Study On Growth Change Of The Rubber Plantation Along An Altitudinal Gradient In Xishuangbanna, Southwest China

To assess the effects of the Indo monsoon on growth dynamics and changes of rubber plantation along altitudinal gradients in rubber plantation of southwest China, five plots were chosen on each of three altitudinal gradients: LE (Low elevations, 550 ~ 600 m), ME (Mid-elevations, 750 ~ 800 m) and HE (High elevations, 950 ~ 1050 m) and over 8 items as water content, phenology, leaf area index, girth at breast height, biomass, litter-fall, yield of dry latex, net primary production and so on were observed in Xishuangbanna, China. The results were as following:1. In LE, ME and HE sequence, the aboveground biomass were 108.35±11.48 Mg·hm-2, 79.71±14.48 Mg·hm-2, 29.93±4.12 Mg·hm-2; the biomass of the stems and its percentage to aboveground biomass were 90.96±9.68 Mg·hm-2 (83.93 %), 58.45±11.00 Mg·hm-2 (72.88 %), 21.43±2.95 Mg·hm-2 (71.58 %); those of the branches were 13.71±1.43 Mg·hm-2 (12.67 %), 17.28±2.96 Mg·hm-2 (21.89 %), 6.94±0.96 Mg·hm-2 (23.19 %); similarly, those of leaves were 3.68±0.37 Mg·hm-2 (3.40 %), 3.97±0.54 Mg·hm-2 (5.23 %), 1.56±0.21 Mg·hm-2 (5.23 %). The biomass of organs in three altitudinal gradients ranked in sequence: stem > branch > leaf. In contrast to the biomass of branches and leaves, the difference of aboveground biomass and the biomass of stems among altitudinal gradients were significant. The results showed that the biomass of the rubber plantation in Xishuangbanna was influenced significantly by the altitudinal gradients and...