Deadwood Quantification v1.0

1.0

Introduction

This Module provides the requirements and procedures for the quantification of net carbon dioxide equivalent (CO₂e) removal from the atmosphere via improvements to deadwood carbon stocks in forested systems. This Module sits under the Reforestation, Agroforestry, and Improved Forest Management Protocols.

Deadwood broadly includes dead woody biomass, whether standing or downed, and represents an important carbon pool within forests. Globally, it is estimated that 8% of the total carbon stored by forests is stored within deadwood¹. In addition to carbon storage, deadwood also provides habitat, supporting biodiversity in fungi, insects and vertebrates². Deadwood also plays a role in nutrient cycling and can enhance water retention³.

However, deadwood dynamics can be temporally and spatially variable. Deadwood stocks, input rates, and decay rates vary across the globe with differences in vegetation communities, temperature, and moisture, and also vary over time with differences in management and disturbance⁴. As such, assessment and quantification of deadwood carbon storage within a given Project requires rigorous monitoring, reporting, and validation.

Project Proponents must meet all the requirements set out in the relevant Protocols and Modules, as well as the requirements set out in this Module. Where this Module contains requirements that duplicate or conflict with those in other Modules, this Module takes precedence.

Throughout this Module, the use of "must" indicates a requirement, "should" indicates a recommendation, and "may" indicates an option or permission.

2.0

Future Versions

This Module was developed based on the current state of the art, publicly available science regarding quantification of deadwood and long-term monitoring of terrestrial ecosystems. This Module aims to be scientifically stringent and robust. We recognize that some requirements may exceed the status quo in the market and that there will be opportunities to improve the rigor of this Module.

Additionally, this Module will be reviewed when there is an update to published scientific literature, government policies, or legal requirements which would affect net CO₂e removal quantification or the monitoring guidelines outlined in this Module, or at a minimum of every 2 years.

3.0

Applicability

R-9E44-0

In order to prevent double counting, the eligibility of deadwood pools is dependent on the method being used for quantification of living woody biomass:

Projects using the Area-based Quantification of Woody Biomass Module may include both standing and downed deadwood. The field manual must include clear procedures for the distinction between living standing biomass and dead standing biomass.
Projects using either the LiDAR-based Quantification of Woody Biomass Module or the Earth Observation-based Quantification of Woody Biomass Module may only include downed deadwood and must, by default, exclude standing deadwood. These methods cannot easily distinguish living standing biomass from dead standing biomass, so this represents a conservative approach to decrease risk of double counting across the living woody biomass pool and deadwood biomass pool. Projects may include standing deadwood only with demonstration of a project-specific correction for removal of standing deadwood biomass from the living woody biomass estimate. This must be re-validated as part of each benchmarking event for the LiDAR or Earth Observation data.

Where The Project opts into quantification of deadwood using this Module, it must be done for the remainder of the Crediting Period and projects are liable for maintenance of the pool and any reversals through the remainder of the Project Commitment Period. However, Projects may elect to use a longer Reporting Period for deadwood quantification than for the living woody biomass pools (i.e., quantify deadwood less frequently). The frequency of deadwood quantification should be informed by relevant ecological dynamics of deadwood generation and decay within the project area ecosystem.

R-4CQ3-0

Projects may elect to begin crediting the deadwood pool after project initiation. Where the start of the first Reporting Period for deadwood quantification is after project initiation (i.e., the initial deadwood quantification occurs after the project initiation), Projects must provide justification that either:

The pre-project land cover and land use contained negligible deadwood stock (i.e., was devoid of woody vegetation); or
The project interventions since initiation did not involve any practices which could have led to a loss in the deadwood stock outside of expected decay (i.e., no removal of deadwood, etc)

3.1

Deadwood Pool Definition

The components of the deadwood pool eligible for quantification under this Module include aboveground standing dead trees and downed coarse woody debris within the Project Area.

