Community structure characteristics and productivity of varied Pinus densiflora forest types in Kunyu Mountain, Shandong Province of eastern China

It held the largest area of nature Pinus densiflora forests in the world in Kunyu Mountain National Nature Reserve, Shandong Province of eastern China. According to the slope aspect, slope position, soil thickness of the sites and dominant tree species, we classified P. densiflora forests in this reserve into 4 groups, and then investigated the structure and productivity of the forest community in relation to different forest types. The results showed that the pure P. densiflora forests occupied the largest area in this reserve, and it was predominately characterized by evenaged stands and halfmature forests of 30-50 years old mixed with Quercus spp. The shrub and herb layers of undergrowth developed well, and we recorded about 20 species of shrub and 40 species of herb in the sample plots. The stand productivity, however, was rather lower. The middleaged forest located at suitable sites held 30-50 m3/hm2 of the stand volume and 1-2 m3/hm2 of the annual average increment. In addition, the stand volume of the mixed forest of P. densiflora and broadleaved tree species was more than 90 m3/hm2 and the annual increment was 2-3 m3/hm2.