The potential of cropland soil carbon sequestration in the Loess Plateau, China

It is generally accepted that cropland soils could be managed to store significant carbon (C), however little information is available regarding the cropland soil C sequestration potential of the Loess Plateau in northern China. This study aimed to estimate the cropland soil C sequestration potential in this area using the United Nations Intergovernmental Panel on Climate Change (IPCC) method with region-specific C stock change factors. The results show that the C sequestration potential can reach 6.054 Tg C yr^?1 (1Tg?=?10¹² g) in cropland soils of the Loess Plateau using techniques that are currently available (no-tillage and high residue incorporation). Although the results show a high degree of uncertainty in this estimate with 95 % confidence interval ranges from 2.623 to 11.94 Tg C yr^?1, our study suggests that cropland soil C sequestration could play a meaningful role in helping to mitigate greenhouse gas increases in the Chinese Loess Plateau.     

Forest land use change in the philippines and climate change mitigation

Tropical forests in countries like thePhilippines are important sources and sinks of carbon(C). The paper analyzes the contribution of Philippineforests in climate change mitigation. Since the 1500s,deforestation of 20.9 M ha (10⁶ ha) of Philippineforests contributed 3.7 Pg (10¹⁵ g) of C to theatmosphere of which 2.6 Pg were released this century. At present, forest land uses store 1091 Tg(10¹² g) of C and sequester 30.5 Tg C/yr whilereleasing 11.4 Tg C/yr through deforestation andharvesting. In the year 2015, it is expected that thetotal C storage will decline by 8% (1005 Tg) andtotal rate of C sequestration will increase by 17%(35.5 Tg/yr). This trend is due to the decline innatural forest area accompanied by an increase intree plantation area. We have shown that uncertaintyin national C estimates still exists because they arereadily affected by the source of biomass and Cdensity data. Philippine forests can act as C sink by:conserving existing C sinks, expanding C stocks, andsubstituting wood products for fossil fuels. Here weanalyze the possible implications of the provisions ofthe Kyoto Protocol to Philippine forests. Finally, wepresent current research and development efforts ontropical forests and climate change in the Philippinesto improve assessments of their role in the nations Cbudgets.     

基于InVEST模型的北京山区森林生态系统碳储量评估分析

本文基于北京山区遥感影像数据和标准样地调查数据,利用In VEST模型碳储量模块,评估分析了北京山区森林生态系统的碳储量。结果表明,北京山区森林生态系统的平均碳密度为99. 95 Mg/hm~2,其中乔木层、灌木层、草本层、凋落物层和土壤层平均碳密度分别为10. 51、3. 16、0. 86、8. 61、76. 81 Mg/hm~2。植被碳密度与土壤碳密度呈现显著正相关关系,土壤碳密度与凋落物碳密度呈现显著正相关关系。各林分类型平均碳密度表现为落叶针叶林(153. 99 Mg/hm~2)针阔混交林(132. 45Mg/hm~2)落叶阔叶林(125. 10 Mg/hm~2)常绿针叶林(111. 78 Mg/hm~2)灌木林(72. 26 Mg/hm~2)。北京山区森林生态系统总碳储量为77. 41 Tg,其中乔木层、灌木层、草本层、凋落物层和土壤层的碳储量分别为8. 14、2. 45、0. 67、6. 67、59. 48 Tg。各林分类型总碳储量表现为落叶阔叶林(43. 23 Tg)灌木林(25. 90 Tg)常绿针叶林(6. 21 Tg)针阔混交林(1. 42 Tg)落叶针叶林(0. 65 Tg)。落叶阔叶林和灌木林是北京山区森林生态系统碳储量的主要贡献者,分别占55. 84%和33. 46%。在北京山区各个区县中,怀柔区碳储量最高(15. 37 Tg),平谷区碳储量最低(4. 89 Tg)。北京山区森林生态系统碳储量分布不均,总体表现为北京山区北部区县较高,西部区县偏低,中部和东部最低。     

