Greenhouse gas emission reduction evaluation method for coastal salt marsh wetland vegetation restoration project

Abstract

The invention discloses a greenhouse gas emission reduction evaluation method for a coastal salt marsh wetland vegetation restoration project, and belongs to methodology in the fields of forestry and other carbon sink types. According to the salt marsh vegetation restoration project meeting the conditions, a greenhouse gas voluntary emission reduction project can be designed and approved according to the file requirements; and accounting and checking the emission reduction amount of the greenhouse gas voluntary emission reduction project. According to the method, the greenhouse gas emission reduction effect of the coastal salt marsh wetland vegetation restoration project can be scientifically and systematically evaluated, and powerful support is provided for project design and approval.

Description

Technical Field

[0001] The present invention relates to the methodology in the field of forestry and other carbon sink types, and specifically to a method for assessing greenhouse gas emission reduction in a coastal salt marsh wetland vegetation restoration project. Background Art

[0002] As global warming intensifies, reducing greenhouse gas emissions has become a focus of international attention. As an important coastal ecosystem, coastal salt marsh wetlands have ecological functions such as maintaining coastal safety, regulating climate, purifying water, fixing sand and promoting siltation, fixing carbon and storing carbon, and maintaining biodiversity. Vegetation restoration of coastal salt marsh wetlands can remove carbon dioxide by increasing the area of ​​salt marsh vegetation and the carbon storage of the ecosystem, and is an important way to enhance the carbon sink capacity of coastal ecosystems. However, there is currently a lack of a scientific and systematic assessment method for accurately calculating and verifying the greenhouse gas emission reduction of coastal salt marsh wetland vegetation restoration projects. Summary of the invention

[0003] The purpose of the present invention is to provide a method for evaluating greenhouse gas emission reduction in a coastal salt marsh wetland vegetation restoration project.

[0004] To achieve the above objectives, the present invention is implemented through the following technical solutions.

[0005] A method for evaluating greenhouse gas emission reduction in a coastal salt marsh wetland vegetation restoration project comprises the following steps:

[0006] S1: Clarify the project boundaries, project crediting period, project life, selected carbon pools and greenhouse gas emission sources;

[0007] 1. Project Boundary

[0008] The coastal salt marsh wetland vegetation restoration project area may include several discontinuous planting plots, each of which should have specific geographical boundaries, and the project boundary does not include areas exceeding 400m 2 The above ponds, roads, ditches and tidal gullies with a width greater than 3m, and salt marsh plots that existed before the project and have a coverage greater than 5% are not included. The project boundary can be determined by one of the following methods:

[0009] a) Use the Beidou satellite navigation system to directly determine the coordinates of the turning points of the project site boundary, with a single-point positioning error of no more than ±2m;

[0010] b) Using high-resolution geospatial data such as satellite remote sensing images, aerial images, coastal salt marsh wetland distribution maps, and coastal protection and restoration planning maps, the boundary coordinates of the project plot can be directly read with the assistance of a geographic information system;

[0011] (II) Project credit period

[0012] The project crediting period is the time limit for applying for project emission reduction registration, starting from the time when the project emission reduction is generated and applied for registration by the project owner. The shortest period is not less than 20 years and the longest period is not more than 40 years. The project crediting period must be within the life of the project.

[0013] (III) Project life span

[0014] The life of the project shall be within the effective period of the project owner's ownership or right to use the sea and land within the project boundary. The start time of the project life is the start date of the first habitat restoration, land preparation, sowing or planting project within the project boundary;

[0015] S2: Carry out the calculation of project emission reductions, complete the baseline scenario identification, additionality demonstration and project carbon layer division, and then carry out the baseline removal calculation, project removal calculation, project leakage calculation and project emission reduction accounting;

[0016] 1. Baseline scenario identification

[0017] The baseline scenario for the coastal salt marsh wetland vegetation restoration project is: before the implementation of the vegetation restoration project, the sea or land resources within the project boundary are developed and utilized in the form of unvegetated tidal flats or human activities that can be cleared, such as marine aquaculture, abandonment or illegal engineering occupation;

[0018] 2. Additionality Argument

[0019] Coastal salt marsh wetland vegetation restoration is a non-profit public welfare activity. Coastal salt marsh wetlands are susceptible to extreme climate events and human activities. Usually, activities such as salt marsh vegetation planting and subsequent management are costly and not financially attractive. For projects that meet the applicable conditions, their additionality is exempted from demonstration.

[0020] (III) Project carbon layer division

[0021] In order to improve the accuracy of carbon stock change calculation and reduce the number of monitoring plots under certain accuracy requirements, the plots within the project boundary should be divided into different levels according to different stratification factors, including carbon stratification in the project design stage and carbon stratification in the project implementation stage;

[0022] The carbon layers divided during the project design phase are used to estimate the change in carbon storage. The carbon layers are divided by comprehensively considering the habitat conditions of the plots within the project boundary before the salt marsh vegetation is planted, such as geographical location, soil substrate and tidal flat elevation, as well as factors such as plant selection, planting time and planting density. Plots with no significant differences are divided into the same carbon layer.

[0023] The carbon layers divided during the project implementation phase are used to calculate the change in carbon storage, which is mainly based on the division of carbon layers during the project design phase and is adjusted and determined in combination with the actual situation of salt marsh vegetation restoration activities; if there are natural factors such as pests and diseases, fires, extreme droughts / rainfalls, typhoon storm surges and cold waves, or human influences such as plant death caused by mowing, which increase the heterogeneity of the original carbon layer, or if the boundaries of the carbon layer change due to changes in the use of the sea area or land use types, the project carbon layer must be adjusted;

[0024] S3: The use of monitoring methodology in the process of calculating project emission reductions, including the parameters and data that need to be determined in the project design phase, the parameters and data that need to be monitored in the project implementation phase, and the data management requirements for project implementation and monitoring;

[0025] Data management requirements for project implementation and monitoring

[0026] 1. General requirements

[0027] Project owners should take the following measures to ensure the quality of monitoring parameters and data:

[0028] a) Follow the data monitoring procedures and method requirements determined during the project design phase and formulate a detailed monitoring plan;

[0029] b) Establish a credible and transparent internal management system and quality assurance system, including but not limited to reliable field measurements, mutual inspection and verification of field measurements, and input, calculation and verification of internal data;

[0030] c) Clarify the responsible departments and their responsibilities, specific work requirements, data management procedures, and work time nodes;

[0031] d) Designate dedicated personnel to monitor, collect, record and cross-check project boundaries, project implementation and vegetation cover data;

[0032] (II) Project boundary monitoring requirements

[0033] During the project design phase, the project owner must clearly identify the project plot boundaries where salt marsh vegetation is planned to be planted and provide vector data files of all project plot boundaries. During the project implementation phase, the project owner must measure the boundaries of the plots where the project is actually planted;

[0034] During the crediting period, the project owner shall monitor the project boundary according to the monitoring plan to check whether the actual boundary of the project is consistent with the project design document; if the actual boundary is outside the boundary described in the project design document, the boundary shall be based on the project design document; if the actual boundary is within the boundary described in the project design document, the actual boundary shall prevail and a new project boundary vector data file shall be provided;

[0035] If there are any changes in the project boundary, such as changes in the use of sea areas or land use types, the geographical coordinates and area of ​​the expropriated land parcels should be determined, and these parcels should be removed from the project boundary and explained in the subsequent emission reduction accounting report, and will no longer be included in the project boundary;

[0036] (III) Project implementation monitoring requirements

[0037] During the project implementation phase, the main tasks are to monitor and record the implementation of salt marsh vegetation planting, management and greenhouse gas emission-related project activities within the project boundary, and to determine whether they are consistent with the project documents and monitoring plan. The main contents include:

[0038] a) New construction activities for salt marsh vegetation protection: habitat transformation methods, leveling methods, tree species to be planted, planting density, restoration time, planting area, vegetation survival rate and preservation rate, and replanting measures;

[0039] b) Management and protection activities: patrol, replanting, weeding, control of Spartina alterniflora pests and cleaning of marine debris;

[0040] c) The occurrence of natural disasters such as pests and diseases, fire, extreme drought / rainfall, typhoon storm surge, cold wave and sea level rise erosion, human interference such as mowing, and changes in sea area use or land use within the project boundary, such as time, location, area, boundary, and damage intensity;

[0041] (IV) Requirements for project carbon layer division

[0042] During the project implementation phase, if any of the following situations occurs within the project boundary, the project owner must adjust the last divided carbon layer before each monitoring:

[0043] a) The actual activities of the project are inconsistent with the project design and affect the uniformity of the project carbon layer, such as changes in plant selection, planting time, planting density, planting area and project boundaries;

[0044] b) Increased heterogeneity within the carbon layer due to natural factors such as pests and diseases, fires, extreme drought / rainfall, typhoon storm surges and cold waves, and human disturbances such as mowing;

[0045] c) Changes in carbon layer boundaries due to changes in sea area use or land use types;

[0046] If the last monitoring found that two or more carbon layers have similar carbon storage and changes, these different carbon layers can be merged into one carbon layer to reduce the monitoring workload;

