An Economic Analysis of the Interplanting of Calamus simplicifolius with Gmelina arborea Plantation

The objective of this study was to analyze the economic benefit of rattan plantation and to determine the impact of harvesting regimes and management technique on economic return in the forestland.Data were obtained from the permanent plots established in Calamus simplicifolius plantation where 5 different harvesting regimes were set,including first harvesting at 5,6,7,8,9 years and harvesting intervals of 8,7,6,5,4 years respectively.In addition,field investigation on the upper support trees,20-year-old Gmelina arborea mixed with C.simplicifolius was made and 2 temporary plots nearby were also established in pure stands to know the effect of rattan planting on the growth and yield of support trees.Harvesting regimes had eminent effect on economics of 13-year-old rattan plantation.Under the regime of first harvesting at 9 years with 4 years'interval afterward,optimal economic benefit was gained in C.simplicifolius plantation,being 20 255 yuan·hm-2,20.08%,1.38 in term of net present value (NPV),internal return rate (IRR) and the ratio of benefit to cost (B/C).Rattans had unfavorable effect on the growth and yield of upper trees.As a result,the net income and NPV from G.arborea plantation interplanted with C.simplicifolius decreased by 4 000 yuan·hm-2 and 1 500 yuan·hm-2 respectively over those from pure stand.However,the economic loss in the upper stand could be compensated with the monetary gain from rattan plantation generating considerable economic benefit.The level of economic gain and the increment of NPV by interplanting G.arborea with C.simplicifolius under various harvesting regimes were estimated to range from 12.49% to 91.10% and 706 yuan·hm-2 to 5 145 yuan·hm-2.