Harvested Wood Products Research Articles

A Review of Cradle-to-Gate Greenhouse Gas Emission Factors for Canada’s Harvested Wood Products

Abstract With the previous decade’s (2010 through 2019) greenhouse gas emissions remaining the highest on record, focus on emissions mitigation efforts is paramount. Harvested wood products (HWPs) can store carbon for various timespans depending on the product and its end uses. Life cycle inventories (LCIs) are the base for life cycle analyses (LCAs), as they represent a comprehensive catalogue of the raw data essential to complete an LCA. However, most LCI documentation is in the form of case studies of different types of HWPs, with varying LCI results that reflect varied system boundaries, case-specific conditions, and assumptions. Our goal was to conduct a systematic literature review to evaluate, analyze, and synthesize previously reported Canadian HWP data and to initiate a Canadian database based on reported cradle-to-gate HWP emission factors. HWPs were categorized as lumber, traditional structural panels, mass timber, nonstructural panels, and wood pellets. Based on our analysis, we found that softwood lumber produced the lowest cradle-to-gate emission factor (61.99 kg of CO2 equivalent [CO2eq] per m3 HWP) while I-joists produced the highest (218.55 kg of CO2eq per m3 HWP). Resource extraction emissions accounted for most of the overall emissions for softwood lumber, oriented strand board, cross-laminated timber, and glue-laminated timber. Meanwhile, manufacturing accounted for most of the emissions for plywood, I-joists, cellulosic fiberboard, particleboard, and wood pellets. Substantial gaps exist in published LCI data and, when possible, publishing detailed LCI data is encouraged to support additional HWP life cycle analyses.

Development of national post-fire restoration system to assess net GHG impacts and salvage biomass availability

In light of the recent unprecedented wildfires in Canada and the potential for increasing burned areas in the future, there is a need to explore post-fire salvage harvest and restoration and the implications for greenhouse gas (GHG) emissions. Salvage logging and replanting initiatives offer a potential solution by regrowing forests more quickly while meeting societal demands for wood and bioenergy.This study presents a comprehensive modeling framework to estimate post-fire salvage biomass and net GHG emissions relative to a ‘do-nothing’ baseline for all of Canada's harvest-eligible forests. Forest ecosystem carbon emissions and removals were modeled at 1-ha spatial resolution for Canadian forests using the Generic Carbon Budget Model (GCBM) from 1990 to 2070 using several forest inventory data sources with future harvest and wildfires.Building upon previous research, our work integrated the Canadian Forest Fire Danger Rating System fire intensity to estimate fire severity of future wildfires. For 2024 to 2070, we assessed the changes in ecosystem carbon, emissions from harvested wood products, and substitution benefits from avoided emissions-intensive materials, relative to a forward-looking baseline. Our prototype system provides a comprehensive framework, configuration files, links to datasets to quantify the net GHG of post-fire restoration, and sample results for validation.•Developed spatially explicit forest carbon modeling system for all of Canada's forests.•Assessed the net GHG reduction from post-fire restoration.•Used system approach to consider forests, wood products and substitution benefits.

Understanding substitution impacts of harvested wood and processing residues to mitigate climate change: A case of Chattogram, Bangladesh

