树的碳汇量如何计算
森林碳汇的计算
CDM Capacity Development in Eastern and Southern AfricaCharlene WatsonLondon School of Economics and Political Sciencec.watson2@ DisclaimerThe views expressed in this publication are those of the author and do not necessarily represent those of the United Nations, UNDP, UNEP, UNEP Risoe Centre or their Member States.Forest Carbon Accounting: Overview & PrinciplesExecutive SummaryForests play an important role in the global carbon balance. As both carbon sources and sinks, they have the potential to form an important component in efforts to combat global climate change. Accounting for the carbon within forest ecosystems and changes in carbon stocks resulting from human activities is a necessary first step towards the better representation of forests in climate change policy at regional, national and global scales.The United Nations Development Programme (UNDP), as part of the UNDP-UNEP CDM Capacity Development Project for Eastern & Southern Africa, is seeking to promote carbon projects in sub-Saharan Africa, in the important bio-carbon sector and others. This report reinforces UNDP’s capacity building efforts by presenting the main principles, practices and challenges of carbon accounting in the forestry sector.Forest carbon accounting can be divided into three forms. Stock accounting assesses the magnitude of carbon stored in forest ecosystems at a single point in time. Emissions accounting assesses the net greenhouse gas emissions to the atmosphere resulting from forests. Emission reductions accounting assesses the decrease in emissions from project or policy activities, often so that they can be traded. Forest carbon accounting identifies the carbon-density of areas, providing information for low-carbon-impact land use planning. It prepares territories for accounting and reporting of emissions from the forestry sector. It allows comparison of the climate change impact of the forestry sector relative to other sectors, as well as allowing comparison between territories. Finally, it enables trade of project emission reductions on carbon markets and for emission reductions to be included in policy targets.Good practice in forest carbon accounting must be adhered to. In particular, transparency in methods and accuracy and precision in accounting are required for public and political acceptance of resultant estimates. A basic knowledge of the principles underlying forest carbon accounting is also beneficial. Understanding biomass dynamics and flows between carbon pools in forest ecosystems enables more effective accounting.The practice of forest carbon accounting requires clear identification of the accounting boundary in both space and time. Stratifying the forest into areas with similar carbon characteristics further improves the accuracy of carbon accounting. Data for accounting can be gathered from a variety of sources, including existing secondary data, remotely sensed data and primary data through field surveys. The amount of data from each source depends on the quality of the source as well as the trade-offs that must be made between accounting accuracy and costs of resources and time.All forest carbon accounting estimates contain uncertainty. Practitioners should identify, minimise where possible, and quantify this uncertainty through statistical analysis, published information and expert judgement. Uncertainty of model variables and components, once quantified, can be aggregated through simple propagation of errors or simulated through Monte Carlo analysis. The existence of substantial uncertainty can undermine efforts to reduce carbon emissions from forestry and can erode political support for the accounting process.Forest carbon accounting guidance from the Intergovernmental Panel on Climate Change (IPCC) has become the primary source of information for methods, accounting equations and parameters. However, IPCC guidance is vast and often difficult to navigate. In response, a number of tools for forest carbon accounting have emerged. These vary in terms of geographical coverage, forestry activities and the carbon pools accounted for, as well as the level of data input required. In light of such diversity, practitioners require an understanding of the forest carbon accounting process, irrespective of whether these tools are utilised.Despite substantial progress in the field of forest carbon accounting over the last decade, challenges still remain. Terminology relating to forests and managed lands is ambiguous and requires standardisation between stakeholders. More scientific research into forest biomass