Carbon balance of forest stands,wood products and their utilization in South Korea

Forests provide wood products and feedstock for bioenergy and bio-based products that can mitigate climate change by reducing carbon emissions. In order to assess the effects of forest products on reducing carbon emissions, we analyzed the carbon balance for individual carbon pools across the forest supply chain over a long period of time. We simulated particular forest supply chain activities pertaining to even-aged management of pine stands in South Korea to demonstrate our methods. Two different rotation scenarios (i.e., 40 and 70 years) were assessed over the 280-year time horizon in terms of temporal changes in carbon stock in each carbon pool along the supply chain, carbon transfer between carbon pools, substitution effects, and delayed carbon release by wood products. We found that the average carbon stock level was higher for the 70-year rotation scenario, but the total amount of gain in carbon was higher for the 40-year rotation at the end of the time horizon. This study confirms that forest products and energy feedstock can both reduce carbon emissions and increase carbon storage. However, the complexity of carbon accounting along the supply chain warrants a thorough evaluation from diverse perspectives when it is used to assess forest carbon management options.     

Forest carbon storage in the northeastern United States: Net effects of harvesting frequency,post-harvest retention,and wood products

Temperate forests are an important carbon sink, yet there is debate regarding the net effect of forest management practices on carbon storage. Few studies have investigated the effects of different silvicultural systems on forest carbon stocks, and the relative strength of in situ forest carbon versus wood products pools remains in question. Our research describes (1) the impact of harvesting frequency and proportion of post-harvest structural retention on carbon storage in northern hardwood-conifer forests, and (2) tests the significance of including harvested wood products in carbon accounting at the stand scale. We stratified Forest Inventory and Analysis (FIA) plots to control for environmental, forest structural and compositional variables, resulting in 32 FIA plots distributed throughout the northeastern U.S. We used the USDA Forest Service's Forest Vegetation Simulator to project stand development over a 160 year period under nine different forest management scenarios. Simulated treatments represented a gradient of increasing structural retention and decreasing harvesting frequencies, including a “no harvest” scenario. The simulations incorporated carbon flux between aboveground forest biomass (dead and live pools) and harvested wood products. Mean carbon storage over the simulation period was calculated for each silvicultural scenario. We investigated tradeoffs among scenarios using a factorial treatment design and two-way ANOVA. Mean carbon sequestration was significantly (α = 0.05) greater for “no management” compared to any of the active management scenarios. Of the harvest treatments, those favoring high levels of structural retention and decreased harvesting frequency stored the greatest amounts of carbon. Classification and regression tree analysis showed that management scenario was the strongest predictor of total carbon storage, though site-specific variables were important secondary predictors. In order to isolate the effect of in situ forest carbon storage and harvested wood products, we did not include the emissions benefits associated with substituting wood fiber for other construction materials or energy sources. Modeling results from this study show that harvesting frequency and structural retention significantly affect mean carbon storage. Our results illustrate the importance of both post-harvest forest structure and harvesting frequency in carbon storage, and are valuable to land owners interested in managing forests for carbon sequestration.     

The potential of REDD+ for carbon sequestration in tropical forests: Supply curves for carbon storage for Kalimantan,Indonesia

We study the potential of tropical multi-age multi-species forests for sequestering carbon in response to financial incentives from REDD+. Following existing carbon crediting schemes, the use of reduced impact logging techniques (RIL) allows a forest manager to apply for carbon credits whereas conventional logging (CL) does not. This paper is the first to develop a Hartman model with selective cutting in this setting that takes additionality of carbon sequestration explicitly into account. We apply the model using data for Kalimantan, Indonesia, for both private and government forest managers. The latter have a lower discount rate and are exempt from taxes. RIL leads to less damages on the residual stand than CL and has lower variable but higher fixed costs. We find that a system of carbon credits through REDD+ can increase carbon stored per hectare by 15.8% if the forest is privately managed and by 22% under government management if the carbon price equals the average 2015 price in the European Union's Emission Trading Scheme. Interestingly, awarding carbon credits to carbon stored in end-use wood products does not increase the amount of carbon stored, nor Land Expectation Value.     

