STRATEGY & METHODS FOR
ESTIMATING & PROJECTING
CARBON STOCK CHANGES
 GOAL: To estimate carbon benefits from forestry
mitigation projects
C-stock change in baseline scenario
C-stock change in project scenario
Net C-stock change or additionality
 TWO PHASES
Project development phase
Project implementation phase
Steps for Carbon inventory
 Step 1: Definition of objectives, land use
systems and area for estimating carbon benefits
of a project
 Step 2: Description of project activities and area
 Step 3: Selection of C-pools and methods for
measurement and monitoring the pools by
selecting the parameters for each pool
 Step 4: Definition of the project boundary and
map preparation
 Step 5: Stratification of the ecosystem and land
use
Contd………….
 Step 6: Developing sampling design and strategy for
biomass and soil carbon
 Step 7: Laying plots in different land use systems
 Step 8: Field measurements, data format and data
recording
 Step 9: Data analysis for biomass and soil carbon
estimation
 Step 10: Projecting C-stock changes using PROCOMAP
model
 Step 11:Reporting C-stocks for different pools under
baseline and project scenario
 Step 12: Reporting of incremental carbon benefits
Step-1: Objective;
i) Estimating C-stock changes in BSL & Project
scenario
Step-2 & 3: Land use systems & project
activities
Land use systems: Degraded forestland,
farmland, village commons
Project activities: A&R- Natural regeneration,
mixed-species forestry, plantation
Area under these categories
Step-4: Selection of carbon
pools
Project
activities
Teak
AGB
BGB
Woody SOC
litter
X
X
X
X
Eucalyptus
X
X
X
X
Secondary
forest
X
X
X
X
Step 5: Selection of Methods
Carbon pools
Method
AGB
Plot method
Woody litter
Plot method
BGB
Root:Shoot ratio
SOC
Field sampling
Laboratory studies
Step-6: Parameters to be measured
Carbon pool
Method
AGB of trees and
shrubs
- Baseline scenario
- Project scenario
Plot method
AGB of herb or
ground
layer
vegetation
Plot method
Woody litter
Plot method
Soil carbon
Field method
Laboratory;
Walkley
and
Black procedure
Parameters
- Species name
- DBH
- Height
- Regenerated or planted
- Damaged/cut or not
- Dead trees
- Species name
- Density (number/ha)
- Fresh weight of herb layer
biomass
- Dry weight of herb layer
biomass
- Fresh weight of woody litter
- Dry weight of woody litter
- Soil samples at 0-15 and 1530 cm depth
- Bulk density for soil
- Soil organic carbon (%)
Project boundary and map
Step-8: Stratification of project
area
Ecosystem
Forests
Grassland
Cropland
Water bodies
Other LUS
Dense forest
Managed
grassland
Irrigated land
Banks or bunds of
streams
Settlement
Open forest
Open access
Rainfed land
Tank/ pond/lake
Avenue or roads
Protected
forest
Private
grassland
Perrennial crops or
garden
River banks
Fallow land
Canals border
Degraded
Plantations
Homestead
gardens
Soil types
Slope
land
Soil types
Level
land
Grazing
density
Soil types
Proximity to
village
Commercial
crops
Traditional
crops
Perrennial
Seasonal
Without
tree
vegetation
With tree
vegetation
Sampling at project
development phase
Baseline scenario:
Degraded forestland
Degraded pasture land
Degraded farmland
Project scenario-Activities:
Natural regeneration
Different years (near by area)
Mixed species plantation
Different years (near by area)
Monoculture plantation
Different age (near by area)
Plots to be laid in all such land categories
Step-9: Sampling design & Strategy
 METHOD: ‘Plot method’ / ‘Quadrat method’
 TYPE OF PLOT: Quadrat, circular, strip
Size & Number of Plots
Statistical approach: Based on estimates;
variance of C-stock, cost of sampling and
precision
Thumb rule; used most often
Sampling separately for trees, shrubs, herbs
Examples of Number & Size of
plots
Land use
systems
Trees
Size of
plot (m)
Shrub
No. of
plots
Size of
plot (m)
Herb/Grass
No. of
plots
Size of
plot (m)
No. of
plots
Soil
Size of
plot (m)
No. of
plots
Natural
regeneration or
Heterogenous
vegetation
50 X 40
5
5X5
10
1X1
20
1X1
20
50 X 50
4
5X5
10
1X1
20
1X1
20
Plantations with
homogenous
vegetation or
Uniform species
distribution and
density
50 X 20
or 40 X
25
5
5X5
8
1X1
16
1X1
16
Degraded forest
or barren or
fallow land
50 X 40
5
5X5
10
1X1
20
1X1
20
Sampling sites at Project
development phase
Baseline scenario- Land use systems
Degraded forestland
Degraded village commons
Farmland
Project activities
Teak regeneration; 5 or 10 or 15 yrs
Secondary forest regeneration; 5 or 12 or 20
yrs
Natural forest (old growth)
Step 10: Laying of plots in
the field
I. Stratified Random Sampling
II. Systematic Sampling
Stratified Random Sampling
Involves locating the plots in the field in an unbiased
way & suitable to both heterogeneous and
homogenous vegetation
Sampling approach involves following steps:
Step 1: Stratify land use systems & project activity
areas
Step 2: Prepare a grid map of the project area,
demarcating each land use system or project activity.