Trees as carbon sinks and sources in the European Union

The carbon (C) sinks and sources of trees that may be accounted for under Article 3.3 of the Kyoto Protocol during the first commitment period from 2008 to 2012 were estimated for the countries of the European Union (EU) based on existing forest inventory data. Two sets of definitions for the accounted activities, afforestation, reforestation and deforestation, were applied. Applying the definitions by the Food and Agricultural Organization of the United Nations (FAO), the trees were estimated to be a C source in eight and a C sink in seven countries, and in the whole EU a C source of 5.4 Tg year⁻¹. Applying the definitions by the Intergovernmental Panel of Climate Change (IPCC), the trees were estimated to be a C source in three and a C sink in 12 countries, and in the whole EU a C sink of 0.1 Tg year⁻¹. These estimates are small compared with the C sink of trees in all EU forests, 63 Tg year⁻¹, the anthropogenic CO₂ emissions of the EU, 880 Tg C year⁻¹, and the reduction target of the CO₂ emissions, 8%. In individual countries, the estimated C sink of the trees accounted for under Article 3.3 was at largest 8% and the C source 12% compared with the CO₂ emissions.     

Baseline Carbon Stocks Assessment and Projection of Future Carbon Benefits of a Carbon Sequestration Project in East Timor

Climate change is one of the most pressing environmental problems humanity is facing today. Forest ecosystems serve as a source or sink of greenhouse gases, primarily CO₂. With support from the Canadian Climate Change Fund, the Community-based Natural Resource Management for Carbon Sequestration project in East Timor (CBNRM-ET) was implemented to “maintain carbon (C) stocks and increase C sequestration through the development of community-based resource management systems that will simultaneously improve livelihood security”. Project sites were in the Laclubar and Remexio Sub-districts of the Laclo watershed. The objective of this study was to quantify baseline C stocks and sequestration benefits of project components (reforestation with fast-growing species, primarily Casuarina equisetifolia, and agroforestry involving integration of Paraserianthes falcataria). Field measurements show that mature stands (≥30 years) of P. falcataria and C. equisetifolia contain up to 200 Mg C ha⁻¹ in above ground biomass, indicating the vast potential of project sites to sequester carbon. Baseline C stocks in above ground biomass were very low in both Laclubar (6.2 Mg C ha⁻¹ for reforestation sites and 5.2 Mg C ha⁻¹ for agroforestry sites and Remexio (3.0 Mg C ha⁻¹ for reforestation and 2.5 Mg C ha⁻¹ for agroforestry). Baseline soil organic C levels were much higher reaching up to 160 Mg C ha⁻¹ in Laclubar and 70 Mg C ha⁻¹ in Remexio. For the next 25 years, it is projected that 137 671 Mg C and 84 621 Mg C will be sequestered under high- and low C stock scenarios, respectively.     

Estimating net primary production and annual plant carbon inputs, and modelling future changes in soil carbon stocks in arable farmlands of northern Japan