[0047] (V) Sampling design requirements

[0048] (VI) Sample site setting requirements

[0049] (VII) Monitoring frequency and time requirements

[0050] The project owner should determine the monitoring frequency of fixed sample plots during the project design phase, generally at least once every five years; the first monitoring time should not be earlier than the project application registration time;

[0051] (VIII) Biomass carbon storage monitoring and calculation requirements

[0052] Monitoring of carbon stocks in herbaceous biomass;

[0053] (IX) Data accuracy control and correction requirements

[0054] (X) Data management and archiving requirements

[0055] For the collected monitoring data, the project owner shall establish an original record and ledger management system for data and information, and properly preserve the original records of vegetation surveys, project boundary and carbon layer monitoring data, project boundary and carbon layer adjustment records and related written documents. The original records and ledgers shall clearly state the data source, data acquisition time and relevant responsible persons for filling in the ledgers;

[0056] All data monitored by the project should be electronically archived and kept for at least 10 years after the last phase of the voluntary greenhouse gas emission reduction project is registered to ensure that the relevant data is traceable;

[0057] S4: During the project review and verification stage, the key points to be noted include: review and verification of project applicable conditions, review and verification of project start time, review and verification of project boundaries, review and verification of project emission reduction accounting, review and verification of sample site monitoring, and review and verification of parameters;

[0058] Key points for verification and assessment of sample plot monitoring

[0059] Herbaceous vegetation coverage: The measurement error of the plot vegetation coverage shall not exceed ±5%;

[0060] Number of trees: The measurement error of each shrub species in the sample plot shall not exceed ±5%;

[0061] Crown diameter: The measurement error of crown diameter of the sample site shall not exceed ±10%.

[0062] Furthermore,

[0063] Baseline Removal Calculation

[0064] According to the applicable conditions of this document, the baseline removal volume in the tth year after the start of the project is calculated as 0, that is:

[0065] ΔC BSL，t =0 (1)

[0066] Where:

[0067] ΔC BSL，t , the baseline removal amount of the project in year t, in tons of carbon dioxide equivalent per year (tCO2e·a -1 );

[0068] t, the number of years since the start of the project, t = 1, 2, 3, ..., dimensionless;

[0069] Project removal calculation

[0070] The project removal volume in the tth year after the project starts is calculated according to formula (2):

[0071]

[0072] Where:

[0073] ΔC PROJ，t , the project removal amount in the tth year of the project, in tons of carbon dioxide equivalent per year (tCO2e·a -1 );

[0074] ΔC Biomass_HerbPROJ，t , the change in carbon stock of herbaceous biomass in the tth year of the project, in tons of carbon per year (tC·a -1 );

[0075] ΔC Biomass_ShrubPROJ，t , the change in shrub biomass carbon stock in the tth year of the project, in tons of carbon per year (tC·a -1 );

[0076] ΔSOC PROJ，t , the change in soil organic carbon storage in the tth year of the project, in tons of carbon per year (t C·a -1 );

[0077] The ratio of the relative molecular mass of carbon dioxide to carbon;

[0078] GHG PROJ，t , the non-CO2 greenhouse gas emissions caused by soil microbial metabolism in year t of the project, in tons of carbon dioxide equivalent per year (tCO2e·a -1 );

[0079] t, the number of years since the start of the project, t = 1, 2, 3, ..., dimensionless;

[0080] Changes in carbon storage of herbaceous biomass in the project

[0081] Assuming that the change of carbon stock of herbaceous biomass in each carbon layer within the project boundary within a certain period of time (from t1 to t2) is linear, the change of carbon stock of herbaceous biomass in the project is calculated according to formula (3):

[0082]

[0083] Where:

[0084] ΔC Biomass_HerbPROJ，t , the change in carbon stock of herbaceous biomass in the monitored project in year t, in tons of carbon per year (t C·a -1 );

[0085] C Biomass_Herb，i，t , the carbon stock of herbaceous biomass in the carbon layer of the i-th project in year t, in tons of carbon (tC);

[0086] i, project carbon layer, i = 1, 2, 3..., dimensionless;

[0087] t, the number of years since the start of the project, t = 1, 2, 3, ..., dimensionless;

[0088] t1, t2, the t1th and t2th year after the start of the project, with t1≤t≤t2, the unit is year(a).

[0089] The carbon storage of herbaceous biomass in each carbon layer is calculated according to formulas (4) and (5):

[0090] C Biomass_Herb，i，t =A i，t ×c Biomass_Herb，i，t (4)

[0091]

[0092] Where:

[0093] C Biomass_Herb，i，t , the carbon stock of herbaceous biomass in the carbon layer of the i-th project in year t, in tons of carbon (tC);

[0094] A i，t , in year t, the carbon layer area of ​​item i, in hectares (hm 2 );

[0095] c Biomass_Herb，i，t , in year t, the carbon stock of herbaceous biomass per unit area in the carbon layer of item i, in tons of carbon per hectare (tC·hm -2 );

[0096] c Biomass_Herb，i，p，t , in year t, the carbon storage per unit area of ​​herbaceous biomass in the i-th project carbon layer plot p, in tons of carbon per hectare (tC·hm -2 );

[0097] n i , the number of sample plots in the carbon layer of the i-th project, dimensionless;

[0098] i, project carbon layer, i = 1, 2, 3..., dimensionless;

[0099] t, the number of years since the start of the project, t = 1, 2, 3, ..., dimensionless;

[0100] p, the plot in the carbon layer of the i-th project, p = 1, 2, 3, ..., n i , dimensionless.

[0101] The biomass carbon storage per unit area of ​​each plot was calculated based on the biomass of herbaceous vegetation:

[0102] c Biomass_Herb，i，p，t =∑ j (B Biomass_Herb，i，p，t，j ×CF j ) (6)

[0103] Where:

[0104] c Biomass_Herb，i，p，t , in year t, the carbon storage per unit area of ​​herbaceous biomass in the i-th project carbon layer plot p, in tons of carbon per hectare (tC·hm -2 );

[0105] B Biomass_Herb，i，p，t，j , in year t, the biomass per unit area of ​​herbaceous vegetation species j in the i-th project carbon layer plot p, in tons per hectare (td·m·hm -2 );

[0106] CF j , the carbon content of biomass of vegetation species j, in tons of carbon per ton (t C (t dm) -1 );

[0107] i, project carbon layer, i = 1, 2, 3..., dimensionless;

[0108] t, the number of years since the start of the project, t = 1, 2, 3, ..., dimensionless;

[0109] p, the sample plot in the carbon layer of the i-th project, p = 1, 2, 3..., n i , dimensionless;

[0110] j, salt marsh vegetation species, j = 1, 2, 3, ..., dimensionless;

[0111] During the project design and monitoring phases, the biomass per unit area of ​​each herbaceous vegetation in the sample plots was calculated using the default value method:

[0112] B Biomass_Herb，p，j =b Biomass_Herb，p，j ×CC Biomass_Herb，i，p，t ×(1+R j ) (7)

[0113] Where:

[0114] B Biomass_Herb，p，j , the biomass per unit area of ​​herbaceous vegetation species j in plot p, in tons per hectare (td·m·hm -2 );

[0115] b Biomass_Herb，p，j , when the vegetation coverage of plot p is 1.0, the aboveground biomass per unit area of ​​herbaceous vegetation species j, in tons per hectare (td·m·hm -2 );

[0116] CC Biomass_Herb，i，p，t , the vegetation cover of the i-th project carbon layer plot p in the t-th year, expressed as a decimal, dimensionless;

[0117] R j , the ratio of belowground to aboveground biomass of vegetation species j, dimensionless;

[0118] p, the sample plot in the carbon layer of the i-th project, p = 1, 2, 3..., n i , dimensionless;

[0119] j, salt marsh vegetation species, j = 1, 2, 3, ..., dimensionless;

[0120] Project Shrub Biomass Carbon Stock Changes

[0121] Assuming that the change of shrub biomass carbon stock in each carbon layer within the project boundary within a certain period of time (from t1 to t2) is linear, the change of shrub biomass carbon stock in the project is calculated according to formula (8):

[0122]

[0123] Where:

[0124] ΔC Biomass_ShurbPROJ，t , the change in shrub biomass carbon stock in the monitored project in year t, in tons of carbon per year (t C·a -1 );

[0125] C Biomass_Shurb，i，t , the shrub biomass carbon stock in the i-th project carbon layer in year t, in tons of carbon (tC);

[0126] i, project carbon layer, i = 1, 2, 3..., dimensionless;

[0127] t, the number of years since the start of the project, t = 1, 2, 3, ..., dimensionless;

[0128] t1, t2, the t1th and t2th year after the start of the project, with t1≤t≤t2, the unit is year(a).