In Bangladesh, the role of harvested wood (e.g. wood products and associated processing residues) to mitigate climate change is less known and often ignored. This study aims to understand the substitution impacts of harvested wood products and associated processing residues in Chattogram city area, Bangladesh. Additionally, we also explored sellers' and users' perceptions towards the use of wood biomass and associated effects, with users’ level of satisfaction with using different categories of products of wood, bamboo, steel, and plastic. The study only considered sawn wood from sawmills to the wooden furniture and building materials, and associated residues, but excluded carbon in the forest ecosystem. A survey, using three different types of pre-tested questionnaires consisting of open and close-ended questions, was carried out in 36 sawmills, 62 timber merchants, and 55 furniture manufacturers or shops, with their owners or managers in Chattogram City Corporation area, Bangladesh. We used the general displacement factors of 0.5, 0.45, 1, and 1.3 tC tC−1 for processing residues, composite wood furniture, solid wood furniture, and building materials, respectively. The amount of wood products and associated residues and their avoided emissions due to substitution were presented in m3 industry−1 year−1 and Mg industry−1 year−1. Results revealed that the highest mean annual consumptions of timber (783.95 m3 industry−1 year−1) and processing residues (196.05 m3 industry−1 year−1) were in the sawmills and the lowest (60.56 and 0.66 m3 industry−1 year−1) in the furniture manufacturers. Altogether, the processing of round logs generated 36% residues of its mass from sawmilling to furniture manufacture. Sawn wood (of sawmills and timber merchants) consumed in the building houses produced the highest annual avoided emissions (1029.51 Mg CO2 industry−1 year−1). The development of efficient products with long lifespans, in addition to factors such as forest management, emissions, waste generation, and life cycle assessments of products likely play a significant role in determining the overall impact on displacement factors. The future study should focus on developing material flow analysis integrated with a life cycle assessment approach for various products for the construction and associated sectors, thus generating a country-specific displacement factor. The perception-based study documented that wood furniture and processing residues as bioenergy were perceived as a good substitute for non-wood furniture (e.g., steel, plastic) and fossil fuels (gas, oil) and thus lowering fossil emissions as wood products were perceived as user-and-environment-friendly and attractive. However, environmental awareness of both consumers and sellers about wood and bioenergy use and forest degradation is crucial for turning them into positive from neutral perceptions.

Opportunities and challenges towards a circular bioeconomy of the Philippines’ veneer and plywood industry

Using harvested wood products (HWPs) in a circular bioeconomy, such as veneer and plywood, is a promising approach to addressing environmental concerns and ensuring sustainable resource management. This paper attempts to conceptualize a veneer and plywood circular bioeconomy system (VPCBES) model and analyse the opportunities and challenges these wood-based industries face in contributing to the circular economy of the Philippines. A systematic literature review and contextualized SWOT analysis were employed to explore potential pathways for sustainable development and circular practices in the country. It adopts the butterfly framework and presents the VPCBES model, exploring the continuous flow of materials, emphasizing waste reduction, products and materials circulation, and nature regeneration. The opportunities for the veneer and plywood industry in the circular bioeconomy include using recycled wood waste, adopting resin as a binding agent, and cascading wood waste in time and value. However, challenges persist, including meeting demands while ensuring regeneration goals, low innovation investments, harvesting practices, waste routes issues, non-compliance to cleaner production and industrial symbiosis, and policy‐related barriers. Addressing these challenges and capitalizing on opportunities will enable the veneer and plywood industry to play a vital role in the Philippine circular bioeconomy.

Climate change mitigation potentials of wood industry related measures in Hungary

Harvested wood products (HWPs) store a significant amount of carbon while long-lived products and wooden buildings can be among the most effective means for carbon storage. Wood products’ lifetime extension and appropriate waste management, recycling, and reuse can further contribute to the achievement of climate goals. In our study we projected under 10 different scenarios the carbon storage, carbon dioxide and methane emissions of the Hungarian HWP pool up to 2050 in order to find the combination of wood industry-related measures with the highest climate change mitigation effect. For the projection we used the country-specific HWP-RIAL model to predict emissions associated with the end-of-life and waste management of wood products. The main conclusion is that without additional measures the Hungarian HWP pool would turn from a carbon sink to a source of emissions by 2047. To maintain the Hungarian HWP pool to be a continuous carbon sink it is essential to implement additional climate mitigation measures including cascading product value chains, and approaches of a circular bioeconomy. We find the most effective individual measures are increasing product half-life, increasing recycling rate and increasing industrial wood production through increased industrial wood assortments and increased harvest. With the combination of these measures a maximum average annual climate change mitigation potential of 1.5 Mt CO2 equivalents could be reached during the 2022–2050 period.