Soil C sequestration in croplands is deemed to be one of the most promising greenhouse gas mitigation options for Japan's agriculture. In this context, changes in soil C stocks in northern Japan's arable farming area over the period of 1971-2010, specifically in the region's typical Andosol (volcanic ash-derived) and non-Andosol soils, were simulated using soil-type-specific versions of the Rothamsted carbon model (RothC). The models were then used to predict the effects, over the period of 2011-2050, of three potential management scenarios: (i) baseline: maintenance of present crop residue returns and green manure crops, as well as composted cattle manure C inputs (24-34 Mg ha⁻¹ yr⁻¹ applied on 3-55% of arable land according to crop), (ii) cattle manure: all arable fields receive 20 Mg ha⁻¹ yr⁻¹ of composted cattle manure, increased C inputs from crop residues and present C inputs from green manure are assumed, and (iii) minimum input: all above-ground crop residues removed, no green manure crop, no cattle manure applied. Above- and below-ground residue biomass C inputs contributed by 8 major crops, and oats employed as a green manure crop, were drawn from yield statistics recorded at the township level and crop-specific allometric relationships (e.g. ratio of above-ground residue biomass to harvested biomass on a dry weight basis). Estimated crop net primary production (NPP) ranged from 1.60 Mg C ha⁻¹ yr⁻¹ for adzuki bean to 8.75 Mg C ha⁻¹ yr⁻¹ for silage corn. For the whole region (143 × 10³ ha), overall NPP was estimated at 952 ± 60 Gg C yr⁻¹ (6.66 ± 0.42 Mg C ha⁻¹ yr⁻¹). Plant C inputs to the soil also varied widely amongst the crops, ranging from 0.50 Mg C ha⁻¹ yr⁻¹ for potato to 3.26 Mg C ha⁻¹ yr⁻¹ for winter wheat. Annual plant C inputs to the soil were estimated at 360 ± 45 Gg C yr⁻¹ (2.52 ± 0.32 Mg C ha⁻¹ yr⁻¹), representing 38% of the cropland NPP. The RothC simulations suggest that the region's soil C stock (0-30 cm horizon), across all soils, has decreased from 13.96 Tg C (107.5 Mg C ha⁻¹ yr⁻¹) in 1970 to 12.46 Tg C (96.0 Mg C ha⁻¹ yr⁻¹) in 2010. For the baseline, cattle manure and minimum input scenarios, soil C stocks of 12.13, 13.27 and 9.82 Tg C, respectively, were projected for 2050. Over the period of 2011-2050, compared to the baseline scenario, soil C was sequestered (+0.219 Mg C ha⁻¹ yr⁻¹) by enhanced cattle manure application, but was lost (−0.445 Mg C ha⁻¹ yr⁻¹) under the minimum input scenario. The effect of variations of input data (monthly mean temperature, monthly precipitation, plant C inputs and cattle manure C inputs) on the uncertainty of model outputs for each scenario was assessed using a Monte Carlo approach. Taking into account the uncertainty (standard deviation as % of the mean) for the model's outputs for 2050 (5.1-6.1%), it is clear that the minimum input scenario would lead to a rapid decrease in soil C stocks for arable farmlands in northern Japan.     

1980—2014年中亚地区植被净初级生产力对气候和CO2变化的响应

中亚干旱区分布着世界80%以上的温带荒漠,受气候变化影响显著。论文首先收集实验观测数据验证了干旱区生态系统模型（AEM）,然后运用AEM开展数值模拟实验量化研究了1980—2014年中亚净初级生产力（NPP）的时空格局,评估了不同环境因子（降水、温度、CO₂）的相对贡献率及其交互效应。结果表明：过去35 a中亚干旱区年均NPP总量为1 125±129 Tg C（1 T=10¹²）或218±25 g C/m²。哈萨克斯坦北部地区年NPP值较高（349±39 g C/m²）,而南疆地区年NPP值较低（123±45 g C/m²）。1980—2014年间,中亚NPP总体呈减少趋势 [-0.71 g C/(m²·a)],南疆极端干旱区的NPP降低最为显著 [-2.05 g C/(m²·a)]。相较于1980—1984年NPP均值,在1985—2014年中亚区域NPP总体降低了118 Tg（-10%）。其中CO₂施肥效应促进NPP增加了99.7 Tg （+8%）,气温升高的正效应促进NPP增加了35.4 Tg（+2%）,而降水减少导致NPP降低了221 Tg（-18%）。研究区内9%的地区的NPP主要控制因子为温度,主要分布在天山和哈萨克斯坦北部等高纬高寒地区。降水主控区面积占整个研究区的69%,主要分布在荒漠平原特别是南疆等植被受水分限制的区域。CO₂主控区占研究区面积的20%,主要分布在天山中山带森林区和低海拔地区等水热条件好的区域。研究表明新疆南部地区是中亚的关键生态脆弱区,其生态安全面临着气候变化的挑战,但21世纪的升温不大可能因刺激自养呼吸而对中亚区域NPP造成显著影响。     

