Landscape-scale variation in the structure and biomass of the hill dipterocarp forest of Sumatra: Implications for carbon stock assessments

One of the first steps in estimating the potential for reducing emissions from deforestation and forest degradation (REDD) initiatives is the proper estimation of the carbon components. There are still considerable uncertainties about carbon stocks in tropical rain forest, coming essentially from poor knowledge of the quantity and spatial distribution of forest biomass at the landscape level.     

Carbon sink by the forest sector—options and needs for implementation

The important role of forests in the carbon cycle suggests that the management of forests might be used to offset emissions. Newly developing markets will support these socially desirable ends only if a new specified policy framework is formulated and the landowners develop individually tailored projects. From the point of view of the developing countries, carbon-sink policy needs to be integrated in an overall policy against deforestation and forest degradation. Managing the risk of climatic change is an underestimated challenge for all branches of forest science and might bring dramatic changes to all stakeholders in the forest sector. Most worrisome is the current state of the quality of global forest information. But further uneasy scientific questions about forest carbon sinks remain open.     

Tropical forest fragmentation and greenhouse gas emissions

Rainforest fragments in central Amazonia have been found to experience a marked loss of above-ground biomass caused by sharply increased rates of tree mortality and damage near fragment margins. These findings suggest that fragmentation of tropical forests is likely to increase emissions of CO₂ and other greenhouse gases above and beyond that caused by deforestation per se. We estimated committed carbon emissions from deforestation and fragmentation in Amazonia, using three simulated models of landscape change: a ‘Rondônia scenario,' which mimicked settlement schemes of small farmers in the southern Amazon; a ‘Pará scenario,' which imitated large cattle ranches in the eastern Amazon; and a ‘random scenario,' in which forest tracts were cleared randomly. Estimates of carbon emissions for specific landscapes were from 0.3 to 42% too low, depending on the amount and spatial pattern of clearing, when based solely on deforestation. Because they created irregular habitat edges or many forest perforations which increased tree mortality, the Rondônia and random-clearing scenarios produced 2–5 times more fragmentation-induced carbon emissions than did the Pará scenario, for any given level of clearing. Using current estimates of forest conversion, our simulations suggest that committed carbon emissions from forest fragmentation alone will range from 3.0 to 15.6 million t/year in the Brazilian Amazon, and from 22 to 149 million t/year for tropical forests globally.     

A Small-Scale Forestry Perspective on Constraints to Including REDD in International Carbon Markets

In this article the authors contend that the constraints to including reduced emissions from avoided tropical forest deforestation and degradation in international carbon markets stem from problems associated with: (1) correctly measuring emissions savings from avoided tropical forest deforestation and degradation; (2) the permanence and ‘leakage’ of tropical forest conservation regimes; (3) ensuring economic incentives for the avoidance of tropical forest deforestation and degradation are sufficiently effective; (4) the exclusion of reduced emissions from avoided tropical forest deforestation and degradation from critical international climate change policy agreements; and (5) the behaviour of investors in carbon markets. Case analysis of the ‘Emissions Biodiversity Exchange Project for the 21st Century’ (EBEX21) program of Landcare Research New Zealand is used to examine how a government-supported market-based forest conservation initiative can be used to address these constraints, particularly in the context of small-scale forestry conservation.     

Past,present and future land-use in Xishuangbanna,China and the implications for carbon dynamics

