE at first analysis, the coefficient of determination is0.161with weak correlation which suggesting that IA in Guangxi province is not affected by a single factor but several ones. F1have entered MVRE at second analysis, the determination coefficient was-0.083which means the correlation is also very weak. Combined with the fact that density is quite balanced among Guangxi province, it illustrates that the vast amount of Guangxi Invasive animals have smoothed the differences between environmental factors. After the canonical correspondence analysis(CCA) of IA distributing mode and environmental factors, it shows that Per Capital GDP and Gross output of Grain have played an dominant role with coefficient of determinations of0.43and0.42.1. The quantity of invasive species in Guangxi province is affected simultaneously by various factors, the human activities factor such as per Capita GDP, Gross output of Grain, total population can affect it weakly;2. Density of IA in Guangxi province is relatively homogeneous so that none of single factor affect it effectively. Abundant IA species erased the difference among environmental factors.3. The major factors that affect the distribution patterns of invasive animals in Guangxi province is the per Capita GDP and Gross output of Grain, which is more emphasize in human activity compared to the situation of all of our country.