森林水源涵养生态效益的估算与评价研究

以2008年生态观测定位站调查数据和Landsat-5 TM遥感影像为基础数据,建立森林水源涵养生态效益的常规多元统计模型得到回归模型的决定系数为0.788,平均检验精度81.1%。以模型估计的参数作为地理信息系统(GIS)的输入数据,估算2008年老山施业区物理量和价值量的空间分布特征,并核算出水源涵养生态效益物理量总量I=263.78万t,建立货币构造模型估算出水源涵养生态效益价值量总量E=131.89万元。分析物理量随地形变化的特征,其变化符合客观实际。     

建立森林生态效益补偿制度的博弈分析

森林生态效益补偿制度的建立是保证我国生态公益林可持续发展的关键性措施．文章从外部性和公共物品理论角度出发,指出建立森林生态效益补偿制度的必要性,即用财政政策调节存在于森林生态价值循环补偿中的“市场失灵”．运用博弈论理论和方法,构建了一个生态效益补偿政策下生态保护实施者与生态保护受益者之间的博弈模型．通过模拟现实中各方的行动策略和得益,分析均衡结果,以验证森林生态效益补偿制度是否安排有效,是否能使个人理性选择的结果符合集体理性的要求．     

林分效能评价技术方法

１ 前言 为建立森林效益计量和评价体系及补偿机制,我国的林学家们开展了森林效能的经济评价研究。通过定位研究与典型流域对比测定,对森林的直接经济效益（木材生产效益）、生态效益（涵养水源、保持水土、改良土壤等）和社会效益（净化大气、景观效益等）的量值进行测定,采用效益和价值相结合的方法对森林多种效益进行计量,从经济上反应其效益值的大小,由等效益物替代原则和森林效益的社会属性原则,最终统一到货币量纲上进行效益评价。在此基础上,按照“谁受益,谁补偿”的原则和国情、省情,以省为单位对森林提出较合理的补偿值及…     

墨江县森林生态效益评价研究

应用西方经济学的效用价值论为基础的森林生态效益评价方法建立各项生态效益评价模型,利用这些模型对墨江县森林进行生态效益评价.利用权重指标、支付意愿系数等体现森林生态产品的供求状况、公众的支付意愿和能力等对森林生态效益价值大小的影响.评价结果,墨江县年森林生态效益总价值为5.11亿元.     

我国森林生态效益补偿问题研究

把森林生态补偿从狭义界定扩展到广义界定,包括狭义森林生态效益补偿、税费、投资、贷款贴息和市场补偿等各种手段。森林生态效益补偿制度安排可以划分为以政府补偿为主导和以市场为主导两种基本形式,以政府补偿为主导的形式目前还停留在森林生态效益狭义补偿阶段和整体负补偿阶段。影响森林生态效益补偿制度安排的主要因素包括产权不清、补偿主体不明确、交易成本高以及包括计量困难在内的森林生态效益复杂性等。需要从明晰产权,社区参与、生态宣传、生态产品计量与评价等方面促进森林生态效益补偿制度不断完善。     

温州珊溪水利枢纽工程水源区森林生态效益研究

从温州珊溪水利枢纽工程水域区的自然环境、水土流失、森林资源、优化水源区森林生态效益的对策、生态效益评估等方面进行探讨和研究,对其森林生态效益进行全面评估计算,特别是通过等效益物替代和货币置换法计量森林生态效益,在衡量生态效益方面作出了新的尝试,为今后国家设立森林生态效益补偿基金、建立森林生态效益补偿机制提供理论基础和科学依据.     

试论森林生态功能的价值决定

森林的生态功能价值与生态效益价值是两个完全不同的概念。它们的形成过程、计量范围、权力归属及研究意义都有着根本的区别。森林生态功能价值不仅决定于森林生产过程，还与市场供求相联系。森林资源稀缺程度的不同和森林产品需求收入弹性的差异，使森林生态功能价值在时间上和空间上不能统一，因而对其计量只能采取个量分析。还对森林生态功能价值的替代计量进行了评价。     

中国森林生态效益计量研究

通过对森林多种生态效益的分析,确定计量森林生态效益的因变量指标集为:涵养水源效益、保持水土效益、抑制风沙效益、改善小气候效益、吸收二氧化碳效益、净化大气效益、减轻水旱灾效益、游憩资源效益和野生生物保护效益。同时,从影响因变量的众多因素中筛选出主要变量建立自变量集,并将之划分为区域自变量(经度、纬度、海拔、年降雨量、年平均风速和年≥10 ℃积温)和林分自变量(森林蓄积量和森林覆被率)。按照以上建立的计量指标体系,建立了森林生态效益计量的多元线性模型。利用该多元线性模型对我国森林的生态效益进行了计量,得到我国森林每年产生的生态效益为7 238.16亿元,占国内生产总值的23.07%。     