Land use/land cover change is an important driver of global change and changes in carbon stocks. Estimating the changes in carbon stocks due to tropical deforestation has been difficult, mainly because of uncertainties in estimating deforestation rates and the biomass in the forest that have been cut. In this study, we combined detailed land-use change over a 27-year period based on satellite images and forest inventory data to estimate changes in biomass carbon stocks in the Xishuangbanna prefecture (1.9 million ha) of China. Xishuangbanna is located in southwestern China in the upper watershed of the Mekong River, and the major forest types are tropical seasonal rain forest, mountain rain forest, and subtropical evergreen broadleaf forest. In the past when the region was completely forested the total biomass carbon would have been approximately 212.65 ± 8.75 Tg C. By 1976 forest cover had been reduced to 70%, and in addition many forests had been degraded resulting in a large decrease in the total biomass carbon stocks (86.97 ± 3.70 Tg C). From 1976 to 2003, the mean deforestation rate was 13 722 ha year⁻¹ (1.12%), and this resulted in the loss of 370,494 ha of forest, and by 2003 total biomass carbon stocks had been reduced to 80.85 ± 2.64 Tg C. The annual carbon emissions due to land-use change, mainly forest conversion to agriculture and rubber plantations, were 0.37 ± 0.03 Tg C year⁻¹ between 1976 and 1988 and 0.13 ± 0.04 Tg C year⁻¹ between 1988 and 2003. During the next 20 years, if rubber plantations expand into forests outside of reserves, shrublands, grasslands, and shifting cultivation below 1500 m the total biomass carbon stocks of Xishuangbanna will decrease to 76.45 ± 1.49 Tg C in 2023. This would reflect a loss of 4.13 ± 1.14 Tg C between 2003 and 2023, or an annual loss of 0.21 ± 0.06 Tg C year⁻¹. Alternatively, if rubber plantations only expand into areas of shifting cultivation below 1500 m, and all areas presently in shrublands and grasslands are allowed to recover into secondary forests, total biomass carbon stock of the region would increase to 92.65 ± 3.80 Tg C in 2023. Under this scenario, the growth of existing forests and the expansion of new forests would result in a net sequestration of 0.60 ± 0.06 Tg C year⁻¹. This study demonstrates that the uncertainty of biomass estimates can be greatly reduced if detailed land-use analyses are combined with forest inventory data, and that slight changes in future land-use practices can have large implications for carbon fluxes.     

国外森林碳融资模式比较及其对我国的启示

林业在应对气候变化方面的作用和地位越来越为各国和国际社会所重视。与其他缓解气候变化的选择相比, 森林碳减排的成本相对较低。但是, 资金缺口目前已成为REDD和REDD+面临的主要挑战之一, 也成为各国政府、学术界和企业界共同关注的焦点。文中对国外森林碳融资模式进行归纳分析, 指出其发展趋势, 提出国外实践对我国发展森林碳融资的借鉴意义。     

木材合法性认证及其对中国木质林产品贸易的影响

木材非法采伐及其相关贸易是导致许多发展中国家毁林和森林退化的重要原因。森林破坏反过来导致约20%的全球碳排放。许多政府和私人部门以及国际社会纷纷采取措施确保木材的合法性。随之而来的木材合法性认证越来越普遍。文中概述木材合法性认证的概念及认证体系,归纳木材合法性认证的要点、局限性和启示,简要分析木材合法性认证对中国木质林产品贸易的影响。     

Preliminary estimation of carbon stock in a logging concession with a forest management plan in East Cameroon

ABSTRACT

Logging operations in Cameroon are based on the extraction of wood from natural forests. In this article, we assessed the carbon stock in a forest management unit (FMU) located in East Cameroon from field inventory to postfelling operations up to sawmill and export terminals. Tree basal area and aboveground biomass were calculated based on trees inventoried in the annual allowable cut. We observed that from an exploitable tree potential of 0.696 trees ha^?1 inventoried within a diameter range of 50–110 cm, 0.141 tree ha^?1 (i.e., 20% of the inventoried trees) were logged. In other words, out of 6.78 tC ha^?1 inventoried, 1.84 tC ha^?1 (i.e., 27% was logged), 1.62 tC ha^?1 arrived in the log yard and 1.3 tC ha^?1 arrived in sawmill, while 0.32 tC ha^?1 reached the export terminal. In terms of damages caused on vegetation, 4.45% of all the annual allowance cut (AAC) were affected during logging activities, this represents almost 33,188.07 tons of carbon. These findings show that the implementation of reduced-impact logging (RIL) could reduce these losses throughout the logging steps and help propose a process for the valuation of wood waste in the forest and sawmill. In this context, reducing emissions from deforestation and degradation will be engaged with the right approach.     

森林采运作业过程碳排放分析

合理的森林采伐能开发利用森林资源,促进林木生长,但盲目采伐会导致生态环境的破坏。以生命周期评价法的B2B（business-to-business）模式为基础,采用过程分析法,核算森林采运过程各阶段的温室气体排放量。结果表明：采运过程中产生的碳排放约为7.530 6~11.659 8 kg/m3,约占其固碳能力的2.2%~5.7%;燃油消耗是最主要的碳排放源,CO2是其排放的最主要温室气体,碳排放量与集运材距离呈正相关;采伐段碳排放最少,仅0.573 6 kg/m3,索道集材、拖拉机集材排放分别是采伐段的1.04、1.72倍,运材段产生的排放量最多,当运材距离为40 km时,汽车运材和农用车运材排放量分别是采伐段的11.1和17.6倍;油锯采伐＋索道集材＋汽车运材为最优作业模式。研究结果可为森工作业的减排提供理论参考。     

