Valuing habitat regime models for the red-cockaded woodpecker in Mississippi

Managing Mississippi's forest lands to produce both quality wildlife habitat as well as merchantable timber can be a daunting challenge for forest managers and a source of great concern for the public. In some cases, producing both the quantity and quality of habitat needed and the timber desired is all but impossible. In other cases, a delicate balance that achieves both objectives can be struck. The objective of this study was to quantitatively estimate monetary gains and losses and changes in timber inventories relative to the timber growing stock when producing more or less habitat for the red-cockaded woodpecker (RCW) (Picoides borealis). USDA Forest Service vegetation data, habitat ratings, and economic variables were compiled for those regions of Mississippi best suited for RCWs. Data was then analyzed with Spectrum, the USDA Forest Service-based forest planning software. Models maximizing such objectives as net present value (NPV) alone as well as five different levels of RCW habitat quality over a 50-year rotation were developed. Revenue foregone, acres and volumes harvested, land expectation value (LEV), and equivalent annual income (EAI) were compared for all objectives for the South Central Hills and Pine Belt regions of Mississippi (1,036,208 acres) for three ownership types. As expected, when maximizing for any quality level of RCW habitat, revenue forgone was higher ($0.11–$49/acre/year) than for NPV alone. Volume harvested for high-quality habitat ranged from 152,296 to 10,237,649 cunits, while harvests from low-quality habitat ranged from 637,491 to 116,357,673 cunits. Lower levels of habitat management allowed for an increased emphasis on timber harvesting. In general, we determined that increases in habitat quality resulted in lower timber harvest levels and increased revenue forgone than regimes maximizing NPVs. While this result may be expected, of greater importance are the relative differences between regimes and the ability to use these values for policy decisions.     