The following are excluded from the deadwood carbon pool:

Fine woody debris below the size threshold (Section 5.2)
Stumps and standing dead stems shorter than the threshold (Section 5.3)
Belowground dead biomass and root structures
Wood removed from the Project Area

Belowground dead biomass is conservatively excluded due to measurement challenges and its poorly constrained decomposition.

4.0

Quantification of CO|2|e|DW

Quantification of CO₂e_DW

This Module quantifies the cumulative increase in additional carbon storage in deadwood within the project area ( $CO_2e_{DW,net,cum}$ ). This is calculated as the difference between the cumulative storage increase and the cumulative counterfactual:

 $CO_2e_{DW,net,cum,t} = CO_2e_{DW,storage,cum,t} - CO_2e_{DW,counterfactual,cum,t}$

(Equation 1)

Where:

$CO_2e_{DW,net,cum,t}$ is the net additional cumulative carbon storage as deadwood at time $t$ , in tonnes CO₂e
$CO_2e_{DW,storage,cum,t}$ is the cumulative increase in carbon storage as deadwood in the project area at time $t$ since the start of the first Reporting Period where deadwood is quantified, in tonnes CO₂e
$CO_2e_{DW,counterfactual,cum,t}$ is the counterfactual cumulative increase in carbon storage as deadwood between time $t$ and the start of the first Reporting Period where deadwood is quantified that would have happened in absence of project interventions, in tonnes CO₂e, calculated as described in Section 6

The change in project carbon storage within deadwood is calculated as the difference between deadwood carbon stocks. At any given time $t$ , the carbon stock stored as deadwood in the project area is calculated as:

 $CO_2e_{DW,t} = \bar{m}_{DW}(t) \times A \times CF_{DW} \times \frac{44}{12}$

(Equation 2)

Where:

$CO_2e_{DW,t}$ is the project area carbon stock stored as deadwood at time $t$ , in tonnes CO₂e
$\bar{m}_{DW}(t)$ is the mean deadwood density in the project area at time $t$ , in tonnes per hectare
$A$ is the total project area in hectares
$CF_{DW}$ is the deadwood carbon fraction
$\frac{44}{12}$ converts the mass of carbon to CO₂e

R-K05Q-0

Projects should not use the same $CF$ value that is applied to living woody biomass, and, given the challenges in species identification of deadwood, a species-weighted or biome-level value is preferred. For the deadwood carbon fraction, The Project must determine a $CF_{DW}$ value from the following hierarchy:

Species-weighted deadwood-specific $CF_{DW}$ value based on the project species mix
Biome-specific mean deadwood $CF_{DW}$ from Martin et al., (2021)⁵

This calculation may be applied in a stratified manner over the Project Area. Where stratification is used, spatial boundaries of the strata must be provided and the stratification design and covariates must be described and justified as appropriate to the deadwood carbon stocks.

4.1

Scaling Plot Measurements to Project Area

The project area mean deadwood density is derived from field plot measurements of deadwood in the project area:

 $\bar{m}_{DW}(t) = \frac{\sum_{i=1}^nm_{DW,plot,i}(t)a_{plot,i}}{\sum_{i=1}^na_{plot,i}}$

(Equation 3)

Where:

$m_{DW,plot,i}(t)$ is the total measured deadwood density in plot $i$ (of $n$ total) at time $t$ , in tonnes ha^-1
$a_{plot,i}$ is the area of plot $i$ , in ha

The total deadwood density within each plot is assessed as the sum of the downed coarse woody debris density and the standing aboveground density measured within the plot:

 $m_{DW,plot,i}(t)= m_{standing,i}(t) + m_{downed,i}(t)$

(Equation 4)

Where:

$m_{standing,i}(t)$ is the standing deadwood density at time $t$ , in tonnes ha^-1
$m_{downed,i}(t)$ is the downed coarse woody debris density at time $t$ , in tonnes ha^-1

Where a project is using either LiDAR-based quantification or Earth Observation-based quantification for living woody biomass without an approved correction, the density of standing woody biomass must be conservatively set to 0 to avoid double counting of these individuals.