林业碳汇项目基准线和监测方法学及应用分析——以贵州省贞丰县林业碳汇项目为例

气候变化给全球社会经济发展带来了重大影响,林业碳汇在适应和减缓气候变化、促进可持续发展三方面的重要作用日益被世界各国所认可。林业碳汇项目实施的难点在于准确掌握林业碳汇项目设计的规则、标准体系,重点在于基准线判别、碳汇计量、监测的方法学和工具。本文系统介绍了国际清洁发展机制造林再造林(CDM A/R)项目方法学和国内碳汇造林项目方法学、标准体系等最新成果,并以贵州省贞丰县林业碳汇项目为例,分析了基准线和监测方法学在林业碳汇项目开发设计中的实际应用。     

水稻光合同化碳向土壤有机碳库输入的定量研究:14C连续标记法

应用14C连续标记示踪技术,以当地主栽水稻品种"中优169"为供试作物,分别选取亚热带区4种典型稻田土壤,在密闭系统模拟研究水稻根际输入光合碳对土壤有机碳(SOC)及其组分的影响.结果表明,标记种植80 d后,水稻地上部和地下部的累积的总碳量范围分别为1.86～5.60 g.pot-1和0.46～0.78 g.pot-1.种植水稻后供试土壤的14C-SOC含量范围为114.3～348.2 mg.kg-1,而14C-DOC、14C-MBC含量范围为4.05～8.65 mg.kg-1、12.5～37.6 mg.kg-1.水稻生长期间内,不同土壤条件下,土壤14C-SOC与14C-水稻碳量的比率范围为5.09%～6.62%,这说明尽管不同土壤的光合生产能力不同,但根际沉积效率相似.土壤可溶解性有机碳(DOC)、微生物量碳(MBC)和SOC的更新率分别为6.72%～14.64%、1.70%～7.67%和0.73%～1.99%.而且,水稻光合碳的分配和转化对土壤活性碳组分的DOC、MBC含量变化影响较大,而对土壤有机碳影响较小.本研究进一步量化了水稻生长期间光合碳对土壤有机碳库各组分(SOC、DOC和MBC)的贡献,为水稻土有机质积累持续机制与固碳潜力研究提供了数据支撑.     

Soil carbon sequestration and associated economic costs for farming systems of the Indo-Gangetic Plain: A meta-analysis

Soil organic carbon sequestration rates over 20 years based on the Intergovernmental Panel for Climate Change (IPCC) methodology were combined with local economic data to determine the potential for soil C sequestration in wheat-based production systems on the Indo-Gangetic Plain (IGP). The C sequestration potential of rice-wheat systems of India on conversion to no-tillage is estimated to be 44.1 Mt C over 20 years. Implementing no-tillage practices in maize-wheat and cotton-wheat production systems would yield an additional 6.6 Mt C. This offset is equivalent to 9.6% of India's annual greenhouse gas emissions (519 Mt C) from all sectors (excluding land use change and forestry), or less than one percent per annum. The economic analysis was summarized as carbon supply curves expressing the total additional C accumulated over 20 year for a price per tonne of carbon sequestered ranging from zero to USD 200. At a carbon price of USD 25 Mg C⁻¹, 3 Mt C (7% of the soil C sequestration potential) could be sequestered over 20 years through the implementation of no-till cropping practices in rice-wheat systems of the Indian States of the IGP, increasing to 7.3 Mt C (17% of the soil C sequestration potential) at USD 50 Mg C⁻¹. Maximum levels of sequestration could be attained with carbon prices approaching USD 200 Mg C⁻¹ for the States of Bihar and Punjab. At this carbon price, a total of 34.7 Mt C (79% of the estimated C sequestration potential) could be sequestered over 20 years across the rice-wheat region of India, with Uttar Pradesh contributing 13.9 Mt C.     