[0129] The carbon storage of shrub biomass in each carbon layer is calculated according to formulas (9) and (10):

[0130] C Biomass_Shurb，i，t =A i，t ×c Biomass_Shurb，i，t (9)

[0131]

[0132] Where:

[0133] C Biomass_Shurb，i，t , the shrub biomass carbon stock in the i-th project carbon layer in year t, in tons of carbon (tC);

[0134] A i，t , in year t, the carbon layer area of ​​item i, in hectares (hm 2 );

[0135] c Biomass_Shurb，i，t , in year t, the carbon stock of shrub biomass per unit area in the i-th project carbon layer, in tons of carbon per hectare (tC·hm -2 );

[0136] c Biomass_Shurb，i，p，t , in year t, the carbon storage per unit area of ​​shrub biomass in the i-th project carbon layer plot p, in tons of carbon per hectare (tC·hm -2 );

[0137] n i , the number of sample plots in the carbon layer of the i-th project, dimensionless;

[0138] i, project carbon layer, i = 1, 2, 3..., dimensionless;

[0139] t, the number of years since the start of the project, t = 1, 2, 3, ..., dimensionless;

[0140] p, the sample plot in the carbon layer of the i-th project, p = 1, 2, 3..., n i , dimensionless;

[0141] The biomass carbon storage per unit area of ​​each plot was calculated based on the biomass of shrub vegetation:

[0142] c Biomass_Shurb，i，p，t =∑ j (B Biomass_Shurb，i，p，t，j ×CF j ) (11)Where:

[0143] c Biomass_Shurb，i，p，t , in year t, the carbon storage per unit area of ​​shrub biomass in the i-th project carbon layer plot p, in tons of carbon per hectare (tC·hm -2 );

[0144] B Biomass_Shurb，i，p，t，j , in year t, the biomass per unit area of ​​shrub vegetation species j in the i-th project carbon layer plot p, in tons per hectare (td·m·hm -2 );

[0145] CF j , the carbon content of biomass of vegetation species j, in tons of carbon per ton (t C (t dm) -1 );

[0146] i, project carbon layer, i = 1, 2, 3..., dimensionless;

[0147] t, the number of years since the start of the project, t = 1, 2, 3, ..., dimensionless;

[0148] p, the plot in the carbon layer of the i-th project, p = 1, 2, 3, ..., n i , dimensionless;

[0149] j, salt marsh vegetation species, j = 1, 2, 3, ..., dimensionless;

[0150] During the project design and monitoring phases, the biomass per unit area of ​​each vegetation species was calculated using the monitoring data of the tree measurement factor using the biomass equation:

[0151] B Biomass_Shurb，p，j =b Biomass_Shurb，p，j ×(1+R j ) (12)

[0152] Where:

[0153] B Biomass_Shurb，p，j , the biomass per unit area of ​​shrub vegetation species j in plot p, in tons per hectare (td·m·hm -2 );

[0154] b Biomass_SHurb，p，j , the aboveground biomass per unit area of ​​shrub vegetation species j in plot p, in tons per hectare (td·m·hm -2 )

[0155] R j , the ratio of belowground to aboveground biomass of vegetation species j, dimensionless;

[0156] p, the plot in the carbon layer of the i-th project, p = 1, 2, 3, ..., n i , dimensionless;

[0157] j, salt marsh vegetation species, j = 1, 2, 3, ..., dimensionless;

[0158]

[0159] Where:

[0160] b Biomass_Shurb，p，j , the aboveground biomass per unit area of ​​shrub vegetation species j in plot p, in tons per hectare (td·m·hm -2 );

[0161] f j (x 1，p，m , x 2，p，m , x 3，p，m , ...), the equation for converting the measured factors (x1, x2, x3 ...) of the mth plant of shrub vegetation species j in plot p into the biomass of a single plant, in tons (t dm);

[0162] A s , monitoring plot area, unit is hectare (hm 2 );

[0163] p, the sample plot in the carbon layer of the i-th project, p = 1, 2, 3..., n i , dimensionless;

[0164] j, salt marsh vegetation species, j = 1, 2, 3, ..., dimensionless;

[0165] m, the mth plant of salt marsh vegetation species j, m = 1, 2, 3, ...;

[0166] Changes in soil organic carbon storage in the project

[0167] Assuming that after the salt marsh vegetation is planted, the increase in soil organic carbon storage in each carbon layer is linear; the change in soil organic carbon storage within the project boundary is calculated according to formula (14):

[0168]

[0169] Where:

[0170] ΔSOC PROJ，t , the annual change in soil organic carbon storage within the project boundary, in tons of carbon per year (t C·a -1 );

[0171] Annual change in soil organic carbon storage per unit area, in tons of carbon per hectare per year (tC·hm -2 a -1 );

[0172] A i，t , the area of ​​the carbon layer of the i-th project in year t, in hectares (hm 2 );

[0173] i, project carbon layer, i = 1, 2, 3..., dimensionless;

[0174] t, the number of years since the start of the project, t = 1, 2, 3, ..., dimensionless;

[0175] Project soil non-CO2 greenhouse gas emissions

[0176] The non-CO2 greenhouse gas emissions from soils of the project are the sum of CH4 and N2O emissions from soils in each carbon layer:

[0177]

[0178] Where:

[0179] ΔGHG PROJ，t , CO2 equivalent emissions of soil CH4 and N2O within the project boundary in year t, in tons of carbon dioxide equivalent per year (tCO2e·a -1 );

[0180] In year t, the CO2 equivalent emissions of CH4 and N2O from the carbon layer of the i-th project are expressed in tons of carbon dioxide equivalent per year (t CO2e·a -1 );

[0181] In year t, the CO2 equivalent emission of soil N2O in the carbon layer of project i is expressed in tons of carbon dioxide equivalent per year (tCO2e·a -1 );

[0182] In year t, the CH4 emission per unit area of ​​soil is expressed in tons of methane per hectare per year (tCH4·hm -2 ·a -1 );

[0183] In year t, the N2O emission per unit area of ​​soil is expressed in tons of nitrous oxide per hectare per year (tN2O·hm -2 ·a -1 );

[0184] The global warming potential of CH4 on a 100-year time scale;

[0185] The global warming potential of N2O on a 100-year time scale;

[0186] A i，t , the area of ​​the carbon layer of the i-th project in year t, in hectares (hm 2 );

[0187] i, project carbon layer, i = 1, 2, 3..., dimensionless;

[0188] t, the number of years since the start of the project, t = 1, 2, 3, ..., dimensionless;

[0189] Project leakage calculation

[0190] Leakage is not considered in the project according to applicable conditions;

[0191] Project emission reduction calculation

[0192] The emission reduction of the project in the tth year after the project starts is calculated according to formula (18):

[0193] CDR t =(ΔC PROJ，t -ΔC BSL，t -LK t )×(1-K RISK ) (18)

[0194] Where:

[0195] CDR t , the emission reduction of the project in the tth year, in tons of carbon dioxide equivalent per year (t CO2e·a -1 );

[0196] ΔC PROJ，t , the project removal amount in the tth year of the project, in tons of carbon dioxide equivalent per year (t CO2e·a -1 );

[0197] ΔC BSL，t Baseline removals in year t of the project, in tons of carbon dioxide equivalent per year (t CO2e·a -1 );

[0198] LK t , the leakage amount of the project in year t, in tons of carbon dioxide equivalent per year (t CO2e·a -1 ); LK t =0;

[0199] K RISK , the non-persistent risk deduction rate of the project, in percentage (%);

[0200] t, the number of years since the start of the project, t = 1, 2, 3, ..., dimensionless.

[0201] Beneficial effects of the present invention:

[0202] The present invention belongs to the methodology in the field of forestry and other carbon sink types. Qualified salt marsh vegetation restoration projects can design and approve voluntary greenhouse gas emission reduction projects, as well as calculate and verify the emission reduction amounts of voluntary greenhouse gas emission reduction projects in accordance with this method. This method can scientifically and systematically evaluate the greenhouse gas emission reduction effects of coastal salt marsh wetland vegetation restoration projects, and provide strong support for the design and approval of projects. DETAILED DESCRIPTION

[0203] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0204] Example:

[0205] Applicable conditions

[0206] The coastal salt marsh wetland vegetation restoration project using the present invention must meet the following conditions:

[0207] a) In unvegetated tidal flats where the habitat is suitable or the habitat is restored to be suitable for the growth of salt marsh plants, the land or sea area use mode under the baseline scenario is anthropogenic activities that can be cleared (such as marine aquaculture, abandoned or illegal engineering occupation, etc.), and the project scenario is the activity of constructing salt marsh vegetation through artificial planting;

[0208] b) The ownership of the sea areas and land within the project boundary is clear, with ownership certification documents issued or issued by the people's government at or above the county level or the competent department of natural resources (ocean);

[0209] c) The continuous area of ​​artificially planted salt marsh vegetation is not less than 400m 2 ;

[0210] d) The intertidal zone attributes of the land within the project boundary shall not be changed, that is, the tidal flat surface after filling, raising or leveling shall still be completely covered by sea water at the average high tide;

[0211] e) The project shall not apply fertilizers or harvest salt marsh plants for firewood, etc.;

[0212] f) The project should comply with laws and regulations and industry development policies.