Cost-effectiveness of natural forest regeneration and plantations for climate mitigation

Mitigating climate change cost-effectively requires identifying least-cost-per-ton GHG abatement methods. Here, we estimate and map GHG abatement cost (US$ per tCO2) for two common reforestation methods: natural regeneration and plantations. We do so by producing and integrating new maps of implementation costs and opportunity costs of reforestation, likely plantation genus and carbon accumulation by means of natural regeneration and plantations, accounting for storage in harvested wood products. We find natural regeneration (46%) and plantations (54%) would each have lower abatement cost across about half the area considered suitable for reforestation of 138 low- and middle-income countries. Using the more cost-effective method at each location, the 30 year, time-discounted abatement potential of reforestation below US$50 per tCO2 is 31.4 GtCO2 (24.2–34.3 GtCO2 below US$20–100 per tCO2)—44% more than natural regeneration alone or 39% more than plantations alone. We find that reforestation offers 10.3 (2.8) times more abatement below US$20 per tCO2 (US$50 per tCO2) than the most recent IPCC estimate.

Shifting wood between material and energy use: Modeling the effects of substitution

AbstractWood as a renewable material is relevant for climate change mitigation: Carbon sequestration in forests and carbon storage in harvested wood products (HWPs) contribute to carbon reduction in the atmosphere, and the substitution of carbon‐intensive products with wood products can reduce greenhouse gas (GHG) emissions. Since wood is a limited resource, it must be used efficiently and sustainably. Shifting wood from one application to another might result in decreased GHG emissions due to substitution effects. However, which wood application will lead to a GHG emission reduction is currently unknown. This study investigates the effects of shifting wood between applications and the resulting substitution effects from a system perspective. A system dynamics model describes the wood utilization system of Austria, including the value chains from the forest to wood‐processing industries and the substitution that takes place in these industries. These value chains are associated with the global warming potential. Seven wood utilization scenarios shifting between material use and use for energy are simulated. The results show that wood shifts lead to both a substitution effect (emission reduction) in industries where wood utilization is increased and a counter effect (emission increase) where wood is replaced. The two effects potentially outweigh each other partly, leading to comparatively small net effects. However, carbon sequestration in HWPs and future changes in substitution effects might lead to additional effects. To substantially contribute to climate change mitigation, alternatives other than shifting wood between material and energy value chains need to be found within the wood utilization system.

Measuring the forest-based bioeconomy in Estonia, Latvia, Lithuania, and Finland

ABSTRACT This paper aims to present an input-output model of the forest-based bioeconomy, enabling insight into its contribution to total gross value added (GDP), employment, and CO2 emissions in Estonia, Latvia, Lithuania, and Finland. To quantify this contribution, the paper utilizes input-output tables of the four countries. The forest-based bioeconomy includes forestry, the processing of forestry products (forward linkages), and the direct and indirect use of inputs (backward linkages) from forestry and processing industries. Our analysis reveals that while forestry itself is a small industry, contributing minimally to GDP (ranging from 0.40% in Lithuania to 1.90% in Finland), and the forest-based bioeconomy is considerably larger. For instance, its contribution to GDP ranges from 3.59% in Lithuania to 7.22% in Estonia. Moreover, the forestry-based bioeconomy exhibits negative net CO2 emissions, primarily due to CO2 sequestration by forest lands and harvested wood products. Despite the substantial negative CO2 emissions associated with forestry activities, without sequestration, the forestry-based bioeconomy's share in total emissions ranges from 5.14% in Lithuania to 14.88% in Finland.

An alternative pathway to negative emissions – revitalising the wood-based panel production in Sweden

Among different possibilities to mitigate climate change, the utilisation of carbon sinks has rendered increased interest with the emergence of net-zero targets. In Sweden, despite large forest resources, the product category wood-based panels has turned from being a carbon sink to an emission source. Production data and the Intergovernmental Panel on Climate Change (IPCC) accounting approach has been used in this paper to construct the pool of biogenic carbon sequestered in wood-based panels. We used indices to compare this development and found that it is unparalleled in other countries. We show that it is possible to achieve an increased carbon sink in harvested wood products in Sweden and argue that all options producing real and quantifiable carbon sinks should be given opportunities in the regulatory frameworks for climate change mitigation. We conclude that the increased importance of carbon sinks to mitigate climate change justifies a critical discussion of bioenergy policy in Sweden and the rest of Europe. Additionally, we suggest a policy direction that will promote the cascading use of by-products for wood-based panels without proposing a mandated hierarchy of biomass use.

