Overview
How this pathway works
Afforestation, Reforestation and Revegetation (ARR) projects establish or re-establish tree or woody vegetation cover on land that has been without such cover - sequestering atmospheric CO₂ into growing biomass (above-ground and below-ground) and soil organic carbon over multi-decadal timescales. ARR is the most widely deployed nature-based carbon pathway and the largest source of nature-based carbon credits globally.
Under Teravent's Nature-Based Carbon Standard (TNS v1.0) Annex A, ARR projects earn Teravent Nature Credits (TNCs) for verified, additional increases in carbon stocks across all material pools - aboveground biomass, belowground biomass, dead organic matter, and soil organic carbon - relative to a documented baseline. The project area must have been without tree cover for a minimum of 10 consecutive years before project start, verified by satellite time-series or historical land use records.
Five distinct methodology variants are approved under Annex A, ranging from afforestation on chronically degraded bare land (ARR-M01) through assisted natural regeneration (ARR-M04) to commercial plantation forestry with verified carbon and biodiversity co-benefits (ARR-M05). Each methodology carries its own allometric requirements, monitoring frequency, leakage deduction rates, and biodiversity safeguard obligations.
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Class II - Ecological permanence. All credits under TNS Annex A carry Class II Ecological permanence, reflecting the 100–500 year storage horizon of established forest carbon stocks subject to fire, pest, drought, and land-use-change risk. Buffer pool contributions of 10–30% of gross verified credits are required, with the specific rate determined by the project's Non-Permanence Risk Rating (NPRR) assessed by an accredited VVB at validation and each verification.
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10-year minimum land-use history. The project area must be verifiably devoid of tree cover for a minimum of 10 consecutive years before the project start date, demonstrated by satellite imagery (Landsat, Sentinel-2, or equivalent), aerial photography, or documented land use records accepted by the VVB. Land cleared for logging within 10 years of project start is not eligible under ARR - it falls under IFM (TNS Annex H) or Ecosystem Restoration (TNS Annex D).
Governing Standard
TNS v1.0 - Annex A
This pathway is governed exclusively by the Teravent Nature-Based Carbon Standard (TNS v1.0). All requirements - additionality, biomass quantification, MRV, safeguards, permanence risk, and credit issuance - are defined within TNS v1.0 and Annex A. No external standard, methodology framework, or registry is referenced or incorporated.
TCR›
TNS v1.0›
Annex A - Afforestation, Reforestation & Revegetation›
ARR-M01 through ARR-M05
M02
Three-test additionality - regulatory surplus, financial additionality, common practice survey (<20% regional adoption threshold)
M03
Five-pool biomass quantification - allometric equations, stratified sampling, soil carbon to 30 cm, dead organic matter included
M04
Class II Ecological permanence · Buffer pool 10–30% · NPRR covers fire, drought, pest, tenure, and market risks
M05
Biodiversity Impact Assessment mandatory · Native species preference · FPIC on indigenous and community lands
M06
30-year initial crediting period + up to 2 renewals of 20 years; baseline must include historical deforestation rate evidence
M07
TNC serial: TCR–TNS–ARR–[Country]–[ProjectID]–[Vintage]–[Unit] · Harvested Wood Product accounting where commercial harvest occurs
Teravent Nature Credit - Serial Number Format (TNS Annex A)
TCR
–
TNS
–
ARR
–
IN
–
00142
–
2025
–
000001
Methodologies Accepted
Five approved methodology variants
TNS v1.0 Annex A approves five distinct ARR methodology types. Each code defines a specific tree-establishment or regeneration activity, its eligible vegetation types, carbon pool accounting requirements, biomass measurement approach, and leakage provisions. A project may register under multiple ARR methodology codes where different activities occur within distinct spatial strata of the project boundary.
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Allometric equations: All ARR projects must use species- and region-validated allometric equations for aboveground biomass estimation. Where published validated allometrics are unavailable for a species, the developer must develop and validate site-specific allometrics from a minimum of 50 destructive or non-destructive harvest samples before the first verification event. The TSA maintains a list of approved allometric equation sources updated annually.
