Disturbance regimes and gaps characteristics of the desert riparian forest at the middle reaches of Tarim River Disturbance Regimes and the Characteristics of Gaps in Maolan Karst Forest, Guizhou Province Gap Disturbance Regime in a Broadleaved-Korean pine Forest in the Changbai Mountain Natural Reserve Gap natural disturbance regime in the Castanopsis kawakamii forest Forest gap characteristic in a coniferous-Picea likiangensis forest in the Yulong Snow Mountain Natural Reserve,Yunnan Province,China