The Distribution Pattern Of Major Invasive Alien Species Diversity And Its Influencing Factors In China

Biological invasions have caused serious environmental impacts and huge economic losses worldwide,making them more and more concerned by ecologists.Studying the characteristics of areas at risk of invasion is essential to understand the process of alien species invasion.However,although there are already many studies on the distribution patterns of invasive species and related influencing factors in China,few studies have assessed the effects of human activities of different periods on multiple invasive taxa,including invasive plants,invasive animals and invasive microorganisms.China is a vast country with high biodiversity and a long history of introduction of alien species,making it vulnerable to invasive species.Many kinds of invasive species are widely distributed in China.Therefore,the study of invasive species in China has important significance for the development of invasion ecology.In this study,515 Chinese invasive plants,114 invasive insects,and 62 invasive microbes were selected.First,we analyzed the basic information on the species composition and introduction characteristics of invasive alien species in the country,divided the country into seven regions,and compared the similarities and differences of these information in the seven regions with the country.We then collected species richness data from 31 provincial-level administrative units in China,and used ordinary least squares to calculate the correlations between the indicators of each factor and the richness of invasive taxa,and used an autoregressive model to explain the spatial autonomy in the residuals.Residual analysis was used to verify the influence of human factors on the distribution patterns of invasive taxa.Finally,the following conclusions were drawn:(1)The largest family of invasive alien species in the country is Poaceae;North America has the highest source frequency;the purpose of intentional introduction with the highest frequency is ornamental;the peak period of introduction time was1840-1948.Compared with the whole country,the introduction characteristics of invasive alien species in the seven regions are most similar to the situation in East China,so special attention should be paid to prevention and control.Analysis of the first introduction site shows that plants and insects with invasive potential should be strictly controlled in the southeast;each region should try to prevent the outflow of products parasitized by microbial taxa.(2)The distribution of the three invasive alien taxa in all provinces in China showed a similar pattern,that is,more in the southeast and less in the northwest.Compared with invasive plants and invasive insects,the abundance of invasive microorganisms in Northeast China and North China is also higher.(3)Contemporary mean annual temperature,annual precipitation and GDP in2000 were the most influential indicators of plant and insect richness,and all showed significant positive correlations;GDP in 2000,GDP in 1978 and altitude were significantly correlated with microbial richness.(4)After controlling for the effects of natural factors,GDP in 2000 still significantly influenced the distribution patterns of richness of the plant taxa,and was also the largest factor affecting insect and microbial taxa.This shows that the influence of contemporary social and economic activities in China on the abundance of invasive alien species is increasing year by year.In order to alleviate the harm of biological invasion,the management and control of invasive species should be strengthened accordingly.