Carbon sequestration in Spanish Mediterranean forests under two management alternatives: a modeling approach

Management implications associated with two different silvicultural strategies in two Spanish pine forests (Scots pine stands in northern Spain and Mediterranean Maritime pine stands in Central Spain) were explored. Whole-stand yield, growth models and individual tree equations were used to estimate carbon stock in forests under different silvicultural alternatives and site indexes. Each alternative was evaluated on the basis of the land expectation value (LEV). Results reveal the appropriateness of implementing carbon payments, because it can clearly complement traditional management objectives in economic terms. Longer rotations on the poorest sites result in a positive economic return by introducing carbon output. The proportion of carbon stock in the final harvest relative to total fixed carbon is always higher in long rotation scenarios. However, short rotation systems produce the highest values of carbon MAI regardless of site index. The impact of carbon price is higher on the Maritime pine stands than on Scots pine stands. For both the species, changes in the discount rate have a minor impact on Carbon LEV. Notwithstanding, the proportion of total LEV due to carbon is greater when the discount rate increases.     

Climate change mitigation through increased wood use in the European construction sector—towards an integrated modelling framework

Using wood as a building material affects the carbon balance through several mechanisms. This paper describes a modelling approach that integrates a wood product substitution model, a global partial equilibrium model, a regional forest model and a stand-level model. Three different scenarios were compared with a business-as-usual scenario over a 23-year period (2008?C2030). Two scenarios assumed an additional one million apartment flats per year will be built of wood instead of non-wood materials by 2030. These scenarios had little effect on markets and forest management and reduced annual carbon emissions by 0.2?C0.5% of the total 1990 European GHG emissions. However, the scenarios are associated with high specific CO₂ emission reductions per unit of wood used. The third scenario, an extreme assumption that all European countries will consume 1-m³ sawn wood per capita by 2030, had large effects on carbon emission, volumes and trade flows. The price changes of this scenario, however, also affected forest management in ways that greatly deviated from the partial equilibrium model projections. Our results suggest that increased wood construction will have a minor impact on forest management and forest carbon stocks. To analyse larger perturbations on the demand side, a market equilibrium model seems crucial. However, for that analytical system to work properly, the market and forest regional models must be better synchronized than here, in particular regarding assumptions on timber supply behaviour. Also, bioenergy as a commodity in market and forest models needs to be considered to study new market developments; those modules are currently missing.     

Financial feasibility of increasing carbon sequestration in harvested wood products in Mississippi

Longer forest rotation ages can potentially increase accumulation of carbon in harvested wood products due to a larger proportion of sawlogs that can be used for manufacturing durable wood products such as lumber and plywood. This study quantified amounts of carbon accumulated in wood products harvested from loblolly pine (Pinus taeda L.) stands grown in Mississippi by extending rotation ages traditionally used to manage these stands for timber. The financial viability of this approach was examined based on carbon payments received by landowners for sequestering carbon in standing trees and harvested wood products. Results indicated a potential to increase carbon accumulated in wood products by 16.11 metric tons (t) of carbon dioxide equivalent (CO₂e) per hectare (ha) for a rotation increase of 5 years and 67.07 tCO₂e/ha for a rotation increase of 65 years. Carbon prices of $50/tCO₂e and $110/tCO₂e would be required to provide a sufficient incentive to forest landowners to extend rotations by 5 and 10 years, respectively. With 2.8 million ha of loblolly pine stands in Mississippi, this translates to a possible increase in wood products carbon of 45 million tCO₂e and 80 million tCO₂e for harvest ages increased by 5 and 10 years, respectively. Higher carbon prices lengthened rotation ages modestly due to low present values of carbon accumulated with long rotations.     

