Forestry-based carbon sequestration projects demand a comprehensive quantification of the different climate change mitigation effects. In our study, we modeled a life cycle of managed pure stands consisting of the four main tree species in Bavaria (spruce, pine, beech and oak). For spruce and beech, an unmanaged stand was additionally integrated in order to analyze the differences in climate change mitigation effects compared to the managed stands. We developed a climate change mitigation model, where stand development and silvicultural treatments including harvested timber volumes were conducted using the tree growth model Silva 2.3. The harvested wood products (HWP), including their substitution effects were calculated with a subsequent model. For unmanaged beech forests, we compiled measured data from the literature, and Bavarian strict forest reserves for validating our model results. The results for the managed stands reveal that spruce provides the highest total climate change mitigation effects. After a simulation period of 180 years, one hectare leads to a mean mitigation benefit of 13.5 Mg CO₂ ha⁻¹ year⁻¹. In comparison, results for pine, beech and oak reveal lesser benefits with 10.1 Mg CO₂ ha⁻¹ year⁻¹, 9.1 Mg CO₂ ha⁻¹ year⁻¹ and 7.2 Mg CO₂ ha⁻¹ year⁻¹, respectively. However, these results assume current growing conditions. Considering climate change, it is very likely that spruce will not be suitable in several regions of Bavaria in the future. Furthermore, excessive disturbances could affect spruce more drastically than the other tree species. In that case, the order could change and beech could exceed spruce. Thus the results cannot be seen as a general recommendation to establish spruce stands in order to achieve optimal climate change mitigation benefits. Nevertheless, results for spruce illustrate that high increment and especially wood use in long-lived products is crucial for high climate change mitigation effects. Mitigation effects in unmanaged spruce and beech stands do not differ in the first decades from their managed counterparts, but are below them in the long term with a total climate change mitigation benefit of 8.0 Mg CO₂ ha⁻¹ year⁻¹ and 7.2 Mg CO₂ ha⁻¹ year⁻¹, respectively. These differences are mainly caused by the missing substitution effects in the unmanaged stands. However, the precise dimensions of substitution effects still remain uncertain and the lack of data should be reduced via additional life cycle assessments for more products and product classes. However, neglecting substitution effects in climate change mitigation models leads to severe underestimations of the mitigation effects in managed forests. Full article

We perform simulations using the integrated Land Use in Rural New Zealand (LURNZ) model to analyze the effect of various New Zealand emissions trading scheme (ETS) scenarios on land use, emissions and output in a temporally and spatially explicit manner. We compare the impact of afforestation to the impact of other land-use change on net greenhouse gas emissions and evaluate the importance of the forestry component of the ETS relative to the agricultural component. We find that the effect of including agriculture in the ETS is small relative to the effect of including forestry. We also examine the effect of land-use change on the time profile of net emissions from the forestry sector. Finally, we present projections of future agricultural output under various policy scenarios. Full article

To quantify the climate change impacts of forestry and forest management options, we must consider the entire forestry system: the carbon dynamics of the forest, the life cycle of harvested wood products, and the substitution benefit of using biomass and wood products compared to more greenhouse gas intensive options. This paper presents modelled estimates of the greenhouse gas balance of two key native forest areas managed for production in New South Wales for a period of 200 years, and compares it to the option of managing for conservation only. These two case studies show that forests managed for production provide the greatest ongoing greenhouse gas benefits, with long-term carbon storage in products, and product substitution benefits critical to the outcome. Thus native forests could play a significant part in climate change mitigation, particularly when sustainably managed for production of wood and non-wood products including biomass for bioenergy. The potential role of production forestry in mitigating climate change, though substantial, has been largely overlooked in recent Australian climate change policy. Full article