Assessment of Carbon Balance in Community Forests in Dolakha, Nepal

This study assessed the net above-ground carbon stock in six community forests in the Dolakha district, Nepal. A survey was conducted of above-ground timber species, using random sampling. A tree-ring chronology for Pinus roxburghii was created to construct a growth model representative of the various mainly-pine species. The allometric model combined with tree ring analysis was used to estimate carbon stock and annual growth in the above-ground tree biomass. The out-take of forest biomass for construction material and fuelwood was estimated on the basis of interviews and official records of community forest user groups. The average annual carbon increment of the community forests was 2.19 ton/ha, and the average annual carbon out-take of timber and fuelwood was 0.25 ton/ha. The net average carbon balance of 1.94 ton/ha was equivalent to 117.44 tons of carbon per community forest annually. All the community forests were actively managed leading to a sustainable forest institution, which acts as a carbon sink. It is concluded that community forests have the potential to reduce emissions by avoiding deforestation and forest degradation, enhance forest carbon sink and improve livelihoods for local communities.     

Biomass and greenhouse-gas emissions from land-use change in Brazil's Amazonian “arc of deforestation”: The states of Mato Grosso and Rondônia

We calculate greenhouse-gas emissions from land-use change in Mato Grosso and Rondônia, two states that are responsible for more than half of the deforestation in Brazilian Amazonia. In addition to deforestation (clearing of forest), we also estimate clearing rates and emissions for savannas (especially the cerrado, or central Brazilian savanna), which have not been included in Brazil's monitoring of deforestation. The rate of clearing of savannas was much more rapid in the 1980s and 1990s than in recent years. Over the 2006–2007 period (one year) 204 × 10³ ha of forest and 30 × 10³ ha of savanna were cleared in Mato Grosso, representing a gross loss of biomass carbon (above + belowground) of 66.0 and 1.8 × 10⁶ MgC, respectively. In the same year in Rondônia, 130 × 10³ ha of forest was cleared, representing gross losses of biomass of 40.4 × 10⁶ MgC. Data on clearing of savanna in Rondônia are unavailable, but the rate is believed to be small in the year in question. Net losses of carbon stock for Mato Grosso forest, Mato Grosso savanna and Rondônia forest were 29.0, 0.5 and 18.5 × 10⁶ MgC, respectively. Including soil carbon loss and the effects of trace-gas emissions (using global warming potentials for CH₄ and N₂O from the IPCC's 2007 Fourth Assessment Report), the impact of these emission sources totaled 30.9, 0.6 and 25.4 × 10⁶ Mg CO₂-equivalent C, respectively. These impacts approximate the combined effect of logging and clearing because the forest biomasses used are based on surveys conducted before many forests were exposed to logging. The total emission from Mato Grosso and Rondônia of 56.9 × 10⁶ Mg CO₂-equivalent C can be compared with Brazil's annual emission of approximately 80 × 10⁶ MgC from fossil–fuel combustion.     

Carbon uptake by secondary forests in Brazilian Amazonia

Estimating the contribution of deforestation to greenhouse gas emissions requires calculations of the uptake of carbon by the vegetation that replaces the forest, as well as the emissions from burning and decay of forest biomass and from altered emissions and uptakes by the soil. The role of regeneration in offsetting emissions from deforestation in the Brazilian Legal Amazon has sometimes been exaggerated. Unlike many other tropical areas, cattle pasture (rather than shifting cultivation) usually replaces forest in Brazilian Amazonia. Degraded cattle pastures regenerate secondary forests more slowly than do fallows in shifting cultivation systems, leading to lower uptake of carbon. The calculations presented here indicate that in 1990 the 410 × 10³ km² deforested landscape was taking up 29 × 10⁶ t of carbon (C) annually (0.7 t C ha⁻¹ year⁻¹). This does not include the emissions from clearing of secondary forests, which in 1990 released an estimated 27 × 10⁶ t C, almost completely offsetting the uptake from the landscape. Were the present land-use change processes to continue, carbon uptake would rise to 365 × 10⁶ t annually (0.9 t C ha⁻¹ year⁻¹) in 2090 in the 3.9 × 10⁶ km⁶ area that would have been deforested by that year. The 1990 rate of emissions from deforestation in the region greatly exceeded the uptake from regrowth of replacement vegetation.     