[0213] A method for evaluating greenhouse gas emission reduction in a coastal salt marsh wetland vegetation restoration project comprises the following steps:

[0214] S1: Clarify the project boundaries, project crediting period, project life, selected carbon pools and greenhouse gas emission sources;

[0215] 1. Project Boundary

[0216] The coastal salt marsh wetland vegetation restoration project area may include several discontinuous planting plots, each of which should have specific geographical boundaries, and the project boundary does not include areas exceeding 400m 2 The above ponds, roads, ditches and tidal gullies with a width greater than 3m, and salt marsh plots that existed before the project and have a coverage greater than 5% are not included. The project boundary can be determined by one of the following methods:

[0217] a) Use the Beidou Satellite Navigation System (BDS) to directly determine the coordinates of the turning points of the project site boundary, with a single-point positioning error of no more than ±2m;

[0218] b) Using high-resolution (spatial resolution better than 2m) geospatial data such as satellite remote sensing images, aerial images, coastal salt marsh wetland distribution maps, and coastal protection and restoration planning maps, the boundary coordinates of the project plot can be directly read with the assistance of a geographic information system (GIS);

[0219] (II) Project credit period

[0220] The project crediting period is the time limit for applying for project emission reduction registration, starting from the time when the project emission reduction is generated and applied for registration by the project owner. The shortest period is not less than 20 years and the longest period is not more than 40 years. The project crediting period must be within the life of the project.

[0221] (III) Project life span

[0222] The life of the project shall be within the effective period of the project owner's ownership or right to use the sea and land within the project boundary. The start time of the project life is the start date of the first habitat restoration, land preparation, sowing or planting project within the project boundary;

[0223] 4. Selection of carbon pools and greenhouse gas emission sources

[0224] The carbon pools selected or not selected within the project boundary are shown in Table 1.

[0225] Table 1 Selection of carbon pools

[0226]

[0227] The greenhouse gas emission sources and types selected or not selected within the project boundary are shown in Table 2.

[0228] Table 2 Selection of greenhouse gas emission sources

[0229]

[0230] S2: Carry out the calculation of project emission reductions, complete the baseline scenario identification, additionality demonstration and project carbon layer division, and then carry out the baseline removal calculation, project removal calculation, project leakage calculation and project emission reduction accounting;

[0231] 1. Baseline scenario identification

[0232] The baseline scenario for the coastal salt marsh wetland vegetation restoration project is: before the implementation of the vegetation restoration project, the sea or land resources within the project boundary are developed and utilized in the form of unvegetated tidal flats or human activities that can be cleared, such as marine aquaculture, abandonment or illegal engineering occupation;

[0233] 2. Additionality Argument

[0234] Coastal salt marsh wetland vegetation restoration is a non-profit public welfare activity. Coastal salt marsh wetlands are susceptible to extreme climate events and human activities. Usually, activities such as salt marsh vegetation planting and subsequent management are costly and not financially attractive. For projects that meet the applicable conditions, their additionality is exempted from demonstration.

[0235] (III) Project carbon layer division

[0236] In order to improve the accuracy of carbon stock change calculation and reduce the number of monitoring plots under certain accuracy requirements, the plots within the project boundary should be divided into different levels according to different stratification factors, including carbon stratification in the project design stage and carbon stratification in the project implementation stage;

[0237] The carbon layers divided during the project design phase are used to estimate the change in carbon storage. The carbon layers are divided by comprehensively considering the habitat conditions of the plots within the project boundary before the salt marsh vegetation is planted, such as geographical location, soil substrate and tidal flat elevation, as well as factors such as plant selection, planting time and planting density. Plots with no significant differences are divided into the same carbon layer.

[0238] The carbon layers divided during the project implementation phase are used to calculate the change in carbon storage, which is mainly based on the division of carbon layers during the project design phase and is adjusted and determined in combination with the actual situation of salt marsh vegetation restoration activities; if there are natural factors such as pests and diseases, fires, extreme droughts / rainfalls, typhoon storm surges and cold waves, or human influences such as plant death caused by mowing, which increase the heterogeneity of the original carbon layer, or if the boundaries of the carbon layer change due to changes in the use of the sea area or land use types, the project carbon layer must be adjusted;

[0239] S3: The use of monitoring methodology in the process of calculating project emission reductions, including the parameters and data that need to be determined in the project design phase, the parameters and data that need to be monitored in the project implementation phase, and the data management requirements for project implementation and monitoring;

[0240] Data management requirements for project implementation and monitoring

[0241] 1. General requirements

[0242] Project owners should take the following measures to ensure the quality of monitoring parameters and data:

[0243] a) Follow the data monitoring procedures and method requirements determined during the project design phase and formulate a detailed monitoring plan;

[0244] b) Establish a credible and transparent internal management system and quality assurance system, including but not limited to reliable field measurements, mutual inspection and verification of field measurements, and input, calculation and verification of internal data;

[0245] c) Clarify the responsible departments and their responsibilities, specific work requirements, data management procedures, and work time nodes;

[0246] d) Designate dedicated personnel to monitor, collect, record and cross-check project boundaries, project implementation and vegetation cover data;

[0247] (II) Project boundary monitoring requirements

[0248] During the project design phase, the project owner must clearly identify the project plot boundaries where salt marsh vegetation is planned to be planted and provide vector data files of all project plot boundaries. During the project implementation phase, the project owner must measure the boundaries of the plots where the project is actually planted;

[0249] During the crediting period, the project owner shall monitor the project boundary according to the monitoring plan to check whether the actual boundary of the project is consistent with the project design document; if the actual boundary is outside the boundary described in the project design document, the boundary shall be based on the project design document; if the actual boundary is within the boundary described in the project design document, the actual boundary shall prevail and a new project boundary vector data file shall be provided;

[0250] If there are any changes in the project boundary, such as changes in the use of sea areas or land use types, the geographical coordinates and area of ​​the expropriated land parcels should be determined, and these parcels should be removed from the project boundary and explained in the subsequent emission reduction accounting report, and will no longer be included in the project boundary;

[0251] (III) Project implementation monitoring requirements

[0252] During the project implementation phase, the main tasks are to monitor and record the implementation of salt marsh vegetation planting, management and greenhouse gas emission-related project activities within the project boundary, and to determine whether they are consistent with the project documents and monitoring plan. The main contents include:

[0253] a) New construction activities for salt marsh vegetation protection: habitat transformation methods, leveling methods, tree species to be planted, planting density, restoration time, planting area, vegetation survival rate and preservation rate, and replanting measures;

[0254] b) Management and protection activities: patrol, replanting, weeding, control of Spartina alterniflora pests and cleaning of marine debris;

[0255] c) The occurrence of natural disasters such as pests and diseases, fire, extreme drought / rainfall, typhoon storm surge, cold wave and sea level rise erosion, human interference such as mowing, and changes in sea area use or land use within the project boundary, such as time, location, area, boundary, and damage intensity;

[0256] (IV) Requirements for project carbon layer division

[0257] During the project implementation phase, if any of the following situations occurs within the project boundary, the project owner must adjust the last divided carbon layer before each monitoring:

[0258] a) The actual activities of the project are inconsistent with the project design and affect the uniformity of the project carbon layer, such as changes in plant selection, planting time, planting density, planting area and project boundaries;

[0259] b) Increased heterogeneity within the carbon layer due to natural factors such as pests and diseases, fires, extreme drought / rainfall, typhoon storm surges and cold waves, and human disturbances such as mowing;

[0260] c) Changes in carbon layer boundaries due to changes in sea area use or land use types;

[0261] If the last monitoring found that two or more carbon layers have similar carbon storage and changes, these different carbon layers can be merged into one carbon layer to reduce the monitoring workload;

[0262] (V) Sampling design requirements

[0263] (VI) Sample site setting requirements

[0264] (VII) Monitoring frequency and time requirements

[0265] The project owner should determine the monitoring frequency of fixed sample plots during the project design phase, generally at least once every five years; the first monitoring time should not be earlier than the project application registration time;

[0266] (VIII) Biomass carbon storage monitoring and calculation requirements

[0267] Monitoring of carbon stocks in herbaceous biomass;

[0268] (IX) Data accuracy control and correction requirements

[0269] (X) Data management and archiving requirements

[0270] For the collected monitoring data, the project owner shall establish an original record and ledger management system for data and information, and properly preserve the original records of vegetation surveys, project boundary and carbon layer monitoring data, project boundary and carbon layer adjustment records and related written documents. The original records and ledgers shall clearly state the data source, data acquisition time and relevant responsible persons for filling in the ledgers;

[0271] All data monitored by the project should be electronically archived and kept for at least 10 years after the last phase of the voluntary greenhouse gas emission reduction project is registered to ensure that the relevant data is traceable;

[0272] S4: During the project review and verification stage, the key points to be noted include: review and verification of project applicable conditions, review and verification of project start time, review and verification of project boundaries, review and verification of project emission reduction accounting, review and verification of sample site monitoring, and review and verification of parameters;

[0273] Key points for verification and assessment of sample plot monitoring

[0274] Herbaceous vegetation coverage: The measurement error of the plot vegetation coverage shall not exceed ±5%;

[0275] Number of trees: The measurement error of each shrub species in the sample plot shall not exceed ±5%;

[0276] Crown diameter: The measurement error of crown diameter of the sample site shall not exceed ±10%.