China's role in the global forest sector: how will the US recovery and a diminished Chinese demand influence global wood markets?

Over the last decade, while the size of China's economy more than doubled, China has simultaneously become a major producer and exporter of forest products. Although China's domestic supply of wood is significantly constrained both by a limited natural supply and by conservation-oriented policies, the country is increasingly regarded as the world's “wood workshop.” Furthermore, China is the largest driver of demand for the trade in tropical logs and is becoming a significant driver of demand for trade in coniferous logs. In this paper, we describe a spatial equilibrium model adapted to study forest sector markets and policies that affect them. We present the model and the result of two alternative future scenarios. The first scenario analyzes the impact on global forest products markets of a US recovery in wood markets. The second scenario examines the effect on global forest products markets of decelerating growth in Chinese demand for wood products. Through these two scenarios, the modeling output sheds light on the role China's wood products markets have on resource supply and trade around the world. The trade model shows substantial potential changes in global prices, production, and trade activity associated with the recovery in domestic demand in the USA.     

Bioenergy from the forest sector: Economic potential and interactions with timber and forest products markets in Norway

Abstract

A partial equilibrium forest sector model which is augmented to include bioenergy was applied to project the use of bioenergy based on forest fuels and forest industry by-products in Norway for three different scenarios of the future prices of electricity and oil. The impacts on forestry and forest industries of the different energy price scenarios were also studied. The advantage of the suggested methodology is that it allows for assessments of the economic potential of bioenergy, taking into account the competition for raw materials, the specific heat demand of various regions, and interregional and international trade. Bioenergy will, according to this study, be fairly competitive in some market segments with the current price levels of electricity and oil, and only a minor increase (decrease) in energy (roundwood) prices would release substantially increased bioenergy production levels. Pulpwood prices of pine and non-coniferous species are projected to increase substantially when assuming increasing energy prices. Except for particleboard mills, production levels of forest industries appeared relatively insensitive to the energy price changes.     

Economic impacts of accelerating forest growth in Europe

The global forest sector model EFI-GTM was applied to assess regional impacts in Europe of increased timber supply caused by potential acceleration of forest growth in Europe. The EFI-GTM is a multi-periodic partial equilibrium model, which contains 31 European regions and 30 regions for the rest of the world, and trade between the regions. The endogenous sectors include 26 forest industry products and six wood categories. Three alternative forest growth scenarios were analysed: a base line assuming the present annual rate of growth in the European countries, and two accelerating growth scenarios corresponding to a 20 and 40% increase after 20 years in the forest growth relative to the baseline growth. In the accelerated growth scenarios equilibrium prices for logs and sawnwood decreased significantly from the baseline levels, whereas the other forest product prices were not affected much. Depending on region and timber category, the log prices in 2020 were 7–9 and 13–17% lower than the base line prices in the medium and high forest growth scenarios, respectively. For sawnwood, the corresponding price decreases were 2 and 3.5–4.5%. In Western Europe, log harvest and sawnwood production increased because accelerated forest growth substituted for imports of these commodities from Russia and Eastern European countries. This decreased the harvests in Russia and Eastern Europe relative to the base case. In all the three forest growth scenarios the forest owners income as well as the forest industry profit increase over time.     

Carbon balance for different management practices for fast growing tree species planted on former pastureland in southern Europe: a case study using the CO2Fix model