4.2

Downed Coarse Woody Debris Density

The downed coarse woody debris density is derived from line intersection sampling⁶:

 $m_{downed,i}(t) = \frac{\pi^2}{8L_i}\sum_{k=1}^{K_i}\left(d_{k,1}d_{k,2} - h_{k,1}h_{k,2}\right)\rho_{sound,k}\,RF_{downed,c(k)}$

(Equation 5)

Where:

$m_{downed,i}(t)$ is the downed coarse woody debris density in plot $i$ at time $t$ , in tonnes ha^-1
$L_i$ is the total slope-corrected length of all transects associated with plot $i$ , in m
$K_i$ is the number of pieces intersected by the transects of plot $i$
$d_{k,1}$ and $d_{k,2}$ are the perpendicular cross-sectional diameters (e.g., width and height) of piece $k$ at the point of intersection, in cm
$h_{k,1}$ and $h_{k,2}$ are the perpendicular diameters of any internal hollow or void in piece $k$ at the point of intersection, in cm (0 where no void is present)
$\rho_{sound,k}$ is the sound (undecayed) wood density corresponding to piece $k$ , in tonnes m^-3
$RF_{downed,c(k)}$ is the dimensionless downed density reduction factor for the decay class $c$ of piece $k$

Where species cannot be identified, Projects must use the basal-area-weighted wood density of living trees in the plot.

4.3

Standing Deadwood Density

The standing deadwood density is derived from the volumetric estimates of individually measured standing deadwood stems within the plot:

 $m_{standing}(t) = \frac{1}{a_{plot}}\sum_jV_{stem,j}\rho_{sound,j}RF_{standing,c(j)}$

(Equation 6)

Where:

$a_{plot}$ is the plot area, in ha
$V_{stem,j}$ is the retained standing-stem volume of tree $j$ , in m³
$\rho_{sound,j}$ is the sound wood density corresponding to tree $j$ , in tonnes m³
$RF_{standing, c(j)}$ is the dimensionless standing reduction factor for decay class $c$

Where species cannot be identified, Projects must use the basal-area-weighted wood density of living trees in the plot.

R-T9X1-0

Because of the loss of portions (branches, crown, etc) of the tree, an allometric model for whole, living trees must not be used to estimate volume of broken snags. $V_{stem,j}$ must be estimated by one of the following, in order of preference:

A species/region-specific taper equation, integrated over the retained height only.
A frustum of the retained stem from a measured base diameter and an upper/top diameter (Smalian's or Newton's formula), where the top is measureable.
Where only DBH is measureable, the retained stem may be modeled as a parabaloid, or a demonstrably more conservative approach.

4.4

Density Reduction Factors

R-1KMB-0

For both downed and standing deadwood, a reduction factor ( $RF$ ) is applied to the sound wood density to account for progressive density loss with decay. $RF$ values are expected to vary not only with decay class, but also for the biome and species, as well as for standing vs downed deadwood. In order to ensure that an appropriate and conservative value is selected, the following hierarchy must be applied for each combination of species, decay class, and standing/downed deadwood:

Species/genus-specific density values
Regional/biome-specific values
- For temperate and boreal ecosystems, the distinct standing and deadwood density reduction factor values from Harmon et al., (2011)⁷ should be used

Where data within a given tier are separated by downed/standing deadwood, these must be applied following this distinction. Projects must demonstrate the lack of availability of appropriate data in each tier before moving to a lower tier. As evidence of this search, Projects must provide a list of the search terms used and the scientific databases consulted. Note that literature may express relevant data in terms of absolute densities rather than a proportional factor. These data should still be used, and the derivation of the $RF$ value clearly described. $RF$ values must represent the ratio of decayed to sound wood density (dry mass per current volume). Mass-loss or mass-remaining factors must not be used, as volume loss is captured directly through field measurement.

Where no suitable literature values are available, the Project Proponent must directly measure its own density reduction factors via destructive sampling and measurement of oven-dry mass relative to the volume. These must be delineated by decay class and by standing deadwood vs downed deadwood. Projects measuring their own values must submit details on the sampling and measurement procedures used, as well as the data. Projects for which literature values are available may elect to measure their own values, but must provide justification that the project-measured values are conservative relative to the literature values.

