Effect of Thinning on Quercus wutaishanica Trees Form Quality by the Analytic Hierarchy Process in Huanglong Mountains

【Objective 】 In this study,the effects of thinning on Quercus wutaishanica trees form quality were investigated by the analytic hierarchy process in Huanglong Mountains in order to provide theoretical basis of trees form quality evaluation system and thinning on Q. wutaishanica on Loess Plateau.【Method】 Experimental sample plots,which are the heavy thinning( keeping canopy density of 0. 6),medium thinning( keeping canopy density of 0. 7),light thinning( keeping canopy density of 0. 8) and control plots( canopy density of 0. 9) on Q. wutaishanica forest in Huanglong Mountains of the Loess Plateau were set up. In order to keep invariant canopy density of different thinning intensities of the experimental sample plots,every three years proceed on a tending thinning. The Q. wutaishanica form quality evaluation system was constructed by using the analytic hierarchy process( AHP),with growth situation( height mean increment,DBH mean annual increment,crown diameter ratio,health condition),stem form situation( ratio