characteristics is also required to better incorporate the heterogeneity of forests, their growth dynamics and the fate of carbon in harvested wood products into forest carbon accounting methods.Forest carbon accounting is a multi-disciplinary task. Building capacity is essential. Investment is also necessary to improve and standardise carbon accounting methods. If future climate change policy and strategy are to adequately reflect the substantial role forests play in the global carbon balance, good forest carbon accounting is imperative.Table of ContentsExecutive Summary (2)List of Figures (5)1. Introduction (6)1.1. Report structure (6)1.2. What is forest carbon accounting? (6)2. Principles of forest carbon accounting (8)2.1. Accounting good practice (8)2.2. Biomass, carbon pools and stock accounting (9)2.3. Approaches to emission accounting (11)2.4. Accounting for emission reductions (12)2.4.1. Baselines (13)2.4.2. Additionality (13)2.4.3. Leakage (14)2.4.4. Permanence (14)3. Practice of forest carbon accounting (15)3.1. Establishing the accounting area (15)3.2.1. Collating existing forest data (17)3.2.2. Using remote sensing (17)3.2.3. Data from field sampling (19)3.3. Accounting for forest carbon stocks (19)3.3.1. Above-ground biomass (AGB) (19)3.3.2. Below-ground biomass (BGB) (20)3.3.3. Dead organic matter (wood) (21)3.3.4. Dead organic matter (litter) (21)3.3.5. Soil organic matter (SOM) (21)3.4. Accounting for forest carbon emissions (22)3.4.1. Accounting for carbon stock changes in carbon pools (22)3.4.2. Accounting for carbon stored in harvested wood products (HWPs) (22)3.4.3. Accounting for nitrous oxide and methane emissions from disturbances (24)3.5. Quantifying uncertainty in carbon accounting (25)4. Guidance and tools for forest carbon accounting (26)4.1. IPCC guidelines (26)4.2. Carbon accounting tools (26)4.3. Bilan Carbone (27)5. Challenges for forest carbon accounting (28)5.1. Clarifying terminology (28)5.1.1. Definition of ‘forest’ (28)5.1.2. Direct human-induced impacts (29)5.2. Forest Characteristics (30)5.2.1. Heterogeneity of forests (30)5.2.2. Forest growth and equilibrium (30)5.2.3. Accounting for harvested wood products (31)6. Conclusion (31)7. Appendices (33)7.1. Appendix I: References (33)7.2. Appendix II: Acronyms (38)7.3. Appendix III: Glossary (39)7.4. Appendix IV: Examples of default equations and data for forest carbon accounting (41)List of TablesTable 1. Good practice for forest carbon accounting (9)Table 2. Default forest biomass and annual biomass increment under tier 1 IPCC guidance (18)Table 3. Factors affecting forest carbon stocks (29)Table A4:1. Exemplary above-ground biomass regression equations for tropical trees (41)Table A4:2. Default mineral soil organic carbon stocks (41)List of FiguresFigure 1. Diagrammatic Representation of Carbon Pools (10)Figure 2. Generalised flow of carbon between pools (11)Figure 3. Outline of the practice of forest carbon accounting (16)1. Introduction1.1. Report structureThere has been considerable and growing interest in forest carbon and its role in international climate change policy. This interest stems from the substantial greenhouse gas (GHG) emissions that arise from the forestry sector and the potential for forests to deliver cheap-and-deep emission reductions. Forest Carbon Accounting: Overview & Principles presents the main principles, practices and challenges for carbon accounting in the forestry sector. In order to be accessible, the report is not overly technical and should not, therefore, be considered a stand-alone guide for forestry carbon accounting. It does, however, present guidance for good practice in accounting and indicates further sources of guidance. Section 1 outlines the historic, current and future needs for forest carbon accounting. Section 2 focuses on principles and good practice. The process of forest carbon accounting is outlined in Section 3. Section 4 highlights existing guidance and toolkits available for forestry carbon accounting and Section 5 presents the challenges and limitations to date. Section 6 concludes.1.2. What is forest carbon accounting?Carbon accounting is the practice of making scientifically robust and verifiable measurements of GHG emissions. Although characteristics of forests have been recorded for numerous historical purposes, accounting for carbon is a more recent addition to forest inventories. This follows the growing need to quantify the stocks, sources and sinks of carbon and other GHGs in the context of anthropogenic impacts on the global climate.Historically, forest inventories recorded stand