ARR-M01 covers deliberate tree planting on bare, degraded, eroded, or heavily degraded land - land that has carried no meaningful tree cover for at least 10 consecutive years and where natural regeneration is absent or severely impeded. Eligible land types include mined land, severely degraded agricultural soils, eroded hillslopes, and post-industrial brownfields where ecological conditions have been sufficiently restored to support tree establishment. The primary carbon pools are aboveground and belowground tree biomass; SOC is an optional pool credited where a 10%+ increase over baseline is projected by the VVB-approved carbon model.
Permanence
Class II · Ecological
Buffer Pool
15–25% (by NPRR)
Crediting Period
30 yr + up to 2×20 yr
Biomass Measurement
Allometric + stratified plot inventory
Monitoring Frequency
Annual (yrs 1–5); every 3 yr thereafter
Leakage Deduction
5% default (activity-shifting)
Key Monitoring Indicators
- Tree survival rate (%) by species and planting cohort - annual for first 5 years
- Mean DBH (diameter at breast height, cm) and height (m) per monitoring plot per species
- Aboveground biomass estimate (tCO₂e/ha) via approved allometric equations per species
- Belowground biomass (root-to-shoot ratio by species or IPCC default)
- Soil organic carbon at 0–30 cm at permanent plots - every 5 years
- Land use integrity verification via satellite imagery - annual
- Mortality events (fire, drought, pest) - event-based reporting within 30 days
ARR-M02 applies to lands that were formerly forested and subsequently cleared for agriculture, pastoralism, or other land uses - where the clearing occurred between 10 and 50 years before the project start date. The baseline carbon stock is typically near-zero or low-shrub; the project baseline must be verified by satellite time-series showing the historical forest cover and subsequent clearing event. Reforestation under this methodology carries a higher inherent permanence risk than ARR-M01 where agricultural pressure that drove the original deforestation remains active in the landscape.
Permanence
Class II · Ecological
Buffer Pool
20–30% (elevated - LUC history)
Crediting Period
30 yr + up to 2×20 yr
Satellite Requirement
10-yr historical deforestation time-series
Leakage Deduction
10–20% (market leakage - agricultural displacement)
Threat Model
Active threat to reversion must be documented
Key Monitoring Indicators
- Canopy cover (%) via satellite NDVI or field measurement - annual
- Tree density (stems/ha) by species and cohort at permanent plots
- DBH and height per species at permanent plots - every 3 years after year 5
- Encroachment risk assessment - agricultural frontier proximity monitored annually
- Historical satellite imagery confirming land use change record at validation
- SOC at 0–30 cm at permanent plots - every 5 years (SOC recovery expected over longer timeframe)
ARR-M03 covers deliberate planting of native, locally-provenant tree and shrub species to restore native vegetation communities on degraded open land. This methodology is distinct from ARR-M01 in that it specifically requires native species - no exotic species are eligible under ARR-M03. This methodology attracts the highest biodiversity co-benefit ratings of any ARR variant and is preferred by Teravent for projects where a Biodiversity+ or Indigenous Stewardship quality label is sought. Mixed native species plantings must achieve a minimum of 70% species diversity relative to the reference ecosystem community.
Permanence
Class II · Ecological
Buffer Pool
10–20% (lower - native resilience)
Species Requirement
100% native, locally-provenant species
Diversity Threshold
≥70% of reference ecosystem species
Leakage Deduction
5% default
Biodiversity Monitoring
Mandatory - BIA required at validation
Key Monitoring Indicators
- Species richness and composition at permanent vegetation monitoring plots - every 3 years
- Native vs. exotic species ratio - VVB verified at each monitoring event
- Aboveground biomass per species using approved native species allometrics
- Canopy cover (%) and vegetation height stratification
- Invasive species incursion - reported within 60 days of detection; management plan required
- Fauna indicators (bird species richness, indicator taxa) - where Biodiversity+ label sought
Assisted Natural Regeneration supports and accelerates the spontaneous recovery of forest vegetation on land where the natural seed bank, root stock, or dispersal mechanisms are still functional but regeneration is suppressed by grazing, fire, invasive species, or human disturbance. ANR activities include fencing to exclude livestock, removal of invasive species, fire management, selective enrichment planting to fill species gaps, and soil scarification to improve germination conditions. ANR is typically the lowest-cost ARR methodology and generates strong biodiversity outcomes because succession is driven by locally-adapted species.