Review - Roger A. Sedjo (2003): Economics of Forestry

Ashgate Publishing Limited, Gower House, Croft Road, Aldershot, Hants GU11 3HR, England (www.ashgate.com). 498 p. £ 100.00. ISBN 0-7546-2237-1 (hardback).Being one volume in the series of the International Library of Environmental Economics and Policy (T. Tietenberg and W. Morrison, gen. eds.), this book is a collection of some of the most significant journal essays in forest economics and forest policy. In compiling this volume, Roger Sedjo did a great service to the forest economics profession.This volume includes twenty-five essays originally published between 1849 and 1996 in a dozen journals, and one chapter from the Third Assessment Report of the International Panel on Climate Change (IPCC, 2001) which addresses the biological sequestration of carbon in terrestrial ecosystems. These are organized into four parts: the harvest rotation issue, timber supply, multiple-use and non-timber outputs, and global issues. An introduction essay to this volume, written by the editor, provides an overview of the major issues in forest resource management and discusses some the most important contributions to the forest economics literature.The eleven essays in the first part of the book provide a rather complete coverage of the most important contributions to the literature on optimal rotation age, which is a fundamental issue in forest management and forestry investment. Four of the essays (Faustmann 1849, Ohlin 1921, Bentley and Teeguarden 1965, and Samuelson 1976) address the basic formulation and interpretation of the optimal rotation model. Four essays (Löfgren 1985, Newman, Gilbert and Hyde 1985, Reed 1984, and Brazee and Mendelsohn 1988) extend the basic rotation model to examine the rotation age decision in the presence of deterministic trends and uncertainty in timber yield and price, respectively. Based on the Faustamnn rotation model, Klemperer (1976) and Chang (1982) examine the impacts of taxation on forest value and on the optimal rotation age. Koskela (1989) provides a detailed analysis of the impacts of taxation on timber harvest decisions under price uncertainty. What I feel missing in this part is a comparative statics analysis examining the impacts of changing economic parameters on the optimal rotation age.Part II includes five essays on economic analysis of long-run timber supply. Clawson (1979) reviews the historical development of forest resource and forest utilization in the United States. Vaux (1973) examines the long-run potential supply of timber from forest plantations in California. Berck (1979) investigates the difference in harvesting behavior between private forest owners and public managers. Lyon (1981) and Lyon and Sedjo (1983) examine the optimal exploitation of old-growth natural forests and the transition to steady state. While these essays all focus on the long-run timber supply in the United States, the methods developed and used in these papers could be applied for any other region. The exploitation of old-growth natural forests and the long-term availability of timber have been without doubt two major concerns in the United States. In many parts of the world, however, concerns about timber supply in the short-run have also had great influences on the development of forest policy. It would have been appreciated if a couple of essays addressing the short-run supply of timber had been included.Part III contains three essays dealing with the problem of multiple-use forest management. Gregory (1955) develops an economic framework for multiple-use management based joint production theory. Hartman (1976) examines the multiple-use rotation age decision. Swallow, Parks and Wear (1990) investigate the problem of non-convexities involved in multiple-use rotation age decisions. The merits of these essays lie in that they use rather simple models to demonstrate the importance of incorporating non-timber benefits in forestry decisions and the complexities of the multiple-use problem. In his 1976 essay, Hartman points out that in many situations management practices applied to one stand affect the value of non-timber outputs derived from the adjacent stands; such interdependence needs to be incorporated into multiple-use decision analysis. I certainly would like to find in this volume one or two essays examining the impacts of stand interdependence on the optimal decision. Another important issue in multiple-use management, which is not covered in this volume either, is the valuation of non-market priced outputs and services. Yet I believe that this omission is well motivated, for there are two separate volumes in this series devoted to non-market valuation methods (R. T. Carson, ed. Direct Environmental Valuation Methods, Volumes I and II).The seven essays in Part IV deal with a set of forest economic and policy issues related to global warming and biodiversity conservation. Parks and Hardie (1995) examine the cost-effective subsidies to convert marginal agricultural land to forests for the purpose of carbon sequestration. Hoen and Solberg (1993) analyze the potential and cost-effectiveness of increasing carbon sequestration in existing forests by changing forestry practices. van Kooten, Binkley and Delcourt (1995) examine the effect of carbon taxes and subsidies on the optimal rotation age. The chapter from the Third Assessment Report of IPCC (2001) provides a comprehensive review of the literature on the ecological, environmental, social and economic aspects of carbon sequestration in terrestrial ecosystems. While forests and forest management could play an important role in mitigating climate change, increasing level of atmospheric dioxide and climate change would inevitably affect the productivity of forest ecosystems, thereby could have significant impacts on future timber growth, harvest and inventory as well as carbon storage in forest ecosystems. Joyce et al. (1995) present a framework for analyzing the potential effects of climate change on the forest sector. The remaining two essays in this part examine the costs and benefits of biodiversity preservation, respectively. Montgomery, Brown and Adams (1994) estimate the marginal cost of preserving the northern spotted owl. Simpson, Sedjo and Reid (1996) examine the expected value of the marginal species as an input to pharmaceuticals.The editor points out in the introduction chapter that there are many other important contributions that are not included in this volume, some of these are mentioned, others not. In addition to the few omissions noted earlier, several important economic and policy issues such as uneven-aged stand management, deforestation, international trade, sustainable forestry, forest recreation, wildlife management and so on are not discussed. Moreover, none of the journal essays published since 1997 is selected. That there are many other important contributions does not mean the essays included in this volume are less important, however. While each forest economist may present a different list of the most important papers, most (if not all) of the essays in this volume would appear on anyone's list. I strongly recommend this book for research scientists and graduate students of forest economics as an essential addition to their reference library.     

A modified production possibility frontier for efficient forestry management under the New Zealand Emissions Trading Scheme

Carbon sequestered through increased forest biomass provides a low cost means to curb emissions and has become a major focus of New Zealand's Emissions Trading Scheme. We present a forest planning optimisation model where land use is governed by forest owners maximising the returns to both timber harvest and carbon sequestration. By varying carbon prices, we model efficient trade‐offs between the two forest activities along a modified production possibility frontier for four distinct wood supply regions in New Zealand. Results show that while more productive regions such as the Central North Island (CNI) and Northland have a greater capacity as a carbon sink, it is the less productive regions that have a comparative advantage in carbon sequestration in terms of a lower cost of wood production revenue foregone. However, moderate increases in carbon uptake can be achieved in the CNI at low opportunity cost by subtle changes in forestry management. The implication for policy‐makers is that initial increases in carbon sequestration will be achieved at the lowest cost to society by favouring high volume timber production in some productive woodland areas and/or by more carbon farming in less productive areas.     