structure, age, growth rate, biomass accumulation, and the wood densities of tree species. These have served both commercial purposes, such as determining merchantable timber volumes and use in the paper and pulp industry, as well as national or regional planning purposes, such as creating forest and land use inventories for land-use permits, land-use plans and agricultural expansion.In 1946, the Food and Agriculture Organisation (FAO) established the Forest Resource Assessment (FRA) which, published every five to ten years, compiles data gathered through national statistics and country-level reporting processes. Although criticised (see Grainger, 2008; Houghton, 2005), the FRA still provides the most comprehensive assessment of global forest cover, management and trends to date. In combination with the substantial body of forest science research literature, the FRA and similar forest inventories provide the background for carbon accounting.The forestry sector plays a vital role in the global balance of GHGs. Deforestation alone accounts for approximately 20% of anthropogenic emissions (FAO 2006; Stern, 2006) and the forestry sector represents upwards of 50% of global greenhouse gas mitigation potential (IPCC, 2007). As forests riseup the climate change agenda, three types of forest carbon accounting have developed: stock accounting, emissions accounting and project emission reductions accounting.∙Stock accountingForest carbon stock accounting often forms a starting point for emissions and project-level accounting. Establishing the terrestrial carbon stock of a territory and averagecarbon stocks for particular land uses, stock accounting allows carbon-dense areas to beprioritised in regional land use planning. An early form of forest carbon accounting,emissions and emission reductions accounting have evolved from the principlesestablished for stock accounting.∙Emissions accountingEmissions accounting is necessary to assess the scale of emissions from the forestrysector relative to other sectors. It also aids realistic goal-setting for GHG emissionstargets. Under the United Nations Framework Convention on Climate Change (UNFCCC)and the Kyoto Protocol, countries are mandated to undertake some land use, land usechange and forestry (LULUCF) carbon accounting (see Box 1). With a significant portionof developing country emissions arising from the LULUCF sector, the forestry sector islikely to play a prominent role in climate change strategies in these countries.∙Project emission reductions accountingCarbon accounting for forestry project emission reductions is required for both projectsundertaken under the flexible mechanisms of the Kyoto Protocol and the voluntarycarbon markets. Both necessitate good carbon accounting to ensure that emissionsreductions are real, permanent and verifiable. For projects to generate tradableemission reductions, accounting methods between countries, regions and projectsmust be standardised in both developed and developing countries.Past forest inventories and research outputs provide a substantial source of information on forest biomass characteristics. The challenge is to translate this information into carbon estimates, in particular increasing the coverage and/or scaling-up research that often focuses on ecological zones or specific territories. Ultimately, the quality of forest carbon estimates will be governed by a number of factors, not least time and financial resource constraints. Acknowledging that trade-offs between factors in the accounting process are inevitable, the carbon accounting process must adhere to good practice guidance if forestry is to be adopted more comprehensively in climate change policy.2. Principles of forest carbon accounting2.1. Accounting good practiceRegardless of the type of accounting – stock, emissions or project emission reductions – there are a number of principles for carbon accounting that should be followed (see Table 1). Adherence to good practice promotes better understanding, legitimacy and trust in the accounting system, which is critical for both political and public acceptance (Greenhalgh et al., 2006).Although publications commonly discuss ‘carbon’ accounting, completeness calls for the inclusion of other relevant GHGs in emissions and project emission reductions accounting. Thus, carbonaccounting often refers to accounting of carbon dioxide equivalent (CO2e), a metric which allows standardisation of the six major GHGs based on their global warming potential. In the forestry sector, management regimes influence the scale of methane (CH4) and nitrous oxide (N2O) emissions in addition to carbon emissions. Methane emissions result from burning and decomposition of organic matter in oxygen-free environments, such as waterlogged soils. Nitrous oxide is emitted during burning, decomposition of organic matter, soil organic matter mineralisation and land fertilisation by nitrogen fertilisers. Although these gases tend to be produced in lower volumes than CO2 they have greater global warming potential. To adhere to good practice, CH4 and N2O emissions should be fully accounted for where significant. However, where minor, meaning less than 1% of the total (IPCC, 2003), such emissions can be omitted from accounting.Sources: Greenhalgh et al., 2006; Pearson et al., 2005; IPCC, 20002.2. Biomass, carbon pools and stock accountingForest biomass is organic matter resulting from primary production through photosynthesis minus consumption through respiration and harvest. Assessment of biomass provides information on the structure and functional attributes of a forest and is used to estimate the quantity of timber, fuel and fodder components (Brown, 1997). With approximately 50% of dry forest biomass comprised of carbon (Westlake, 1966), biomass assessments also illustrate the amount of carbon that may lost orsequestered under different forest management regimes. Carbon is lost to the atmosphere as CO2. To convert carbon in biomass to CO2, the tonnes of carbon are multiplied by the ratio of the molecular weight of carbon dioxide to the atomic weight of carbon (44/12). Estimating the biomass density of forest components is, therefore, the first step in forest carbon accounting.Carbon pools are components of the ecosystem that can either accumulate or release carbon and have classically been split into five main categories: living above-ground biomass (AGB), living below-ground biomass (BGB), dead organic matter (DOM) in wood, DOM in litter and soil organic matter (SOM) (see Figure 1). The classification of carbon pools is not strict and it is not the number of categories that is important but their completeness; pools must not be double-counted and significant pools should not be excluded (refer to Table 1, Section 2.1.). With harvested wood products (HWPs) increasingly recognised as an additional and potentially substantial carbon pool which exists outside of traditional forest boundaries (Lui & Han, 2009), many carbon pool classifications are being adapted to also include HWPs.Figure 1. Diagrammatic Representation of Carbon Pools(AGB above-ground biomass; BGB below-ground biomass; SOM soil organic matter;DOM dead organic matter; HWPs harvested wood products)A carbon source is a carbon pool from which more carbon flows out than flows in: forests can often represent a net source (rather than sink) of carbon due to the processes of decay, combustion and respiration. A carbon sink is a carbon pool from which more carbon flows in than out: forests can act as sink through the process of tree growth and resultant biological carbon sequestration (Brown, 2002). Forests can switch between being a source and a sink of carbon over time, with the stock of the forest referring to the absolute quantity of carbon held within a forest component at a specified time. The transfer of carbon between carbon pools is represented in Figure 2.Stock accounting sums carbon pools at a single point in time. Decisions on which carbon pools should be included are largely dependent on the availability of existing data, costs of measurement and the level of conservativeness required (MacDicken, 1997). Trees often represent the greatest fraction of total biomass of a forested area, with other carbon pools only a fraction of the total tree biomass. The understorey is estimated to be equivalent to 3% of above-ground tree biomass, dead wood 5-40%, and fine litter only 5% of that in the above-ground tree biomass. BGB is more variable, rangingbetween 4 - 230%, and can be more than two times greater than that in the above-ground tree biomass (Brown, 1997). AGB in trees also responds more rapidly and significantly as a result of land-use change than other carbon pools. As a consequence, the majority of carbon accounting efforts are focussed on tree AGB, for which there is a considerable forest science research base.Figure 2. Generalised flow of carbon between pools(source IPCC, 2006)2.3. Approaches to emission accountingAlthough many natural processes lead to emissions and removals of GHGs – for example, fires, insect attacks and local climate variability –anthropogenic activities such as slash and burn, fire management and harvesting have accelerated