Permanence
Class II · Ecological
Buffer Pool
15–25% (by NPRR)
Enrichment Planting
Permitted - up to 30% of stocking density
Grazing Exclusion
Mandatory - fencing records required
Leakage Deduction
5% default (livestock displacement)
Biomass Trajectory
Chronosequence model or field-measured reference plots
Key Monitoring Indicators
- Regenerating stems density (stems/ha) by height class - annual in early years, every 3 yr thereafter
- Species composition and regeneration source (seed vs. coppice vs. planted enrichment)
- Grazing exclusion fence integrity - VVB site inspection at every verification event
- Invasive species cover (%) - annual assessment with management records
- Canopy closure rate (%) via satellite NDVI - annual
- Biomass accumulation via approved chronosequence model or permanent plot allometrics - every 3 years
ARR-M05 permits commercial timber, pulp, or agroforestry plantation projects where carbon and biodiversity co-benefits are independently verified alongside the commercial harvest objective. This is the most technically complex ARR methodology, requiring full Harvested Wood Product (HWP) carbon accounting, rotation-adjusted biomass modelling, and market leakage assessment for timber and commodity supply. Projects must demonstrate net carbon positivity across the full rotation cycle including harvest, product fate, and replanting phases. Monoculture exotic species plantations must include mandatory biodiversity enhancement measures as a condition of registration.
Permanence
Class II · Ecological
Buffer Pool
20–30% (by NPRR)
HWP Accounting
Mandatory - full rotation lifecycle
Market Leakage
15–25% (timber market displacement)
Biodiversity Measures
Mandatory - minimum 10% habitat set-asides
Rotation Accounting
Net carbon per full rotation cycle required
Key Monitoring Indicators
- Standing volume (m³/ha) per species and age class - every 3 years and at harvest
- Harvest volume records with timber product fate documentation - per harvest event
- HWP carbon accounting: product mix, half-life values per product category (sawnwood, panels, paper), and end-of-life
- Replanting schedule and species mix - compliance verified at VVB site inspection
- Biodiversity set-aside area (ha) and habitat quality - every 5 years
- Market leakage assessment - updated at each crediting period renewal
- Net carbon balance across full rotation including all harvest and product pools
Carbon Pool Accounting
Which pools must be counted
TNS v1.0 Module 3 requires assessment of all material carbon pools. ARR projects involve a richer set of pools than most other nature-based pathways - growing biomass both above and below ground is the primary removal mechanism, with SOC and dead organic matter as secondary pools that may be credited where material. HWP accounting is mandatory for ARR-M05 where commercial harvest occurs.
Required - Primary
Aboveground Biomass (AGB)
Living tree stems, branches, bark, and foliage. Estimated from DBH and height measurements at permanent plots using species- and region-specific allometric equations. This is the dominant carbon pool in all ARR methodologies.
Required
Belowground Biomass (BGB)
Live root systems. Estimated from aboveground biomass using IPCC root-to-shoot ratios by forest type and climate zone, or directly measured where site-specific equations are available. Typically 20–30% of AGB depending on forest type.
Required where material
Soil Organic Carbon (SOC)
Carbon in mineral soil to minimum 30 cm depth. Credited where a VVB-approved carbon model projects ≥10% SOC increase above baseline over the crediting period. Measured by dry combustion CHNS analysis at permanent plots every 5 years.
Required where material
Dead Organic Matter (DOM)
Dead wood (standing and fallen) and litter. Assessed at permanent plots using the line-intercept method for coarse woody debris and litter mass per unit area. Material in mature plantations and older natural regeneration areas.
