We obtain the representative formulas of the basic reproduction numbers and the invasion reproductive numbers.

Allee effect and its significance to small population management in nature reservation and biological invasions;

As an opening region with high population and booming foreign trade in seaboard,Zhejiang Province now is being suffered from a serious biological invasions of waterhyacinth(Eichhornia crassipes),pine wood nematode(Bursaphelenchus xylophilus),smooth cord-grass(Spartina alterniflor),canada goldenrod(Solidago Canadensis),et al.

At individual level, researchers were mostly concentrated on evolution and adaptation of alien species when they invaded new environments,as well as responses of native species facing biological invasions.

The impact of biological invasion on biodiversity and grassland agroecosystem;

On evaluation and predication of biological invasion;

Effects of biological invasion on ecological safety of Fujian Province;

Present situation and strategy against bio-invasion in Jilin Province;

Based on the former research in bio-invasion risk assessment,aiming at the status quo of exotic plant invasion in Xiamen,we have established a Risk Assessment System for alien plants.

The correct understanding of landscape plant introduction and bio-invasion has an important significance to China’s urban landscape construction.

The idea of ecological invasion,the pathways of invasion,the factor influencing invasion and the impact of invasion on the ecosystem services of vegetation are mentioned.

This is a typical kind of green-pollution and has become one of the most serious-harmful ecological invasion plants.

This paper,using ecological invasion theory,sets up an evaluation indicator system of industry easy invasion degree,calculates the easy invasion degree and provides reference data to t.