Accounting for farmers’ production responses to environmental restrictions within landscape planning

Environmental planning aims to safeguard and foster the ecological functionality of agricultural landscapes. In order to reach a sustainable development of agricultural landscapes, in addition to ecological objectives socio-economic ones also need to be considered. In this context, the authors draw attention to three points. First, whenever ecologically sensitive areas (“ecological sites”) are used for agricultural production, it is necessary to take account of the fact that farmers tend to adapt to environmental requirements by production responses outside the ecological site itself. Second, in order to identify the socially most “desirable” land-use responses it is necessary to supplement the above-mentioned environmental objectives by socio-economic ones. Third, when choosing an appropriate model for such multi-criteria decision analysis, the question of substitutability between criteria is of utmost importance. The paper discusses the above-mentioned issues against the background of a case study of environmental planning for an ecologically very valuable agricultural landscape in Germany, the Bayerisches Donauried. Two models of multi-criteria decision analysis (MCDA) are applied, one based on the “single synthesizing criterion” method, and the other one based on the “synthesis by outranking” method. The models serve to evaluate four different land-use options, using criteria mainly derived from landscape functions and weights gained from interviews with major stakeholders. The paper presents the models’ results concerning the ranking of the different land-use options and discusses the implications for agri-environmental policies and rural development planning.     

