马尾松脂材两用人工林经济效益分析与评价——以广西国有派阳山林场为例

采用项目投资的财务效益评估手段,以脂材两用经营模式16a生马尾松采脂林为对象,对其经济效益进行了分析评价。结果表明:在该经营模式下,采脂林分总产值、净收益、净现值(NPV)、内部收益率(IRR)分别为147 173.1元.hm-2、85556.9元.hm-2、15 587.7元.hm-2、37%,比未采脂林分提高194.5%、214.1%、342%、76.2%;采脂林分动态投资回收期为10.6a,比未采脂林分缩短4.8a。运用该模式经营马尾松人工林能获得极高的经济收益和在较短时间内收回投资成本,提高资金的利用效率。     

马尾松优良家系人工造林经济效益评价分析

采用项目投资的财务效益评估方法,对马尾松优良家系营造的人工林与普通商品种、初级种子园混系种营造的人工林,以及不同优良家系采脂与未采脂林分、间伐与未间伐林分的经济效益进行了比较分析。研究表明,采用优良家系造林比普通商品种在单位面积蓄积量上提高17.3～97.4%,出材量提高10.1～91.0%,木材产值增加3346.25元.hm-2,木材年均产值增加555.30元.hm-2;优良家系采脂林的净收益、净现值(NPV)分别为85759.96元.hm-2和972.56元.hm-2,比普通商品种采脂林分高46%和123%,通过采脂能有效地提高人工林分单位面积产值和净收益值,缩短投资成本的回收期,不论是优良家系还是普通商品种均提前了2～2.5a。另外,优良家系人工林分间伐效果明显,其净收益和净现值上是未间伐林分的0.6～2.4倍和6.1～22.4倍。     

福建省沿海地区湿地松工业原料林基地建设若干问题研究

通过调查研究林分生长现状和经济效益的分析，提出建设湿地松工业原料林适度规模基地面临的风险和对策，为基地建设提供决策依据。     

不同经营主体和立地条件的马尾松经营经济效益评价

以马尾松为例,采用NPV、IRR、LEV三个指标,并运用现金流量表分析马尾松经营周期内资金的变化情况,分别对比了不同经营主体、不同立地条件投入产出的差异及其构成。结果表明:(1)农户和林场马尾松经营的NPV、LEV差异明显,但IRR差异并不大,而不同立地条件三者均存在明显差异;(2)农户和林场现金流出、流入、净现金流量差异明显,林场明显高于农户,且用工成本构成了现金流出的主要部分;(3)立地条件好的地块现金流出量、流入量、净现金流量要明显高于立地条件中等和差的地块。并针对以上结论,提出增加马尾松营林面积和森林蓄积的政策建议。     

生物质锅炉技术经济评价与分析

采用技术经济的动态分析法,对1 t/h生物质打捆燃料锅炉与生物质成型燃料锅炉进行评价。生物质打捆燃料锅炉投资回收期T_P为2.8 a,净现值NPV为23 401元,效益-费用比B/C为1.22,内部收益率IRR为40.13%,在技术经济上是可行的,产业化前景较好。     

巧用Excel计算内部收益率

内部收益率是建设项目评价的主要方法,特别是林业项目的可行性论证需要计算,但计算比较繁琐、复杂。一般内部收益率是通过逐次测试法来求算,即先估计一个内部收益率i1,然后按此贴现率计算净现值,若净现值正好为零,则内部收益率可求;若净现值为正,说明i1估计过小,则再估计一个高一点的i1测试;若净现值为负,说明i1估计过大,再估计一个低一点的i1测试,直到净现接近或等于零为止。在实际工作中往往用内插法求算,其公式为:内部收益率(IRR)=i1 (i2-i1)×NPV1÷(NPV1 NPV2),i1、i2分别为计算的低、高贴现率。计算时,对应的每个贴现率都要计算…     

不同整地和施肥方式对马尾松幼林生长及其效益评估影响

通过对相同立地的实验地采取不同的整地、施肥方式的马尾松幼林林分胸径、树高的调查,对其林木进行资产评估,并对树高、胸径、资产评估值进行方差分析与多重比较分析。试验结果表明:在龙岩Ⅱ类立地条件下,整地方式对林分树高的生长影响大小分别为:全面整地>块状整地>不整地;施肥处理对林分树高的生长影响分别为:施追肥>施基肥>不施肥,对林分胸径的生长影响分别为:施基肥>施追肥>不施肥。整地方式对马尾松幼林资产评估值的影响分别为:全面整地>块状整地>不整地;施肥处理对马尾松幼林资产评估值的影响大小分别为:施追肥>施基肥>不施肥。因此,全面整地和施追肥是马尾松幼林取得最大资产评估值的最好的营林措施;块状整地和施追肥是马尾松幼林生长最快及取得最大经济效益的营林措施。     