Amount of carbon fixed, transit time and fate of harvested wood products define the climate change mitigation potential of boreal forest management—A model analysis

Boreal forests are often managed to maximize wood production, but other goals, among which climate change mitigation, are increasingly important. Hence, it is necessary to examine synergies and trade-offs between forest production and its potential for carbon sequestration and climate change mitigation in forest stands. To this aim, we develop a novel mass-balanced process-based compartmental model that allows following the carbon path from its photosynthetic fixation until its return to the atmosphere by autotrophic or heterotrophic respiration, or by being burnt as wood product. Following carbon in the system allows to account for how long forest ecosystems and wood products retain carbon away from the atmosphere (i.e., the carbon transit time). As example, we apply the model to four management scenarios, i.e., mixed-aged pine, even-aged pine, even-aged spruce, and even-aged mixed forest, and contrast metrics of performance relative to wood production, carbon sequestration, and climate change mitigation potential. While at the end of an 80 yr rotation the even-aged forests held up to 31% more carbon than the mixed-aged forest, the mixed-aged forest was superior during almost the entire rotation when factoring in the carbon retention time away from the atmosphere, i.e., in terms of climate change mitigation potential. Importantly, scenarios that maximize production or amount of carbon stored in the ecosystems are not necessarily the most beneficial for carbon retention away from the atmosphere. These results underline the importance of considering carbon transit time when evaluating forest management options for potential climate change mitigation.

Projection of the Carbon Balance of the Hungarian Forestry and Wood Industry Sector Using the Forest Industry Carbon Model

As forest-based climate change mitigation has become a crucial element of international climate policy it is of increasing importance to understand the processes leading to the carbon offsetting capacity of the sector. In our study, we assessed the climate benefits of contrasting forest management strategies: decreasing harvest and enlarging the forest carbon stock, or increasing harvest to increase carbon uptake, wood product carbon pools, and substitution effects. We developed the Forest Industry Carbon Model (FICM) which is a new carbon accounting tool covering forest biomass, dead organic matter, soil, and harvested wood product pools, as well as avoided emissions through product and energy substitution. We modeled the carbon balance of the Hungarian forest industry under three different scenarios. In the business as usual (BAU) scenario, we assumed no changes in the current harvest and afforestation levels. In the extensification scenario, we assumed that the harvest and afforestation levels drop to half, while in the intensification scenario, we assumed an increase in afforestation, improved industrial wood assortments, and a gradual increase in logging, reaching the highest level as per sustainability criteria by 2050. Our results show that the intensification scenario is characterized by the largest net removals and the maximized product and energy substitution effects. By 2050, the net forest industry carbon balance reaches −8447 kt CO2 eq under the BAU scenario, while −7011 kt CO2 eq is reached under the extensification scenario and −22,135 kt CO2 eq is reached under the intensification scenario. Although substitution effects are not accounted for under the land-based (LULUCF) sector in the greenhouse gas inventory, the emission reductions in the industry and energy sectors have beneficial effects on the national carbon balance. Modeling results show that the 2030 LULUCF greenhouse gas removal target set by EU legislation for Hungary is reached under the intensification scenario. To achieve this outcome, widespread innovation is needed in the wood sector. The modeling results show that nonutilization of forests can only be a very short-term solution; however, its favorable effects will be reversed by 2050 resulting in additional emissions compared to the BAU scenario.

The potential use of mass timber in mid-to high-rise construction and the associated carbon benefits in the United States.