4.5

Uncertainty

R-3VYM-0

Uncertainty in the value of $CO_2e_{DW,net,cum,t}$ must be quantified and propagated jointly with the other woody biomass pools in a Monte Carlo simulation, as prescribed by the governing Protocol. The uncertainty characterization must represent deadwood-specific uncertainty sources⁸, and their correlation with uncertainty sources for other pools within the governing Protocol, as appropriate:

Uncertainty in factors used in deadwood stock estimate (e.g., deadwood carbon fraction, density reduction factor)
Cross-section measurement error for downed coarse woody debris⁸
Census/measurement error deriving from field sampling and measurements
Counterfactual uncertainty, including the $R$ value (see Section 6)

5.0

Field Measurements and Sampling Design

R-QGT9-0

Deadwood stock is estimated from field measurements collected within the project area⁹. The field sampling and measurements must follow a prescribed field manual and best practice guidelines, with distinct treatment of standing dead trees and downed coarse woody debris. The field measurements are designed to resample the deadwood population at each time point in a stock difference approach, rather than rely on individual piece tracking.

It is recommended that field sampling be seasonally consistent across sampling points to help account for seasonal variability in deadwood production and detectability.

5.1

Sampling Design

R-B5NY-0

G-HD9N-0

Deadwood sampling must be co-located with the field plot campaign for quantification of living aboveground woody biomass, unless justification can be provided for a distinct sampling design. For all sampling designs, the description, GPS coordinates, shape, size, orientation, and design justification of plots and transects must be provided. Under a shared sampling approach the following are required, with best practice recommendations further listed as sub-bullets:

G-5JXS-0Standing dead trees must be recorded on the same fixed-area plots as are used for living woody biomass quantification, with the same requirements applying for field plot design.
G-AMAT-0Downed coarse woody debris must be sampled on line-intersect transects that are anchored at each plot and justification must be provided for the design (transect number, orientation, length, etc.) capturing a representative sample.
- Recommendation: It is recommended to use a layout where the transect radiates from the plot centers on fixed azimuths. Projects should determine the transect number, orientation, and total length per plot based on the setting. Greater transect length may be required in areas with sparse or heterogeneous coarse woody debris.
G-Y96F-0Transects for sampling downed coarse woody debris must be determined a priori.
- Recommendation: Permanent transects are recommended, with monumenting of the origin and azimuth to enable accurate remeasurement.
G-HY24-0Transect length for downed coarse woody debris must be slope-corrected to yield the true horizontal distance.

5.2

Line-Intersect Sampling of Downed Coarse Woody Debris

G-VG3Q-0

Line-intersect sampling for downed coarse woody debris must follow the below requirements for sampling and data collection:

A piece of downed coarse woody debris must be tallied each time that the transect crosses its central longitudinal axis.
The minimum size threshold for inclusion is 10 cm in diameter at the point of intersection.
At the point of intersection, the cross-sectional diameter must be measured across two perpendicular axes (i.e., width and height) in order to enable assessment of the elliptical cross-sectional area and any flattening that occurs with decay.
The decay class must be recorded for each piece.
The threshold for inclusion as downed coarse woody debris (as opposed to standing) is that it must be leaning at least 45 degrees from vertical, otherwise it would be considered standing.
If the piece contains hollows or voids, the internal cross-sectional diameter of the void must be measured across two perpendicular axes and subtracted from the volume as in Equation 5.
If the piece is partially buried, the exposed cross section should be measured above the ground surface. Wholly buried material must be excluded from quantification.