Required for ARR-M05
Harvested Wood Products (HWP)
Carbon retained in wood products post-harvest across the product service life. Product mix (sawnwood, wood panels, paper) and TSA-approved half-life values determine the time-averaged carbon stock in HWP. Mandatory only for ARR-M05.
Excluded
Non-CO₂ GHG from Soil
N₂O and CH₄ from forest soils excluded for ARR projects - not material under typical forest management. Required only where significant nitrogen fertilisation occurs in plantation establishment (ARR-M05) or where former wetland soils are afforested.
Biomass Measurement Protocol
Plot Design
Permanent circular or rectangular plots; minimum 0.1 ha per plot
Plot Density
Minimum 1 plot per 25 ha; stratified by species and age class
DBH Threshold
All stems ≥5 cm DBH measured; stems ≥2 cm in first 3 years
Allometric Source
TSA-approved species-specific equations; IPCC Tier 2 defaults permitted where validated equations unavailable
Height Measurement
Hypsometer or clinometer; subset of 20% of DBH-measured trees
Carbon Fraction
0.47 tC/t dry biomass (IPCC default); species-specific where measured
MRV Confidence
Measurement, reporting
& verification
ARR has among the highest MRV confidence ratings of any nature-based pathway due to mature satellite monitoring technology, well-established allometric science, and decades of operational experience. The principal uncertainty sources are allometric equation selection for less-studied species and soil carbon dynamics in the decades following afforestation.
Remote Sensing - Canopy Cover & AGBVery High
Field Biomass Inventory AccuracyHigh
Permanence ConfidenceMedium–High
Additionality ClarityHigh
HWP Accounting Accuracy (ARR-M05)High
🔬 Remote Sensing Standard - TNS Module 3
All ARR projects must use satellite-based canopy monitoring at minimum annual frequency throughout the crediting period. Acceptable sources include Sentinel-2 (10 m), Landsat (30 m), or equivalent optical sensors with seasonal compositing. A minimum of three cloud-free composite images per year is required. UAV-based LiDAR surveys are accepted as supplementary data for biomass validation at permanent plot level. All remote sensing data and processing scripts must be archived and available for VVB audit. Where fire or other disturbance is detected via satellite, the project must initiate a reversal assessment within 30 days per TNS Module 4.
Additionality
Demonstrating additionality
TNS v1.0 Module 2 requires ARR projects to satisfy all three additionality tests. ARR additionality is generally stronger than agricultural soil carbon projects because tree planting carries significant upfront costs - seedling purchase, labour, fencing, water - that are rarely viable without carbon revenue on degraded land with no market timber value.
1
Regulatory Surplus Test
The tree planting activity must not be legally mandated under national reforestation obligations, court-ordered revegetation, or mandatory environmental mitigation requirements attached to a development permit. In India, compensatory afforestation under the Forest Conservation Act is not eligible as an ARR project under Teravent because it is a regulatory obligation rather than a voluntary, additional activity. Where government reforestation subsidies are received, an analysis must confirm that the subsidy does not cover the full cost of the activity and that carbon revenue is still required for financial viability.
2
Financial Additionality Test
Carbon revenue must be a necessary condition for the project to be financially viable. Project developers must submit either: (a) a discounted cash flow analysis demonstrating that without carbon revenue the IRR falls below the applicable hurdle rate for comparable investments in the project country; or (b) an investment barrier analysis documenting specific financial constraints - absence of debt financing, negative land return without carbon, or cost of capital barriers - that prevent implementation without carbon finance. For community-based projects, group-level financial assessments are accepted where individual analysis is impractical.
3
Common Practice Test
Voluntary afforestation or revegetation of degraded land without carbon finance or equivalent government incentive must not be common practice in the project geography. A survey of at least 50 comparable land holdings in the same district or agro-ecological zone must document that fewer than 20% have voluntarily planted trees on comparable degraded land without external carbon or subsidy support. For ANR (ARR-M04), the common practice test applies to active management interventions (fencing, invasive removal) rather than passive vegetation recovery.