分析技术投资合理性的四种新方法

现代生产技术日新月异地发展,给会计理论和方法带来了巨大冲击。尽管诸如计算机联合制造(CIM)之类的现代生产技术,能够通过提高生产率、减少废品、返工和缩短生产周期来促进企业的发展;但利用投资回收期、投资收益率(ROI)、净现值(NPV)、内部收益率(IRR)和现金流量预测等传统分析方法来证明这些投资的合理性,是相当困难的。在美国,一些公司因为现金流量分析不能证明技术投资的合理性而放弃生产自动化的选择,并随后由于使用了无效的决策方法而遭受损失的事例屡见不鲜。     

折旧方法对固定资产投资决策评价指标的影响

在固定资产投资决策中,一般以税前或税后利润(Pt)加折旧(Dt)所形成的现金净流量(NCFt)为依据,采用投资回收期(PP)、净现值(NPV)和内含报酬率(IRR)等评价指标进行优选评估.在计算时,固定资产可以用平均年限法(直线法)、年数总和法、双倍余额递减法等折旧方法计算折旧额.折旧方法的不同并不能改变该项固定资产在整个使用期限内应计提的折旧总额,但从投资决策各期间看,不同折旧方法确定的年折旧额并不相同.那么,折旧方法对决策指标有无影响?是什么性质的影响?实践中应注意什么?笔者就此略述管见.现举例说明如下:     

不同整地和施肥方式对马尾松幼林生长及其效益评估影响

通过对相同立地的实验地采取不同的整地、施肥方式的马尾松幼林林分胸径、树高的调查，对其林木进行资产评估，并对树高、胸径、资产评估值进行方差分析与多重比较分析。试验结果表明：在龙岩Ⅱ类立地条件下，整地方式对林分树高的生长影响大小分别为：全面整地〉块状整地〉不整地：施肥处理对林分树高的生长影响分别为：施追肥〉施基肥〉不施肥．对林分胸径的生长影响分别为：施基肥〉施追肥〉不施肥。整地方式对马尾松幼林资产评估值的影响分别为：全面整地〉块状整地〉不整地：施肥处理对马尾松幼林资产评估值的影响大小分别为：施追肥〉施基肥〉不施肥。因此，全面整地和施追肥是马尾松幼林取得最大资产评估值的最好的营林措施；块状整地和施追肥是马尾松幼林生长最快及取得最大经济效益的营林措施。     

松材线虫病对浙江省环境影响经济评价

松材线虫是中国头号外来林业有害生物,是松树的毁灭性病害,对我国松林造成了不可估量的损失。浙江省是松材线虫病危害最为严重的区域,通过对浙江省松材线虫病的环境影响进行经济评价,为全国松材线虫病乃至森林有害生物的环境影响评价提供方法借鉴。     

东北红松阔叶混交林的特点及其分布规律

红松阔叶混交林在东北东部山区分布极为广泛，是该地区水平地带性和垂直地带性森林；将东北红松阔叶混文林分为3部分：典型阔叶红松混交林，河岸、河谷阶地阔叶红松混交林和山脊、陡坡阔叶红松混交林；介绍了红松阔叶温交林组成、分布规律及其地势的特点。     

Adapting the optimal selective-logging of Scots pine (Pinus sylvestris L.) stands in NE Spain to increasing CO2 concentrations

Predicted increases in CO₂ concentrations will affect forest ecosystems. In particular, they will impact tree growth, which in turn affects reproduction and mortality and consequently, forest planning. This study integrates different climate change scenarios of future biogeochemical processes and an economic model into a forest management model to determine the optimal selective-logging regime of Scots pine stands. It analyzes the economic implications of the management changes in comparison with the business as usual strategy. Adaption to new climatic conditions shows that it is optimal to increase the number of standing trees and to reduce the age of the logged trees. The results suggest that the failure to adapt the management regime has clear implications on the profitability of forests. Moreover, they show that higher mortality is likely to have a significant impact on the optimal forest management regime.     