the release of GHGs from forests (Canadell et al., 2007). These forest management practices affect the balance of emissions into the atmosphere through biomass fluctuation, soil and litter disturbance (Sajwaj et al., 2008) and so have differing impacts on the various carbon pools.The purpose of emissions accounting is to quantify the exchange of GHGs between the atmosphere, terrestrial vegetation and soils through photosynthesis, respiration, decomposition and combustion. There are two main approaches to emissions accounting: the inventory approach and the activity-based approach, which are outlined below and mathematically represented in Box 2. Both approaches are supported under IPCC guidance (IPCC, 2003) and are based on the underlying assumption that the flows of GHGs to or from the atmosphere are equal to changes in carbon stocks in the biomass and soils.The inventory approach measures the difference in carbon stocks averaged between two points in time (Box 2, equation 1). Also called periodic accounting, or the stock-difference approach,measurement of stock change in this way can cover large areas and a variety of species and site conditions. The inventory-based system also captures non-linear changes in carbon stocks, for example biomass accumulation through growth. However, relying on the addition of carbon pools and assessments conducted in this way often leaves out smaller biomass components such as leaf biomass, ground vegetation and litter.In contrast, the activity-based approach estimates the net balance of additions to and removals from a carbon pool (Box 2, equation 2). The activity-based approach, also called the gain-loss or flux approach, estimates changes in carbon stocks by first establishing the rate of area change in land use and multiplying this by the response of carbon stocks under a particular land use. This biological response of a given land use is based indirectly on rates of carbon losses and gains by an area or it is directly measured with the aid of technology (for an example see Baldocchi, 2003). Where the gains and losses in carbon stock can be given as a standard rate of emissions per unit activity, an emissions factor replaces (C1– C2) in Equation 2 (Box 2). The activity-based approach is useful where individual carbon pools are difficult to measure and is less susceptible to short-term variation in carbon stocks. However, emission factors require non-linear carbon stock changes to be time-averaged and assumptions must be made explicit.In general, the accounting approach chosenmust reflect both purpose and acceptabilityto policy-makers, with decisions also likelyto rely on the availability and form ofexisting forest data within a territory. Asthe profile of the forestry sector rises upthe climate agenda, new accountingapproaches are being proposed (see Cowieet al., 2007). A consensus on whichaccounting approach to adopt into thefuture has yet to be reached and inventoryand activity-based accounting remain thedominant accounting approaches.2.4. Accounting for emission reductionsAccounting for emission reductions is most commonly required at the project level, but are also relevant when policy targets must be met. Where forestry carbon projects generate emission reductions, these can be traded as offsets either under the Kyoto Protocol or on the voluntary carbon markets.Accounting for emission reductions requires an understanding of a number of supplementary principles: the complexities of baseline establishment, demonstration of additionality, issues of leakage, and the permanence of emissions reductions. These principles have commonly been blamed for the limited demand and limited inclusion of the forestry sector in carbon trading mechanisms todate. These concepts are briefly outlined below and further guidance for project-specific forest carbon accounting is available from the World Resources Institute (Greenhalgh et al., 2006), World Bank and Winrock (Pearson et al., 2005) and the Voluntary Carbon Standard (VCS, 2008).2.4.1. BaselinesIn order to set emission reduction targets, a baseline scenario must be developed. Also called a counterfactual, this baseline scenario estimates what would have happened in the absence of a policy or project. It is required so that the mitigation impact of a project or policy can be quantified. In the forestry sector, the baseline is particularly important in attempts to reduce emissions from deforestation and degradation, and raises both technical and political considerations (Bond et al., 2009).Creation of a baseline scenario relies on a detailed understanding