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Compensatory afforestation exclusion: Projects established to fulfil compensatory afforestation obligations under the Forest Conservation Act (India), equivalent national legislation, or conditions attached to an Environmental Impact Assessment approval are explicitly excluded from registration under TNS Annex A. Carbon credits cannot be generated from legally mandated activities.
Leakage Assessment
Leakage types & deductions
ARR projects are subject to two primary leakage categories. Activity-shifting leakage - where land users displaced from the project area shift degrading activities to adjacent unprotected land - is the most significant risk for reforestation projects in active agricultural or grazing landscapes. Market leakage from timber displacement affects only ARR-M05 commercial plantation projects.
Activity-Shifting Leakage
Displaced Grazing & Agriculture
Where livestock or agricultural activities are excluded from the project area, they may shift to adjacent unmonitored land, reducing carbon stocks there. The spatial extent and intensity of any displaced activity must be assessed in the PDD using a minimum 5 km buffer zone analysis of the surrounding landscape.
Default: 5–15% · Higher for ANR (ARR-M04) where livestock pressure is significant
Market Leakage
Timber Market Displacement
Applies only to ARR-M05 commercial plantation projects. Where the plantation produces timber that displaces equivalent production from other forests - potentially including native forests - a market leakage deduction of 15–25% of gross credits applies. Projects supplying less than 5% of regional timber demand may apply for a reduced deduction subject to VVB approval.
Default: 15–25% · ARR-M05 only · TSA-approved regional market data required
Upstream Input Leakage
Embodied Emissions in Inputs
GHG emissions embodied in nursery production, seedling transport, fencing materials, and irrigation infrastructure must be assessed. For most ARR projects, this is de minimis (below 2% of gross carbon benefit) and excluded. Large-scale plantations with significant material inputs must include this assessment.
De minimis threshold: 2% of gross benefit · Excluded for most ARR-M01–M04
Fire Risk Leakage
Landscape Fire Pressure
Where ARR projects in fire-prone landscapes actively suppress fires on the project area, this may increase fire pressure on adjacent unprotected land. A fire leakage assessment using regional fire frequency data must be conducted for all projects in savanna, dryland, or Mediterranean biomes. This feeds directly into the NPRR and buffer pool contribution.
Assessed case-by-case · Elevated buffer pool contribution where material
Permanence & Non-Permanence Risk
Buffer pool & reversal risk
ARR credits carry Class II Ecological permanence (100–500 year storage horizon). Buffer contributions protect buyers against fire, drought, pest and disease, and land-use-change reversals. Buffer rates are determined by the project's Non-Permanence Risk Rating (NPRR) covering five risk dimensions assessed by the VVB at validation and every subsequent verification.
| Methodology |
NPRR Rating |
Buffer Pool Rate |
Primary Reversal Risks |
| ARR-M01 Afforestation - Degraded Land |
Low–Medium |
15–20% |
Drought; wildfire; land tenure dispute; pest and disease outbreak |
| ARR-M02 Reforestation - Cleared Forest |
Medium–High |
20–30% |
Agricultural encroachment; land tenure; fire; political or policy change |
| ARR-M03 Native Species Revegetation |
Low |
10–20% |
Invasive species; drought; isolated fire events |
| ARR-M04 Assisted Natural Regeneration |
Low–Medium |
15–25% |
Grazing exclusion failure; invasive species; drought; fence degradation |
| ARR-M05 Commercial Plantation |
Medium |
20–30% |
Harvest timing; market price shifts; pest (e.g. Hypsipyla for mahogany); wildfire |
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Reversal notification: Project proponents must notify the TSA within 30 days of discovering a reversal event - fire damage exceeding 5% of project area, confirmed disease-related mortality affecting more than 10% of standing biomass, or any land use change within the project boundary. Satellite-detected fire events are flagged directly to project proponents via the Teravent Registry monitoring system. Buffer pool credits absorb the reversal on behalf of credit buyers.
Eligibility Requirements
Key registration criteria
All of the following must be satisfied for registration under TNS Annex A. Methodology-specific requirements (HWP accounting, biodiversity monitoring, commercial harvest plans) are detailed in the individual ARR-M code specifications within Annex A.
