Investigation And Invasion Risk Assessment Of Exotic Garden Plants In Ninggia

In the 21st century,with the continuous development of economy and frequent exchanges at home and abroad,the geographical and natural isolation of organisms is constantly broken,which speeds up the invasion of alien plants,leading to the outbreak of alien plants in new environments,and at the same time brings huge losses to the global ecosystem.Introduction of garden plants is a long-standing and eternal theme,which is also one of the reasons directly leading to the increase in the proportion of exotic plants.Therefore,it is urgent to investigate the present situation of exotic garden plants in Ningxia and carry out risk assessment.Through literature,specimen reference and field investigation,basic information of exotic plants in Ningxia was obtained,a list of exotic plants in Ningxia was established,and a list of exotic garden plants in Ningxia was screened.The diversity of exotic garden plants in Ningxia was analyzed,and the risk of exotic garden plants in Ningxia was comprehensively evaluated.According to the evaluation results,the corresponding prevention and management countermeasures were put forward,providing reference for ecological security,protection and development of landscape in Ningxia.The main results are as follows:1.A list of 177 exotic plants belonging to 119 genera and 44 families was established by investigating and analyzing the exotic plants in Ningxia.A list of 1 17 exotic garden plants belonging to 38 families and 79 genera was established by screening exotic plants.2.Among the exotic garden plants in Ningxia,compositae was the largest with 22 species,accounting for 18.8%of the total species,followed by Rosaceae with 14 species,accounting for 12.0%of the total species.Herbs were the main exotic plants with 59 species,accounting for 50.4%of the total species,followed by 34 species of trees,accounting for 29.1%of the total species.The main life forms were annual or biennial flowers.The largest number of native origin was from America,with 72 species,accounting for 61.5 of the total.Europe followed with 29 species,accounting for 24.8%of total species.110 species were introduced intentionally,accounting for 94.0%of the total species.7 species were introduced unintentionally,accounting for 6%of the total species.There were 79 genera of exotic garden plants in Ningxia,and 25 genera(31.6%)were distributed in pan tropics,followed by 20 genera(25.3%)in north temperate zone.3.The risk assessment of exotic garden plants in Ningxia was divided into three grades:high,medium and low.Among them,7 species of exotic garden plants are of high risk,43 species are of intermediate risk,and 67 species are of low risk.4.There are many exotic garden plants in Ningxia and their distribution is wide.It is urgent to prevent and control exotic garden plants in Ningxia.Suggestions and countermeasures were put forward,such as strengthening the research,raising the understanding,introducing the exotic plants rationally,perfecting the database of exotic plants and constructing the distribution map of exotic plants in Ningxia.