Although it is known that forestry mitigates carbon emissions to some degree, there is still a need to investigate the extent to which changes in forest management regimes affect the carbon cycle. In a climate-change scenario, forest management schemes must be optimized to maximize product supply and minimize environmental impacts. It is difficult to predict the mitigating effects of different silvicultural regimes because of differences in the growth characteristics of each species, destination of products, and industrial efficiencies. The objective of the present study was to use a modeling approach to evaluate the effects of different management regimes for fast growing species in southern temperate Europe in relation to mitigating climate change. A comprehensive study was carried out considering the C sink effect in biomass, soil and wood products, the substitutive effect of bioenergy, and particular conditions of the forest industry in southern Europe. The mechanistic CO₂Fix model was parameterized for three species used in fast growing plantations in southern Europe: Eucalyptus globulus, Eucalyptus nitens, and Pinus radiata. Data from 120 plots covering the complete age range observed for each species were used to calculate changes in C stocks in aboveground biomass and organic and mineral soil and to validate the parameterized model for these conditions. Additional information about the efficiency of forest industry processes in the region was also considered. A strong bias in soil organic carbon estimation was observed and attributed to overestimations in the decomposition rates of soil compartments. Slight bias was also observed in the carbon biomass estimation when forest-specific yield models were used to simulate afforestation over former pastureland. As regards the model sensitivity, the Yasso model was strongly robust to turnover of leaves, roots, and branches. The chip wood production alternative yielded higher carbon stock in biomass and products, as well as in bioenergy substitution effect, than the sawn wood production alternative. Nevertheless, the sawn wood alternative was the most effective as regards the C stock in the soil. Site index had an important effect for all species, alternatives, and compartments, and mitigating effects increased with site index. Harvesting of clearcutting and thinning slash for bioenergy use led to a slight decrease in the soil carbon equilibrium but significantly increased the mitigation effect through bioenergy use.     

Short- and long-term responses of total soil organic carbon to harvesting in a northern hardwood forest

The long-term response of total soil organic carbon pools (‘total SOC’, i.e. soil and dead wood) to different harvesting scenarios in even-aged northern hardwood forest stands was evaluated using two soil carbon models, CENTURY and YASSO, that were calibrated with forest plot empirical data in the Green Mountains of Vermont. Overall, 13 different harvesting scenarios that included four levels of aboveground biomass removal (20%, 40%, 60% and 90%) and four different rotation lengths (60 year, 90 year, 120 year, and No Rotation (NR)) were simulated for a 360 year period. Simulations indicate that following an initial post-harvest increase, total SOC decreases for several decades until carbon inputs into the soil pool from the re-growth are greater than losses due to decomposition. At this point total SOC begins to gradually increase until the next harvest. One consequence of this recovery pattern is that between harvests, the size of the SOC pool in a stand may change from −7 to 18% of the pre-harvest pool, depending on the soil pool considered. Over 360 years, the average annual decrease in total SOC depends on the amount of biomass removed, the rotation length, and the soil pool considered. After 360 years a stand undergoing the 90yr-40% scenario will have 15% less total SOC than a non-harvested stand. Long-term declines in total SOC greater than 10% were observed in the 60yr-60%, 60yr-90%, and 90yr-90% scenarios. Long-term declines less than 5% were observed in scenarios with 120 year rotations that remove 60% or less of the aboveground biomass. The long-term decreases simulated here for common management scenarios in this region would require intensive sampling procedures to be detectable.     

An integrated assessment approach to optimal forest bioenergy production for young Scots pine stands

Background: Bioenergy is re-shaping opportunities and imperatives of forest management. This study demonstrates,through a case study in Scots pine(Pinus sylvestris L.), how forest bioenergy policies affect stand management strategies.Methods: Optimization studies were examined for 15 Scots pine stands of different initial stand densities, site types, and temperature sum regions in Finland. Stand development was model ed using the Pipe Qual stand simulator coupled with the simulation-optimization tool Opti For Bioenergy to assess three forest bioenergy policies on energy wood harvest from early thinnings.Results: The optimal solutions maximizing bare land value indicate that conventional forest management regimes remain optimal for sparse stands. Energy harvests occurred only when profitable, led to lower financial returns. A forest bioenergy policy which included compulsory energy wood harvesting was optimal for denser stands. At a higher interest rate(4 %), increasing energy wood price postponed energy wood harvesting. In addition, our results show that early thinning somewhat reduced wood quality for stands in fertile sites. For less fertile sites, the changes were insignificant.Conclusions: A constraint of profitable energy wood harvest is not rational. It is optimal to carry out the first thinning with a flexible forest bioenergy policy depending on stand density.     