5.3

Measurement of Standing Dead Trees

G-F4ZC-0

Standing dead trees are measured within the fixed-area sample plots and the following requirements must be followed for sampling and data collection:

The minimum size threshold for inclusion is 10 cm DBH and must be tall enough to record a DBH (i.e., 1.3 m).
The field protocol must include processes for assessing if the standing tree is alive or dead (e.g., no live foliage, negative cambium scratch test). Note that this must be assessed for the tree as a whole. A living tree with dead foliage must be classified as living biomass.
For each dead standing tree, the DBH, retained height (i.e., height to break for broken snags or full height for intact stems), and decay class must be recorded.
- Recommended: Where possible, a second upper/top diameter measurement should be recorded to enable use of a two-diameter frustum.

5.4

Decay Class Categorization

R-648X-0

The decay classification is a critical piece of information for each piece of recorded deadwood which captures the state of decay. Projects must use a recognized published decay classification system with justification for its appropriateness to the project system. The system must include at least three distinct classes. Some examples include:

The decay classification system must be consistent with the decay class system used as the basis for the density reduction factors (Section 4.4).

Implementation of the decay classification should combine both a visual assessment and a tactile/penetration test.

G-2SV1-0

The field manual must include detailed descriptions and supplementary photographs of the classification system, as well as the procedure for crew calibration to ensure the assignment is consistent and auditable.

6.0

Counterfactual

The counterfactual for the deadwood pool assesses the changes in the deadwood carbon storage that would have occurred in the Project Area in absence of the project interventions. The deadwood counterfactual is estimated by scaling the counterfactual for aboveground living biomass calculated in the governing Protocol by a ratio describing the amount of deadwood biomass to living aboveground biomass in a given ecosystem:

 $CO_2e_{DW,counterfactual,cum,t} = R \times CO_2e_{AGB,counterfactual,cum,t}$

(Equation 7)

Where:

$R$ is the dimensionless ecosystem deadwood biomass to living aboveground biomass
$CO_2e_{AGB,counterfactual,cum,t}$ is the cumulative aboveground biomass counterfactual from the start of the first Reporting Period where deadwood is quantified to time $t$ assessed following the governing Protocol, in tonnes CO₂e

R-SS4J-0

The value of $R$ is ecosystem specific. As a default, projects must identify and justify which of the following values is appropriate for the project system:

Table 1. Deadwood to aboveground biomass ratios by ecosystem type¹²^,¹³

Ecosystem Type	R Value [-]
Tropical	0.11
Evergreen	0.20
Deciduous	0.14

G-XRE0-0

These values represent the median values assessed across a range of measurements in primarily natural, steady-state biomass forests. As such, these are expected to be conservative by design for application in actively recovering forests. Projects may identify and justify the use of an $R$ value that is more specific to the project setting when one is available. This justification must show that the value is more appropriate than the broad defaults in terms of ecosystem specificity, species composition, climate, and/or forest growth stage.

7.0

Durability and Reversals

The deadwood carbon pool is subject to the same monitoring duration and liability as the living woody biomass pools under the governing Protocol, and thus carries the same durability label. Reversals in the deadwood pool are assessed at the aggregate stock level, and are subject to the same reversal monitoring and reporting requirements in the governing Protocol.

As disturbance events can generate a transient spike in the deadwood carbon stock, there are additional requirements for deadwood accounting in the event of a Reversal within the Project Area. These are further dependent on whether the Reversal occurs within the Crediting Period and as such will have regular continued monitoring of deadwood following the disturbance, or if the Reversal occurs during an Ongoing Monitoring Period where regular quantification will no longer occur.

7.1

Reversals During the Crediting Period

Immediately following the disturbance the deadwood carbon pool must be quantified as part of Reversal reporting. If there is a decline in the deadwood carbon stock from the last pre-disturbance measurement, the deficit must be treated as a Reversal in accordance with the governing Protocol's requirements. If there is an increase in deadwood carbon stock, the deadwood carbon stock is temporarily capped at the pre-disturbance measured stock. This represents a conservative measure to ensure that losses in living woody biomass cannot be offset by short-term gains in deadwood stock.

Projects are eligible to resume deadwood crediting under the following conditions:

The Reversal event constituted less than a 50% loss in the living woody biomass pools.
Deadwood cannot be credited for the 15 years following the Reversal event to ensure the quantification captures persistent, rather than transient, dynamics. This change in deadwood stock for crediting is assessed relative to the pre-disturbance stock and not the post-disturbance stock.
Any subsequent disturbance restarts the 15 year clock and the cap remains in place from prior to the first event.