Nonresidential and mid- to high-rise multifamily residential structures in the United States currently use little wood per unit floor area installed, because earlier building codes lacked provisions for structural wood use in those types of buildings. However, revisions to the International Building Code allow for increased wood use in the form of mass timber, as structural and fire safety concerns have been addressed through new science-based design standards and through newly specified construction materials and measures. This study used multiple models to describe alternative futures for new construction, mass timber adoption rates, and the associated carbon benefits in higher than three-story buildings in the United States. The use of mass timber, in place of traditional constructions (i.e., structures dominated by concrete and steel), in projected new higher than three-story buildings was shown to provide combined carbon benefits (i.e., global warming mitigation benefits), including avoided embodied carbon emissions due to the substitution of non-wood alternatives and additional biogenic carbon storage in mass timber materials, of between 9.9 and 16.5 million t CO2e/yr spanning 50 years, 2020 to 2070. These carbon benefits equate to 12% to 20% of the total U.S. harvested wood products carbon storage for 2020. Future research is needed to understand how greater mass timber adoption leads to changes in forest product markets, land use, and total forest sector carbon.

Forest Carbon Modeling in Poplar and Black Locust Short Rotation Coppice Plantation in Hungary

Forest carbon dynamic modeling for estimating the carbon stock in short rotation coppice bioenergy plantation in Hungary will be vital for better comprehending the role of black locust (Robinia pseudoacacia) and poplar (Populus sp.) in carbon dioxide sequestration from the atmosphere. The research aims were to estimate the potential carbon stock and describe the carbon distribution of the short rotation coppice bioenergy plantation above and below ground. Various sources were used to acquire parameterization data for developing forest carbon dynamic models. CO2FIX modeling V.3.2 was utilized in the data analysis to estimate the total carbon stock in biomass, soil, harvested wood products, and bioenergy compartments. Modeling has been around for 45 years. In this research, the total carbon stock of black locust and poplar at the end of the simulation period was 64.13 and 131.08 MgC.ha-1, respectively. The average carbon allocation above and below ground for black locust and poplar was 0.76, 19.76, 1.80, and 21.67 MgC.ha-1, respectively. In conclusion, poplar outperformed black locust regarding carbon storage in the short rotation coppice bioenergy plantation. Below ground carbon allocation was much higher than above ground. Therefore, more attention should be paid on below ground allocation through environmentally friendly soil management. Keywords: bioenergy plantation, carbon dynamics, climate change mitigation, CO2FIX model, fast growing species

CLIMATE CHANGE MITIGATION THROUGH CARBON STORAGE AND PRODUCT SUBSTITUTION IN THE HUNGARIAN WOOD INDUSTRY

In our study we estimated under two different scenarios the historic and future carbon balance of the Hungarian harvested wood product (HWP) pool using the HWP-RIAL model. We also estimated the effect of product and energy substitution and the magnitude of avoided emissions based on international substitution factors. According to our results in the period 1985–2021 the average of the HWP net emissions plus substitution effects was -3,800 kt CO2. In this period the 49% of the forest industry-related climate benefits was attributable to carbon storage in forests, while 4% was attributable to carbon storage in wood products and 47% to product and energy substitution. According to our projection the HWP net emissions plus substitution effects could reach -14,994 kt CO2 up to 2050 under an intensified domestic wood processing industry. This means that product substitution benefits could be tripled, while the net removals of the HWP pool could be 5 times higher than the historic values.

Climate change substitution factors for Canadian forest-based products and bioenergy

