摘要
在定量计算天然次生林经5种不同强度采伐(弱度18.6%、中度28.2%、强度45.5%、极强度75.5%、皆伐100%)10 a后的经济效益指标,定位测定伐后10 a林地土壤肥力和蓄水保土指标变化量的基础上,采用集对分析方法,定量计算天然次生林不同强度伐后10 a的综合效益,从而确定最优采伐强度。结果表明,仅考虑经济效益,皆伐最优,极强度择伐次之,弱度择伐最差,其评价值依次为0.566、0.553和0.430;仅考虑生态效益,弱度择伐最优,中度择伐次之,皆伐最差,其评价值依次为0.754、0.651和0.472;综合考虑经济和生态效益,中度择伐最优,其余从大到小依次为弱度择伐、强度择伐、极强度择伐和皆伐,其评价值依次为0.601、0.589、0.535、0.509和0.508。研究表明,"中度择伐"是闽北天然次生林伐区作业的最优采伐强度,适合类似本试验自然条件的林区借鉴。
This paper is aimed at studying the benefits of the natural secondary forest that can be gained from the cut a decade later. To be exact, the benefits that can be gained from the tow intensity cutting, from the med intensity cutting and the high intensity. Repeated experiments have made us work out the results of such cuttings, which can be illustrated as follows： the benefit from low intensity cutting is 18.6% while that from the med intensity cutting is 28.2%, with that from high intensity cutting being 45.5 % and that of over-high intensity being 75.5%, and that of clear cutting-to be 100%. Thus the optimum cutting intensity has been determined. In addition, the socalled benefit can actually be divided into economic benefit and ecological benefit, which may include variations of soil fertility, soil conservation and water conservation. According to the results, clear cutting can be thought of as the optimal version, whose beneficial value works out at 0. 566 while over-high intensity accounts for the second, with its value being 0.553. Whereas the low intensity selective cutting is the worst （0.430） in terms of economic benefit merely, it can be regarded as the optimal one in terms of ecological benefit. The ecological benefit for low cutting, med-intensity selective cutting and that of clear cutting can be listed as 0.754, 0.651, 0.472 respectively. When considering both economic benefit and ecological benefit, the beneficial order should be： medium intensity selective cutting 〉 low intensity selective cutting 〉 high intensity selective cutting 〉 over-high intensity selective cutting 〉 clear cutting, whose calculation values are 0.601, 0. 589, 0.535,0.509, 0.508 respectively. In conclusion, the middle intensity selective cutting＂ proves the optimal cutting intensity for natural secondary forest in the north of Fujian province, which is the desirable version that is deduced and recommended to be taken from the results of our experiments.
出处
《安全与环境学报》
CAS
CSCD
北大核心
2009年第4期97-101,共5页
Journal of Safety and Environment
基金
福建省自然科学基金项目(2008J0327
2009J0101)
福建省科技厅重点科学基金项目(2007N0002
2006F5006)
福建省林业厅科学基金项目(闽林科[2006]7号第14项)
关键词
森林工程
综合效益评价
采伐强度选优
集对分析方法
天然次生林
forest engineering
comprehensive benefits evaluation
selecting of the optimum cutting intensity
set-pair analysis
natural secondary forest