7.2

Reversals During an Ongoing Monitoring Period

Where the governing Protocol includes an Ongoing Monitoring Period, deadwood carbon stocks are not routinely quantified during this period and there is no mechanism for determining what the long-term impacts are on the deadwood stock. As part of the required Reversal reporting under the governing Protocol, the deadwood carbon stock must be quantified. If there is a decline in the deadwood carbon stock from the measured stock at the end of the Crediting Period, the deficit must be treated as a Reversal in accordance with the governing Protocol's requirements. If there is an increase in deadwood carbon stock, the deadwood carbon stock is capped at the level from the end of the Crediting Period to prevent offsetting of losses in living woody biomass with short-term gains in deadwood.

8.0

Reporting

Project Proponents must report the following in the Project Design Document (PDD) and at each Verification:

Field manual followed; description, GPS coordinates, shape, size, orientation, and design justification of plots and transects; measurement approaches and instruments.
Raw field data for both components, including per-piece/per-stem dimensions and decay class.
Density values and their source/tier; the stem-volume/taper equation and source; carbon fraction and source.
Counterfactual parameter ( $R$ ).
Assessment of major uncertainty sources and the joint Monte Carlo treatment; report conservative CO₂e_DW estimates.
Deadwood-management practices, including any prescribed burning, fuelwood collection, or removal of dead wood.

9.0

Acknowledgements

Isometric would like to thank the following external contributors to this Module:

Brandon K. Craft (NCX)

10.0

Definitions and Acronyms

BiodiversityThe diversity of life across taxonomic and spatial scales. Biodiversity can be measured within species (i.e. genetic diversity and variations in allele frequencies across populations), between species (i.e. the total number and abundance of species within and across defined regions), within ecosystems (i.e. the variation in functional diversity, such as guilds, life-history traits, and food-webs), and between ecosystems (variation in the services of abiotic and biotic communities across large, landscape-level scales) that support ecoregions and biomes.
Carbon Dioxide Equivalent Emissions (CO₂e)The amount of CO₂ emissions that would cause the same integrated radiative forcing or temperature change, over a given time horizon, as an emitted amount of GHG or a mixture of GHGs. One common metric of CO₂e is the 100-year Global Warming Potential.
ConservativePurposefully erring on the side of caution under conditions of Uncertainty by choosing input parameter values that will result in a lower net CO₂ Removal or GHG Reduction than if using the median input values. This is done to increase the likelihood that a given Removal or Reduction calculation is an underestimation rather than an overestimation.
CounterfactualAn assessment of what would have happened in the absence of a particular intervention – i.e., assuming the Baseline scenario.
Crediting PeriodThe period of time over which a Project Design Document is valid, and over which Removals, Reductions or Environmental Attributes may be Verified, resulting in Issued Certificates.
Double CountingImproperly allocating the same Removal or Reduction from a Project Proponent more than once to multiple Buyers.
DurabilityThe amount of time carbon removed from the atmosphere by an intervention – for example, a CDR project – is expected to reside in a given Reservoir, taking into account both physical risks and socioeconomic constructs (such as contracts) to protect the Reservoir in question.
Global Positioning System (GPS)A satellite-based navigation system.
Light Detection and Ranging (LiDAR)LiDAR is a remote sensing technology that uses laser pulses to create highly accurate three-dimensional maps of forest structure, enabling measurements of tree height, canopy density, and biomass.
Lossesfor open systems, biogeochemical and/or physical interactions which occur during the removal process that decrease the CO₂ removal .
ModuleIndependent components of Isometric Certified Protocols which are transferable between and applicable to different Protocols.
Monte Carlo SimulationsA mathematical approach for estimating the possible outcomes of an uncertain event through repeated random sampling. It can also be referred to as a "multiple probability simulation".
ProjectAn activity or process or group of activities or processes that alter the condition of a Baseline and leads to Removals or Reductions.
Project Design Document (PDD)The document that clearly outlines how a Project will generate rigorously quantifiable Additional high-quality Removals or Reductions.
Project ProponentThe organization that develops and/or has overall legal ownership or control of a Removal or Reduction Project.
ProtocolA document that describes how to quantitatively assess the net amount of CO₂ removed by a process. To Isometric, a Protocol is specific to a Project Proponent's process and comprised of Modules representing the Carbon Fluxes involved in the CDR process. A Protocol measures the full carbon impact of a process against the Baseline of it not occurring.
RemovalThe term used to represent the CO₂ taken out of the atmosphere as a result of a CDR process.
ReversalThe escape of CO₂ to the atmosphere after it has been stored, and after a Certificate has been Issued. A Reversal is classified as avoidable if a Project Proponent has influence or control over it and it likely could have been averted through application of reasonable risk mitigation measures. Any other Reversals will be classified as unavoidable.
StorageDescribes the addition of carbon dioxide removed from the atmosphere to a reservoir, which serves as its ultimate destination. This is also referred to as “sequestration”.
UncertaintyA lack of knowledge of the exact greenhouse gas impact (removal, reduction, or avoidance) associated with a particular process or Environmental Attribute. Uncertainty may be quantified using probability distributions, confidence intervals, or variance estimates.
ValidationA systematic and independent process for evaluating the reasonableness of the assumptions, limitations and methods that support a Project and assessing whether the Project conforms to the criteria set forth in the Isometric Standard and the Protocol by which the Project is governed. Validation must be completed by an Isometric approved third-party (VVB).
VerificationA process for evaluating and confirming the net Removals and Reductions for a Project, using data and information collected from the Project and assessing conformity with the criteria set forth in the Isometric Standard and the Protocol by which it is governed. Verification must be completed by an Isometric approved third-party (VVB).