Evaluating the climate change mitigation potential of the forest sector requires a holistic approach based on forest carbon (C) sequestration, C storage in harvested wood products (HWP) and substitution on markets. High uncertainty is associated with substitution factors, that express avoided fossil greenhouse gas (GHG) emissions from the use of forest-based products in replacement of GHG-intensive materials and fossil fuels. Few studies have focused on the development of substitution factors in Canada, resulting in the use of unrepresentative generic data. Here, we provide a framework to reduce uncertainties related to substitution factors for primary wood products in a Canadian context. A life cycle assessment framework is used to quantify fossil GHG emissions for a baseline and a wood-intensive scenario. For solid product substitution, we focused on the construction sector and analyzed a range of innovative wood buildings with steel and reinforced concrete as alternative materials. We found non-weighted averages of 0.80 tC/tC for sawnwood and 0.81 tC/tC for panels. For energy substitution, we analyzed cases with different specifications on biomass product, facility type and alternative fossil fuel source in non-residential heat production and biofuel transportation sectors. We found a non-weighted average of 0.80 tC/tC for non-residential heat production and 0.51 tC/tC for biofuel transportation, that can be interpreted as 0.91 tC/tC for heavy fuel oil, 0.69 tC/tC for light fuel oil and 0.68 tC/tC for natural gas substitution. These results provide a benchmark for substitution factors in Canada, to help guide forest management strategies for climate change mitigation.

Carbon fractions in wood for estimating embodied carbon in the built environment

Determining wood carbon (C) fractions (CFs)—or the concentration of elemental C in wood on a per unit mass basis—in harvested wood products (HWP) is vital for accurately accounting embodied C in the built environment. Most estimates of embodied C assume that all wood-based building material is comprised of 50 % C on a per mass basis: an erroneous assumption that emerges from the literature on tree- and forest-scale C estimation, which has been shown to lead to substantial errors in C accounting. Here, we use published wood CF data from live trees, alongside laboratory analyses of sawn lumber, to quantify generalizable wood CFs for HWPs. Wood CFs in lumber average 51.7 %, deviating significantly from a 50 % default wood CF, as well as from CFs in live wood globally (which average 47.6 % across all species, and 47.1 % in tree species not typically employed in construction). Additionally, the volatile CF in lumber—i.e., the quantity of C lost upon heating of wood samples, but often overlooked in C accounting—is lower than the volatile CF in live wood, but significantly >0 % suggesting that industrial lumber drying processes remove some, but not all, of volatile C-based compounds. Our results demonstrate that empirically-supported wood CFs for construction material can correct meaningful systematic biases when estimating C storage in the built environment.

Estimation of annual harvested wood products based on remote sensing and TPO survey data

ABSTRACT Accurate estimation of Timber Product Output (TPO) is important for carbon budget accounting, since wood products can act as delayed release carbon pools. However, the existing timber harvest data in the US relies on Forest Service’s TPO survey, and the survey does not happen every year. In this study, we proposed a methodological framework to produce annual TPO volume estimates for seven southeastern states (North Carolina, South Carolina, Alabama, Florida, Georgia, Mississippi, and Tennessee) of the US by integrating TPO survey data, Landsat Time Series Stacks (LTSS), and National Land Cover Database (NLCD). First, a forest disturbance product was derived based on Vegetation Change Tracker (VCT) algorithm using LTSS from 1985 to 2016. Then, by linking the predictor variables derived from the disturbance data and the TPO survey data, two regression algorithms were tested and compared, and Random Forest was selected to create TPO estimation models for different wood types. The results show that from 1986 to 2015, the region produced more than 5 × 109 m3 wood products, including 3.7 × 109 m3 softwood products and 1.6 × 109 m3 hardwood products. The derived TPO estimates had large spatial variations among the counties within each state as well as large temporal variations across the study period. The TPO data derived through this study can provide an observational basis for calculating the amount of C transferred from the standing biomass to the wood products through logging and for partitioning of harvested C among different wood product pools.