Using indicators of deforestation and land-use dynamics to support conservation strategies: A case study of central Rondônia,Brazil

In Rondônia State, Brazil, settlement processes have cleared 68,000 km² of tropical forests since the 1970s. The intensity of deforestation has differed by region depending on driving factors like roads and economic activities. Different histories of land-use activities and rates of change have resulted in mosaics of forest patches embedded in an agricultural matrix. Yet, most assessments of deforestation and its effects on vegetation, soil and water typically focus on landscape patterns of current conditions, yet historical deforestation dynamics can influence current conditions strongly. Here, we develop and describe the use of four land-use dynamic indicators to capture historical land-use changes of catchments and to measure the rate of deforestation (annual deforestation rate), forest regeneration level (secondary forest mean proportion), time since disturbance (mean time since deforestation) and deforestation profile (deforestation profile curvature). We used the proposed indices to analyze a watershed located in central Rondônia. Landsat TM and ETM+ images were used to produce historical land-use maps of the last 18 years, each even year from 1984 to 2002 for 20 catchments. We found that the land-use dynamics indicators are able to distinguish catchments with different land-use change profiles. Four categories of historical land-use were identified: old and dominant pasture cover on small properties, recent deforestation and dominance of secondary growth, old extensive pastures and large forest remnants and, recent deforestation, pasture and large forest remnants. Knowing historical deforestation processes is important to develop appropriate conservation strategies and define priorities and actions for conserving forests currently under deforestation.     

Estimation of aboveground tree carbon stock using SPOT-HRG data (a case study: Darabkola forests)

Forests are among the most important carbon sinks on earth. However, their complex structure and vast areas preclude accurate estimation of forest carbon stocks. Data sets from forest monitoring using advanced satellite imagery are now used in international policy agreements. Data sets enable tracking of emissions of CO₂ into the atmosphere caused by deforestation and other types of land-use changes. The aim of this study is to determine the capability of SPOT-HRG Satellite data to estimate aboveground carbon stock in a district of Darabkola research and training forest, Iran. Preprocessing to eliminate or reduce geometric error and atmospheric error were performed on the images. Using cluster sampling, 165 sample plots were taken. Of 165 plots, 81 were in natural habitats, and 84 were in forest plantations. Following the collection of ground data, biomass and carbon stocks were quantified for the sample plots on a per hectare basis. Nonparametric regression models such as support vector regression were used for modeling purposes with different kernels including linear, sigmoid, polynomial, and radial basis function. The results showed that a third-degree polynomial was the best model for the entire studied areas having an root mean square error, bias and accuracy, respectively, of 38.41, 5.31, and 62.2; 42.77, 16.58, and 57.3% for the best polynomial for natural forest; and 44.71, 2.31, and 64.3% for afforestation. Overall, these results indicate that SPOT-HRG satellite data and support vector machines are useful for estimating aboveground carbon stock.     

Estimating the biomass and carbon pool of stump systems at a national scale

Countries that are signatories to the UNFCCC and its supplementary Kyoto Protocol are obliged to report changes in carbon pools. These should include the pool of carbon held in tree stumps and roots but, to date, few countries have been able to report this or separate it from the dead-wood pool. The aim of this study was to develop a general system for estimating and monitoring changes in stump system carbon using data from a traditional National Forest Inventory. The system was derived using data based on measurements of carbon (biomass) in inventoried permanent sample plots representing all relevant classes of land-use. With this design it was possible to trace matched carbon at the level of individual trees or stumps back to land-use prior to the 1990 baseline year. Between 1990 and 2003 in Sweden, the average annual net sink of stump systems was estimated to amount to 6.7 Mt CO₂ equiv. year⁻¹ – comparable to the reported net sink in 2008 of about 15 Mt CO₂ equiv. year⁻¹ from the whole Land Use, Land-Use Change and Forestry sector, which excluded any carbon in stump systems. In 2003 the carbon stock of stumps and roots was estimated at 495 Mt CO₂ equiv.; approximately five times that of the dead-wood pool as defined in Sweden, i.e. dead wood that mainly consists of boles. The Intergovernmental Panel on Climate Change requests that reported carbon should be matched to land-use and traced back to the 1990 base year; however, the present study confirms expectations that most carbon in stumps and roots is found on Forest land. The minimum requirements for estimating the carbon pool in stump systems at a national scale using the proposed methodology are that there should be: (i) a consistent time-series of harvest data, usually estimated as merchantable volume; (ii) conversion factors from merchantable volume to stump system biomass at death; and (iii) a representative decomposition model.     

