Optimal management of a flammable forest providing timber and carbon sequestration benefits: an Australian case study*

In deciding to keep or fell a forest stand given its age, the risk of loss of timber through wildfire is an important consideration. If trees also have value from sequestration of carbon, another effect of fire is the unplanned loss of stored carbon. Factors affecting the decision to keep or fell trees, and how much to spend on fire protection, are investigated using stochastic dynamic programming, using carbon sequestration in stands of mountain ash in Victoria as a case study. The effect of treating sawlogs as a permanent carbon sink after harvesting is explored.     

Designing afforestation subsidies that account for the benefits of carbon sequestration: A case study using data from China's Loess Plateau

This paper presents a method for determining the subsidy required to motivate farmers to participate in timber afforestation programs designed to maximize social well-being. The method incorporates a carbon sequestration benefit function into the land expected value model in order to quantify the social benefit arising from carbon sequestration by the planted trees. This is used to calculate the optimal rotation age for newly planted forests that maximizes social utility. The minimum subsidy required to motivate farmers to participate in the afforestation program was calculated using a modified decision model that accounts for the subsidy's impact. The maximum subsidy offered by the government was taken to be the NPV of the carbon sequestration achieved by afforestation. Data on Robinia pseudoacacia L. trees planted on the Loess Plateau were used in an empirical test of the model, which in this case predicts an optimal subsidy of 254.38 yuan/ha over 40 years. This would guarantee the maintenance of forest on land designated for afforestation until they reached the socially optimal rotation age. The method presented herein offers a new framework for designing afforestation subsidy programs that account for the environmental service (specially, the carbon sequestration) provided by forests.     

UK land use and soil carbon sequestration

This review explores the role of land use and land use change as a determinant of the soil's ability to sequester and store carbon in the UK. Over 95 percent of the UK land carbon stock is located in soils which are subjected to a range of land uses and global changes. Land use change can result in rapid soil loss of carbon from peatlands, grasslands, plantation forest and native woodland. Soil carbon accumulates more slowly (decadal) but gains can be made when croplands are converted to grasslands, plantation forest or native woodland. The need for land for food production and renewable forms of energy could have considerable influence on UK soil carbon storage in the future. There is a need to recognise the risk of soil carbon losses occurring when land use change to increase carbon storage is offset by compensatory land use conversions elsewhere that result in net carbon release. The protection of peatland and other organic soil carbon stocks, and the management of cropland, grassland and forest soils to increase carbon sequestration, will be crucial to the maintenance of the UK carbon balance. It will be necessary to develop policy to balance trade-offs between soil carbon gains with other land use priorities. These include the sustainable production of food, bio-energy and fibre crops and livestock, water quality and hydrology, greenhouse gas emission control and waste management, all of which are underpinned by the soil.     

The sustainability of timber production from Eastern Amazonian forests

Although the regulations are imperfectly enforced, logging firms in the Brazilian Amazon are subject to forest management regulations intended to reduce environmental damage and protect future forest productivity. Additionally, voluntary best practices firms adopt to achieve environmental performance that exceed regulatory requirements are largely limited to reduced impact logging (RIL) systems that reduce harvest damage relative to conventional logging systems used by a large majority of firms in the region. Existing regulations combined with best practices may not be adequate to ensure sustained yields. This inadequacy is an important issue as Brazil implements an ambitious program of forest concessions on public lands. We analyze the profitability and environmental outcomes of best logging practices and proposed sustainability requirements. We propose two operational definitions of sustainability (the first focusing on sustaining stand-level timber volumes and the other focusing on sustaining species-level volumes within the stand) based on sustaining timber inventories across cutting cycles rather than on sustaining overall harvest yields. RIL is shown to be profitable for loggers and increase the timber available for future harvests. While volume predicted to be available for the second and third harvests are significantly lower than the available timber in the unlogged forest, the second and third harvests are projected to be profitable and have the potential for sustainability despite high opportunity costs. However, as harvesting is repeated into the future, results show the composition of the harvest shifts from higher-value shade-tolerant and emergent species toward a greater reliance on longer-lived, lower-value pioneer species. This shift may create pressure to expand the forest base under management in order to continue to supply high-value species or increase the risk of timber trespass in conservation units and areas under community or indigenous management.     

Afforestation with carbon sequestration and land use policy in Northern Ireland

In forestry Northern Ireland is one of the most impoverished parts of the European Union as well as the United Kingdom. During the last 10–15 years as afforestation projects gathered speed in many parts of the British Isles there has been no notable change in Ulster. One main contributor to this problem was the political uncertainty and violence which has now largely been remedied since the establishment of the devolved government in 2007.     