Potential Impact of Forest Bioenergy on Environment in China

Forest bioenergy is an alternative to fossil energy.Although forest bioenergy is of great value to ease energy supply,there is still a strong call for the research of what impact forest bioenergy plantation will exert on environment if under large scale development.By discussing the resource potential and development status of forest bioenergy,the paper attempts to explore the potential impact of forest bioenergy on environment and give some recommendations to mitigate and even avoid negative impact.     

Estimates of residual fibre supply and the impacts of new bioenergy capacity from a forest sector transportation model of the Canadian Prairie Provinces

Increasing interest in making use of forest sector processing residuals for renewable energy production has led to the need for careful analyses of fibre supply, and the ways in which existing forest sector firms could be affected by new sources of fibre demand. In this paper we present a forest sector transportation model of the three Canadian Prairie Provinces, and use the model to estimate residual fibre production, utilization and surpluses, as well as some potential forest sector impacts from bioenergy capacity additions. Under our base-case assumptions and using 2010 product prices, we estimate that 6.9 million cubic meters (round-wood equivalent) of processing residuals would be traded over the course of a year, with sawmills being the most significant source and pulp and paper mills being the most significant user. Approximately 33% of residuals would be used to produce bioenergy-related products (wood pellets, electricity sold to the grid, or internal electricity and power at pulp mills). Results show that some surpluses of processing residuals may be present in the existing supply chain, though the availability of these residuals is sensitive to lumber prices. At the same time, new bioenergy capacity itself may trigger higher sawmill output, making additional fibre available for both new and existing users. Roadside harvesting residuals are not an economically viable source of fibre under our base-case assumptions; however, their viability is sensitive to roadside processing costs and electricity prices.     

Forest management and carbon sequestration in wood products

Wood products are considered to contribute to the mitigation of carbon dioxide emissions. A critical gap in the life cycle of wood products is to transfer the raw timber from the forest to the processing wood industry and, thus, the primary wood products. Therefore, often rough estimates are used for this step to obtain total forestry carbon balances. The objectives of this study were (1) to examine the fate of timber harvested in Thuringian state forests (central Germany), representing a large, intensively managed forested region, and (2) to quantify carbon stocks and the lifetime of primary wood products made from this timber. The analyses were based on the amount and assortments of actually sold timber, and production parameters of the companies that bought and processed this timber. In addition, for coniferous stands of a selected Thuringian forest district, we calculated potential effects of management, as expressed by different thinning regimes on wood products and their lifetimes. Total annual timber sale of soft- and hardwoods from Thuringian state forests (195,000 ha) increased from about 136,893 t C (~0.7 t C ha⁻¹ year⁻¹) in 1996 to 280,194 t C (~1.4 t C ha⁻¹ year⁻¹) in 2005. About 47% of annual total timber harvest went into short-lived wood products with a mean residence time (MRT) < 25 years. Thirty-one per cent of the total harvest went into wood products with an MRT of 25–43 years, and only 22% was used as construction wood and glued wood, products with the longest MRT (50 years). The average MRT of carbon in harvested wood products was 20 years. Thinning from above throughout the rotation of spruce forests would lead to an average MRT in harvested wood products of about 23 years, thinning from below of about 18 years. A comparison of our calculations with estimates that resulted from the products module of the CO2FIX model (Nabuurs et al. 2001) demonstrates the influence of regional differences in forest management and wood processing industry on the lifetime of harvested wood products. To our knowledge, the present study provides for the first time real carbon inputs of a defined forest management unit to the wood product sector by linking data on raw timber production, timber sales and wood processing. With this new approach and using this data, it should be possible to substantially improve the net-carbon balance of the entire forestry sector.     