[0277] Furthermore,

[0278] Baseline Removal Calculation

[0279] According to the applicable conditions of this document, the baseline removal volume in the tth year after the start of the project is calculated as 0, that is:

[0280] ΔC BSL，t =0 (1)

[0281] Where:

[0282] ΔC BSL，i , the baseline removal amount of the project in year t, in tons of carbon dioxide equivalent per year (tCO2e·a -1 );

[0283] t, the number of years since the start of the project, t = 1, 2, 3, ..., dimensionless;

[0284] Project removal calculation

[0285] The project removal volume in the tth year after the project starts is calculated according to formula (2):

[0286]

[0287] Where:

[0288] ΔC PROJ，t , the project removal amount in the tth year of the project, in tons of carbon dioxide equivalent per year (tCO2e·a -1 );

[0289] ΔC Biomass_HerbPROJ，t , the change in carbon stock of herbaceous biomass in the tth year of the project, in tons of carbon per year (tC·a -1 );

[0290] ΔC Biomass_ShrubPROJ，t , the change in shrub biomass carbon stock in the tth year of the project, in tons of carbon per year (tC·a -1 );

[0291] ΔSOC PROJ，t , the change in soil organic carbon storage in the tth year of the project, in tons of carbon per year (t C·a -1 );

[0292] The ratio of the relative molecular mass of carbon dioxide to carbon;

[0293] GHG PROJ，t , the non-CO2 greenhouse gas emissions caused by soil microbial metabolism in year t of the project, in tons of carbon dioxide equivalent per year (tCO2e·a -1 );

[0294] t, the number of years since the start of the project, t = 1, 2, 3, ..., dimensionless;

[0295] Changes in carbon storage of herbaceous biomass in the project

[0296] Assuming that the change of carbon stock of herbaceous biomass in each carbon layer within the project boundary within a certain period of time (from t1 to t2) is linear, the change of carbon stock of herbaceous biomass in the project is calculated according to formula (3):

[0297]

[0298] Where:

[0299] ΔC Biomass_HerbPROJ，t , the change in carbon stock of herbaceous biomass in the monitored project in year t, in tons of carbon per year (t C·a -1 );

[0300] C Biomass_Herb，i，t , the carbon stock of herbaceous biomass in the carbon layer of the i-th project in year t, in tons of carbon (tC);

[0301] i, project carbon layer, i = 1, 2, 3..., dimensionless;

[0302] t, the number of years since the start of the project, t = 1, 2, 3, ..., dimensionless;

[0303] t1, t2, the t1th and t2th year after the start of the project, with t1≤t≤t2, the unit is year(a).

[0304] The carbon storage of herbaceous biomass in each carbon layer is calculated according to formulas (4) and (5):

[0305] C Biomass_Herb，i，t =A i，t ×c Biomass_Herb，i，t (4)

[0306]

[0307] Where:

[0308] C Biomass_Herb，i，t , the carbon stock of herbaceous biomass in the carbon layer of the i-th project in year t, in tons of carbon (tC);

[0309] A i，t , in year t, the carbon layer area of ​​item i, in hectares (hm 2 );

[0310] c Biomass_Herb，i，t , in year t, the carbon stock of herbaceous biomass per unit area in the carbon layer of item i, in tons of carbon per hectare (tC·hm -2 );

[0311] C Biomass_Herb,i,p,t , in year t, the carbon storage per unit area of ​​herbaceous biomass in the i-th project carbon layer plot p, in tons of carbon per hectare (tC·hm -2 );

[0312] n i , the number of sample plots in the carbon layer of the i-th project, dimensionless;

[0313] i, project carbon layer, i = 1, 2, 3..., dimensionless;

[0314] t, the number of years since the start of the project, t = 1, 2, 3, ..., dimensionless;

[0315] p, the plot in the carbon layer of the i-th project, p = 1, 2, 3, ..., n i , dimensionless.

[0316] The biomass carbon storage per unit area of ​​each plot was calculated based on the biomass of herbaceous vegetation:

[0317] C Biomass_herb,i,p,t =Σ j (B Biomass_Herb,i,p,t,j ×CF j ) (6)

[0318] Where:

[0319] C Biomass_Herb,i,p,t , in year t, the carbon storage per unit area of ​​herbaceous biomass in the i-th project carbon layer plot p, in tons of carbon per hectare (tC·hm-2 );

[0320] C Biomass_Herb,i,p,t , in year t, the biomass per unit area of ​​herbaceous vegetation species j in the i-th project carbon layer plot p, in tons per hectare (td·m·hm -2 );

[0321] CF j , the carbon content of biomass of vegetation species j, in tons of carbon per ton (t C (t dm) -1 );

[0322] i, project carbon layer, i = 1, 2, 3..., dimensionless;

[0323] t, the number of years since the start of the project, t = 1, 2, 3, ..., dimensionless;

[0324] p, the sample plot in the carbon layer of the i-th project, p = 1, 2, 3..., n i , dimensionless;

[0325] j, salt marsh vegetation species, j = 1, 2, 3, ..., dimensionless;

[0326] During the project design and monitoring phases, the biomass per unit area of ​​each herbaceous vegetation in the sample plots was calculated using the default value method:

[0327] B Biomass_Herb，p，j =b Biomass_Herb，p，j ×CC Biomass_Herb，i，p，t ×(1+R j ) (7)

[0328] Where:

[0329] B Biomass_Herb，p，j , the biomass per unit area of ​​herbaceous vegetation species j in plot p, in tons per hectare (td·m·hm -2 );

[0330] b Biomass_Herb,p,j , when the vegetation coverage of plot p is 1.0, the aboveground biomass per unit area of ​​herbaceous vegetation species j, in tons per hectare (td·m·hm -2 );

[0331] CC Bionmass_Herb，i，p，t , the vegetation cover of the i-th project carbon layer plot p in the t-th year, expressed as a decimal, dimensionless;

[0332] R j , the ratio of belowground to aboveground biomass of vegetation species j, dimensionless;

[0333] p, the sample plot in the carbon layer of the i-th project, p = 1, 2, 3..., n i, dimensionless;

[0334] j, salt marsh vegetation species, j = 1, 2, 3, ..., dimensionless;

[0335] Project Shrub Biomass Carbon Stock Changes

[0336] Assuming that the change of shrub biomass carbon stock in each carbon layer within the project boundary within a certain period of time (from t1 to t2) is linear, the change of shrub biomass carbon stock in the project is calculated according to formula (8):

[0337]

[0338] Where:

[0339] ΔC Biomass_ShurbPROJ，t , the change in shrub biomass carbon stock in the monitored project in year t, in tons of carbon per year (t C·a -1 );

[0340] C Biomass_Shurb，i，t , the shrub biomass carbon stock in the i-th project carbon layer in year t, in tons of carbon (tC);

[0341] i, project carbon layer, i = 1, 2, 3..., dimensionless;

[0342] t, the number of years since the start of the project, t = 1, 2, 3, ..., dimensionless;

[0343] t1, t2, the t1th and t2th year after the start of the project, with t1≤t≤t2, the unit is year(a).

[0344] The carbon storage of shrub biomass in each carbon layer is calculated according to formulas (9) and (10):

[0345] C Biomass_Shurb，i，t =A i，t ×c Biomass_Shurb，i，t (9)

[0346]

[0347] Where:

[0348] C Biomass_Shurb，i，t , the shrub biomass carbon stock in the i-th project carbon layer in year t, in tons of carbon (tC);

[0349] A i，t , in year t, the carbon layer area of ​​item i, in hectares (hm 2 );

[0350] c Biomass_Shurb，i，t , in year t, the carbon stock of shrub biomass per unit area in the i-th project carbon layer, in tons of carbon per hectare (tC·hm-2 );

[0351] c Biomass_Shurb，i，p，t , in year t, the carbon storage per unit area of ​​shrub biomass in the i-th project carbon layer plot p, in tons of carbon per hectare (tC·hm -2 );

[0352] n i , the number of sample plots in the carbon layer of the i-th project, dimensionless;

[0353] i, project carbon layer, i = 1, 2, 3..., dimensionless;

[0354] t, the number of years since the start of the project, t = 1, 2, 3, ..., dimensionless;

[0355] p, the plot in the carbon layer of the i-th project, p = 1, 2, 3, ..., n i , dimensionless;

[0356] The biomass carbon storage per unit area of ​​each plot was calculated based on the biomass of shrub vegetation:

[0357] C Biomass_herb,i,p,t =Σ j (B Biomass_Herb,i,p,t,j ×CF j ) (11)

[0358] Where:

[0359] c Biomass_Shurb，i，p，t , in year t, the carbon storage per unit area of ​​shrub biomass in the i-th project carbon layer plot p, in tons of carbon per hectare (tC·hm -2 );

[0360] B Biomass_Shurb，i，p，t，j , in year t, the biomass per unit area of ​​shrub vegetation species j in the i-th project carbon layer plot p, in tons per hectare (td·m·hm -2 );