Evaluation of carbon emission reduction effect of Cryptomeria japonica stand management in Yamagata Prefecture, Japan

Planted forests are in the utilisation phase in Japan, contributing to the increased use of timber and the realisation of carbon neutrality. We simulated and compared the carbon emission reduction effects of three forest management scenarios, including a no final cutting scenario at two geographical scales, in the context of a privately owned Cryptomeria japonica planted forest in Tsuruoka City, Yamagata Prefecture, Japan. We adopted two substitution approaches: the status quo approach and the dynamic approach in line with Japan’s nationally determined contribution. We used hypothetical stands over three rotation periods of 150 years at the stand level, and a harvest schedule of 120 years at the regional level. The harvesting scenarios based on the status quo substitution approach reduced carbon emissions more than the no final cutting scenario for current wood usage at the study site, although those based on the dynamic substitution approach reduced carbon emissions as much as the no final cutting scenario during the first 30 years. Sustainable timber production from forests may reduce carbon emissions as much as unharvested forests until 2050, indicating that the substitution effects of harvested wood products could have a significant impact on the climate change mitigation effect arising from timber.

High emissions or carbon neutral? Inclusion of “anthropogenic” forest sinks leads to underreporting of forestry emissions

Recent research has shown forest-related emissions reported in national greenhouse gas inventories are much lower than global estimates from models summarized in Intergovernmental Panel on Climate Change reports. A substantial part of this discrepancy could be explained by conceptual differences in what is counted as part of the anthropogenic forest carbon sink and the way countries report on their forest harvesting sectors. With Canada as a case study, we used published National Inventory Report and Common Reporting Format tables to isolate emissions and removals directly associated with forestry from those associated with forests more broadly. Forestry-related factors that affect CO2 emissions and removals include tree harvesting, post-harvest forest regeneration and growth, and carbon storage in long-lived harvested wood products. We found that between 2005 and 2021, forestry in Canada represented a net source of carbon (annual mean = 90.8 Mt. CO2e), and that total area logged was a significant predictor of net forestry emissions. In contrast, Canada’s NIR reported a small net carbon sink during the same time period (annual mean = −4.7 Mt. CO2e). We show this discrepancy can be explained by Canada’s GHG reporting approach that claims GHG emissions from wildfires are natural, but GHG removals from forests at the age of commercial maturity, despite being primarily natural disturbance origin, are anthropogenic. This reporting approach may lead to climate mitigation policies that are ineffectual or detrimental to reducing net carbon in the global atmosphere.

Forest carbon stock development following extreme drought-induced dieback of coniferous stands in Central Europe: a CBM-CFS3 model application

BackgroundWe analyze the forest carbon stock development following the recent historically unprecedented dieback of coniferous stands in the Czech Republic. The drought-induced bark-beetle infestation resulted in record-high sanitary logging and total harvest more than doubled from the previous period. It turned Czech forestry from a long-term carbon sink offsetting about 6% of the country's greenhouse gas emissions since 1990 to a significant source of CO2 emissions in recent years (2018–2021). In 2020, the forestry sector contributed nearly 10% to the country's overall GHG emissions. Using the nationally calibrated Carbon Budget Model of the Canadian Forest Sector (CBM-CFS3) at a regional (NUTS3) spatial resolution, we analyzed four scenarios of forest carbon stock development until 2070. Two critical points arise: the short-term prognosis for reducing current emissions from forestry and the implementation of adaptive forest management focused on tree species change and sustained carbon accumulation.ResultsThis study used four different spruce forest dieback scenarios to assess the impact of adaptive forest management on the forest carbon stock change and CO2 emissions, tree species composition, harvest possibilities, and forest structure in response to the recent unprecedented calamitous dieback in the Czech Republic. The model analysis indicates that Czech forestry may stabilize by 2025 Subsequently, it may become a sustained sink of about 3 Mt CO2 eq./year (excluding the contribution of harvested wood products), while enhancing forest resilience by the gradual implementation of adaptation measures. The speed of adaptation is linked to harvest intensity and severity of the current calamity. Under the pessimistic Black scenario, the proportion of spruce stands declines from the current 43–20% by 2070, in favor of more suited tree species such as fir and broadleaves. These species would also constitute over 50% of the harvest potential, increasingly contributing to harvest levels like those generated by Czech forestry prior to the current calamity. The standing stock would only be recovered in 50 years under the optimistic Green scenario.ConclusionThe results show progress of adaptive management by implementing tree species change and quantify the expected harvest and mitigation potential in Czech forestry until 2070.