森林生态效能资产化及货币化方法探讨

在林地租赁价格森林资产评估项目中,提出仅资产接收方受益的生态效能才进行资产化,并利用生态效能＂政府层面＂效益值占林地所有效益比例,分摊森林培育林地地租的办法,评估森林生态效益,阐述森林生态效能货币化的方法,评估结果同市场成交价格吻合度极高。实践证明,在许多采用传统评估方法难以计量林地效益的公益项目中,采用文中所述森林生态效能资产化和货币化方法评估森林生态效益是切实可行的。     

森林生态补偿制度是生态效益型林业发展的保障

建立森林生态效益计量评价体系和森林生态效益补偿体系,有利于合理制定和实施森林生态补偿制度,有利于加快无偿使用森林生态效益向有偿使用森林生态效益转变,是建立生态效益型林业的前提和保障。     

Browsing Damage on Pine (Pinus sylvestris and P. contorta) by a migrating moose (Alces alces) Population in Winter: Relation to Habitat Composition and Road Barriers

In Scandinavia, moose (Alces alces L.) sometimes cause severe browsing damage to economically-important pine. Moose-vehicle accidents have spurred construction of fences along roads, and these may interfere with moose migration between summer and winter ranges, or the road alone may be a barrier. If this happens and moose build up along roads, landowners may suffer economically. Therefore, this study investigated whether roads, fences or other factors influence the use of young pine stands by moose. Eighty stands along roads in northern Sweden were evaluated in which individually-browsed branches were counted on 9972 pines. Moose browsing was not significantly related to birch (Betula pendula Roth, B. pubescens Ehrh.) density, nor did it differ between pines (Pinus contorta Douglas or P. sylvestris L.). However, increased pine density, site productivity and proximity to a highway were associated with increased browsing. Further large-scale studies are needed to understand moose habitat selection and the effects of roads.     

Effects of Root Freezing on the Physiology and Growth of Picea glauca,Picea mariana and Pinus banksiana Seedlings Under Different Soil Moisture Regimes

The root systems of 2-yr-old Picea glauca, Picea mariana and Pinus banksiana seedlings were submitted to various frost temperatures during an artificial frost to induce different levels of root damage. Frost-damaged and control seedlings were placed in a greenhouse under high and low soil moisture regimes. Seedling growth and physiology were evaluated periodically. Seedling survival was reduced when root damage reached levels of 60-80%. Root systems of all three species showed partial to total recovery by the end of the experiment. In general, root freezing damage caused reductions in seedling growth, with these reductions becoming less significant over time. Root damage had little to no effect on black spruce and jack pine seedling physiology, while white spruce CO 2 uptake decreased with increasing root damage. Shoot nitrogen content of all three species decreased slightly with increasing root damage.     

Stand Structure in Pine,Spruce and Deciduous Forests: A Comparison Between Finnish and Russian Karelia

This study investigated the stand structure in pine, spruce and deciduous forests in the border district of Finland and Russia. A total of 46 mature forest stands was selected as pairs, the members of each pair being as similar as possible with respect to their forest site type, age, moisture and topography. The stands were then compared between the two countries by means of basal areas and number of stems. The proportions of dominating tree species were 2-12% lower, and correspondingly the proportions of secondary tree species higher, in Russian forests. The density of the forest stock was also higher in each forest type in Russia. The forests in the two countries differed most radically in terms of the abundance of dead trees. The amount was two to four times higher in Russian deciduous and spruce forests, and in pine forests the difference was 10-fold. The stand structures indicated that Russian coniferous stands, in particular, were more heterogeneous than intensively managed pine and spruce stands in Finland.     

Growth and Terminal Bud Formation in Picea abies Seedlings Grown with Alternating Diurnal Temperature and Different Light Qualities

The root collar diameter and the height:diameter ratio are of particular importance in container-grown seedlings where a high density in the containers may produce spindly seedlings. Temperature regimes and light quality are known to affect plant growth. The aim of this study was to identify responses in Picea abies (L.) Karst. seedlings grown with light providing different red:far-red ratios and under temperature regimes with alternating day (DT) and night temperature (NT) from negative (DT < NT) to positive (DT > NT) difference (DIF) between DT and NT. Experiments were conducted in controlled environment chambers and in a daylight phytotron. Only limited thermoperiodic responses appeared in P . abies seedlings with respect to seedling height and dry weight accumulation. The formation of terminal buds, however, was clearly delayed in seedlings grown at negative DIF. The results indicate a requirement for day extension light that is high in far-red, to prevent terminal bud formation under natural short-day conditions. An extended study should be conducted to clarify the minimum level of light intensity and the optimal light quality needed to prevent terminal bud formation under natural short-day conditions.     