[0361] CF j , the carbon content of biomass of vegetation species j, in tons of carbon per ton (t C (t dm) -1 );

[0362] i, project carbon layer, i = 1, 2, 3..., dimensionless;

[0363] t, the number of years since the start of the project, t = 1, 2, 3, ..., dimensionless;

[0364] p, the plot in the carbon layer of the i-th project, p = 1, 2, 3, ..., n i , dimensionless;

[0365] j, salt marsh vegetation species, j = 1, 2, 3, ..., dimensionless;

[0366] During the project design and monitoring phases, the biomass per unit area of ​​each vegetation species was calculated using the monitoring data of the tree measurement factor using the biomass equation:

[0367] B Biomass_Shurb，p，j =b Biomass_Shurb，p，j ×(1+R j ) (12)

[0368] Where:

[0369] B Biomass_Shurb，p，j , the biomass per unit area of ​​shrub vegetation species j in plot p, in tons per hectare (td·m·hm -2 );

[0370] b Biomass_Shurb，p，j , the aboveground biomass per unit area of ​​shrub vegetation species j in plot p, in tons per hectare (td·m·hm -2 )

[0371] R j , the ratio of belowground to aboveground biomass of vegetation species j, dimensionless;

[0372] p, the sample plot in the carbon layer of the i-th project, p = 1, 2, 3..., n i , dimensionless;

[0373] j, salt marsh vegetation species, j = 1, 2, 3, ..., dimensionless;

[0374]

[0375] Where:

[0376] b Biomass_Shurb，p，j , the aboveground biomass per unit area of ​​shrub vegetation species j in plot p, in tons per hectare (td·m·hm -2 );

[0377] f j (x 1，p，m , x 2，p，m , x 3，p，m , ...), the equation for converting the measured factors (x1, x2, x3 ...) of the mth plant of shrub vegetation species j in plot p into the biomass of a single plant, in tons (t dm);

[0378] A s , monitoring plot area, unit is hectare (hm 2 );

[0379] p, the sample plot in the carbon layer of the i-th project, p = 1, 2, 3..., ni , dimensionless;

[0380] j, salt marsh vegetation species, j = 1, 2, 3, ..., dimensionless;

[0381] m, the mth plant of salt marsh vegetation species j, m = 1, 2, 3, ...;

[0382] Changes in soil organic carbon storage in the project

[0383] Assuming that after the salt marsh vegetation is planted, the increase in soil organic carbon storage in each carbon layer is linear; the change in soil organic carbon storage within the project boundary is calculated according to formula (14):

[0384]

[0385] Where:

[0386] ΔSOC PROJ，t , the annual change in soil organic carbon storage within the project boundary, in tons of carbon per year (t C·a -1 );

[0387] Annual change in soil organic carbon storage per unit area, in tons of carbon per hectare per year (tC·hm -2 a -1 );

[0388] A i，t , the area of ​​the carbon layer of the i-th project in year t, in hectares (hm 2 );

[0389] i, project carbon layer, i = 1, 2, 3..., dimensionless;

[0390] t, the number of years since the start of the project, t = 1, 2, 3, ..., dimensionless;

[0391] Project soil non-CO2 greenhouse gas emissions

[0392] The non-CO2 greenhouse gas emissions from soils of the project are the sum of CH4 and N2O emissions from soils in each carbon layer:

[0393]

[0394] Where:

[0395] ΔGHG PROJ，t , CO2 equivalent emissions of soil CH4 and N2O within the project boundary in year t, in tons of carbon dioxide equivalent per year (tCO2e·a -1 );

[0396] In year t, the CO2 equivalent emissions of CH4 and N2O from the carbon layer of the i-th project are expressed in tons of carbon dioxide equivalent per year (t CO2e·a -1 );

[0397] In year t, the CO2 equivalent emission of soil N2O in the carbon layer of project i is expressed in tons of carbon dioxide equivalent per year (tCO2e·a -1 );

[0398] In year t, the CH4 emission per unit area of ​​soil is expressed in tons of methane per hectare per year (tCH4·hm -2 ·a -1 );

[0399] In year t, the N2O emission per unit area of ​​soil is expressed in tons of nitrous oxide per hectare per year (tN2O·hm -2 ·a -1 );

[0400] The global warming potential of CH4 on a 100-year time scale;

[0401] The global warming potential of N2O on a 100-year time scale;

[0402] A i，t , the area of ​​the carbon layer of the i-th project in year t, in hectares (hm 2 );

[0403] i, project carbon layer, i = 1, 2, 3..., dimensionless;

[0404] t, the number of years since the start of the project, t = 1, 2, 3, ..., dimensionless;

[0405] Project leakage calculation

[0406] Leakage is not considered in the project according to applicable conditions;

[0407] Project emission reduction calculation

[0408] The emission reduction of the project in the tth year after the project starts is calculated according to formula (18):

[0409] CDR t =(ΔC PROJ，t -ΔC BSL，t -LK t )×(1-K RISK ) (18)

[0410] Where:

[0411] CDR t , the emission reduction of the project in the tth year, in tons of carbon dioxide equivalent per year (t CO2e·a -1 );

[0412] ΔC PROJ，t , the project removal amount in the tth year of the project, in tons of carbon dioxide equivalent per year (t CO2e·a -1 );

[0413] ΔC BSL，t Baseline removals in year t of the project, in tons of carbon dioxide equivalent per year (t CO2e·a -1 );

[0414] LK t , the leakage amount of the project in year t, in tons of carbon dioxide equivalent per year (t CO2e·a -1 ); LK t =0;

[0415] K RISK , the non-persistent risk deduction rate of the project, in percentage (%);

[0416] t, the number of years since the start of the project, t = 1, 2, 3, ..., dimensionless.

[0417] The present invention and its implementation methods are described above, and such description is not restrictive. In short, if ordinary technicians in the field are inspired by it, without departing from the purpose of the invention, they can design structures and embodiments similar to the technical solution without creativity, which should all fall within the protection scope of the present invention.