Economic impacts of adjacency and green-up constraints on timber production at a landscape scale

Although many different forest certification standards exist, harvest adjacency and green-up regulations are common to most certifying bodies. This study develops a means for evaluating trade-offs associated with implementation of nth-order adjacency and green-up constraints on a 1.7 million ha landscape in Oregon in the US. Depending on the type of adjacency structure and delay between harvests, the opportunity cost of the restrictions, estimated by the change in discounted sum of producer and consumer surplus in the regional log market, ranged from 0.25% to 66% (or US $60 million to $15.3 billion) of the unconstrained value. Increasing green-up delays beyond 30–40 years had little effect on estimated opportunity cost of the modeled restrictions.     

我国碳汇渔业发展对策研究

为了应对气候变暖危机,中国率先提出碳汇渔业概念并倡导大力发展。我国发展碳汇渔业一方面能发挥渔业基础资源和人才技术优势,带动科技进步和经济发展,拉动就业。但另一方面存在管理方式和制度粗放,供应链环节薄弱的劣势和来自国际、市场环境的风险。通过对碳汇渔业发展的优势机遇和劣势风险分析,提出保持渔业资源、技术优势,同时建立渔业人才库的进取型战略;政府提供财政补贴,同时完善渔业碳汇计量体系的抵御型战略;加强碳汇渔业主体海水养殖业供应链的管理信息化,同时提高渔民技能的调整型战略;引进海洋牧场等低碳渔业,同时加强网络信息决策服务的增强型战略。四大战略共举,为我国碳汇渔业可持续发展提供有力保障。     

Economic value of carbon sequestration in forests under multiple sources of uncertainty

The purpose of this paper is to calculate the value of stochastic carbon sequestration in climate change mitigation when also carbon dioxide emissions from fossil fuels and abatement costs are stochastic. The replacement cost method is used where the value of carbon sink is calculated as associated cost savings from replacement of more expensive mitigation options for achieving a given emission target. Minimum costs with and without carbon sinks are derived with a safety-first approach in a chance constrained programming framework which also accounts for variability in control costs. The theoretical results show that for high enough risk discount, carbon sink is not included in a cost effective mitigation program even when the carbon sink cost is zero. The empirical application to the EU independent commitment of 20% reduction in carbon dioxides shows large variation in carbon sink value depending on risk discount. Under no uncertainty, the value can correspond to 0.33% of total GDP in EU, but it declines due to the uncertainty associated with forest carbon sink and is zero for high probability levels in achieving the target. Thus, whether or not to recommend the inclusion of carbon sink in the EU climate policy depends on the uncertainty of carbon sinks in relation to other sources and on the importance of reaching stipulated emission reduction targets.     

Economic impacts of closing national forests for commercial timber production in Florida and Liberty County

The paper assesses the impacts of a proposed policy, which suggests a ban on commercial timber harvest in the US national forests. Specifically, this study examines the effect of this policy on a small forest dependent county (Liberty County) in Florida and Florida State by applying a computable general equilibrium (CGE) model. The results indicate that the proposed policy would decrease overall economic output by $5 million in Liberty County. The decrease in economic output at the state level in response to this policy is only $1 million. Results suggest that the welfare index in response to the proposed policy will drop by 2.9% in Liberty County while the change at the state level is negligible. At the county level, where limited alternate opportunities for labor and capital mobility, the negative effect of the proposed policy is shown to have a multiplying effect.     

The carbon footprints of food crop production

The agriculture sector contributes significantly to global carbon emissions from diverse sources such as product and machinery manufacture, transport of materials and direct and indirect soil greenhouse gas emissions. In this article, we use farm survey data from the east of Scotland combined with published estimates of emissions for individual farm operations to quantify the relative contribution of a range of farming operations and determine the carbon footprint of different crops (e.g. legumes, winter and spring cereals, oilseed rape, potato) and farming practices (conventional, integrated and organic). Over all crops and farm types, 75% of the total emissions result from nitrogen fertilizer use (both organic and inorganic)—from production, application, and direct nitrous oxide emissions from the soil resulting from application. Once nitrogen is accounted for, there are no major differences between organic, integrated or conventional farming practices. These data highlight opportunities for carbon mitigation and will be of value for inclusion in full life cycle analyses of arable production systems and in calculations of greenhouse gas balance associated with land-use change.     

Trade-offs between carbon sequestration and rural incomes in the N’hambita Community Carbon Project, Mozambique

This paper presents a preliminary assessment of trade-offs between carbon sequestration and farmers’ incomes from land-use systems implemented in a community-based project, in Mozambique. Systems either focus on carbon sequestration or combine sequestration with cash crop cultivation. The latter provide carbon payments with potential income from cash crop sales. Uncertainty about the future costs and benefits of maintaining and utilizing the land-use systems over time is addressed via application of Monte Carlo simulations. Our results show that compared with sequestration-only systems those that combine sequestration and cash crop production have higher net benefits, although they have less carbon-sequestration potential. Homestead planting provides the most attractive balance among competing policy goals. Carbon payments contribute to cash income and may enable smallholders to overcome initial project investment costs.     