REDD+机制各缔约方观点总结分析及我国对策建议

减少发展中国家毁林及森林退化引起的温室气体排放, 森林保护、可持续森林管理和增加森林碳储量(REDD+)在减缓气候变化行动中的作用越来越明显, 已经成为《联合国气候变化框架公约》谈判的重要议题。近年来各缔约方针对方法学、融资机制和REDD+与清洁发展机制(CDM)关系的谈判争论越来越激烈。在《联合国气候变化框架公约》第18次缔约方会议(COP18)期间, 对REDD+议题提出了新的要求, 除了有关于逐步建立国家水平森林参考排放水平或参考水平等有关方法学的技术与科学问题外, 基金在融资机制中的作用和非碳效益支付议题也有待进行深入的磋商。文中基于对各缔约方提案的分析结果和REDD+示范项目开展情况, 结合我国森林资源现状, 分析了REDD+机制对我国可能产生的影响并提出后续谈判期的对策建议。     

Deforestation in the southern Yucatán peninsular region: an integrative approach

The tensions between development and preservation of tropical forests heighten the need for integrated assessments of deforestation processes and for models that address the fine-tuned location of change. As Mexico’s last tropical forest frontier, the southern Yucatán peninsular region witnesses these tensions, giving rise to a “hot spot” of tropical deforestation. These forests register the imprint of ancient Maya uses and selective logging in the recent past, but significant modern conversion of them for agriculture began in the 1960s. Subsequently, as much as 10% of the region’s forests have been disturbed anthropogenically. The precise rates of conversion and length of successional growth in both upland and wetland forests are tied to policy and political economic conditions. Pressures on upland forests are exacerbated by the development of infrastructure for El Mundo Maya, an archaeological and ecological activity predicated on forest maintenance, and by increased subsistence and market cultivation, including lands on the edge of Mexico’s largest tropical forest biosphere reserve. In this complex setting, the southern Yucatán peninsular region project seeks to unite research in the ecological, social, and remote sensing sciences to provide a firm understanding of the dynamics of deforestation and to work towards spatially explicit assessments and models that can be used to monitor and project forest change under different assumptions.     

Effects of legal regulations on land use change: 2/B applications in Turkish forest law

For the countries struggling with climate change, sustainable forestry is one of the greatest challenges and is difficult to define, implement, and to measure. According to the scientific community’s consensus on climate change, forests are one of the major sinks and sustainable forest management (SFM) is needed to prevent deforestation and its negative effects on natural ecosystems. Despite being a party to many international treaties/agreements related to land use policies (LUP) that are promoting SFM to protect and develop forest resources, the 2/B application in Turkish forest legislation has been causing deforestation in Turkey since the 1970s.

In this study, 2/B applications–political and legal process–causing deforestation by land use change (LUC) are investigated by carrying out a legal analysis. About 500.000 ha of forests have been lost due to the 2/B application and as a LUP directly affects SFM, carbon sequestration capacities (CSC), and therefore, climate change. To exemplify this pre and post-LUC change and effect, the amount of carbon that was prevented from being absorbed as 176,7 tonnes/ha on average in a given forest area for the year 2016. There is a vital need to address the negative effects of ill-defined forest legislation to achieve SFM.     

Estimating annual GPP,NPP and stem growth in Finland using summary models

In this study we introduce and test a new simple approach for estimating annual stand-level gross primary production (GPP), net primary production (NPP) and stem biomass growth based on carbon acquisition and allocation, by combining existing summary models. The focus is on the variation of GPP and NPP across different parts of Finland caused by climate.     

Emission Removal Capability of India’s Forest and Tree Cover

India is the world’s tenth most forested nation with 76.87 M ha of forest and tree cover occupying 23.4% of its geographical area. Forests—with their intrinsic of carbon sequestration and storage values—are in the front line of India’s climate change mitigation strategies. This paper provides estimates of sequestered carbon in India’s forest and tree cover for the years 1995 and 2005 as per the IPCC good practice guidelines method. It is based on the primary data for the soil carbon pool through collecting soil samples by laying out quadrats across the country and secondary data for the growing stock of all forest and tree cover in the country. The estimates are compared with current and future projected emissions. It is found that conservation policies have resulted in increase of the country’s forest carbon stocks from 6244.8 to 6621.6 Mt with an annual increment of 37.7 Mt of the carbon from 1995 to 2005. Annual CO₂ removal by the forests is enough to neutralise 9.3% of the country’s 2000 level emissions. Continued removals by the forest and tree cover would offset 6.5 and 4.9% of India’s projected annual emissions in 2010 and 2020 respectively. Economically, the annual value of this forest carbon in the international market is about US $188 million. The result is of use in the REDD and REDD+ context for India.