【作者】 王如均；

【导师】 陈平留；

【作者基本信息】 福建农林大学 ， 森林经理学， 2010， 硕士

【摘要】 随着可持续理论的不断发展,国家对林业政策的指导方针也由传统林业向可持续林业慢慢改变。主伐年龄是林业生产的根本指标,它不仅是确定森林经营周期以及评估林业企业进行资产价值的重要依据,也是林分采伐作业尤其是采伐限额确定的重要测算指标。如何合理确定林木采伐年龄,使人们在不破坏森林资源的基础上最大限度的从森林资源中获得良好的效益,已经成为森林可持续经营中的重要的环节。对于森林经济成熟龄的确定,首先要对林分的生长规律进行预测,这就要结合林木自身的生长规律以及林分主要测树因子(如年龄、胸径、树高、蓄积量、立地质量等)的数据,建立林分生长及收获模型,从而预测林分在不同立地条件下的蓄积量、平均胸径、平均高、径阶分布状况的规律。因此,本文在收集的杉木样木和样地数据的基础上,应用专门的统计软件进行拟合,通过比较分析,最终选取精度最高的生长方程作为各林分因子的生长收获模型,建立了立地指数模型、林分平均胸径模型、林分蓄积量模型、林分平均高模型、以及林分直径分布模型等,以此来对杉木人工林的生长状况进行预测。建立好生长模型后,需要对林木主伐时的货币收入情况进行研究,这就需要了解评价林木价值的相关经济指标(木材价格、税费等)。由于我国林业政策的不断更新和经济的飞速发展,导致以往的林木经济指标已不再适用于现在的林木货币收入的计算,因此,本文将引入资产评估中更新重置成本的相关概念,根据现行的林业经济政策(即在此次税费计算中,育林金将按照销售价的10%进行计算以及删除维简费的相关计算),对杉木人工林的单木价格进行了计算,并以此建立了杉木人工林货币纯收入模型,从而对不同立地条件下,不同年龄的林分主伐时的货币收入进行了测算。最后,选取合适的经济成熟计算公式计算杉木人工林的经济成熟龄。计算经济成熟的公式很多,许多专家学者也提出了很多经验方程,本文在综合考虑森林可持续经营和资金的时间价值的情况下,选用净现值法、内部收益率法和土地期望价法计算出在不同地位级指数下杉木人工林在不同年龄时主伐时所获得的经济效益,通过分析、比较,估算杉木人工林的经济成熟龄。由于经济成熟龄的计算需要各种经济评价指标作为依据,因此需要在一定的社会经济条件下才能完成。然而随着社会的不断发展,社会经济条件处于不断的变化中,林分经济成熟龄也将受到相关因素的影响。因此,本文最后也对影响杉木经济成熟龄的变化的相关因素进行了敏感性分析。更多还原

【Abstract】 With the theory of forestal sustainable development, national forestry policies on the guidelines has been changed from the tradional forestry to the sustainable forestry gradually. The felling age is the fundamental index of forestry production, it is not only an important basis which is used to confirm the forest management cycle and assess the value of forestry enterprise, but also an important measure indicators of the cutting operation and the cutting quota. How to determine the felling age reasonably, so that people can gain the maximum benefit from the forest resources which is not based on damaging any forest resources, has become the important part of sustainable forest management.To confirm the forest economic mature age, we should estimate the growth law of forest firstly, that must combine the growth law of trees and the data of their main measuring factor (such as the age, height, diameter and height, volume, the site quality, etc.), so that we can estimate the rule of the volume, the average diameter, the average height and the distribution of diameter grade. Therefore, this paper is based on the collection of the sample data of Chinese fir, fitting by the professional statistical software, and finally choosed the growth equations which are the most accurate as the forest harvesting model of forestal every factors by comparing and analyzing their accuracy. To estimate the growth condition of Chinese fir plantation,this papper has established the site index model, the average dimater model, the volume model, the average height model and the distribution of diameter grade model,etc.After established growth model, we need to research the monetary income when the forest is on the felling age. So we must know the relevant economic value evaluation index of forest (wood price, taxes, etc.). With China’s forestry policies updated constantly and the rapid development of economy, the economic indicators in past now no longer applies to the forest of the monetary income, so this paper will introduce the related concepts about updated replacement cost in the assets assessment, and according to the current economic policy of forestry (i.e., the cost of forest culture will be calculated by 10% of the sale price,and delete the dimension cost in this tax computation), calculated the price of one tree, and finally established the net monetary income model of Chinese fir plantation, so as to estimate the condition of the monetary income in different site conditions and different age when the trees is going to be cut.Finally, this paper has chosen the proper formula of calculating economic mature to calculate the economic mature age of Chinese fir plantation. But there are too many formulas of calculating economic mature, and many experts also puts forward a lot of experience equations, so based on comprehensive consideration of sustainable forest management and the time value of money situation, this paper choosed NPV method, the internal rate of return method and land expectation value method to calculate the economic benefit of the Chinese fir plantation in different felling ages and different site conditions, and figured out the economic mature age of Chinese fir by comparing and analyzing them at last.Due to the calculation of the economic mature age is based on economic evaluation index, so it need to be in certain social economic conditions to finish. However, with the development of society, social economic condition is changing constantly, economic mature age stand will be influenced by relevant factors either. Therefore, this paper has conducted the sensitivity analysis with the relevant factors which are influenced on the calculation of the economic mature age of Chinese fir.更多还原