Reducing emissions from agriculture, forestry, and other land uses is considered an essential ingredient of an effective strategy to mitigate global warming. Required changes in land use and forestry, however, often imply foregoing returns from locally more attractive resource use strategies. We assess and compare the prospects of mitigating climate change through emission reductions from forestry and agriculture in the Brazilian Amazon. We use official statistics, literature, and case study material from both old and new colonization frontiers to identify the scope for emission reductions, in terms of potential additionality, opportunity costs, technological complexity, transaction costs, and risks of economic and environmental spillover effects. Our findings point to a comparative advantage in the Brazilian Amazon of forest conservation-based over land-use modifying mitigation options, especially in terms of higher potential additionality in emission reductions. Low-cost mitigation options do exist also in use-modifying agriculture and forestry, but tend to be technologically complex thus requiring more costly intervention schemes. Our review points to a series of regional development deficits that may come to hamper attempts to tap into the large-scale climate change mitigation potential often associated with the Amazon. Low-hanging fruits for mitigation do exist, but must be carefully identified based on the performance indicators we discuss. Full article

Forest carbon stocks—both in terms of the standing biomass and the soil organic carbon (OC)—were monitored in the mangrove plantation reforested from an abandoned shrimp pond for the 10 years following land excavation. Excavation to a level of 25 cm below the existing ground level increased the inundation time of tidal water from 463 to 7,597 hours per year, resulting in a significant increase of survival/growth rates for planted mangrove species, Rhizophora mucronata (RM) and Bruguiera cylindrica (BC), and of carbon stocks as well. RM showed high rates of standing biomass accumulation with 98.7 ton/ha while 28.8 ton/ha for BC was measured over 10 years in the excavated area. In contrast, the unexcavated area showed low rates of biomass accumulation, 1.04 ton/ha for RM and 0.53 ton/ha for BC in the same period. The excavated area recorded a twofold increase of soil OC in the upper 5 cm of the surface soil from 71.8 to 154.8 ton/ha in 10 years, however it decreased to 68.3 ton/ha in the unexcavated area where soil OC is susceptible to decomposition. These results imply that the potential of carbon sinks in reforested land from abandoned areas cannot be developed unless hydraulic conditions are properly recovered. The fast growing species Avicennia marina (AM) grew quickly for the first two years after colonization but its growth slowed down afterwards, showing a limited ability of carbon capture. Full article

As part of its efforts to curb greenhouse gas emissions, China has committed to expanding the country’s forest area by 40 million hectares and stocking volume by 1.3 billion m³ from 2006 to 2020. Our analysis suggests that it is very likely that China will realize its goal of forest area expansion; but the target of volume increase represents only a modest gain, which may absorb about 2% of its cumulative carbon emissions. However, China’s forests can be a much more significant carbon sequester and ecosystem services provider if its forest growth rate and stocking level are boosted by improving forest quality and productivity. To that end, however, the silvicultural practices and governance structure must be transformed. Full article

Enhancement of forest growth through silvicultural modification of stand density is one strategy for increasing carbon (C) sequestration. Using the Fire and Fuels Extension of the Forest Vegetation Simulator, the effects of even-aged, uneven-aged and no-action management scenarios on C sequestration in a southern Appalachian red spruce-Fraser fir forest were modeled. We explicitly considered C stored in standing forest stocks and the fate of forest products derived from harvesting. Over a 100-year simulation period the even-aged scenario (250 Mg C ha⁻¹) outperformed the no-action scenario (241 Mg C ha⁻¹) in total carbon (TC) sequestered. The uneven-aged scenario approached 220 Mg C ha⁻¹, but did not outperform the no-action scenario within the simulation period. While the average annual change in C (AAC) of the no-action scenario approached zero, or carbon neutral, during the simulation, both the even-aged and uneven-aged scenarios surpassed the no-action by year 30 and maintained positive AAC throughout the 100-year simulation. This study demonstrates that silvicultural treatment of forest stands can increase potential C storage, but that careful consideration of: (1) accounting method (i.e., TC versus AAC); (2) fate of harvested products and; (3) length of the planning horizon (e.g., 100 years) will strongly influence the evaluation of C sequestration. Full article

The documented role of United States forests in sequestering carbon, the relatively low cost of forest-based mitigation, and the many co-benefits of increasing forest carbon stocks all contribute to the ongoing trend in the establishment of forest-based carbon offset projects. We present a broad analysis of forest inventory data using site quality indicators to provide guidance to managers planning land acquisition for forest-based greenhouse gas mitigation projects. Specifically, we summarize two condition class indicators of site productivity within the FIA forest inventory database—physclcd and siteclcd—as they relate to current aboveground live tree carbon stocks. Average carbon density is higher on more productive sites, but compared to the overall variability among sites, the differences are relatively small for all but the highest and lowest site classes. Some minor differences in eastern- versus western-forests were apparent in terms of how carbon on the least productive sites differed from most other forest land over time. Overall results suggest that xeric sites in most regions as well as sites that correspond to the lowest, non-productive classifications of forest land should preferentially not be used forestry-based greenhouse gas mitigation projects, but all other forest areas appear to be suitable. Full article

