Biomass of Forest Communities at Different Altitude Regions in Yinggeling Montane Tropical Rainforest, Hainan Island

Abstract:

In order to understand the biomass dynamic changes in tropical montane rainforest with selective harvesting at different altitudes, fifty permanent plots of 10 m×10 m were established to investigate the biomass of forest communities in Yinggeling montane rainforest at each area of high (1063 m), middle (899 m) and low (473 m) altitudes. The results showed that the biomass of above-ground and tree layer in Yinggeling montane rainforest was only 152.6 t hm^-2 and 142.6 t hm^-2, respectively, which was far less than that in natural forests of other areas in Hainan Island. The tree layer biomass of sample plots at high altitude was higher than that at middle and low altitude, amounting to 197.6 t hm^-2, 112.2 t hm^-2 and 117.8 t hm^-2, respectively. The ratio of biomass allocation was in the order of tree layer (94.22%) > snags & fallen log (2.9%) > litter (2.88%), while that of tree layer was in descending order: trunks (72.63%) > branches (15.35%) > barks (9.23%) > leaves (2.79%). Due to selective harvesting, number of large and extra large diameter trees was small, therefore, the ratio of biomass allocation in small diameter trees (5-19.9 cm), middle diameter trees (20-35.9 cm), large diameter trees (36-47.9 cm) and extra large diameter trees (≥ 48 cm) was accounting for 35.89%, 26.24%, 16.01% and 21.86%, respectively. After over 30 year's natural restoration, Yinggeling montane rainforest was still in the midsuccessional stage, which indicated that it would have a great potential on forest carbon sequestration in the future.