of the drivers of land use change. The drivers of deforestation, however, are complex and knowledge is still incomplete. A review by Giest and Lambin (2001) identify three aggregate proximate causes –agricultural expansion, wood extraction and expansion of infrastructure – and five broad categories of underlying driving forces: demographic, economic, technological, policy / institutional, and cultural / socio-political factors. They further identify a group of pre-disposing environmental factors, biophysical drivers and social trigger events that influence the rate of deforestation within a territory. The baseline must consider all of these complex and interlinked causes, forces and pre-disposing factors that vary greatly between countries, regions and over time. Substantial technical difficulties and uncertainties therefore arise when baselines are established.At the 9th COP of the UNFCCC, three baseline approaches for Reduced Emissions from Deforestation and Degradation (REDD) were proposed: extrapolating existing or historical rates of deforestation, also called business-as-usual; estimating changes in carbon stocks from land uses that represents economically attractive courses of action, taking into account barriers to investment; and estimating changes in carbon stocks from the most likely land use at the time the project starts (Bond et al., 2009). The choice of baseline methodology will impact country participation in climate change mitigation activities. For example, countries with historically high rates of deforestation will be rewarded more, and so will be more likely to participate, than those that have been active and successful in conserving forest areas. These latter countries are likely to prefer a perspective, or hybrid, approach to setting the baseline (for a more comprehensive review of baselines see Angelsen 2008 a,b).2.4.2. AdditionalityFor a project to be additional, it must be proven that emission reductions would not have occurred in the absence of a project. This is an important principle when emissions reductions at a project location are used to offset GHG emissions at another location. If there is no additionality, overall GHG emissions will increase as a result of the project activity.For afforestation and reforestation (AR) Clean Development Mechanism (CDM) projects of the Kyoto Protocol, Article 12 lays out additionality requirements that must be met for projects to be validated. The CDM AR Working Group, along with the CDM Executive Board, has developed a tool to demonstrate additionality, whereby project alternatives must first be identified. Additionality can then be proven through either a financial test (the CDM activity must be proven less economically orfinancially attractive than other alternatives) or a barriers test (investment, technological or prevailing practice barriers must be shown that they can only be overcome with CDM finance). A critical requirement of any emissions trading scheme, voluntary carbon market projects also require similar assessments of additionality.2.4.3. LeakageLeakage is a process by which emissions are reduced in one area but are also impacted outside of the area in question. Although positive leakage is a possibility, concern is directed to negative leakage, where emissions are merely shifted to another geographical area and fewer, or no, actual reductions are generated by the project activities (Sohngen & Brown, 2004). Leakage can be sub-divided into a number of categories including slippage, activity shifting, outsourcing, market effects and life-cycle emission shifting (for elaboration see Schwarze et al., 2002; IPCC, 2000; Moura-Costa et al., 2000; Schlamadinger & Marland, 2000; Brown et al., 1997) and can be one-time or recurrent.Adequate assessments of leakage are crucial and identification requires the main drivers of the project baseline to be properly addressed. A number of methods have been proposed to do this (see Aukland et al., 2002) and include socio-economic surveys, remote sensing and assessment of market effects. In general, the challenge of accounting for leakage should not be under-estimated in project development and project design should account for leakage through site selection policies, multi-component projects or leakage buffer and set-aside areas.2.4.4. PermanencePermanence refers to the persistence of emission reductions over time. Unlike other sectors, such as industry, energy, waste management and transport, there is a risk that forest carbon sinks, having delivered emissions reductions, may deteriorate or be depleted over the