不同轮伐期巨尾桉人工林的经济效益分析

【目的】探讨不同轮伐期对人工林经济效益的影响,为从经济视角科学确定人工林的合理轮伐期提供理论依据。【方法】以短(7a)、中(13a)、长(21a)轮伐期的南亚热带巨尾桉人工林为研究对象,对不同轮伐期巨尾桉人工林的蓄积量(Stand volume,SV)、营林成本、净现值(Net present value,NPV)和内部收益率(Internal rate of return,IRR)进行分析,揭示不同轮伐期对经济效益的影响。【结果】随着轮伐期的延长,巨尾桉人工林的蓄积量持续增长,7a、13a、21a轮伐期的蓄积量分别为144.95m~3/hm~2、346.97m~3/hm~2、553.69m~3/hm~2。随着轮伐期的延长,巨尾桉人工林净现值不断增加,在12a时达到最高值(30 297.61元/hm~2),之后逐渐降低,7a、21a轮伐期的净现值分别为17 239.86元/hm~2、22 008.59元/hm~2。内部收益率在13a开始趋近峰值(53.32%),明显高于7a时的39.29%。【结论】在南亚热带,巨尾桉人工林的轮伐期确定在13a左右较为适宜,既可实现经济效益最大化,又可大幅提升蓄积量。

Economic Benefit Analysis of Eucalyptus grandis×E.urophylla Plantations in Difference Rotations

Objective] The effects of different rational rotations on the economic benefits of plantation forests were discussed to provide a theoretical foundation for scientifically determining the reasonable rotation period of plantations from an economic perspective.Methods] The short-term (7 a), medium (13 a), and long (21 a) rotations of the South Asian subtropical Eucalyptus grandis×E.urophylla plantations were studied.The stand volume (SV), establishment and management cost, net present value (NPV) and internal rate of return (IRR) of the Eucalyptus grandis×E.urophylla plantations at different rotations were analyzed to reveal the impact of different rotation periods on economic efficiency.Results] With the extension of the rotation period, the stand volume of E.urophylla plantations sustainably increased, and the stand volume at the turn of 7 a, 13 a, and 21 a were 144.95 m³/hm², 346.97 m³/hm², and 553.69 m³/hm², respectively.With the extension of the rotation period, the net present value also increased continuously, reached the highest value 30 297.61 Yuan/hm² at 12 a, and then gradually decreased.The net present value of the rotation period of 7 a and 21 a were 17 239.86 Yuan/hm² and 22 008.59 Yuan/hm² respectively.On the other hand, internal rate of return approached peak at 13 a (53.32%) which was significantly higher than that in 7 a (39.29%).Conclusion] In the South Asian subtropics, the rotation period of the Eucalyptus grandis×E.urophylla plantations was determined to be appropriate around 13 years, which could maximize the economic benefits and greatly increased the stand quality.