Predicted potential distribution of Praxelis clematidea in China

Abstract

Praxelis clematidea, native to South America, was first reported in 1980s and has already been a noxious weed in China. In order to provide early warning for P. clematidea invasion, GARP and Domain models were applied to predict the species' distribution range based on the 397 recorded points and 146 known points, and the two models were evaluated by AUC and Maxkappa. The results indicated that the distribution records of P. clematidea had increased and it had further spread during the past 10 years. Solar radiation, water vapour pressure, maximum temperature, frost days, and flow direction had little impact, while 8 environmental factors such as wet days, aspect, slope, elevation, annual precipitation, mean annual temperature, topographic index and minimum temperature had great influence on P. clematidea potential range. The invaded vegetation types of P. clematidea were the mosaic of cropland/shrub or grass cover, the shrub cover, the artificial surfaces and associated areas, etc. Model evaluation showed that the results by two models were good. The results of prediction showed that Tibet (except a small area in southeast), Xinjiang, Qinghai, Inner Mongolia, Ningxia, north Shanxi and Shanxi, Heilongjiang, Jilin and Liaoning (except a small area in Liaodong Peninsula) were predicted as less vulnerable to P. clematidea invasion; P. clematidea was most liable to invade Guangdong, Guangxi and Hainan, etc. The invasion of P. clematidea had not been reported in some provinces of central China and the centre of North China Plain, which are likely to be suitable distribution area. Therefore urgent action should be taken and management must be reinforced to prevent this species from further spreading.