Size of the grid as small as feasible (say 50 m X 50 m)
Step 3: Give numbers to each grid
Step 4: Randomly pick the grid numbers, using random
table or lottery system.
Contd……………..
Step 5: Locate tree plots in the grids selected in the
field with respect to some permanent visible land
mark and mark the boundary of each tree plot or use
GPS
Step 6: Prepare and store a map with all the details,
including the location of sample plots marked on it.
Location of sample plots in the field; overlay the land
use system map over the grid scale map
Using GIS & marking plots in the selected grids. GPS
measurements of the corner points of plots must be
recorded on the map for revisits
Systematic sampling
Employs a simple method of selecting every kth unit (grid)
starting with a number chosen at random from 1 to N.
Step 1: Select the number of plots (quadrats) for the study (n),
which have to be laid in the field for sampling, say for example
n = 5 of 50 m X 40 m dimension
Step 2: Stratify the land use system into homogenous sub-strata
Step 3: Obtain a map showing the grids depicting each sampling
stratum and estimate the total number of grids for each strata
(N), say for example 200 grids with an area of 40 ha
Step 4: Calculate the sampling interval ‘k’ by using the following
equation,
k = N/n where, k = sampling interval of grids or plots = 200/5
= 40
Contd…………...
Step 5: Draw a random number which is less than k (sampling
interval for grid), say 25th grid
Step 6: Select and mark the first grid based on the random
number selected
First sampling grid or plot number is 25
Second sampling grid or plot = Sampling interval k (40) + first
sampling grid (25) = 65th grid
Third sampling grid or plot = Sampling interval k (40) +
second sampling grid (65) = 105th grid.
Similarly, the successive grids or plots will be systematically
sampled, till the nth grid or plot (in the example 5th grid) is
located.
Field measurements: Trees
Location: Bogadde minor forest
Date of measurement:
Area of plot: 50 m X 40 m
Land use system: Forest
Sub-strata: Moderately degraded
Tree plot no: TP1
S.
Tree species
Tree
Stem
GBH Planted or Height
Damage
No
number
number
(cm) regenerate
(m)
extent
(including
d
(1)
(2)
dead stem)
(4)
(6)
(3)
(5)
(7)
1
1
Lannea
1
1
135
R
25
No
coramandelica
2
Emblica officinalis
1
1
40
R
20
No
3
Xantolis tomentosa
1
1
75
R
11
No
4
Xantolis tomentosa
1
1
72
R
12
No
2
5
Syzigium cuminni
1
1
30
P
10
Damage(50
% crown)
6
Lannea
1
1
11
P
18
No
coramandelica
7
Lannea
2
16
P
16
No
coramandelica
NOTES: 1R = Regenerated, 2P = Planted
GBH: Girth at breast height (130 cm above ground), for small trees, DBH (diameter at breast height) can be
taken at 130 cm above ground.
GBH/DBH measurement
Field measurements: Shrubs
Location: Bogadde
Date of measurement:
Area of plot: 5 m X 5 m
minor forest
Land use system: Forest Tree plot no: TP1
Shrub plot no: SP1
S.
Species
Diameter (cm)
Height Biomass – Fresh
No.
(m)
weight (kg)
DBH1 DBH2 DBH3
1
Allophyllus cobbe
2.5
2
Ziziphus rugosa
8
5
3
3.0
3
Bridelia sp.