Editorial - Multiple-use forestry

The problem of multiple-use forestry arises because (1) a forest can be managed to provide a wide range of products and services, (2) the different uses are not perfectly compatible with each other, and (3) some products are not priced in markets and many of the services a forest provides have the characteristics of public goods. Examples of major forest products include, in addition to timber, edible berries, fungi, and hunting games. Forests also provide recreation opportunities and various environmental services (such as regulating local climate, reducing soil erosion, reducing pollutants in the atmosphere, regulating the global climate, providing habitats for wildlife, etc.). The outputs of nontimber goods in general depend on the quantity and structure of the forest, which can be changed by various forest management activities. However, a forest state most suitable for the production of one good is usually not optimal with respect to another good. Typically, there does not exist a set of management activities that simultaneously maximize the outputs of timber and all other goods.Another way to understand the conflicts between different uses is to view standing timber as an intermediate product of forestry investment, which is employed as an “input” for the production of timber products and nontimber goods. Thinking in this way, the conflicts arise partly because timber production and nontimber uses compete for the same input, and partly because of the differences in the “production technology” among different nontimber goods. A change in the standing timber may have positive impacts on some nontimber uses, but have negative effects on others. Because of the conflicts among different uses, it requires that both timber products and nontimber goods should be explicitly incorporated into forestry decision-making in order to achieve the greatest benefits to the forest owner and/or the public.Most of the economic analyses of multiple-use forestry decisions have explicitly or implicitly adopted the view that multiple-use should be achieved in individual stands. Each stand should be managed to produce an optimal mix of timber products and nontimber goods. Another view of multiple-use forestry is to manage each stand for a primary use, whereas multiple-use concerns are addressed by allocating different stands in a forest to different uses. A general argument in support of the primary-use view is that specialization makes for efficiency. The production of timber and nontimber goods is a joint process, however. Strictly speaking, one cannot separate timber production and the production of different nontimber goods. For example, managing a stand for timber production does not exclude the possibility of producing some nontimber goods in the stand. Since every stand usually produces more than one product, efficient multiple-use forestry requires that each stand should be managed for an optimal mix of timber and nontimber outputs. On the other hand, it may well be the case that the optimal multiple-use mix for a particular stand consists of a maximum output of one product. In this case the optimal multiple-use management decision would coincide with the optimal decision pertaining to a single use. In other words, it may be optimal to manage a particular stand for one primary use. Using the terminology of economics, primary-use may be efficient for stands in which the multiple-use production set is nonconvex. Recent research has explored several sources of nonconvexity in the multiple-use production set. However, there is no evidence supporting the argument that specialization is always more efficient than multiple-use management of individual stands. From an economics viewpoint, efficient primary-use is special cases of multiple-use stand management.A widely recognized limitation of multiple-use stand management is that, by considering each stand separately, one neglects the interdependence of nontimber benefits and ecological interactions among individual stands. The nontimber benefits of a stand depend on the output of nontimber goods from other stands. Likewise, the nontimber output from one stand affects the value of nontimber goods produced in the other stands. Ecological interactions among individual stands imply that the output of nontimber goods from two stands in a forest differs from the sum of the outputs from two isolated stands. These interdependence and interactions imply that the relationship between the nontimber benefits of a stand and the stand age (or standing timber stock) cannot be unambiguously determined - it depends on the flow of nontimber goods produced in the surrounding stands. Therefore, it is improper to determine optimal decisions for the individual stands independently. In stead, efficient multiple-use forestry decision should be analyzed by considering all the stands in a forest simultaneously.Another serious limitation of multiple-use stand management is that each stand is treated as a homogenous management unit to be managed according to a uniform management regime. One implicitly assumes that the boundaries of each stand is exogenously given and will remain unchanged over time. This assumption imposes a restriction on the multiple-use production set, thereby creates inefficiency. As an example, consider a large stand with a nonconvex production set. It may be possible to eliminate nonconvexity in the production set and push the production possibility frontier outwards by dividing the stand into several parts and managing each part for a primary-use. It may also be efficient to combine two adjacent stands into one to be managed following a uniform regime, because of the presences of fixed management costs, and/or because the relationship between some nontimber outputs and stand area is not linear.In contrast to income from timber production, nontimber goods produced at different time points are not perfect substitutes. The rate at which a forest owner is willing to substitute a nontimber good produced at one time point for that produced at another time point changes with the outputs of the nontimber good at the two time points. In general cases, the nontimber goods produced at one time point cannot be consumed at another time point, and the marginal utility of a nontimber good decreases when its output increases. This provides a motivation for reducing the variation in the output of nontimber goods over time. An effective approach to coordinating nontimber outputs over time is to apply different management regimes to different parts of a stand, or apply the same regime to adjacent stands, which would change the boundaries of the stands. Preserving the existing stand boundaries would limit the possibility of evening out the nontimber outputs over time, and thereby lead to intertemporal inefficiency in multiple-use management.In previous studies of multiple-use forestry decisions the nontimber outputs or benefits are usually modeled as functions of stand age or standing timber stock. Future flows of nontimber goods or benefits are incorporated into a stand/forest harvest decision model to explore the implications of nontimber uses for optimal harvest decisions. While stand age and standing timber stock may have significant impacts on nontimber outputs, other forest state variables, e. g. the spatial distribution of stands of different ages/species, may be of great importance to the production of nontimber goods. Recognition of such forest state variables could change the relationship between timber production and nontimber outputs and therefore change the optimal forest management decisions.In summary, multiple-use forestry is not simply an extension of timber management with additional flows of benefits to be considered when evaluating alternative management regimes. Recognition of multiple uses of a forest leads to two fundamental changes of the forestry decision problem. First, the optimal intertemporal consumption of forestry income is no longer separable from forest management decisions. In general, the optimal intertemporal consumption of forestry income depends on future flows of nontimber goods, implying that the consumption-saving decision should be made simultaneously with the decision on the production of timber and nontimber goods over time. Secondly, it is no longer appropriate to optimize the management regime for each stand separately. The nontimber outputs from a forest depend on the age distribution of individual stands, and on a wide range of other forest state variables such as the spatial distribution of stands of different ages and tree-species composition. Ecological interactions and interdependence among stands imply that management regimes for different stands should be optimized simultaneously. In addition to changing rotation ages and harvest levels, efficient multiple-use forestry requires optimizing the spatial allocation of harvests, redefining the boundaries of stands, coordinating the choices of tree species in regeneration of harvested area and so on.The lack of rigorous production functions for nontimber goods imposes a severe restriction on attempts to perform comprehensive economic analyses of multiple-use forestry decisions. This restriction in itself is no justification for ignoring many of the key aspects of multiple-use forestry problem and modeling the problem as one of determining the optimal rotation age or optimal harvest level. It requires that economic models of multiple-use forestry should be developed with special consideration of the vague and imprecise information regarding the relationships between nontimber outputs and forest state variables.Peichen GongDepartment of Forest EconomicsSE-90183 UmeåSweden     

Analysis of individual private forestry in northern Spain according to economic factors related to management