An open-access method for targeting revegetation based on potential for emissions reduction,carbon sequestration and opportunity cost

We propose a simple heuristic that uses open-access models and government data on agricultural activities to estimate total carbon emissions from agriculture, the gross carbon benefit and the opportunity cost per tonne CO₂-e from revegetating to environmental plantings or plantation forestry. We test this across ten areas of mixed land-use that represent diverse Australian agricultural systems along a rainfall transect. The local value of agricultural production was obtained from government statistics and used to estimate the current economic opportunity cost of converting cleared agricultural land to mixed environmental plantings for carbon sequestration. Gross carbon benefit from revegetation was closely related to current agricultural use, as was financial opportunity cost. These were not related simply to site productivity potential or rainfall. The proportion of land cleared for agriculture that would need to be re-vegetated to achieve a localised zero-carbon land-use scenario was calculated by the ratio of current agricultural emissions to gross carbon benefit from revegetation; this ranged from 13% to 66% for groups of agricultural industries across Australian rainfall transects. While the heuristic does not capture the detail of models built specifically for local research questions it does provide a different lens on the questions policy makers and land managers may ask about the costs and benefits of revegetating agricultural land, and provides open-access methods to guide them.     

Estimated participation in U.S. carbon sequestration programs: A study of NIPF landowners in Massachusetts

Although carbon sequestration programs for non-industrial forestland owners in Massachusetts are being developed, very little is known about the program attributes of importance to different types of landowners or the likelihood that landowners will participate in any given program. This study estimates the probability that Massachusetts landowners will participate in several carbon offset programs using data from a survey of 3000 Massachusetts forestland owners. Results from an ordered logit discrete choice model suggest that the likelihood of enrollment in most programs is quite low. Landowners are clearly motivated by economic factors, but other aspects of carbon sequestration may also be important in their decision making.     

Allocable fixed inputs as a cause of joint production: an empirical investigation

Leathers (1991) shows that while the existence of allocable fixed inputs can cause joint production (as in Shumway, Pope and Nash, 1984), it will not necessarily lead to joint production. The extent to which allocable fixed inputs cause joint production in agriculture is an empirical question. This paper offers an empirical answer. By estimating a short-run joint cost function, it is possible to identify levels of outputs for which joint production may be optimal in the short run but not in the long run. Only in these output regions will there be jointness caused by allocable fixed inputs. For the data in this paper (160 Wisconsin farms), these output regions are very small; thus allocable fixed inputs do not appear to be an important cause of jointness for these farms. Technical causes of jointness appear to be a significant cause of joint production.     

加强水利工程造价工作提高国债项目投资效益

根据国债资金投入数量与项目工程造价之间的关系以及我国水利工程项目的特点,提出应树立水利工程全面造价管理的思想。阐述工程设计阶段进行优化设计和造价控制的重要性,并对工程建设概预算定额及计价依据进行分析。     

鹤岗市农村人饮工程存在的问题及对策

论述了鹤岗市的人饮的现状、人饮普及率等相关情况,对鹤岗市人饮在解决农村人饮工程建设中存在的一些突出问题进行了总结,并提出了相应的对策.     

优化城乡用地结构与布局的对策研究

通过对某县城乡用地现状进行分析,本文指出该县城乡用地结构和布局存在的问题及成因,并针对所存在的问题提出优化其城乡用地结构和布局的对策和建议。     

水产品市场研究进展述评与今后课题

水产品市场研究是水产经济学的核心内容,也是常青课题。从概念内涵以及基本论题等方面回顾中日水产品市场理论与应用研究现状,认为目前中国国内的研究成果取得了一定进展,为进一步的理论升华和应用拓展提供了坚实的根基,但同时普遍存在着应用研究多于理论研究、宏观研究多于微观研究、对策研究多于实证研究、定性分析多于定量分析、静态分析多于动态分析、实物量分析多于价值量分析、文献分析多于调研分析、现况分析多于预测分析等研究现象。因此,水产品市场研究在深度、广度和高度上均需拓展。     

跨所有制合作造林的经济问题初探--浙江庆元县国乡合作造林的调查

通过庆元县国乡合作造林的调查分析 ,阐明了跨所有制合作造林产生的历史背景 ,分析了国乡合作造林暴露的问题 ,提出了巩固和发展国乡合作造林的对策与建议。     

Effects of log export ban policy and dynamics of global tropical wood markets on the growth of timber industry in Ghana

The effects of log export ban (LEB) policy and dynamics of global tropical timber markets on the growth of Ghanaian timber industry were studied. The purpose was to follow the trend in the growth of timber industry from 1984 to 2005 using Fisher index and semi-log regression analysis. The study showed that the volume of plywood, veneer, and processed wood exported before the period of 1984–1995 and during the LEB policy (1996–2005) was, respectively, 6% and 46% of the total exports during those periods. On the contrary, the aggregate price index of all products exported before the LEB policy was up by 129% compared to −3.9% for the period during the LEB policy. A further decline in prices of the most products exported during the LEB policy was found by the study. Thus even though an LEB policy could increase volume share of value-added products, it cannot guarantee growth in prices of wood products.