✓
Project land must have been without tree cover for a minimum of 10 consecutive years before project start - verified by satellite time-series (Landsat, Sentinel-2, or equivalent at ≤30 m resolution), aerial photographs, or documented land use records accepted by the VVB
✓
A baseline carbon stock assessment must be conducted before any project tree-planting activities commence - documenting existing vegetation, SOC (0–30 cm), and any existing dead organic matter stocks at permanent monitoring plots
✓
Species-specific or IPCC Tier 2 allometric equations must be identified and documented in the PDD before validation; where site-specific equations are required, a sampling plan for equation development must be submitted
✓
Three-test additionality demonstrated: regulatory surplus confirmed (no mandatory planting obligation), financial additionality modelled (IRR analysis or investment barrier), common practice survey of minimum 50 comparable land holdings
✓
A Biodiversity Impact Assessment (BIA) is mandatory for all ARR projects - assessing pre-project biodiversity baseline and projecting impacts and benefits of tree establishment on flora, fauna, and ecosystem function
✓
Free, Prior and Informed Consent (FPIC) must be obtained where the project is located on or adjacent to indigenous or community-managed land, or where community land rights or livelihoods may be affected by the project activities
✓
A fire management plan is required for all projects in fire-prone biomes (savanna, dryland, Mediterranean, dry tropical forest) - specifying firebreak design, controlled burn schedule if applicable, and emergency response protocol
✓
Land tenure must be secure and documented - freehold title, long-term lease (minimum crediting period + 5 years), or community land agreement. Unresolved tenure disputes render the project ineligible until resolution
✓
For ARR-M05 (commercial plantation), a full Harvested Wood Product accounting plan must be submitted with the PDD, including rotation length, anticipated product mix by category, and product half-life values per TSA-approved schedule
✓
Monitoring plan submitted with PDD specifying permanent plot GPS coordinates, plot layout, measurement protocols, remote sensing sources, data management system, and VVB verification schedule - minimum every 5 years after year 5
Co-Benefits & SDGs
Sustainable Development
Goal alignment
ARR projects typically deliver the richest co-benefit profile of any Teravent pathway - combining carbon removal with biodiversity restoration, watershed protection, erosion control, and community livelihood benefits. Nine SDGs are systematically tracked. Projects may earn quality labels where independently verified indicators are met at Premium or Frontier certification tier.
SDG 13 · Climate Action
SDG 15 · Life on Land
SDG 6 · Clean Water
SDG 1 · No Poverty
SDG 2 · Zero Hunger
SDG 8 · Decent Work
SDG 11 · Sustainable Cities
SDG 3 · Good Health
SDG 17 · Partnerships
Biodiversity+
ARR projects - particularly ARR-M03 native species revegetation and ARR-M04 ANR - regularly achieve net biodiversity gains demonstrated through species richness surveys. Biodiversity+ label requires independently verified flora and indicator fauna surveys at validation and each 5-year verification.
Water+
Afforestation on degraded watershed land demonstrably improves downstream water quality, reduces sediment load, and stabilises seasonal streamflow. Projects with hydrological monitoring data - stream gauge records, sediment turbidity, or watershed hydrology modelling - are eligible for the Water+ label.
Livelihoods+
ARR projects that generate community employment in nursery operations, planting, maintenance, and monitoring - with verified income figures and employment records - are eligible for Livelihoods+. Projects involving community benefit sharing arrangements must document and verify income distribution annually.
Indigenous Stewardship
ARR projects led or co-designed by indigenous communities using traditional ecological knowledge - with FPIC documented throughout and community members active in monitoring and governance - are eligible for the Indigenous Stewardship quality label at Premium and Frontier tiers.
Priority regions: South and Southeast Asia (degraded uplands of Western Ghats, Deccan, Himalayan foothills, Mekong watershed), Sub-Saharan Africa (Sahel, East African Highlands, Congo Basin margins), and Latin America (Atlantic Forest, Cerrado, Andean slopes) - where degraded land availability, community co-benefit value, and transformation potential are greatest.