In addition to being motivated by profit, the management decisions taken by non-industrial private forest (NIPF) owners involve other considerations beyond timber, such as non-timber goods and services, as well as factors that affect the level of timber output from the land. Ensuring and improving forest profitability to make NIPF management viable is one of the main challenges faced by this type of landowner. This study empirically explores and assesses management by NIPF owners, through analysing attributes of forest economics (investment in holdings, expenditure on planting and silviculture, public subsidies, along with timber and non-timber incomes). With the aim of predicting outcomes, a multiple regression model was also constructed to investigate and quantify the relationship between socioeconomic and holding factors, and the planting activities carried out by NIPF owners. For this, 103 resident forest landowners in a forest region in northern Spain were interviewed in person, during March 2004, about their commitment to and involvement in land management during the period 1999–2003. The results mainly revealed that attractive forest returns and favourable market conditions for timber production are significant factors for investment in and development of forestry, with personal and family conditions also being important factors in explaining the type of land management carried out. In particular, the multiple linear regression model for forest planting activity correctly explained 84.5% of the variability observed in the study population, indicating that both the investments in and the incomes from forestry play an important role in the activity, as does the size of the holding. The findings may be of interest in promoting public measures related to timber markets and economic incentives for forest management, which will allow landowners to develop economically viable practices, as well as enabling fulfilment of social and environmental demands for sustainable forestry and rural development.     

伊春市国有林业资源型城市经济转型的探讨

分析了伊春国有林区在资源、体制、社会、经济等方面的四大矛盾,以及接续替代产业支撑力度弱、创新企业少,优势珍贵树种面临消亡、育林基金严重不足等现状,认为通过实施“天保”工程、停伐红松林、规划四大经济聚集区等,伊春已具备国有林业资源型城市经济转型的条件。为实现转型需采取对策:解放思想转变观念,实施林权制度改革,积极发展林下经济,调减木材产量,发展替代产业,发展非国有经济,搞好对俄贸易等。     

非农就业对家庭营林劳动力投工女性化的影响研究

根据劳动力转移新经济学理论和家庭内部劳动力分工理论,基于2018年浙江省14个县(市)681户营林调查户样本数据,运用Tobit模型分析了非农就业对营林劳动力女性化的影响。结果表明:非农就业对女性劳动力单位面积营林投工量和女性营林投工比例具有显著正向影响;非农就业对不同林种营林投入女性化有明显差异,对经济林农户家庭营林投工女性化有显著正向影响,而对用材林农户家庭营林投工女性化作用不明显。提出完善农村劳动力社会保障制度;加强农村女性劳动力营林生产技能培训;发挥女性劳动力的营林生产优势等建议。     

An assessment of the policies and practices of selective logging and timber utilisation: A case study from natural forests of Tarai Nepal and Queensland Australia

Selective logging (SL) contributes nearly 15 percent of the global timber needs. Considering its role in sustainable timber production, biodiversity conservation and forest carbon enhancement, assessment of SL policies and practices is crucial. This paper assesses the policies and practices of SL in natural production forests of the Tarai region of Nepal and Queensland Australia to explore the key differences in such policies and practices and their possible implications in achieving sustainable forest management objectives. The primary methods applied in the study were review and synthesis of key policy documents and qualitative analysis of the information gathered from key informant interviews and stakeholders’ workshop. Altogether, 53 respondents from a wide range of stakeholder groups (government organizations-15, non-government organizations/networks-15, private sector including the individual landowners-13, local political leaders-3 and independent forest experts/scientists-7) were consulted. Findings suggest that: (1) frequent and inconsistent changes in policy provisions, lengthy administrative procedures and heavy engagement of state forest agencies in forest product harvesting and sales processes play key roles in sub-optimal forest production in Nepal, whereas lower dependency on forest-products, higher labour costs, lack of species-wise royalty rate and flexibility in selecting optional logs are the key factors for increased wastages of forest products in Queensland; (2) recovery and utilisation of the harvested forest product is better in Nepal but policy and practical considerations on biodiversity and environment are better in Queensland; and (3) Forest harvesting specific codes of practice, occupational health and safety standards, and their compliance mechanism of Queensland could be beneficial for Nepal to minimise operational harvesting risks and to attract professional harvesters that support promoting sustainable use and management of natural forests, as we found this aspect almost neglected in Nepal.     

Estimating the long-run impact of forest fires on the eucalyptus timber supply in Galicia,Spain

Using annual data, we have estimated the timber harvest of eucalyptus in the region of Galicia (Spain). The explanatory variables considered were price, pulp exports, and salvage timber. The latter variable was used as a proxy for forest fires. The problems related to spurious regression were addressed by applying the bounds testing approach to cointegration, and confidence intervals were constructed using the bootstrap technique. The results indicate that pulp exports have a positive effect on the harvested timber volume. Moreover, we find that salvage timber positively affects the timber supply. This result indicates that there is no substitution between salvage timber and non-damaged timber. It also suggests that the natural expansion of the eucalyptus in Galicia compensates for the destruction caused by forest fires, avoiding supply shortages. On the other hand, and according to the economic law of supply, the timber price shows a positive effect.     