long term. This could be a result of natural disturbances including fire, pests and disease, or anthropogenic disturbances such as poor management and political instability leading to land-use change. Forestry emission reductions are, therefore, unlike those from other sectors in their certainty of delivery.This uncertainty is reflected in the UNFCCC 9th COP decision in 2003 to establish only temporary credit regimes for AR activities under the CDM of the Kyoto Protocol. Emission reductions generated from AR are effectively leased or rented in one of two forms and must be verified every five years, after which they are re-issued, renewed or replaced. Temporary Certified Emission Reductions (tCERs) expire at the end of the commitment period following the one in which they were issued. After verification, a tCER can either be re-issued (if the sequestered carbon remains intact) or the Annex I buyer must replace the expired tCER with a new tCER or a CER. Long-term Certified Emission Reductions (lCERs) expire at the end of the crediting period of the activity for which they were issued (and can, therefore, have a potential life of 60 years in the CDM AR context), but must be replaced in the interim if verification shows that sequestered carbon has decreased. At expiry, both tCERs and lCERs must be replaced with credits of their own kind (e.g. tCERs can be replaced by new tCERs but not by lCERs, and vice versa) or with permanent CERs.The added complications of temporary crediting have led to low prices and low market demand for tCERs and lCERs. However, outside of the Kyoto Protocol framework, alternative mechanisms to deal with the forestry project permanence risk have been developed. These include periodic, performance-。
中国森林生态系统碳储量——生物量方程
中国森林生态系统的碳储量可以通过生物量方程来估算。
生物量方程是基于森林生物量与生长环境因素之间的关系建立的数学模型。
以下是一个常用的生物量方程示例，用于估算中国森林生态系统的碳储量：
树木生物量方程：树木生物量是森林生态系统中最主要的碳储量组成部分。
树木生物量方程可以基于树种、胸径（或直径）、树高等因素来估算。
例如，常用的树木生物量方程如下：生物量= a × （DBH^b）× （H^c）
其中，生物量表示树木的生物量（单位：吨碳/公顷），DBH表示树木的胸径（单位：厘米），H表示树木的高度（单位：米），a、b、c是树种特定的常数。
地上部分生物量方程：除了树木，森林生态系统中的其他植物部分（如灌木、草本植物等）也有碳储量。
地上部分生物量方程可以根据不同植物群落类型和植物功能类型来建立。
这些方程通常基于植物的生物量测量数据，例如植株的鲜重、干重等。
地下部分生物量方程：森林生态系统的地下部分（如根系）也储存着一定的碳。
地下部分生物量方程可以基于土壤类型、根系密度等因素来估算。
以上只是生物量方程的一些示例，实际的生物量方程需要根据不同地区、植被类型和研究目的进行适当的调整和定制。
此外，还需要结合实地调查和测量数据进行参数的校准和验证，以提高估算的准确性和可靠性。
碳汇计算标准
碳汇计算标准
碳汇的计算标准通常是以活林木的蓄积增长来计算的，即活林木每增长一立方米的蓄积，吸收二氧化碳吨，释放氧气吨。
此外，对于种植业，碳汇的计算可以采用谢鸿宇等的农业碳汇测算方法，计算公式为：Ct=∑iCfDw=∑iCfYw（1-wi）/Hi。
其中，Ct表示农作物全年碳吸收量；i为农作物品种；Cf为农作物进行光合作用合成干物质所需要的碳量，即经济系数；Dw为农作物总生物量；Yw为农作物经济产量；wi为农作物含水量；Hi为农作物碳吸收率。
请注意，以上数据和计算公式可能会随着实际情况的变化而有所不同，因此在实际操作过程中，请以实际情况为准。
森林碳汇量计算公式(二)
森林碳汇量计算公式(二)森林碳汇量计算公式简介森林碳汇量计算公式是用来估算森林生态系统中固定的二氧化碳量的数学公式。
它基于不同因素，如森林的地理位置、类型和面积等，通过对这些因素进行测量和估算来计算森林的碳汇量。
以下是一些常用的森林碳汇量计算公式及其示例解释。
1. 碳密度计算公式碳密度计算公式用于计算单位面积森林中的碳储量。
它通常基于森林类型和植被生物量的测量数据。
公式：碳密度 = 单位面积内的生物量× 碳含量示例：假设在一片森林中，单位面积内的生物量为100吨/公顷，而平均碳含量为50%。
根据碳密度计算公式，该森林的碳密度为100吨/公顷× 50% = 50吨碳/公顷。
2. 碳储量计算公式碳储量计算公式用于计算整个森林的碳储量，它是碳密度与森林面积的乘积。
公式：碳储量 = 碳密度× 森林面积示例：假设某森林的碳密度为50吨碳/公顷，森林面积为1000公顷。
根据碳储量计算公式，该森林的碳储量为50吨碳/公顷× 1000公顷 = 50,000吨碳。
3. 净碳吸收计算公式净碳吸收计算公式用于估算森林生态系统吸收或释放的净碳量。
它考虑了森林的碳汇量和碳排放量之间的差异。
公式：净碳吸收 = 碳汇量 - 碳排放量示例：假设某森林的碳汇量为60,000吨碳，而碳排放量为10,000吨碳。
根据净碳吸收计算公式，该森林的净碳吸收为60,000吨碳 - 10,000吨碳 = 50,000吨碳。
结论森林碳汇量计算公式是估算森林生态系统中碳储量的重要工具。
通过使用不同的公式，我们可以计算出森林碳密度、碳储量和净碳吸收等关键指标，帮助我们了解森林在全球碳循环中的作用。
这些公式可以为森林资源管理、碳排放控制和气候变化政策制定提供支持和指导。
东江源区森林系统碳汇计量
东江源区森林系统碳汇计量冷清波;周早弘【摘要】在阐述森林碳汇概念及碳汇计量方法的基础上,运用材积源生物量法(Volume-biomass method)对东江源区森林系统碳储量进行估算.结果表明:总碳储量为45.11×106 tC,其中森林植被层碳储量为9.17×106 tC、森林植被枯落物层碳储量为0.94×106 tC、森林土壤层碳储量为35.0×106 tC.运用蓄积、面积估算结果是:总碳储量为40.89×106 tC,其中林分生物量碳储量4.13×106 tC,竹林生物量碳储量0.21×106 tC,经济林碳储量0.61×106 tC,枯落物层和土壤层碳储量不变.最后得出东江源区森林系统总碳储量值43×106 tC,东江源区森林系统碳交易潜在价值约合28亿美元.以此,提出了建立东江源区绿色基金会的构想.【期刊名称】《西北林学院学报》【年(卷),期】2013(028)005【总页数】5页(P254-258)【关键词】森林碳汇;碳汇计量方法;东江源区【作者】冷清波;周早弘【作者单位】江西财经大学旅游与城市管理学院,江西南昌330032;江西财经大学旅游与城市管理学院,江西南昌330032【正文语种】中文【中图分类】S718.557东江发源于江西省寻乌县，流域总面积35 340 km2。
东江源区在江西境内主要是指寻乌、安远、定南3县，江西省境内流域面积3 502km2［1］。
东江水源区是东莞、惠州、深圳和香港的主要水源地，江西省境内年径流量约32亿m3，源区每年输入广东省境内约29.21亿m3。
东江承担着深圳、东莞、广州、惠州和香港的供水重任，加强东江源区生态保护和建设，保持其优良的水质和充足的水量，关系到沿江居民，以及香港特别行政区居民饮用水的安全。
为保护好东江源区水源，源区政府和居民作出了巨大牺牲：据史晓燕［2］等（2012）研究，东江源区寻乌县、安远县和定南县2006—2009年生态建设和环境保护的直接投入成本分别为20 168.60、21 607.75、125 234.54万元；加上限制发展的机会成本，3县供给成本总投入分别为247 683.6万元、334 876.36万元和231 563.7万元，合计供给总成本为814 123.65万元。
碳汇计算公式范文
碳汇计算公式范文
1.生物量法：这是最常用的碳汇计算方法之一，它基于生态系统中植物和动物生物量的测量。
公式如下：
碳汇=生物量×碳密度
其中，生物量是植物和动物的总重量，碳密度是生物量中的碳含量。
不同植物和动物的碳密度可以根据其结构和组成进行估算。
2.容积法：这是针对森林生态系统的一种常用方法。
公式如下：
碳汇=生物量×碳容积系数
生物量是森林植物的总体积，碳容积系数是不同植物的体积和碳含量之间的关系系数。
3.土壤碳库法：这是用于估算土壤中有机碳数量的方法。
公式如下：
碳汇=土壤有机碳含量×土壤面积
不同土壤类型的有机碳含量可以通过取样和实验室测试来确定。