The impact of SFM-certification on forest product markets in Western Europe — an analysis using a forest sector simulation model

In the international discussion on labels for sustainably produced wood products based on the certification of sustainable forest management (SFM), little attention has been paid to what is probably the most crucial part of any market-based instrument: the potential impact on forest products markets. This paper analyses the potential impact of SFM-certification on forest products markets using a simulation model of the Western European forest sector. Two scenarios with assumptions regarding certification (chain-of-custody costs, timber supply reduction from certified forests) are projected for the period 1995–2015 and tested against the results of a base scenario (‘business as usual’). In general, the results show that rather modest changes are to be expected from SFM-certification in forest products markets. The market impact of a timber supply reduction from certified forest would be more distinct than the impacts of chain-of-custody costs. Industry gross profits would decrease more than production. Due to the large share of roundwood costs in total costs, the sawmill industry would be affected more by even small changes in raw-material prices than the panel and paper industry.     

马尾松中龄施肥木材密度和干缩率的研究

选用广西马尾松龄施肥材料（连续观测13年），根据国际《木材物理力学试验方法》，研究了施肥对木材密度和干缩率的影响，结果表明：N、P、K三要素中，以N、P肥对木材密度和干缩率的影响较大。⑴总的来说P增加木材密度和干缩率，N肥降低木材密度木材干缩率。N、P肥降低木材差异干缩。施K肥对木材密度和干缩率的影响规律性不明显。⑵N、P、K施肥对木材密度和干缩率的影响及其变化程度，与肥种、施肥量、树干部位、木纹方向、气干或全干状态有关。施P肥木材密度具有增加的趋势，而且树干下部基本密度方差分析各处理间差异显著。N、K肥对木材密度的影响，规律性不明显。P肥使木材干缩率增加，P肥主要增加的是全干干缩率和径向气干干缩率，特别是树干下部径向气干干缩率各处理间差异显著。K肥对干缩率的影响规律性不明显，有待进一步研究。⑶为了保证木材质量，对于纤维用材林，主要施P肥；对于结构用材林，可施P肥，适当考虑N肥、K肥施用应慎重。     

The Restricting Effects of Forest Certification on the International Trade of Wood Products

Forest certification has increased the cost of companies which has affected the international trade of wood products. This paper examines forest certification costs of companies, and based on this, uses partial equilibrium to analyze its trade restriction effects, and uses space price gradient field model to check whether it is a substitution for tariff barriers. Our conclusion shows that forest certification has restricted the trade of wood products due to its high certified cost, and clarifies that in the case of tariff reduction, trade of wood products are hindered by different levels and different costs of forest certification. This paper implies that efforts should be made to increase the amount of certified forests worldwide. It is necessary to lower the certified cost and important that government policy measures to support certification should include consideration of who bears the cost, support for aggregation of smallholder growers and improved communication in timber supply chains.     

Toxicity of emissions from combustion and pyrolysis of wood

Summary Fuels such as wood and forest residuals are becoming important sources of energy; furthermore, wood and wood products are major components of building construction. In both cases environmental impact and health hazard posed by the burning of these materials must be evaluated. Most death and injuries on exposure to burning wood are due to inhalation of toxic gases, smoke, and heat gases, usually carbon monoxide. Any wood or wood products used in building construction must be chosen so as to release the minimum amount of toxic materials as slowly as possible when heated or burned, to allow people time to escape. The emissions from wood burning power plants certainly have local short term and global long term environmental impacts. For example, massive carbon dioxide production from wood burning is believed to affect the earth's energy balance and therefore global climates. This review does not consider this aspect of wood burning, or other environmental hazards due to power plants utilizing wood, about which little seems to be known. The subject of this review is of the literature from 1971–1979 concerned with the toxicity of products of combustion and/or pyrolysis of wood, or wood products, untreated or treated with preservatives.