Forecasting the German forest products trade: A vector error correction model

In the forest sector often very complex models are used that take into account a variety of factors. In addition to variables that describe the natural production of wood, into these models flow among others also such variables that depict nature conservation legislation, market contexts, etc. The limited availability of large amounts of data and more particularly of precise data to all these subject areas considerably weakens the validity of the models. Our study therefore takes up the challenge to develop a model, as simple as possible, that can help to estimate export and import volumes as well as export and import prices of raw timber in Germany. To this end, we apply the technique of time series analysis and develop a simple model that allows for short-term and medium-term forecasting in the German forest sector. We show that using a vector error correction model (VECM) can succeed in a relatively simple modelling of future quantities and prices of raw timber for Germany.     

Deforestation and timber production in Congo after implementation of sustainable management policy: A reaction to the article by J.S. Brandt,C. Nolte and A. Agrawal (Land Use Policy 52:15–22)

This viewpoint paper presents a reaction to the article by Brandt et al. (2016). It highlights the complexities inherent to the attribution of deforestation impacts to policy interventions when using remote-sensing data. This critique argues that in the context of the Congo a suite of factors (i.e., population density in particular) other than those considered by Brandt et al. (e.g., type of forest, distance from roads and markets) play essential roles in determining the fates of forests. It also contends that care is needed when making decisions regarding which units will be included in the comparison group so that contextual factors and on-the-ground information are properly considered (e.g., when logging operations are inactive or when a concession is used for ‘conservation’ purposes). Finally, it proposes that a focus on an analysis of deforestation rates for a given level of timber production might be a metric that more accurately represents one aspect of the consequences of forest management, which should also consider the appraisal of trade-offs associated with a larger set of social, financial and ecological objectives.     

基于土地利用功能最大化的多情景土地利用优化研究

目的 基于土地利用功能价值最大化对自然发展情景、农业生产功能优先情景、经济发展功能优先情景及生态保育功能优先情景下的土地利用结构及布局进行优化,得到2026年保定市土地利用合理结构与布局。方法 文章利用MOP模型优化各情景土地利用结构、FLUS模型优化各情景土地利用空间布局、耦合协调模型分析各情景功能协调性。结果 各情景下草地面积都减少,建设用地及水域面积都增长。除农业生产功能优先情景外,耕地面积都呈下降趋势。经济发展功能优先情景土地利用功能总价值最高,农业生产功能优先情景最低;各情景下建设用地都以外延式增长;林地都以外延式及填充式在山地丘陵地区扩张;农业生产功能优先、经济发展功能优先及生态保育功能优先情景的土地利用结构耦合协调度高于自然发展情景,经济发展功能优先情景下功能间关系最协调。结论 在现行土地利用变化趋势下,未来保定市土地利用功能将严重失调,需严格落实耕地及生态用地保护政策、推动建设用地高效利用,实现土地利用功能协调及价值最大化。     

Integrating a random utility model for non-timber forest users into a strategic forest planning model

In this paper, we developed a mixed-integer non-linear programming model that integrates access road development and a utility theoretic spatial choice model of hunters into a strategic forest harvest-scheduling model. The model was applied to an operationally sized Forest Management Agreement (FMA) area in central Alberta, Canada. The resulting behavioral model had approximately 2.6 million decision variables and about 96,000 constraints, and was used to examine the impacts of timber harvesting on hunters’ preference for hunting sites. We also evaluated the impacts of various levels of hunter welfare on: (i) the degree of tradeoff between timber and hunting benefits, (ii) timber harvest schedules, and (iii) the marginal costs of producing timber products. The results showed significant tradeoffs between timber and hunting benefits and a clear link between landscape characteristics and changes and behavioral responses by hunters.     

