A study on the Development and Biomass of Undergrowth Vegetation in Chinese Fir Plantation with Different Thinning Intensities

The undergrowth vegetation positively plays a role on soil fertility maintenance in forest plantation.The improvement of soil fertility can be achieved through the development of the undergrowth vegetation.In this paper,the study was conducted to explore the influence of undergrowth vegetation in Chinese fir plantation by thinning.The study sites were located at the hilly areas with 14 and 16 site-index in Shanxia Forest Farm,Fenyi County of Jiangxi Province.The study showed that thinning intensity could influence the development of undergrowth vegetation significantly,i,e,the species composition,important value,structure,coverage and biomass of the undergrowth vegetation varied greatly by different thinning intensities.The undergrowth vegetation coverage and biomass in the stands without thinning(CK) or with thinning of low intensity were 35%～60% and 1500～3000 kg/hm2 respectively,which were much less than those in the stand with middle and high intensity thinning,i,e,70%～80% and 5000～7000 kg/hm2 respectively.It was concluded that the middle and high intensity thinning can promote the development of undergrowth vegetation in Chinese fir plantation.