CAD与建筑设计的关系

本文分析了CAD在设计中引起的正面和负面影响,并进行了系统的阐述,从而使设计者在应用中能够保持客观的态度。     

Natural Regeneration in Clear-cuts: Effects of Scarification,Slash Removal and Clear-cut Age

The effects of soil scarification (mounding), slash removal and clear-cut age on the natural regeneration in clear-cuts was evaluated using data from four sites in southern Sweden. The treatments were carried out during a good seed and establishment year for birch ( Betula pubescens Ehrh. and B. pendula Roth). Scarification had the strongest positive effect on the density of naturally regenerated seedlings, especially in birch, but also in pine ( Pinus sylvestris L.) and spruce [ Picea abies (L.) Karst]. Slash removal had a positive effect on birch density. No statistically significant effect of clear-cut age was found. In addition, no statistically significant interactions between clear-cut age and scarification or slash removal were found. The ingrowth of field vegetation was the fastest in areas that were not scarified, less rapid in areas scarified on old clear-cuts, and the slowest after scarification in fresh clear-cuts. In conclusion, it may be possible to control the density of birch during a good establishment year for birch. If birch is desired, the best combination of treatments is to remove the slash and scarify; otherwise, these treatments should be avoided.     

Risk Perception Among Non-industrial Private Forest Owners

Based on an enquiry, risk perception among non-industrial private forest owners is described in relation to climate change and forestry hazards. Of the respondents, 11% took action to remedy the effects of climate change. Out of a given set, hazards were ranked according to each respondent's experience of recent substantial financial loss to the estate and in relation to his or her willingness to make investments aimed at risk reduction. For each hazard, the respondent assessed the risk in four classes ranging from very high to negligible risk. Six hazards were considered most problematic in all three aspects: browsing damage, falling timber prices, damage by wind, spruce bark beetle, root rot and pine weevil. A majority of the respondents claimed to take action to reduce the risk associated with at least one hazard, while 35% did not know whether they did. Excluding climate change, the need for decision support was the largest in relation to damage by wind owing to a combination of perceived high risk and a high level of ignorance in relation to whether risk-reducing measures were taken.     

Interactions in decomposition and N mineralization between tropical legume residue components

In situ produced plant residues contain a mixture of different plant components of varying quality. To assess synergistic or antagonistic interactions occurring during the decomposition and mineralization of such mixtures, individual plant parts (stems, leaves, leaf litter and roots) or the mixture of stems, leaves and leaf litter of the agroforestry species pigeonpea (Cajanus cajan) or of crop residues of peanut (Arachis hypogaea) or of the weed hairy indigo (Indigofera hirsuta) were incubated in pots for 19 weeks. Periodically, remaining plant residues were sieved out (>2 mm), weighed and N content as well as soil mineral N determined. Above- and below-ground residues of peanut decomposed fastest and showed the largest N release in agreement with their high N concentration and low-acid detergent fibre (ADF) : N ratio. Hairy indigo was hypothesized to be of lower quality than pigeonpea because of its high-polyphenol content. However, it decomposed faster than pigeonpea, largely because of the higher N and lower lignin concentration of its components. Ranking of individual plant components for N mineralization resulted in the following pattern, leaves > leaf litter > roots > stems. In mixtures of the different plant components a similar species order in decomposition was obtained, e.g. peanut > hairy indigo > pigeonpea. The amount of N released from the mixture was dominated by stem material that comprised 46–61% of the mixture. The interactions in mixtures were relatively small for peanut (generally high-quality components) as well as for pigeonpea (low proportion of high-quality components, i.e. N rich leaf material). However, a positive interaction occurred during later stages of N mineralization in the mixture of hairy indigo as it had a significant proportion of N rich components and absence of highly reactive polyphenols. Thus, for plants with low to intermediate chemical quality attributes, manipulating plant composition (e.g. by varying harvest age, affecting stem and leaf proportions) will be important to obtain significant interactions during decomposition when its components are mixed.     

Pasture production and tree growth in a young pine plantation fertilized with inorganic fertilizers and milk sewage in northwestern Spain

The use of organic waste materials such as milk sewage as an organic fertilizer could have the dual advantages of organic-waste disposal and reduced dependence on inorganic fertilizers. The effects of fertilization with (1) conventional mineral fertilization, (2) milk sewage sludge at 40 kg N ha⁻¹ target rate and (3) no fertilization on pasture production and tree growth were examined in an experiment consisting of two pasture mixtures under a one-year-old Pinus radiata plantation with a density of 2500 trees ha⁻¹. The two pasture mixtures were: (1) Dactylis glomerata L. var. saborto (25 kg ha⁻¹) + Trifolium repens L. group Ladino (4 kg ha⁻¹) + Trifolium pratense L. var. Marino (1 kg ha⁻¹); (2) Lolium perenne L. var. Tove (25 kg ha⁻¹) + Trifolium repens L. group Ladino (4 kg ha⁻¹) + Trifolium pratense L. var. Marino (1 kg ha⁻¹). The experiment began in the spring of 1995 using a randomized block design with three replicates in Castro Riberas de Lea (Lugo, Galicia, north-western Spain). Plot size was 12 × 8 m², with a 1 m buffer strip between plots. Two-year data showed that fertilization with either material had a positive effect on pasture production, with no significant difference between the two fertilization treatments. Tree growth in the milk sewage sludge plot was significantly higher than in the control plots. Inorganic fertilization increased pasture production, but affected tree growth negatively. The results show that milk sewage sludge could be used as a fertilizer in silvo-pastoral systems. This revised version was published online in June 2006 with corrections to the Cover Date.