A recent policy response to halting global forest deforestation and degradation, and any resulting greenhouse gas emissions is REDD+, which also includes the role of conservation, sustainable management of forests and enhancement of forest carbon stocks. Although still in its infancy, the success of REDD+ will depend significantly on whether it can be economically viable and if any resulting payments are sufficient to cover the opportunity cost plus any transaction cost. Where tenure security over forest is weak, REDD+ can pose a risk for forest communities, who could be dispossessed, excluded and marginalized. This review of existing studies explores how payment for avoided deforestation, and forest tenure impact the success of REDD+ projects in terms of effectiveness, efficiency and equity. Effectiveness refers to the difference between deforestation with and without REDD+, efficiency refers to avoiding deforestation at minimal cost, and equity refers to the implication of REDD+ on benefit sharing. We conclude that the potential success or failure of REDD+ as a means to reduce deforestation and carbon emission on forest commons depends critically on designing projects that work within existing informal tenure institutions to ensure that carbon storage benefits align with livelihood benefits. Full article

Eastern forests of the US are valued both as a carbon sink and a wood resource. The amount of biomass that can be harvested sustainably from this biome for bioenergy without compromising the carbon sink is uncertain. Using past literature and previously validated models, we assessed four scenarios of biomass harvest in the eastern US: partial harvests of mixed hardwood forests, pine plantation management, short-rotation woody cropping systems, and forest residue removal. We also estimated the amount and location of abandoned agricultural lands in the eastern US that could be used for biomass production. Greater carbon storage was estimated to result from partial harvests and residue removals than from plantation management and short-rotation cropping. If woody feedstocks were cultivated with a combination of intensive management on abandoned lands and partial harvests of standing forest, we estimate that roughly 176 Tg biomass y⁻¹ (~330,000 GWh or ~16 billion gallons of ethanol) could be produced sustainably from the temperate forest biome of the eastern US. This biomass could offset up to ~63 Tg C y⁻¹ that are emitted from fossil fuels used for heat and power generation while maintaining a terrestrial C sink of ~8 Tg C y⁻¹. Full article

Assessing the potential for forest carbon (C) capture and storage requires accurate assessments of C in live tree tissues. In the vast majority of local, regional, and global assessments, C content has been assumed to be 50% of tree biomass; however, recent studies indicate that this assumption is not accurate, with substantial variation in C content among tree species as well as among tissue types. Here we conduct a comprehensive literature review to present a global synthesis of C content in tissues of live trees. We found a total of 253 species-specific stem wood C content records in 31 studies, and an additional 34 records of species with C content values of other tissues in addition to stem wood. In all biomes, wood C content varied widely across species ranging from 41.9–51.6% in tropical species, 45.7–60.7% in subtropical/Mediterranean species, and 43.4–55.6% in temperate/boreal species. Stem wood C content varied significantly as a function of biome and species type (conifer, angiosperm). Conifer species exhibited greater wood C content than angiosperm species (50.8 ± 0.7% (95% C.I.) and 47.7 ± 0.3%, respectively), a trend that was consistent among all biomes. Although studies have documented differences in C content among plant tissues, interspecific differences in stem wood appear to be of greater importance overall: among species, stem wood C content explained 37, 76, 48, 81, and 63% respectively of the variation in bark, branch, twig, coarse root, and fine root C content values, respectively. In each case, these intraspecific patterns approximated 1:1 linear relationships. Most published stem wood C content values (and all values for other tree tissues) are based on dried wood samples, and so neglect volatile C constituents that constitute on average 1.3–2.5% of total C in live wood. Capturing this volatile C fraction is an important methodological consideration for future studies. Our review, and associated data compilation, provides empirically supported wood C fractions that can be easily incorporated into forest C accounting, and may correct systematic errors of ~1.6–5.8% in forest C assessments. Full article