Abstract: Natural disturbance is a major force for forest community development. Thecanopy gap dynamics of forest disturbed will go through gap phase, building phase and mature phase. After the basic theory of forest dynamics and the natural disturbance regime including intensity and frequency, and its geographic difference are discussed, the forest canopy dynamics from gap formation to gap closure together with the size and form of gap and the environment and resources changing are reviewed.

Key words: bio-invasion, biodiversity, Conyza canadensis, associated plant, photosynthetic parameter.