Prediction Of Potential Suitable Distribution Of Compositae Invasive Species From North America With Niche Modles Based On GIS

The risk of alien biological invasion in the global scope is growing, China is faceing a great pressure of biological invasion. At present, as the international exchanges of business and culture is becoming more and more frequent, the possibility of alien species invasion is greatly increased. Early warning system based on risk analysis and control measures is critical issues in prevention of alien invasion and spread using MaxEnt ecological niche model based on GIS (Geographic Information System). Among the invasive plants in China, from species classification, compositae species are the most. From the origin regions, most of those species originated from Americas, particularly North America. At present, there are 28 species of compositae invasive plants that came from North America, all of which have caused various degrees of harmfulness in China. In this study, the combination of ecological niche models(GARP&MaxEnt) with GIS (Geographic Information System) were used to comprehensively analyze the correlative environment variables which affect distribution regions of 28 species of compositae invasive plants that came from North America:Conyza canadensis (L.) Cronq., Ageratum conyzoides L., Erigeron annum (L.) Pers, Solidago canadensis L., Bidens tripartita L.,Gaillardia pulchella Foug., Halianthus tuberosus L., Tagetes patula L.,Tithonia diversifolia A. Gray, Tagetes erecta L., Zinnia elegans Jacq.,Coreopsis lanceolata L., Erigeron philadelphicus L., Ageratum houstonianum Mill., Zinnia peruviana (L.) L., Flaveria bidentis (L.) Kuntze, Eupatorium adenophorum Spreng, Aster subulatus Michx., Ambrosia artemisiifolia L., Coreopsis tinctoria Nutt., Ambrosia trifida L., Bidens frondosa L., Iva xanthifolia Nutt., Helenium autumnale L., Cosmos sulphureus Cav., Cosmos bipinnatus Cav.,Coreopsis grandiflora Hogg, Erechtites hieracifotia (L.) Raf. ex DC.Prodr., Cosmos bipinnatus Cav., in order to intuitively and quantitatively predict their potential distribution regions. The predictions were verified by the ROC (Receiver Operating Characteristic) curve. The result shows that: (1) Erigeron philadelphicus may have a wide range of potential distribution regions which include Shanghai, Jiangsu, Zhejiang, Anhui, Henan, Hubei, Hunan, Jiangxi and some other places. However, the currently actual distribution is far less than the maximum range of potential distribution, which means that it may continue to spread. It is suggested that more attentions should be addressed to the harmfulness of this weed. Eradication of the existed populations and strict monitoring of invasion to the most suitable regions may be adopted to prevent the invasion of its spread.(2) The potential distribution regions of Solidago canadensis mainly situated at the east part of China, where the geographical position lies roughly between 24°and 35°north latitude, and 108°and 123°east longitude. The potential distribution regions include the most areas of Shanghai, Jiangsu, Anhui, Hubei, Chongqing, Hunan, Jiangxi, Zhejiang, and some area of Shandong, Henan, Shanxi, Guizhou, Fujian. Low temperature and drought are the key factors to limit Solidago canadensis invasion in northern, western and high altitude areas of our country. Meanwhile, high temperature and temperature difference can influence solidago canadensis invasion in coastal tropical place of China. With comparion of environmental factors of original habitats, the climate niche of Solidago canadensis has shifted after it invaded to China.(3) The results showed that the distribution of Conyza canadensis in China could be well predicted by using Maxent and GARP, but there was a remarkable difference between predicted and actual distribution in China, the climate niche of Conyza canadensis has shifted after invaded to China. The results also showed that, when using presence information of both native region and invasive region, Maxent can produce a better result than GARP, but without presence information of invasive region, this advantage of Maxent would not be exhibited. The sensitivity of the Maxent is better than GARP. (4) All of the 28 compositae invasive species from north America have a wide range of potential distribution regions which include East China, South China, Central China some other places, particularly along the Qinling Mountains-Huaihe River Line and the southwest area of China may be the easiest to be invasived. The key enronmental factors of their invasion are low temperature, average annual temperature, growth day length, evapotranspiration. The 8 species of climate niches have shifted afterinvaded to China. The dispersal way of seeds can not directly determine the the potential distribution of suitable areas and scope. Their potential distribution regions could be divided into 6 types such as southwest and Yangtze drainage area from the geographical view of invasion. Qinlin-Huaihe area and southwest of China may seriously suffer from alien invasion, including Jiangsu, Anhui, Hubei, Jiangxi, Chongqing and Yunnan et al. These 28 invasive species of Asteraceae from North America can be divided into three groups through comparing their current distribution and potential suitable area:Group 1, climax species:the current distribution of which reached 66.7% or more potential suitable area, includeing Conyza Canadensis, Erigeron annuus, Gaillardia pulchella, Tagetes erecta, Tagetes patula, Aster subulatus. Group2, expansion species:the distribution area of which has only reached 66.7%-33.3% potential suitable area, including Ageratum conyzoides, Ageratum houstonianum, Eupatorium adenophorum, Ambrosia artemisiifolia, Bidens frondosa, Bidens tripartita, Coreopsis lanceolata, Coreopsis tinctoria, Cosmos bipinnatus, Cosmos sulphureus, Tithonia diversifolia, Halianthus tuberosus, Solidago canadensis, Zinnia elegans and Zinnia peruviana. Group3, colonization species:the current distribution scope of which only reached less than 33.3% potential maximum range of suitable areas, including Ambrosia trifida, Coreopsis grandiflora, Erechtites hieracifotia, Erigeron philadelphicus, Flaveria bidentis, Helenium autumnale and Iva xanthifoli. Ambrosia trifida, Erigeron philadelphicus, Flaveria bidentis and Iva xanthifolia have not only a wide range potential suitable area but also strong invasive ability, which needs to be vigilant in particular. In order to effectively manage invasion of alien species, integrated management strategy should be adopted improving the regulations, enhancing quarantine, estabolishing early warning systems, developing scientific control techniques, actively carrying out relevant research works and raising public awareness.