我国入侵植物多样性的区域分异及其影响因素——以74个地区数据为基础

Diversity differentiation of invasive plants at a regional scale in China and its influencing factors:accroding to analyses on the data from 74 regions

以我国74个地理单位282种外来入侵植物的分布和环境数据为基础,应用除趋势对应分析、典范对应分析和回归分析方法,探讨了我国境内入侵植物区系组成、地理分布格局及其影响因素。主要结果如下:(1)我国74个地区共有282种外来入侵种,出现频率相对较高的外来入侵种是小飞蓬(Conyza canadensis)、刺苋(Amaranthus spinosus)、一年蓬(Erigeron annuus)、空心莲子草(Alternathera philoxeroides)、土荆芥(Chenopodium ambrosioides)、圆叶牵牛(Pharbitis purpurea)、曼陀罗(Datura stramonium)、皱果苋(Amaranthus viridis)、裂叶牵牛(Pharbitis nil)、反枝苋(Amaranthus retroflexus)、三叶鬼针草(Bidens pilosa)、凤眼莲(Eichhornia crassipes)等;(2)菊科(Compositae,67,种数)、禾本科(Gramineae,32)、豆科(Leguminosae,29)、苋科(Amaranthaceae,23)、旋花科(Convolvulaceae,13)是我国境内含入侵种最丰富的5个科,共计有164种,占我国入侵植物总数的58.16%;(3)我国外来入侵植物主要源自于热带美洲、北美洲、欧洲、地中海-西亚和中亚、非洲和南亚;(4)外来入侵植物多样性在我国的区域分异明显,热带-南亚热带、中(北)亚热带和温带三大区域的入侵种组成有较大差异:马缨丹(Lantana camara)、含羞草(Mimosapudica)、胜红蓟(Ageratum conyzoides)、刺苋、小飞蓬、飞扬草(Euphorbia hirta)、五爪金龙(Ipomoea cairica)、空心莲子草、三叶鬼针草和金腰箭(Synedrella nodiflora)是热带-南亚热带区域中出现频率最高的前10种入侵植物;中亚热带和北亚热带区域出现频率最高的入侵种分别是一年蓬、小飞蓬、刺苋、土荆芥、北美独行菜(Lepidium virginicum)、美洲商陆(Phytolacca americana)、牛筋草(Eleusine indica)、紫茉莉(Mirabilis jalapa)、空心莲子草和三叶鬼针草;温带区域出现频率最高的是反枝苋、小飞蓬、圆叶牵牛、一年蓬、野西瓜苗(Hibiscus trionum)、杂配藜(Chenopodium hybridum)、苦苣菜(Sonchus oleraceus)、野燕麦(Avena fatua)、曼陀罗和皱果苋;(5)年降雨量、年均温度、年极端低温、无霜期和年均积温是影响我国外来入侵种空间分布格局的主要气象因素,年极端高温和年日照时数的影响相对较小;人口密度和交通密度对入侵种的地理分布也均有很大的影响;(6)随着年均温度、无霜期、人口密度、交通密度、年极端低温、年均降雨量和年积温的增加,外来入侵植物的种数呈线性增加,随着纬度的增加,种数则呈线性递减,种数与这8个环境因素间的关系达到极显著的水平;(7)不同地理来源的外来入侵种在我国的分布主要受纬度、年降雨量、年均无霜期、年均温度、交通密度、年极端低温和年均积温的影响。由于外来入侵种在我国分布呈现明显的区域分化,因此,应用建立具有区域特点的外来植物入侵风险评估系统。

A total of 282 invasive alien plants were recorded from 74 geographical units in China,and 11 environmental variables including climatic and social factors were also recorded.Based on the above data,the geographical distribution pattern of 282 invasive alien plants in the 74 geographical units and influencing factors were analyzed using Detrended Correspondence Analyses （ DCA） and Canonical Correspondence Analysis （ CCA） .The main results are as follows：（ 1） In the 74 geographical units, Conyza canadensis, Amaranthus spinosus, Erigeron annuus, Alternathera philoxeroides, Chenopodium ambrosioides, Pharbitis purpurea, Datura stramonium, Amaranthus viridis, Pharbitis nil, Amaranthus retroflexus,Bidens pilosa and Eichhornia crassipes are widely distribution in mainland of China.（ 2 ） Compositae （ 67 species） ,Gramineae（ 32 species） ,Leguminosae（ 29 species） ,Amaranthaceae（ 23 species） ,Convolvulaceae（ 13 species） are five main families,accounting for 58.16% of the total invasive species in China.（ 3） Of the invasive alien plants, 43.97% originated from Tropical America,18.44% from North America,14.89% from Europe,8.87% from the Mediterranean,West Asia to Central Asia,4.26% from Africa and 3.55% from South Asia.（ 4 ） The geographical distribution of invasive plants in China were divided into three regions：the tropical-south subtropical region,central （ north） sub-tropical region,and the temperate region.In the first region,the main invasive plants are Lantana camara,Mimosa pudica,Ageratum conyzoides,Amaranthus spinosus,Conyza canadensis,Euphorbia hirta,Ipomoea cairica,Alternathera philoxeroides,Bidens pilosa and Synedrella nodiflora; in the second region,the main invasive plants are Erigeron annuus, Conyza canadensis,Amaranthus spinosus,Chenopodium ambrosioides,Lepidium virginicum,Phytolacca americana,Eleusine indica,Mirabilis jalapa,Alternathera philoxeroides and Bidens pilosa; while in the third region,Amaranthus retroflexus, Conyza canadensis,Pharbitis purpurea,Erigeron annuus,Hibiscus trionum,Chenopodium hybridum,Sonchus oleraceus, Avena fatua,Datura stramonium and Amaranthus viridis are the ten main invasive plants.（ 5） The main meteorological factors influencing the distribution of invasive plants in China,if ranked as from high to low,are annual average precipitation,annual average temperature,annual extreme minimum temperature,frost-free days and annual accumulated temperature,while annual extreme maximum temperature and annual sunshine hours were of little influence.Human population density and transport density also play important roles on the distribution pattern.（ 6） The number of invasive plants increased almost linearly with the increase of annual average temperature,frost-free days,population density, transport density,annual extreme minimum temperature,annual average precipitation and annual accumulated temperature, and decreased linearly with the increase of latitude.The correlation between the number of invasive species and the eight environmental factors reached a highly significant level,while annual extreme maximum temperature,longitude and annual sunshine hours have little influences.（ 7 ） The main environmental factors influencing the distribution of different geographical elements of invasive plants in China are latitude,annual average precipitation,frost-free days,annual average temperature,transport density, annual extreme minimum temperature, population density and annual accumulated temperature,while annual extreme maximum temperature,longitude and annual sunshine hours have weaker influences than the former eight factors.As for the social and economic factors,population density and transport density both have distinctive influences on the distribution of geographical elements of invasive alien species.The assessment of invasive risk of alien plants should be conducted in regional level,for regional differentiation exists in the distribution of invasive species in China.