11.0

Relevant Works

Pan, Y., Birdsey, R. A., Fang, J., Houghton, R., Kauppi, P. E., Kurz, W. A., ... & Hayes, D. (2011). A large and persistent carbon sink in the world’s forests. science, 333(6045), 988-993. ↩
Stokland, J., Jonsson, B. G., & Siitonen, J. (2012). Biodiversity in dead wood. Cambridge University Press. ↩
Harmon, M. E., Franklin, J. F., Swanson, F. J., Sollins, P., Gregory, S. V., Lattin, J. D., ... & Cummins, K. W. (1986). Ecology of coarse woody debris in temperate ecosystems. Advances in ecological research, 15, 133-302. ↩
Wijas, B. J., Allison, S. D., Austin, A. T., Cornwell, W. K., Cornelissen, J. H. C., Eggleton, P., ... & Zanne, A. E. (2024). The role of deadwood in the carbon cycle: Implications for models, forest management, and future climates. Annual Review of Ecology, Evolution, and Systematics, 55(1), 133-155. ↩
Martin, A. R., Domke, G. M., Doraisami, M., & Thomas, S. C. (2021). Carbon fractions in the world’s dead wood. Nature communications, 12(1), 889. ↩
Van Wagner, C. E. (1968). The line intersect method in forest fuel sampling. Forest science, 14(1), 20-26. ↩
Harmon, M. E., Fasth, B., Sexton, J., & Yatkov, M. (2011). Differences between standing and downed dead tree wood density reduction factors: a comparison across decay classes and tree species. Res. Pap. NRS-15. Newtown Square, PA: US Department of Agriculture, Forest Service, Northern Research Station. 40 p., 15, 1-40. ↩
Campbell, J. L., M. B. Green, R. D. Yanai, C. W. Woodall, S. Fraver, M. E. Harmon, M. A. Hatfield, C. J. Barnett, C. R. See, and G. M. Domke. 2019. Estimating uncertainty in the volume and carbon storage of downed coarse woody debris. Ecological Applications 29(2):e01844. 10.1002/eap.1844 ↩ ↩²
Russell, M. B., Fraver, S., Aakala, T., Gove, J. H., Woodall, C. W., D’Amato, A. W., & Ducey, M. J. (2015). Quantifying carbon stores and decomposition in dead wood: A review. Forest Ecology and Management, 350, 107-128. ↩
Woodall, Christopher W.; Monleon, Vicente J. 2008. Sampling protocol, estimation, and analysis procedures for the down woody materials indicator of the FIA program. Gen. Tech. Rep. NRS-22. Newtown Square, PA: U.S. Department of Agriculture, Forest Service, Northern Research Station. 68 p. ↩
Baker, T. R., & Chao, K. J. (2011). Manual for coarse woody debris measurement in RAINFOR plots (Version 2). RAINFOR. ↩
Harmon, M. E., Krankina, O. N., Yatskov, M., & Matthews, E. (2001). Predicting broad-scale carbon stores of woody detritus from plot-level data. In R. Lal, J. M. Kimble, R. F. Follett, & B. A. Stewart (Eds.), Assessment methods for soil carbon (pp. 533–552). Lewis Publishers / CRC Press. ↩
IPCC. (2003). Good practice guidance for land use, land-use change and forestry (J. Penman, M. Gytarsky, T. Hiraishi, T. Krug, D. Kruger, R. Pipatti, L. Buendia, K. Miwa, T. Ngara, K. Tanabe, & F. Wagner, Eds.). Institute for Global Environmental Strategies (IGES) for the IPCC. Chapter 3.2, Forest Land, Table 3.2.2, p. 3.37. ↩