Effects of gender and length of land tenure on timber supply in Finland

This study investigated timber supply from Finnish non-industrial private forests (NIPF) using the consistent Tobit model and nationwide micropanel survey data on timber sales of 1299 forest owners during 2004–2008. The effects of forest owners’ gender and length of land tenure on timber supply were studied in particular. Women sold one cubic meter per hectare and per year (about 30%) less than men did. Female owners sold less frequently, but larger quantities at a time than did male owners. Short-tenure (<5 years) owners’ harvests were only affected by price, owner's age, income, timber stock and forest acreage. A group with relatively high harvest levels was young, low-income new forest owners.     

Mathematical formulation and exact solution for landing location problem in tropical forest selective logging,a case study in Southeast Cameroon

In Central Africa, creating forest roads and skid trails is one of the most costly and environmentally damaging operations for the forest's ecosystem. An optimized road network is essential for reducing construction costs and improving the sustainable management of timber resources. The location of landings is vital in the development of a future forest road network. In this study, a binary integer programming model similar to the uncapacitated facility location problem is formulated to optimize the locations of the landings. The model is applied to selective logging in Central Africa and tested on an annual logging zone in Southeast Cameroon. The results are compared to that of manual road planning, the currently used method.     

采伐限额制度下实现经济效益最大化问题的研究

分析采伐限额制度的合理性,在这个前提下,探讨如何获得经济收益的最大化。林业资源的经济收益取决于市场状况的同时也受到它本身特性的约束,这里市场状况包括总体用材林限额决定的供给量和整体市场的需求量,林业资源特性包括林业用地的限制、木材培育费用和木材的生长期限。通过将市场状况和林业资源本身特点的结合,得出在不同的情况下如何使用和分配用材林采伐限额,在单位内转结的有效性或者在单位间转让的可能性,以实现在采伐限额制度下取得林业资源经济收益最大化。     

Multifunctional forest management in Northern Portugal: Moving from scenarios to governance for sustainable development

If there is a strong argument in favour of multifunctional forest management, there is also controversy regarding the types of multifunctionality able to instil virtuous circles across landscapes. Managing forests in such a way that user groups, sustainability practitioners and forestry institutions all agree to, is not easy. For any reliable consensus to occur, via viable landscape design procedures, through which multiple functions (production, environmental protection and recreation) may be coordinated by means of innovative planning, there is a need to negotiate a set of common objectives and shared responsibilities. This paper examines the policy dimensions of multifunctional forest management, and, through an exploratory case study, proposes an approach for cooperative planning and institutional design. The case study involved two parishes in the Minho region of Portugal (Gavieira and Entre Ambos-os-Rios) combining the local communities, the National Park, and local forestry officers. The case study created, developed and validated two scenario storylines through a series of participatory processes (two focus group meetings, one comprehensive workshop, and one expert meeting). One scenario focussed on continuity of the traditional management patterns, with an emphasis on direct goods such as timber and livestock grazing (traditional multifunctionality). The other concentrated on indirect ecological services, such as soil and water protection, as well as carbon sequestration (new multifunctionality). An attempt was also made to implement the scenario storylines through initiating a pilot project in both of the case study areas. However, there were neither robust planning mechanisms nor adaptive governance systems with the capacity to put into place forest management “futures” likely to deliver more sustainable landscape-scale uses in these areas. This paper illustrates the difficulties in forging governance systems that have the capacity and the vision to be able to put sustainable development concepts into practice, even when a coherent package of planning measures are tried out, given a policy setting that is confused, contradictory, and where the “status quo” tends to be given prominence.     

关于国有林场改革与发展的调查及建议——以广东省肇庆为案例

肇庆市国有林场通过营林和木材生产、木材销售、综合经营、人事制度一系列改革,调整了林场经济结构,增强了林场的活力,调动了广大职工的积极性,林场改革取得了明显的成效。同时,针对国有林场改革与发展中,特别是在实现生态与产业协调发展方面存在一些有待解决的困难和问题,提出了改革的建议。     

Optimal pest control in greenhouse production of ornamental crops

In this study, we develop a conceptual bioeconomic model of floriculture production with aesthetic benefits, wherein optimal decision rules depend on an intertemporal economic objective to maximize profits subject to economic and biological processes. Necessary conditions of the model identify optimal trajectories (e.g., simultaneous, single, or cycling controls) that define decision rules and economic thresholds for profit maximizing growers producing crops with aesthetic attributes. The necessary conditions also highlight intertemporal trade‐offs between aesthetic benefits and expected future net benefits of arthropod stocks, which have important policy implications. The model is applied to the greenhouse production system of ivy geranium.