渤海中部海域颗粒有机碳季节性变化及碳库估算

依据不同季节的调查,对渤海水体中颗粒有机碳（POC）的时空变化特征、碳库及影响因素进行对比研究.结果表明：春、夏、秋和冬季渤海调查海域颗粒有机碳的平均浓度分别为（338±146）μg/L、（491±136）μg/L、（358±228）μg/L和（2534±2601）μg/L,其中冬季渤海水体中POC浓度最高约是春季的7倍.不同季节渤海调查海域POC分布具有相似的规律,即由近岸浅水区向远岸逐渐降低,高值区多集中在调查海域北侧近岸、黄河入海口以及渤海湾等处.不同季节影响POC分布的因素不同,春、夏和秋季影响渤海调查海域POC分布的因素主要是陆源输入和浮游植物的生长繁殖,沉积物再悬浮是影响冬季渤海调查海域POC分布的主要因素.通过C/N比值探究不同季节渤海水体中POC来源发现,春季有45.3%、52.8%样品的C/N比值分别介于2.6~4.3和4~10之间,夏季有38.7%、32.3%样品的C/N比值分别介于2.6~4.3和4~10之间;秋季有84.4%样品的C/N比值介于4~10;而冬季有72.2%样品的C/N比值大于12,可见渤海水体中POC来源具有季节性差异,春季和夏季渤海调查海域POC主要来源于海洋生物的代谢活动,秋季渤海水体中POC的主要来源是浮游植物,冬季渤海POC的主要来源是再悬浮物作用下沉积物中保留下来的有机物.渤海POC碳库呈季节性变化,春、夏和秋季渤海调查海域POC碳库在6×10⁵~7×10⁵t范围内,冬季碳库最高,为2.5×10⁶t.     

Carbon Monitoring Costs and their Effect on Incentives to Sequester Carbon through Forestry

Technically, forestry projects have thepotential to contribute significantly tothe mitigation of global warming, but manysuch projects may not be economicallyattractive at current estimates of carbon(C) prices. Forest C is, in a sense, a newcommodity that must be measured toacceptable standards for the commodity toexist. This will require that credible Cmeasuring and monitoring procedures be inplace. The amount of sequestered C that canbe claimed by a project is normallyestimated based on sampling a number ofsmall plots, and the precision of thisestimate depends on the number of plotssampled and on the spatial variability ofthe site. Measuring C can be expensive andhence it is important to select anefficient C-monitoring strategy to makeprojects competitive in the C market. Thispaper presents a method to determinewhether a forestry project will benefitfrom C trading, and to find the optimalmanagement strategy in terms of forestcycle length and C-monitoring strategyA model of an Acacia mangiumplantation in southern Sumatra, Indonesiais used to show that forestry projects canbe economically attractive under a range ofconditions, provided that the project islarge enough to absorb fixed costs.Modeling results indicate that between 15and 38 Mg of Certified Emission Reductions(CERs) per hectare can be captured by thesimulated plantation under optimalmanagement, with optimality defined asmaximizing the present value of profitsobtained from timber and C. The optimalcycle length ranged from 12 to 16 years andthe optimal number of sample plots rangedfrom 0 to 30. Costs of C monitoring (inpresent-value terms) were estimated to bebetween 0.45 (Mg C)^-1 to 2.11 (MgC)^-1 depending on the spatialvariability of biomass, the variable costsof C monitoring and the discount rate.     

Soil carbon pool in China and its global significance

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Earth observations for estimating greenhouse gas emissions from deforestation in developing countries

In response to the United Nations Framework Convention on Climate Change (UNFCCC) process investigating the technical issues surrounding the ability to reduce greenhouse gas (GHG) emissions from deforestation in developing countries, this paper reviews technical capabilities for monitoring deforestation and estimating emissions. Implementation of policies to reduce emissions from deforestation require effective deforestation monitoring systems that are reproducible, provide consistent results, meet standards for mapping accuracy, and can be implemented at the national level. Remotely sensed data supported by ground observations are key to effective monitoring. Capacity in developing countries for deforestation monitoring is well-advanced in a few countries and is a feasible goal in most others. Data sources exist to determine base periods in the 1990s as historical reference points. Forest degradation (e.g. from high impact logging and fragmentation) also contribute to greenhouse gas emissions but it is more technically challenging to measure than deforestation. Data on carbon stocks, which are needed to estimate emissions, cannot currently be observed directly over large areas with remote sensing. Guidelines for carbon accounting from deforestation exist and are available in approved Intergovernmental Panel on Climate Change (IPCC) reports and can be applied at national scales in the absence of forest inventory or other data. Key constraints for implementing programs to monitor greenhouse gas emissions from deforestation are international commitment of resources to increase capacity, coordination of observations to ensure pan-tropical coverage, access to free or low-cost data, and standard and consensual protocols for data interpretation and analysis.     

