海南省主要陆生入侵植物在不同生境类型的适生性

Adaptivity of Major Terrestrial Invasive Plants in Different Habitats in Hainan Province

应用Max Ent与Arc GIS技术,结合野外调查数据,对海南省含羞草(Mimosa pudica)、飞机草(Chromolaena odorata)、马缨丹(Lantana camara)、假臭草(Praxelis clematidea)等6种主要陆生入侵植物的适生区进行了预测和分析。结果表明:(1)6种陆生入侵植物适生区的适生等级由沿海向内陆呈逐级递减趋势,可能是气候分布不同所致,可能是海拔升高所致,也可能是土地利用类型的变化等因素所致;(2)刀切法(Jackknife)分析显示,土地利用类型与入侵植物的适生区有着极为重要的关系,是影响6种陆生入侵植物分布的最主要环境因子。另外,海拔、坡向、温度的年较差、降雨季节性变化等环境因子对不同入侵植物的适生区也产生重要的影响;(3)6种入侵植物在村落周边、城镇建设用地、其他建设用地(盐场、工业区、厂矿、采石场等用地)生境中具有极高的适生性;在林地、草地类生境中的适生性较高,但是在有林地(郁闭度>30%的天然林和人工林)和高覆盖率草地(覆盖率>50%的天然草地、改良草地和割草地)生境中的适生性较低。

Environmental data and the data of the invasive plants from field sampling were analyzed by using Max Ent and Arc GIS to predict the distributions of suitable adaptivity areas for six major invasive plants,Chromolaena odorata,Praxelis clematidea,Mimosa pudica,Conyza sumatrensis,Wedelia trilobata,Lantana camara,in Hainan Province,China. Results showed that the adaptivity of the 6 major invasive plants tended to decrease gradually from coastal areas to inland areas,which might be due to difference in climatic distribution,to high elevation,or to the change of landuse types. Jackknife analysis showed that land use types were highly associated with the area of the suitable habitats of the invasive plants and were hence the most important environmental factors affecting the distribution of the six terrestrial invasive plants. Moreover,the area of suitable habitats of different invasive plants is also influenced by elevation,slope aspect,annual range of temperature,and seasonal variation of rainfall. Further analysis using Jackknife method also showed that the adaptivity of the 6 invasive plants was very high in the habitats of the surroundings of the village,the urban construction land and other construction lands like those in salt mine,industrial area,factories,mills,stoneworks,and higher in the habitats of woodland and grassland,but rather weak in the forested land（natural or artificial forests with canopy closure of 〉 30%） and grassland with high vegetation coverage（Natural grassland,improved grassland and cut-and-carry grassland with a vegetation coverage of 〉 50%）.