Claims

1. A greenhouse gas emission reduction assessment method for a coastal salt marsh wetland vegetation restoration project, characterized in that: The specific steps include: S1: Clarify the project boundaries, project crediting period, project life, selected carbon pools and greenhouse gas emission sources; 1. Project Boundary The coastal salt marsh wetland vegetation restoration project area may include several discontinuous planting plots, each of which should have specific geographical boundaries, and the project boundary does not include areas exceeding 400m 2 The above ponds, roads, ditches and tidal gullies with a width greater than 3m, and salt marsh plots that existed before the project and have a coverage greater than 5% are not included. The project boundary can be determined by one of the following methods: a) Use the Beidou satellite navigation system to directly determine the coordinates of the turning points of the project site boundary, with a single-point positioning error of no more than ±2m; b) Using high-resolution geospatial data such as satellite remote sensing images, aerial images, coastal salt marsh wetland distribution maps, and coastal protection and restoration planning maps, the boundary coordinates of the project plot can be directly read with the assistance of a geographic information system; (II) Project credit period The project crediting period is the time limit for applying for project emission reduction registration, starting from the time when the project emission reduction is generated and applied for registration by the project owner. The shortest period is not less than 20 years and the longest period is not more than 40 years. The project crediting period must be within the life of the project. (III) Project life span The life of the project shall be within the effective period of the project owner's ownership or right to use the sea and land within the project boundary. The start time of the project life is the start date of the first habitat restoration, land preparation, sowing or planting project within the project boundary; S2: Carry out the calculation of project emission reductions, complete the baseline scenario identification, additionality demonstration and project carbon layer division, and then carry out the baseline removal calculation, project removal calculation, project leakage calculation and project emission reduction accounting; 1. Baseline scenario identification The baseline scenario for the coastal salt marsh wetland vegetation restoration project is: before the implementation of the vegetation restoration project, the sea or land resources within the project boundary are developed and utilized in the form of unvegetated tidal flats or human activities that can be cleared, such as marine aquaculture, abandonment or illegal engineering occupation; 2. Additionality Argument Coastal salt marsh wetland vegetation restoration is a non-profit public welfare activity. Coastal salt marsh wetlands are susceptible to extreme climate events and human activities. Usually, activities such as salt marsh vegetation planting and subsequent management are costly and not financially attractive. For projects that meet the applicable conditions, their additionality is exempted from demonstration. (III) Project carbon layer division In order to improve the accuracy of carbon stock change calculation and reduce the number of monitoring plots under certain accuracy requirements, the plots within the project boundary should be divided into different levels according to different stratification factors, including carbon stratification in the project design stage and carbon stratification in the project implementation stage; The carbon layers divided during the project design phase are used to estimate the change in carbon storage. The carbon layers are divided by comprehensively considering the habitat conditions of the plots within the project boundary before the salt marsh vegetation is planted, such as geographical location, soil substrate and tidal flat elevation, as well as factors such as plant selection, planting time and planting density. Plots with no significant differences are divided into the same carbon layer. The carbon layers divided during the project implementation phase are used to calculate the change in carbon storage, which is mainly based on the division of carbon layers during the project design phase and is adjusted and determined in combination with the actual situation of salt marsh vegetation restoration activities; if there are natural factors such as pests and diseases, fires, extreme droughts / rainfalls, typhoon storm surges and cold waves, or human influences such as plant death caused by mowing, which increase the heterogeneity of the original carbon layer, or if the boundaries of the carbon layer change due to changes in the use of the sea area or land use types, the project carbon layer must be adjusted; S3: The use of monitoring methodology in the process of calculating project emission reductions, including the parameters and data that need to be determined in the project design phase, the parameters and data that need to be monitored in the project implementation phase, and the data management requirements for project implementation and monitoring; Data management requirements for project implementation and monitoring 1. General requirements Project owners should take the following measures to ensure the quality of monitoring parameters and data: a) Follow the data monitoring procedures and method requirements determined during the project design phase and formulate a detailed monitoring plan; b) Establish a credible and transparent internal management system and quality assurance system, including but not limited to reliable field measurements, mutual inspection and verification of field measurements, and input, calculation and verification of internal data; c) Clarify the responsible departments and their responsibilities, specific work requirements, data management procedures, and work time nodes; d) Designate dedicated personnel to monitor, collect, record and cross-check project boundaries, project implementation and vegetation cover data; (II) Project boundary monitoring requirements During the project design phase, the project owner must clearly identify the project plot boundaries where salt marsh vegetation is planned to be planted and provide vector data files of all project plot boundaries. During the project implementation phase, the project owner must measure the boundaries of the plots where the project is actually planted; During the crediting period, the project owner must monitor the project boundary according to the monitoring plan to check whether the actual project boundary is consistent with the project design documents; If the actual boundary is outside the boundary described in the project design document, the boundary shall be based on the project design document; If the actual boundary is within the boundary described in the project design document, the actual boundary shall prevail and a new project boundary vector data file shall be provided; If there are any changes in the project boundary, such as changes in the use of sea areas or land use types, the geographical coordinates and area of ​​the expropriated land parcels should be determined, and these parcels should be removed from the project boundary and explained in the subsequent emission reduction accounting report, and will no longer be included in the project boundary; (III) Project implementation monitoring requirements During the project implementation phase, the main tasks are to monitor and record the implementation of salt marsh vegetation planting, management and greenhouse gas emission-related project activities within the project boundary, and to determine whether they are consistent with the project documents and monitoring plan. The main contents include: a) New construction activities for salt marsh vegetation protection: habitat transformation methods, leveling methods, tree species to be planted, planting density, restoration time, planting area, vegetation survival rate and preservation rate, and replanting measures; b) Management and protection activities: patrol, replanting, weeding, control of Spartina alterniflora pests and cleaning of marine debris; c) The occurrence of natural disasters such as pests and diseases, fire, extreme drought / rainfall, typhoon storm surge, cold wave and sea level rise erosion, human interference such as mowing, and changes in sea area use or land use within the project boundary, such as time, location, area, boundary, and damage intensity; (IV) Requirements for project carbon layer division During the project implementation phase, if any of the following situations occurs within the project boundary, the project owner must adjust the last divided carbon layer before each monitoring: a) The actual activities of the project are inconsistent with the project design and affect the uniformity of the project carbon layer, such as changes in plant selection, planting time, planting density, planting area and project boundaries; b) Increased heterogeneity within the carbon layer due to natural factors such as pests and diseases, fires, extreme drought / rainfall, typhoon storm surges and cold waves, and human disturbances such as mowing; c) Changes in carbon layer boundaries due to changes in sea area use or land use types; If the last monitoring found that two or more carbon layers have similar carbon storage and changes, these different carbon layers can be merged into one carbon layer to reduce the monitoring workload; (V) Sampling design requirements (VI) Sample site setting requirements (VII) Monitoring frequency and time requirements The project owner should determine the monitoring frequency of fixed sample plots during the project design phase, generally at least once every five years; the first monitoring time should not be earlier than the project application registration time; (VIII) Biomass carbon storage monitoring and calculation requirements Monitoring of carbon stocks in herbaceous biomass; (IX) Data accuracy control and correction requirements (X) Data management and archiving requirements For the collected monitoring data, the project owner shall establish an original record and ledger management system for data and information, and properly preserve the original records of vegetation surveys, project boundary and carbon layer monitoring data, project boundary and carbon layer adjustment records and related written documents. The original records and ledgers shall clearly state the data source, data acquisition time and relevant responsible persons for filling in the ledgers; All data monitored by the project should be electronically archived and kept for at least 10 years after the last phase of the voluntary greenhouse gas emission reduction project is registered to ensure that the relevant data is traceable; S4: During the project review and verification stage, the key points to be noted include: review and verification of project applicable conditions, review and verification of project start time, review and verification of project boundaries, review and verification of project emission reduction accounting, review and verification of sample site monitoring, and review and verification of parameters; Key points for verification and assessment of sample plot monitoring Herbaceous vegetation coverage: The measurement error of the plot vegetation coverage shall not exceed ±5%; Number of trees: The measurement error of each shrub species in the sample plot shall not exceed ±5%; Crown diameter: The measurement error of crown diameter of the sample site shall not exceed ±10%.