Contributors

Isometric

Jeannie Wilkening, Ph.D.

CO_2e_{DW,net,cum,t} = CO_2e_{DW,storage,cum,t} - CO_2e_{DW,counterfactual,cum,t}

\bar{m}_{DW}(t) = \frac{\sum_{i=1}^nm_{DW,plot,i}(t)a_{plot,i}}{\sum_{i=1}^na_{plot,i}}

m_{downed,i}(t) = \frac{\pi^2}{8L_i}\sum_{k=1}^{K_i}\left(d_{k,1}d_{k,2} - h_{k,1}h_{k,2}\right)\rho_{sound,k}\,RF_{downed,c(k)}

m_{standing}(t) = \frac{1}{a_{plot}}\sum_jV_{stem,j}\rho_{sound,j}RF_{standing,c(j)}

CO_2e_{DW,counterfactual,cum,t} = R \times CO_2e_{AGB,counterfactual,cum,t}

Ecosystem Type

R Value [-]

Tropical

0.11

Evergreen

0.20

Deciduous

0.14

Contents

Introduction

Future Versions

Applicability

Deadwood Pool Definition

Quantification of CO2eDW

Scaling Plot Measurements to Project Area

Downed Coarse Woody Debris Density

Standing Deadwood Density

Density Reduction Factors

Uncertainty

Field Measurements and Sampling Design

Sampling Design

Line-Intersect Sampling of Downed Coarse Woody Debris

Measurement of Standing Dead Trees

Decay Class Categorization

Counterfactual

Durability and Reversals

Reversals During the Crediting Period

Reversals During an Ongoing Monitoring Period

Reporting

Acknowledgements

Definitions and Acronyms

Relevant Works

Footnotes

Contributors

Contents

Introduction

Future Versions

Applicability

Deadwood Pool Definition

Quantification of CO2eDW

Scaling Plot Measurements to Project Area

Downed Coarse Woody Debris Density

Standing Deadwood Density

Density Reduction Factors

Uncertainty

Field Measurements and Sampling Design

Sampling Design

Line-Intersect Sampling of Downed Coarse Woody Debris

Measurement of Standing Dead Trees

Decay Class Categorization

Counterfactual

Durability and Reversals

Reversals During the Crediting Period

Reversals During an Ongoing Monitoring Period

Reporting

Acknowledgements

Definitions and Acronyms

Relevant Works

Footnotes

Contributors

Quantification of CO₂e_DW

Quantification of CO₂e_DW