Research On Potential Habitat Of Alien Species Based On WEB Database And GIS

The world trade globalization has greatly promoted with the accelerating of the global economy integration, which provide a pathway for the alien species to invade, disseminate and spread around the world. The biological invasion has caused irreversible ecological disaster and enormous economic losses in many countries in the world. Early detecting the spatial distribution of alien forest species to prevent them from entering suitable habitat, is the prerequisite of making managing measure of biological invasions.Now we can predict the potential geographic distribution of invasive alien species in the target region by using mathematical models. The niche based models were commonly employed to predict the habitat suitable maps of species, which can provide essential technical support for the policy-maker when they formulate the corresponding measures. The principle of ecological niche modeling was based on that there is a special niche - the set of environmental factors that determine where a species can or cannot maintain populations– for each specific species. We can deduce the ecological niche requirement onto the novel area the species never has been found before to predict the suitable maps of the species.Using this risk assessment framework, we analyzed the potential geographic distribution of Bursaphelenchus xylophilus, Hyphantria cunea, Hemiberlesia pitysophila Takagi in China with 6 common used niche models: DOMAIN, BIOCLIM, GARP, LR, MAXENT and CART. The results showed that all of the 6 models can be used to predict the distribution of species with acceptable results, but the performance of different models varied dramatically. The main results are as following:1,Precipitation seasonal changes, annual rainfall, slope topography, composite terrain index are the main influence ecological environment factors of the pine wood nematode distribution. The potential habitat distribution probability is positively correlated with the altitude, annual rainfall, annual temperature changes, and negatively correlated with the precipitation seasonal changes. In Jiangsu, Yixing, Liyang, Jurong, Jintan, Yuntai of Lianyungang are the easily infected areas of pine wood nematode disease, and Yixing, Liyang, Nanjing, Jurong, Xuyi are the main distribution of pine wood nematode disease.2,precipitation of coldest quarter, temperature annual range, forest coverage, temperature seasonal changes are the main encologiacl environment factors of the Hemiberlesia pitysophia Takagi. The potential habitat area of Hemiberlesia pitysophia Takagi include Guangdong, Guangxi, Fujian, and the southern of Guizhou, the southern of Xizang and northeast of Taiwan are also the potential habitat distribution. Potential habitat of Hemiberlesia pitysophia Takagi is far more than the existing distribution.3,Potential habitat of Hyphantria cunea is large than present situation, with a jumping distribution pattern. Along with the global warming, the average risk of Hyphantria cunea invasion is lower for our country forest, and spatial distribution shows from focus to disperse. Distribution center drift from North China to Northwest China. Climate change and temporal imbalance are the two driving factors for potential habitat change of Hyphantria cunea in climate change scenarios.