Impacts of climate change on savannah woodland biomass carbon density and water-use: a modelling study of the Sudanese gum belt region

This paper analyzes potential impacts of climate change on biomass carbon (C) density and water-use (actual evapotranspiration, AET) of savannah woodlands in Sudan. Climate change scenarios were developed from five General Circulation Models (GCMs; CGCM2, CSIRO2, ECHam4, HadCM3 and PCM) under two IPCC (Intergovernmental Panel on Climate Change) emission scenarios (A1FI and B1). Baseline (1961-90) climate and climate change scenarios for 2080s for eight map sheet grids (1° latitude x 1.5° longitude) were constructed. Compared to baseline values, mean annual precipitation (MAP) showed both increases (+112 to +221 mm) and decreases (?13 to ?188 mm) but mean annual temperature (MAT) only showed increases (+1.2 to +8.3 °C). Baseline biomass C densities showed an exponential relationship with MAP (y?=?6.798 e ^0.0054x, R²?=?0.70). Depending on climate change MAP, biomass C densities increased (+14 to +241 g C m^?2) or decreased (?1 to ?148 g?C m^?2). However, because of uncertainty in biomass C density estimates, the changes were only significant (P <0.05) for some of the climate change scenarios and for grids with MAP >260 mm. Under A1FI emission scenarios, only HadCM3 did not have a significant effect while under B1 emission scenarios, only CGCM2 and ECHam4 had a significant effect on biomass C density. AET also showed both increases (+100 to +145 mm for vertisols and +82 to +197 mm for arenosols) and decreases (?12 to ?178 mm for vertisols and ?12 to ?132 mm for arenosols). The largest relative changes in AET (up to 31 %) were associated with grids receiving the lowest rainfall. Thus, even if MAP increases across the study region, the increase will have little impact on biomass levels in the driest areas of the region, emphasizing the need for improved management and use of savannah woodlands.     

基于InVEST-PLUS模型的淮北市碳储量时空演变及预测

研究土地利用时空演变对生态系统碳储量的影响,对研究区未来的国土空间规划以及减排增汇提供理论依据.基于1985、1995、2005、2015和2020年这5期土地利用数据,结合InVEST模型分析了研究区碳储量时空变化,运用PLUS模型预测研究区2035年自然发展情景、耕地保护情景、生态保护情景以及耕地和生态双保护情景土地利用变化并估算不同情景下的生态系统碳储量.结果表明:①1985~2020年研究区耕地面积持续减少,2015~2020年土地利用变化较快,综合土地利用动态度达到了34.62 %;②1985~2020年碳储量呈下降趋势,减少1.55×10⁵ t,其中在2005~2015年间,碳储量减少了1.22×10⁵ t,年均减少量达1.22×10⁴ t;③碳储量较高区域分布在研究区的东部,碳储量较低区域分布在研究区中部和西北部;耕地碳储量占比从66.89 %下降到57.73 %,但耕地仍是研究区最主要的碳库;其他地类向草地和林地转化有利于生态系统碳储量的增加;④2035年,自然发展情景、耕地保护情景、生态保护情景以及双保护情景下的碳储量分别为81.77×10⁵ 、82.45×10⁵、82.82×10⁵和82.51×10⁵ t.     