2. The greenhouse gas emission reduction assessment method for a coastal salt marsh wetland vegetation restoration project according to claim 1 is characterized by: Baseline Removal Calculation According to the applicable conditions of this document, the baseline removal volume in the tth year after the start of the project is calculated as 0, that is: ΔC BSL,t =0 (1) Where: ΔC BSL，t , the baseline removal amount of the project in year t, in tons of carbon dioxide equivalent per year (tCO2e·a -1 ); t, the number of years since the start of the project, t = 1, 2, 3, ..., dimensionless; Project removal calculation The project removal volume in the tth year after the project starts is calculated according to formula (2): Where: ΔC PROJ,t , the project removal amount in the tth year of the project, in tons of carbon dioxide equivalent per year (tCO2e·a -1 ); ΔC Biomass_HerbPROJ，t , the change in carbon stock of herbaceous biomass in the tth year of the project, in tons of carbon per year (tC·a -1 ); ΔC Biomass_ShrubPROJ，t , the change in shrub biomass carbon stock in the tth year of the project, in tons of carbon per year (tC·a -1 ); ΔSOC PROJ，t , the change in soil organic carbon storage in the tth year of the project, in tons of carbon per year (tC·a -1 ); The ratio of the relative molecular mass of carbon dioxide to carbon; GHG PROJ，t , the non-CO2 greenhouse gas emissions caused by soil microbial metabolism in year t of the project, in tons of carbon dioxide equivalent per year (tCO2e·a -1 ); t, the number of years since the start of the project, t = 1, 2, 3, ..., dimensionless; Changes in carbon storage of herbaceous biomass in the project Assuming that the change of carbon stock of herbaceous biomass in each carbon layer within the project boundary within a certain period of time (from t1 to t2) is linear, the change of carbon stock of herbaceous biomass in the project is calculated according to formula (3): Where: ΔC Biomass_HerbPROJ，t , the change in herbaceous biomass carbon stock in the monitored project in year t, in tons of carbon per year (tC·a -1 ); C Biomass_Herb，i，t , the carbon stock of herbaceous biomass in the carbon layer of the i-th project in year t, in tons of carbon (tC); i, project carbon layer, i = 1, 2, 3..., dimensionless; t, the number of years since the start of the project, t = 1, 2, 3, ..., dimensionless; t1, t2, the t1th and t2th year after the start of the project, with t1≤t≤t2, the unit is year(a). The carbon storage of herbaceous biomass in each carbon layer is calculated according to formulas (4) and (5): C Biomass_Herb，i，t =A i，t ×c Biomass_Herb，i，t (4) Where: C Biomass_Herb，i，t , the carbon stock of herbaceous biomass in the carbon layer of the i-th project in year t, in tons of carbon (tC); A i，t , in year t, the carbon layer area of ​​item i, in hectares (hm 2 ); c Biomass_Herb，i，t , in year t, the carbon stock of herbaceous biomass per unit area in the carbon layer of item i, in tons of carbon per hectare (tC·hm -2 ); c Biomass_Herb，i，p，t , in year t, the carbon storage per unit area of ​​herbaceous biomass in the i-th project carbon layer plot p, in tons of carbon per hectare (tC·hm -2 ); n i , the number of sample plots in the carbon layer of the i-th project, dimensionless; i, project carbon layer, i = 1, 2, 3..., dimensionless; t, the number of years since the start of the project, t = 1, 2, 3, ..., dimensionless; p, the plot in the carbon layer of the i-th project, p = 1, 2, 3, ..., n i , dimensionless. The biomass carbon storage per unit area of ​​each plot was calculated based on the biomass of herbaceous vegetation: C Biomass_Herb,i,p,t =∑ j (B Biomass_Herb,i,p,t,j ×CF j ) (6) Where: C Biomass_Herb,i,p,t , in year t, the carbon storage per unit area of ​​herbaceous biomass in the i-th project carbon layer plot p, in tons of carbon per hectare (tC·hm -2 ); B Biomass_Herb,i,p,t,j , in year t, the biomass per unit area of ​​herbaceous vegetation species j in the i-th project carbon layer plot p, in tons per hectare (td·m·hm -2 ); CF j , the carbon content of biomass of vegetation species j, in tons of carbon per ton (tC(t dm) -1 ); i, project carbon layer, i = 1, 2, 3..., dimensionless; t, the number of years since the start of the project, t = 1, 2, 3, ..., dimensionless; p, the sample plot in the carbon layer of the i-th project, p = 1, 2, 3..., n i , dimensionless; j, salt marsh vegetation species, j = 1, 2, 3, ..., dimensionless; During the project design and monitoring phases, the biomass per unit area of ​​each herbaceous vegetation in the sample plots was calculated using the default value method: B Biomass_Herb，p，j =b Biomass_Herb，p，j ×CC Biomass_Herb，i，p，t ×(1+R j ) (7) Where: B Biomass_Herb，p，j , the biomass per unit area of ​​herbaceous vegetation species j in plot p, in tons per hectare (td·m·hm -2 ); b Biomass_Herb，p，j , when the vegetation coverage of plot p is 1.0, the aboveground biomass per unit area of ​​herbaceous vegetation species j, in tons per hectare (td·m·hm -2 ); CC Biomass_Herb，i，p，t , the vegetation cover of the i-th project carbon layer plot p in the t-th year, expressed as a decimal, dimensionless; R j , the ratio of belowground to aboveground biomass of vegetation species j, dimensionless; p, the sample plot in the carbon layer of the i-th project, p = 1, 2, 3..., n i , dimensionless; j, salt marsh vegetation species, j = 1, 2, 3, ..., dimensionless; Project Shrub Biomass Carbon Stock Changes Assuming that the change of shrub biomass carbon stock in each carbon layer within the project boundary within a certain period of time (from t1 to t2) is linear, the change of shrub biomass carbon stock in the project is calculated according to formula (8): Where: ΔC Biomass_ShurbPROJ，t , the change in shrub biomass carbon stock in the monitored project in year t, in tons of carbon per year (tC·a -1 ); C Biomass_Shurb，i，t , the shrub biomass carbon stock in the i-th project carbon layer in year t, in tons of carbon (tC); i, project carbon layer, i = 1, 2, 3..., dimensionless; t, the number of years since the start of the project, t = 1, 2, 3, ..., dimensionless; t1, t2, the t1th and t2th year after the start of the project, with t1≤t≤t2, the unit is year(a). The carbon storage of shrub biomass in each carbon layer is calculated according to formulas (9) and (10): C Biomass_Shurb，i，t =A i，t ×c Biomass+Shurb，i，t (9) Where: C Biomass_Shurb，i，t , the shrub biomass carbon stock in the i-th project carbon layer in year t, in tons of carbon (tC); A i，t , in year t, the carbon layer area of ​​item i, in hectares (hm 2 ); c Biomass_Shurb，i，t , in year t, the carbon stock of shrub biomass per unit area in the i-th project carbon layer, in tons of carbon per hectare (tC·hm -2 ); c Biomass_Shurb，i，p，t , in year t, the carbon storage per unit area of ​​shrub biomass in the i-th project carbon layer plot p, in tons of carbon per hectare (tC·hm -2 ); n i , the number of sample plots in the carbon layer of the i-th project, dimensionless; i, project carbon layer, i = 1, 2, 3..., dimensionless; t, the number of years since the start of the project, t = 1, 2, 3, ..., dimensionless; p, the plot in the carbon layer of the i-th project, p = 1, 2, 3, ..., n i , dimensionless; The biomass carbon storage per unit area of ​​each plot was calculated based on the biomass of shrub vegetation: c Bionmass_shurb，i，p，t =S j (B Biomass_shurb，i，p，t，j ×CF j ) (11) Where: c Biomass_shurb，i，p，t , in year t, the carbon storage per unit area of ​​shrub biomass in the i-th project carbon layer plot p, in tons of carbon per hectare (tC·hm -2 ); B Biomass_shurb，i，p，t，j , in year t, the biomass per unit area of ​​shrub vegetation species j in the i-th project carbon layer plot p, in tons per hectare (td·m·hm -2 ); CF j , the carbon content of biomass of vegetation species j, in tons of carbon per ton (tC(t dm) -1 ); i, project carbon layer, i = 1, 2, 3..., dimensionless; t, the number of years since the start of the project, t = 1, 2, 3, ..., dimensionless; p, the sample plot in the carbon layer of the i-th project, p = 1, 2, 3..., n i , dimensionless; j, salt marsh vegetation species, j = 1, 2, 3, ..., dimensionless; During the project design and monitoring phases, the biomass per unit area of ​​each vegetation species was calculated using the monitoring data of the tree measurement factor using the biomass equation: B Biomass_Shurb，p，j =b Biomass_Shurb，p，j ×(1+R j ) (12) Where: B Biomass_Shurb，p，j , the biomass per unit area of ​​shrub vegetation species j in plot p, in tons per hectare (td·m·hm -2 ); b Biomass_Shurb，p，j , the aboveground biomass per unit area of ​​shrub vegetation species j in plot p, in tons per hectare (td·m·hm -2 ) R j , the ratio of belowground to aboveground biomass of vegetation species j, dimensionless; p, the plot in the carbon layer of the i-th project, p = 1, 2, 3, ..., n i , dimensionless; j, salt marsh vegetation species, j = 1, 2, 3, ..., dimensionless; Where: b Bionmass_shurb，p，j , the aboveground biomass per unit area of ​​shrub vegetation species j in plot p, in tons per hectare (td·m·hm -2 ); f j (x 1，p，m , x 2，p，m , x 3，p，m , ...), the equation for converting the measured factors (x1, x2, x3 ...) of the mth plant of shrub vegetation species j in plot p into the biomass of a single plant, in tons (t dm); A S , monitoring plot area, unit is hectare (hm 2 ); p, the sample plot in the carbon layer of the i-th project, p = 1, 2, 3..., n i , dimensionless; j, salt marsh vegetation species, j = 1, 2, 3, ..., dimensionless; m, the mth plant of salt marsh vegetation species j, m = 1, 2, 3, ...; Changes in soil organic carbon storage in the project Assuming that after the salt marsh vegetation is planted, the increase in soil organic carbon storage in each carbon layer is linear; the change in soil organic carbon storage within the project boundary is calculated according to formula (14): Where: ΔSOC PROJ，t , the annual change in soil organic carbon storage within the project boundary, in tons of carbon per year (t C·a -1 ); Annual change in soil organic carbon storage per unit area, in tons of carbon per hectare per year (tC·hm -2 a -1 ); A i，t , the area of ​​the carbon layer of the i-th project in year t, in hectares (hm 2 ); i, project carbon layer, i = 1, 2, 3..., dimensionless; t, the number of years since the start of the project, t = 1, 2, 3, ..., dimensionless; Project soil non-CO2 greenhouse gas emissions The non-CO2 greenhouse gas emissions from soils of the project are the sum of CH4 and N2O emissions from soils in each carbon layer: Where: ΔGHG PROJ，t , CO2 equivalent emissions of soil CH4 and N2O within the project boundary in year t, in tons of carbon dioxide equivalent per year (tCO2e·a -1 ); In year t, the CO2 equivalent emissions of CH4 and N2O from the carbon layer of the i-th project are expressed in tons of carbon dioxide equivalent per year (t CO2e·a -1 ); In year t, the CO2 equivalent emission of soil N2O in the carbon layer of project i is expressed in tons of carbon dioxide equivalent per year (tCO2e·a -1 ); In year t, the amount of CH4 emitted per unit area of ​​soil is expressed in tons of methane per hectare per year (t CH4·hm -2 ·a -1 ); In year t, the N2O emission per unit area of ​​soil is expressed in tons of nitrous oxide per hectare per year (tN2O·hm -2 ·a -1 ); The global warming potential of CH4 on a 100-year time scale; The global warming potential of N2O on a 100-year time scale; A i，t , the area of ​​the carbon layer of the i-th project in year t, in hectares (hm 2 ); i, project carbon layer, i = 1, 2, 3..., dimensionless; t, the number of years since the start of the project, t = 1, 2, 3, ..., dimensionless; Project leakage calculation Leakage is not considered in the project according to applicable conditions; Project emission reduction calculation The emission reduction of the project in the tth year after the project starts is calculated according to formula (18): CDR t =(ΔC PROJ，t -ΔC BSL，t -LK t )×(1-K RISK ) (18) Where: CDR t , the emission reduction of the project in the tth year, in tons of carbon dioxide equivalent per year (t CO2e·a -1 ); ΔC PROJ，t , the project removal amount in the tth year of the project, in tons of carbon dioxide equivalent per year (t CO2e·a -1 ); ΔC BSL，t Baseline removals in year t of the project, in tons of carbon dioxide equivalent per year (t CO2e·a -1 ); LK t , the leakage amount of the project in year t, in tons of carbon dioxide equivalent per year (t CO2e·a -1 ); LK t =0; K RISK , the non-persistent risk deduction rate of the project, in percentage (%); t, the number of years since the start of the project, t = 1, 2, 3, ..., dimensionless.

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