4.净初级生产力法：这个方法是基于生态系统内生物群落进行光合作用所固定的碳量来估算的。
碳汇=净初级生产力×碳转化效率
净初级生产力是生态系统内光合作用产生的总碳量，碳转化效率是将净初级生产力转化为固定碳的比例。
5.净碳收支法：这是综合考虑碳的输入和输出量来估算碳汇的方法。
公式如下：
碳汇=碳输入量-碳输出量
碳输入量包括大气中的碳通过光合作用固定到生态系统中的量，碳输出量包括生态系统中的呼吸作用和有机物分解释放的碳等。
这些碳汇计算公式可以根据具体的生态系统类型和环境条件进行调整和修改。
此外，还可以利用遥感技术、碳同位素分析等方法来辅助碳汇的估算和计算。
碳汇的计算对于评估和监测生态系统对 climate change的响应和调节具有重要意义，也有助于制定和评估碳交易和碳减排政策。
碳汇量计算方法
碳汇量计算方法
碳汇量计算方法主要是通过监测土地利用变化、森林覆盖率、森林生长状况等因素，结合相关参数和公式进行计算。
以下是具体的计算方法：
1. 森林碳汇量计算：一般采用排放因子法，即根据森林面积和单位面积森林的碳汇量来计算。
碳汇量与树种、林龄、郁闭度等因素有关，需要获取相关数据并进行计算。
2. 草地碳汇量计算：采用吸收增量法，即通过监测草地覆盖变化和草地地上生物量来计算。
一般采用遥感监测和地面调查相结合的方法获取相关数据，并根据草地生长模型和碳含量模型进行计算。
3. 农田碳汇量计算：采用排放因子法，即根据农田面积和单位面积农田的碳汇量来计算。
碳汇量与作物种类、耕作方式、施肥量等因素有关，需要获取相关数据并进行计算。
4. 湿地碳汇量计算：采用吸收增量法和排放因子法相结合的方法，即通过监测湿地覆盖变化和湿地地上生物量来计算。
一般采用遥感监测和地面调查相结合的方法获取相关数据，并根据湿地生长模型和碳含量模型进行计算。
总之，碳汇量计算方法需要综合考虑多种因素，包括土地利用变化、植被覆盖率、生物量等。
在具体操作中，需要结合实际情况选择合适的方法，并进行参数调整和模型验证。
林业碳汇怎么算？
林业碳汇收益怎么算？（一）不断增加林业碳汇森林资源是储存碳汇的物质基础。
目前，我国人均森林面积仅为世界平均水平的1/4,人均森林蓄积量只有世界平均水平的l∕7o 森林资源总量不足、质量不高，严重制约着林业碳汇功能的充分发挥。
我们将继续组织开展大规模国土绿化行动，扎实推进天然林资源保护、退耕还林、防护林体系建设等林业重点工程，深入开展全民义务植树活动，林业碳汇，统筹做好部门绿化和城乡绿化，积极开展碳汇造林,扩大森林面积，增加森林碳汇。
大力开展森林抚育，加强森林经营基础设施建设，提升森林经营管理水平，促进森林结构不断优化、质量继续提升、固碳能力明显增强。
（二）努力减少林业排放增加森林碳汇，既要通过造林做好加法，也要切实做好减法，防止森林碳汇损失。
我们将加强森林资源管理，坚决遏制林地流失势头，科学确定林木采伐限额，改进林木采伐方式，林业碳汇收益怎么算，严厉打击滥采乱伐行为，减少因林地流失、森林退化增加的碳排放。
完善森林火灾预警与响应机制，提升森林火灾监测、火源管控和应急处置能力，减少火灾导致的碳排放。
加强林业有害生物防治，林业碳汇开发市场，强化监测预警、检疫御灾和防灾减灾，减少有害生物灾害造成的毁林。
加强科技创新，依靠科技进步，提升林业生态保护与修复水平和林业适应气候变化的能力。
（三）加强湿地保护修复湿地在植物生长、促淤造陆等生态过程中积累了大量的无机碳和有机碳，在减缓气候变化方面发挥着重要作用。
多次强调，要实施湖泊湿地保护修复工程，制止继续围垦占用湖泊湿地的行为，对有条件恢复的湖泊湿地要退耕还湖还湿。
根据这一重要指示精神，我们将认真贯彻落实《湿地保护修复制度方案》，将所有湿地纳入保护范围，严格实施湿地用途管制、湿地建设项目审批制度，保护自然湿地，禁止任何破坏湿地的开发行为。
对退化的沼泽、河流、湖泊、滨海湿地进行综合治理，提升湿地生态系统功能。
推进湿地保护立法，加强湿地自然保护区和湿地公园建设，健全湿地保护网络体系，完善湿地保护补助政策和湿地生态效益补偿制度，提升湿地保护水平。
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树的碳汇量如何计算
CDM这个项目咱们国家起步比较晚，但发展势头非常快。
我本来准备了咱们国家在CDM 上发展现状及发展趋势的PPT材料，但刚才赵所长在论述中提到了生态建设碳的减排，我又改变了主意，想谈点“森林碳汇减排项目的现状和前景的分析”。
应该说温室效应气体对整个环境的影响，尤其是生态的影响是非常大的。
所以我想这个话题可能会和我们所谈的生态问题更紧密一些，也想跟大家共同的探讨一下。
森林碳汇是指森林通过光合作用将大气中的温室气体CO2吸收并以生物量的形式贮存在植物体内和土壤中的能力。
森林的这种碳汇作用可以在一定时期内减少大气中温室气体的积累，从而减少该气体在大气中的浓度。
森林作为陆地生态系统重要组成部分，有着巨大的生物量，是地球碳循环重要的汇和库，它与气候变化有着直接的联系。
数据表明，森林每生长1m3生物量，平均吸收1.83t CO2，有着很强的碳汇功能。
周国逸等最新研究成果表明，成熟森林在地上部分净生产力几乎为零的情况下，土壤持续积累有机碳，表现出强大的碳汇功能。
实施造林和再造林，增加森林的碳汇量是世界公认的最经济有效的解决CO2上升的办法。
由于工业化进程加速，致使燃烧大量化石燃料产生大量CO2，加之土地利用结构的变化使固碳作用下降，碳汇与碳源不能达到平衡，出现碳失汇，大气CO2浓度增加导致了温室效应，并影响到全球碳循环。
降低和稳定大气中温室气体浓度的方式主要有两种，一是污染物减排，二是吸收温室气体，后者则与森林有着密切联系，这是因为森林具有通过光合作用和森林土地利用可以吸收、固定CO 2的森林碳汇功能。
通过植树造林吸收、固定二氧化碳，通常其长期单位成本远远低于通过工业产业升级、利用工业污染治理减排的成本。
这也是近些年林业碳汇项目日益受到国际社会普遍重视的一个主要原因。
一、森林碳汇发展背景节能减排已成为一种不容忽视的社会责任。
地球向大气层排放的温室气体与日俱增, 削减向大气中排放温室气体，保护人类的共同利益，已经成为共识。
《联合国气候变化框架公约》是1992年5月22日联合国政府间谈判委员会就气候变化问题达成的公约，于1992年6月4日在巴西里约热内卢举行的联合国环发大会（地球首脑会议）上通过，该公约是世界上第一个为全面控制二氧化碳等温室气体排放，以应对全球气候变暖给人类经济和社会带来不利影响的国际公约，也是国际社会在对付全球气候变化问题上进行国际合作的一个基本框架。
公约于1994年3月21日正式生效，具有法律约束力，旨在控制大气中二氧化碳等温室气体的排放，将温室气体的浓度稳定在使气候系统免遭破坏的水平上。
为缓解全球气候变暖趋势，1997年12月149个国家地区的代表在日本京都审议通过了《京都议定书》，2005年2月16日正式生效。
《京都议定书》规定所有发达国家在2008年到2012年间必须将温室气体的排放量比1990年削减5.2％。
有约束的温室气体排放机制为碳交易的形成与发展奠定了基础。
目前，国际上碳交易主要有CDM (清洁发展机制)、JI(联合履行)、ET(排放贸易)三种机制。
碳交易已成为面对气候变迁的一个市场解决方案。
其它一系列气候公约国际谈判中，国际社会对森林碳汇作用越来越予以关注，如《波恩政治协议》、《马喀什协定》都将造林再造林等林业活动纳入《京都议定书》确立的CDM(清洁发展机制)，鼓励各国通过绿化、造林来抵消一部分工业源CO2的排放量。
2003年l2月召开的《联合国气候变化框架公约》第9次缔约方大会，国际社会已将造林再造林等林业活动纳入碳汇项目达成了一致意见，制定了新的运作规则，为正式启动实施造林再造林碳汇项目创造了有利条件。
《京都议定书》不但规定了41个工
业化国家的减限排额度和时间表，还在3.3和3.4条款引入了温室气体吸收汇，允许通过造林、再造林和森林管理等活动获得的碳汇用于抵消工业和能源部门的温室气体减限排量。
同时还在第6条规定可通过包括林业活动在内的项目活动获得的碳汇来抵消减限排额度。
同时，《波恩政治协定》为附件1国家利用造林碳汇项目设定了上限，即附件1国家在第一承诺期的每年中从CDM 造林碳汇项目中获得的减排抵消额不得超过其减排年排放量的1％，也就是说附件1国家所承诺减排任务的20％可以通过COM 碳汇项目来完成。
但森林碳汇必须是森林固碳能力减去造林活动、林地流转造成所产生的排放量相抵后的净吸收量。
二、森林碳汇项目开发现状综观整个《京都议定书》框架下的国际碳交易市场，国际碳市场所交易的大都是减少排放的工业项目，而森林碳汇项目由于规则、方法有待进一步研究以及不确定性和不稳定性等诸多因素，目前实现交易少。
因此，森林碳汇在CDM中的项目所占的比例和交易量都比较小。
以巴西为首的拉美国家和印度等在森林碳汇工作踊跃，特别是处于热带地区的部分国家拥有得天独厚的自然条件，森林的碳吸收速率比较快，造林成本相对较低，再加上他们过去的造林规模有限，现在可以用来进行造林和再造林的土地潜力较大。
而且这些国家开展相关研究和试点早，积累了一定的经验。
按照有关规定，在《京都议定书》框架下的第一承诺期内，发达国家可以通过造林再造林碳汇项目实现的减排量占其减排量的比例有限，即不超过总减排量的1%。
也就是说，在全球流动可以抵工业减排量的森林碳汇大约为3500万吨，已在国际森林碳汇活动形成竞争机制。
我国开展森林碳汇相对较晚，但发展势头较好。
我国政府于2001年启动了全球碳汇项目，对开展造林再造林碳汇项目及其相关工作给予了充分重视和积极支持。
2003年底国家林业局针对气候谈判出现的新进展，成立了国家林业局碳汇管理办公室以来，国内推行碳汇项目试点和研究日增。
2 007年颁布的《中国应对气候变化国家方案》强调，植树造林、保护森林、最大限度地发挥森林的碳汇功能等是应对气候变暖的重要措施。
国家发改委和国家林业局等部门积极搭建碳汇信息交流平台，组织实施全球第一个清洁发展机制林业碳汇项目和多个林业碳汇试点项目。
由中国国家林业局与意大利环境和国土资源部签署的中国第一个林业碳汇项目落户内蒙古自治区赤峰市敖汉旗，双方约定，在第一个5年有效期内，意大利投资153万美元，在敖汉旗荒沙地造林4.5万亩，项目产生的可认证的二氧化碳减排指标将归意大利所有，通过该项目碳汇交易筹集了生态补偿资金，减轻财政补偿公益林的压力。
以中国科学院为首的一些科研院所，也对全国森林生态系统的碳循环和碳储量以及碳汇功能等进行了初步观测和研究。
国家林业局、中国石油天然气股份有限公司及中国绿化基金会等已联合发起了中国绿色碳基金，以促进吸纳民间资金开展以固定大气中二氧化碳为目的的造林、森林经营及能源林基地建设，鼓励企业减少碳排放，并投资森林碳汇项目进一步降低“碳足迹”。
北京市将建立中国绿色碳基金北京专项，专门管理北京市企业、社会团体以及个人为林业碳汇造林所捐赠的资金。