土壤自养微生物同化碳向土壤有机碳库输入的定量研究：14C连续标记法

自养微生物在土壤中广泛存在,但其CO2同化能力及其向土壤碳库的输入机制尚不明确.应用14C连续标记示踪技术,选取亚热带区4种典型稻田土壤在密闭系统模拟培养,探讨了土壤自养微生物同化碳向土壤碳库的输入过程和机制及其对土壤碳库活性组分的影响.结果表明,土壤微生物具有客观的CO2同化能力.标记培养110 d后,供试土壤的14C-SOC含量范围为69.06～133.81 mg.kg-1,而14C-DOC、14C-MBC含量范围为2.54～8.10 mg.kg-1、19.50～49.16 mg.kg-1.土壤自养微生物同化碳(14C-SOC)与其微生物截留碳(14C-MBC)呈极显著的正相关关系.土壤可溶解性有机碳(DOC)、微生物量碳(MBC)和SOC的更新率分别为5.65%～24.91%、4.23%～20.02%和0.58%～0.92%.而且,土壤自养微生物同化碳的输入对土壤活性碳组分的DOC、MBC含量变化影响较大,而对SOC影响较小.对微生物在土壤碳循环过程的基本功能的认识在本研究中得以丰富和加深.     

Carbon dioxide release due to change in land usein China mainland

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Forest Management for Greenhouse Gas Benefits: Resolving Monitoring Issues Across Project and National Boundaries

Demand for new environmental services from forests requires improved monitoring of these services at three scales: project-, regional-, and national-level. Most forest management activities are organized at the project scale, while the Framework Convention on Climate Change (FCCC) recognizes the nation as the party to the agreement. Hence, measurement and monitoring issues are emerging at the intersections of the project and national scales, referred to here as monitoring-domain edge effects. The following actions are necessary to improve existing monitoring capabilities and to help resolve project/national edge effects: (1) consensus on standard methods and protocols for monitoring mitigation activities, their off-site greenhouse gas (GHG) impacts, the fate of forest products and their relation to national GHG inventories (baselines); (2) a global program for collecting land use, land cover, biomass burning, and other data essential for national baselines; (3) the development of new nested-monitoring-domain methods that allow projects to be identified in national GHG inventories (baselines), and permit tracking of leakage of GHGs and wood product flows outside project boundary and over time; and (4) presentation of a set of credible, carefully designed, and well-documented forest mitigation activities that resolve most of the current issues.     

Carbon Offset Potentials of Four Alternative Forest Management Strategies in Canada: A Simulation Study

Using an Integrated TerrestrialEcosystem C-budget model (InTEC), we simulated thecarbon (C) offset potentials of four alternativeforest management strategies in Canada: afforestation,reforestation, nitrogen (N) fertilization, andsubstitution of fossil fuel with wood, under differentclimatic and disturbance scenarios. C offset potentialis defined as additional C uptake by forest ecosystemsor reduced fossil C emissions when a strategy isimplemented to the theoretical maximum possibleextent. The simulations provided the followingestimated gains from management: (1) Afforesting allthe estimated 7.2 Mha of marginal agricultural landand urban areas in 1999 would create an average Coffset potential of 8 Tg C y^-1 during 1999–2100,at a cost of 3.4 Tg fossil C emission in 1999. (2)Prompt reforestation of all forest lands disturbed inthe previous year during 1999–2100 would produce anaverage C offset potential of 57 Tg C y^-1 forthis period, at a cost of 1.33 Tg C y^-1. (3)Application of N fertilization (at the low rate of 5kg N ha^-1 y^-1) to the 125 Mha ofsemi-mature forest during 1999–2100 would create anaverage C offset of 58 Tg C y^-1 for this period,at a cost of 0.24 Tg C y^-1. (4) Increasingforest harvesting by 20% above current average ratesduring 1999–2100, and using the extra wood products tosubstitute for fossil energy would reduce averageemissions by 11 Tg C y^-1, at a cost of 0.54 TgC y^-1. If implemented to the maximum extent, thecombined C offset potential of all four strategieswould be 2–7 times the GHG emission reductionsprojected for the National Action Plan for ClimateChange (NAPCC) initiatives during 2000–2020, and anorder of magnitude larger than the projected increasein C uptake by Canada's agricultural soils due toimproved agricultural practices during 2000–2010.