中国西部地区归化植物时空分布特征研究

Temporal and spatial distribution characteristics of naturalized plants in West China

归化是外来植物越过一系列障碍成为入侵植物的基本前提,对归化植物的种类组成及分布规律进行研究,有助于预防和管控植物入侵。该文基于文献报道和标本记录,对中国西部地区共12省(区)126个地级市的归化植物进行统计(包含所有维管束植物),并分析了这些植物的组成和时空分布特征。结果表明:(1)西部地区共有归化植物826种,分属107科473属,约占全国归化植物总数(1099种)的75.16%。(2)时间上,根据回归拟合,15世纪前,西部地区的归化植物累积增长平稳,随后呈Logistic模式增长,1936年增长速率最大。目前,增长速度趋缓,但无意引入比例显著高于其他时期。(3)空间上,物种数及密度均呈自西北向东南、内陆向边境递增的趋势,且存在“强省会”现象。(4)回归树分析表明,年降水量、国内生产总值(GDP)、年均气温和耕地比例是西部地区归化植物分布格局的主要驱动因素。该研究结果丰富了西部地区归化植物的基础资料,有助于摸清西部地区外来植物入侵现状,并为其综合管控提供科学依据。

Naturalization is the basic premise for exotic plants to surmount a series of obstacles and become invasive plants.It is helpful to prevent and control plant invasion for studying the species composition and distribution of naturalized plants.Based on literature reports and specimen records,we firstly maked statistics on naturalized plants in 126 prefecture-level cities in 12 provinces(regions)in West China,included all vascular plants,and analyzed the plant composition and temporal and spatial distribution characteristics.The results were as follows:(1)There were 826 species of naturalized plants belonging to 107 families and 473 genera in the western region,accounting for about 75.16%of 1099 species of naturalized plants in the country.(2)In terms of time,according to regression fitting,the cumulative growth of naturalized plants in the western region was stable before the 15th century,and then showed a Logistic pattern of growth,and the growth rate was the largest in 1936.At present,the growth rate slowed down but the proportion of unintentional introduction was significantly higher than that in other periods.(3)Spatially,the number and density of species were increasing from northwest to southeast and inland to the border,and there was a phenomenon of strong provincial capitals.(4)Regression tree analysis showed that annual precipitation,GDP,average annual temperature and cropland ratio were the main driving factors for the distribution pattern of naturalized plants in the western region.These results enriches the basic data of naturalized plants in the western region,are conducive for finding out the current situation of alien plant invasion in the western region,and provide scientific basis for its comprehensive control.