6
4
2.0
4
Cleorodendron sp.
1.7
25 kg
5
Bryenia sp.
3.1
6
Leea indica
2.1
NOTES: Species 4, 5, 6 are shrubs with no measurable stems and thus the above ground
vegetation of these species harvested and fresh weight taken (25 Kg)
Woody litter including Fallen
deadwood
Woody litter production
Standing woody litter
STEPS: STANDING WOODY LITTER
Step 1: Select and use the shrub plots marked in the
field
Step 2: Select the peak month when the litter fall is
maximum based on local experience
Step 3: Collect woody litter from all shrub plots and
merge to one heap & estimate the fresh weight
Step 4: Take a sample of say 1 kg for dry weight
estimation in the laboratory as % of fresh weight
Step 5: Estimate weight of dry woody litter per hectare
using fresh and dry weight litter data and area of shrub
plots.
Soil carbon
Soil carbon is the dominant C-pool in many
projects
Soil carbon in top 15 & 30 cm
Collecting soil sample for carbon estimation
involves the following steps:
Step 1: Select the plots marked for shrub
biomass estimation, 8 to 10 plots
Step 2: Mark the mid-point of the 5mx5m
shrub plot or any point randomly
Contd……...
Step 3: Using the soil agar, drill the soil to a
depth of 0-15 cm and collect the sample. Repeat
procedure for 15-30 cm depth.
Step 4: Merge soil samples of 0-15 cm from the
two shrub plots of a tree plot. Remove plant
debris. Collect about 0.5 kg of fresh soil into a
plastic bag for laboratory analysis. Repeat for 1530 cm soil depth.
Bulk density
Converting SOC concentration (in % terms) to tC/ha
needs bulk density
Step 1: Select 1 shrub plot, out of 2 plots laid per tree
plot
Step 2: Weigh an empty bottle & fill this with soil. Tap
the bottle, keep filling the soil till the level reaches the
brim. Mark the level of soil in the bottle. The
compaction of the soil in the bottle may be comparable
to what is present in the field
Step 3: Note down the weight of the bottle with the soil
Step 4: Empty the bottle and add water to the
container till the marked level. Note down the volume
of the water by pouring it in the measuring cylinder
Equations for SOC
Bulk density (g/cc) = (Weight of the soil in the
bottle)/ (Volume of the water in the bottle)
Soil mass (t/ha) = [Area (10,000 m2) X Depth
(0.3 m) X Bulk density X 103
grams/Kg]/(1000Kg/tonne)
SOC (tonne/ha) = (Soil mass in 0-30 cm) X SOC
concentration (%)/100
Biomass estimation
AGB; i) Using biomass equations
Generic
Species specific
Based on: DBH, Height & Basal area
ii) Volume estimation of trees
iii) Harvest method; plantations
BGB; AGB X 0.26
Litter; Stock at base-year and project-year
Carbon; Biomass X 0.5
Estimating Net Additional
Incremental Carbon Benefit
Reporting incremental carbon benefits requires
estimation and reporting of:
Net change in C-stock covering all C-pools in
baseline scenario & project scenario
Estimation of leakage of carbon benefits
Incremental carbon benefit (in tC for the period
selected) = (net change in C-stock in project
scenario) - (net change in C-stock in baseline
scenario) - (estimated leakage)
Contd……..
Carbon benefits of the project = [(Total carbon
stock at end of 5 years) – (Total carbon stock at
year 0)]
Net incremental carbon benefits = (Estimates of
carbon benefits under the project scenario) (Baseline scenario carbon stock change) - (Leakage
estimates)
Monitoring of C-stock
changes
Adopt plot method
Select frequency of monitoring
AGB: 2 or 3 years
SOC: 5 years
Conduct field & Lab studies
Estimate C-stocks
Criteria for Selection of
Project Site
Availability of multiple land categories
Community lands/Government lands
Open forest land
Farm land for afforestation
Forestland subjected to extensive extraction
Contiguous parcel (cluster of villages)
with in a forest division or range
10 to 30 villages
5000 to 10,000 ha
Contd……..
Potential for Community forestry/JFM
Case study - I
Potential for ‘Industry-farmers’
cooperative
Case study- II
Potential for high carbon sequestration
growth rates - Initial phase
Soil status
Rainfall