新一轮退耕还林对农户收入影响的机理研究 ——基于赣南、鄂北农户调查的实证分析

研究目的：新一轮退耕还林补助资金即将到期之际,分析新一轮退耕还林对农户家庭收入的净效应并揭示其内在机制。研究方法：理论上阐述了新一轮退耕还林政策促进农户收入增长的作用机理,基于赣南、鄂北地区农户调查数据,利用倾向得分匹配法进行实证分析。研究结果：（1）无论是否包含退耕补贴,新一轮退耕还林政策对农户收入有正向影响;（2）退耕林种对农户收入的作用机理不同：种植经济林的农户增加了林果业收入和非农经营收入,减少了工资性收入;种植生态林的农户通过提高工资性收入,进而提高总收入水平。研究结论：新一轮退耕还林加快了农户生计转型的进程。政策实施5年后,农户形成与生态环境相适应且稳定的生产方式,为补偿政策的逐步退出创造有利条件,实现了新一轮退耕还林政策的造血功能。     

Integrating neighbourhood effects in the calculation of optimal final tree diameters

Modern silvicultural treatments are based on single trees whereas classic forest economics look at the stand level. To accompany each other it is necessary to transfer the established economic models to the single tree level. This paper is an approach to use the Faustmann model and the corresponding marginal rate of return (Pressler percent) to derive value increment rates of single trees taking into account neighbourhood effects due to competition between individual trees. Furthermore, optimal rotation periods and optimal final diameters for future trees will be calculated.     

红松松仁中天然产物的研究进展

松仁为松属PinusL.多种植物成熟种子去皮后所得到的种仁的统称,具有软化血管、降低血脂、胆固醇、甘油三脂及防止衰老的功能,具有广阔的应用开发潜力;对红松松仁的营养成分、功能以及天然产物中的蛋白、多糖、油脂的研究进展进行了阐述。     

The external costs of pasture weed spread: an economic assessment of serrated tussock control

The external cost associated with the spread of pasture weeds such as serrated tussock (Nassella trichotoma) is an important economic problem. This problem is complicated in many parts of south‐eastern Australia where low rainfall and low soil fertility prevent the economic viability of control of this weed through pasture improvement. A consequence of serrated tussock spread in this region has been calls for increased public intervention in its control. However, because there have been no attempts to measure the external costs of serrated tussock spread, one of the major economic grounds on which this activity might be justified has not been quantified. The purpose of this paper is to provide this information. A stochastic simulation model is developed to determine the size of the external cost associated with the spread of serrated tussock and to evaluate the economic benefits of a range of control scenarios. It is concluded that on low rainfall‐low soil fertility country the socially optimal control option for serrated tussock is to retire land from agriculture and re‐vegetate it with trees.     

Extensification of agriculture and deforestation: empirical evidence from Sudan

Extensification of agriculture is one of the major factors contributing to the destruction of forests in Africa. In Sudan, such horizontal expansion comes at the expense of land devoted to trees and other vegetation, thereby inducing conditions that are inimical to sustainable agricultural production. Different factors have contributed to extensification. Although high economic returns from crop (mainly sorghum) production was an important factor encouraging extensification of rainfed mechanized farming, other factors outside agriculture have also contributed to that expansion. This paper uses data from eastern Sudan and an acreage response model, to identify the most important factors influencing acreage expansion. Different measures and forms of risk were used in the acreage response model. The paper shows how policies in the energy sector can indirectly influence acreage expansion in the agricultural sector.     

Is native timber tree intercropping an economically feasible alternative for smallholder farmers in the Philippines?

Integration of trees on upland farms in the Philippines has been slower than expected and desirable from an environmental perspective. Our economic and risk analysis points to current policies as part of the problem. The study compares three domesticated indigenous timber trees (Shorea contorta V., Pterocarpus indicus J., and Vitex parviflora W.) intercropped with maize against a benchmark of the widely used exotic mahogany (Swietenia macrophylla K.). We used a biophysical simulation model (WaNuLCAS 3.1) to represent interaction between trees and crops for a fundamental level of water, nutrient and light capture as the basis for production functions. External conditions affecting systems profitability were accounted for in the Policy Analysis Matrix (PAM). Elements of risk were introduced through Monte Carlo simulation. Study results revealed that from a farmer’s perspective intercropping systems provide similar (within an uncertainty range of + or ? 10%) returns to monocropping scenarios. When net subsidies and taxes are accounted for, social profitability evaluations favour tree intercropping at high tree densities. The net effect of the current bias in price policies towards food production therefore refrains farmers from making decisions to integrate trees on farms; a decision that is actually in the national interest on economic grounds, even without consideration of positive environmental effects.     

柞蚕业的发展在我国国民经济中的合理性

柞蚕业在我国发展至今，一直与国民经济建设的总目标相一致，现在这种一致性更为突出，柞蚕业体现了柞蚕场，柞蚕种，蚕区劳动力与柞蚕放养技术资源的合理配置，柞蚕丝绸商品有巩固的国内外市场地位，一批新的柞蚕生物新产品正中以较高的科技含量挺进市场，柞蚕放养业在农村还一直保持有相当高的劳动生产率。连年养蚕收益成为人们保护蚕场资源的经济动力，柞树又具有超强的保水保肥功能，秋柞蚕的放养特点表明，柞蚕取食柞叶不会对柞树造成伤害。