Pool 
Balance equation (BE), fluxes (IN and OUT), or other equations 
Equations, variables and parameters
(pools and
processes (in oneyear steps) are in terms of tC) 
Above
ground
woody biomass 
BE 
Aboveground woody biomass = aboveground woody
biomass_{t1}
+ woody increment – mortality – thinnings  final cuttings
AGWB_{t}
= AGWB_{t1} + CAIC – M – TH – FC 
Flux IN

current
annual increment of aboveground woody biomass = current annual increment
(of tree volume) * wood density * carbon content of wood
CAIC
= CAI * d * cf
d =
weight of ovendry biomass / volume of fresh wood (at the stand level),
tdm m^{3}
cf =
carbon fraction of (oven dry) wood 

mortality = aboveground woody biomass_{t1} * (density dependent
mortality ratio + density independent mortality ratio)
M =
AGWB_{ t1} * (ddm + dim)
ddm:
sepcies dependent
dim:
randomly generated
ddm +
dim <= 0,4 

thinnings = aboveground woody biomass_{t1} * thinning ratio
TH =
AGWB_{t1} * thr
Thr =
species specific, depends on age and yield class 

final cuttings = aboveground woody biomass_{t1} of stands of rotation age
FC =
AGWB_{t1} of stands of rotation age
(final
cutting is supposed to take place at the beginning of the year, and is
immediately followed by regeneration)
Rotation
age: species specific, depends on yield class

Dead
wood 
BE 
dead
wood = dead wood_{t1} + deadwood increment  decomposition of
(i.e., emission from) decomposable dead wood
DW_{t} =
DW_{t1} + DWI – EW 

increase
of deadwood = (mortality + thinnings * (1 – wood product part of thinning
– fuelwood part of thinning) + final cuttings* (1  wood product part of
final cutting – fuelwood part of final cutting) )* (1  nondecomposable
fraction)
DWI =
[M + TH * (1 – wpTH – fpTH) + FC * (1 – wpFC – fpFC)] * (1ndf) 
Flux OUT 
emission
due to decomposition of deadwood = dead wood_{ti}
* (1exp(k_{DW})) + deadwood increment *
(k_{DW}  1 + exp(k_{DW})) / k_{DW }
where k_{DW} = ln(2) / half life time of deadwood
EW = DW_{ti }*
(1exp(k_{DW})) + DWI * (k_{DW}
 1 + exp(k_{DW}) /
k_{DW} 
Flux to SINK 
Non
decomposable dead wood fraction = (M + TH – nonproductTH * FC – nonproductFC)
* ndf
UWI =
(M + TH – nonproductTH * FC – nonproductFC) * ndf 
Leaves 
BE 
amount
of (living) leaves at the end of year = amount of leaves at the end of previous
year + increment due to tree growth – decomposable leaf loss due to
harvest and mortality – undecomposable leaf loss due to harvest and
mortality
LL_{t} =
LL_{t1} + LI – DLI – DLI * ndf / (1  ndf) 
Flux IN 
increment of leaves = aboveground woody biomass increment * (leaf
increment/AG woody biomass increment)
LI =
CAIC * increment ratio 

amount of decomposable leaves that die in year (due to harvest and
within year and endofyear leaf mortality)
=
[(leaves_{t1} + increment of leaves) * nonliving/living +
(leaves_{t1} + increment of leaves) * nonliving/living *
(1nonliving/living) * fraction of leaves dying and falling at the end of
year)] * (1  nondecomposable fraction)
DLI =
[(LL_{t1} + LI) * nll + (LL_{ t1} +LI) * (1  nll) *
fdlleaves] * (1ndf)
fdlleaves: species specific (broadleaves: 1; conifers: <1) 

nonliving/living biomass ratio = increase of deadwood / aboveground woody
biomass of the previous year
nll =
DWI/AGWB_{t1} 
Flux to SINK 
Non
decomposable fraction = amount of leaves that become decomposable dead *
ndf/(1ndf)
ULI =
DLI * ndf / (1ndf) 
Dead
leaves 
BE

dead
decomposable leaves = dead decomposable leaves_{t1}
+ amount of decomposable leaves that die in year – decomposition of dead
leaves
DL_{t} =
DL_{t1} + DLI – EL 
Flux OUT 
emission
due to decomposition of dead leaves = dead leaves_{ti}
* (1exp(k_{DL})) + amount of decomposable leaves that die in
year * (k_{DL}  1 + exp(k_{DL})) / k_{DL }
where k_{DL} = ln(2) / half life time of dead leaves
EL = DL_{ti }*
(1exp(k_{DL})) + DLI * (k_{DL}  1 + exp(k_{DL})
/ k_{D}_{L} 
Roots
(below ground biomass) 
BE 
Roots at
the end of year = Roots_{t1} + increase of root biomass – amount
of decomposable roots that die in year – amount of undecomposable dead
root that die in year
R_{t} = R_{t1}
+ RI – DRI – DRI * ndf / (1ndf) 
Flux IN 
increase
of root biomass = current annual woody increment * (roottoshoot ratio)
RI =
CAIC * rts 

Decomposable dead roots increment =
= [(Root
biomass_{t1} + increase of root biomass ) * (nonliving/living) +
(increase of root biomasss ) * (1  nonliving/living) * Fraction of roots
of trees (relative to root increment) that dies at the end of year ] * (1
– non decomposable fraction)
DRI =
[(R_{t1} + RI) * nll + (LI_{ t1} + LRI) * (1nll) *
fdlroots] * (1ndf) 
Flux to SINK 
Non
decomposable dead root biomass increment = decomposable dead roots
increment * ndf/(1ndf)
URI =
DRI * ndf/(1ndf) 
Dead
Roots 
BE 
Dead
decomposable roots at the end of year = carbon in dead decomposable roots_{t1}
+ total decomposable dead roots increment – decomposition of (i.e.,
emission from) decomposable dead roots
DR_{t} =
DR_{t1} + DRI – ER 
Flux OUT 
emission
due to decomposition of dead roots = carbon in dead decomposable roots_{ti}
* (1exp(k_{DR})) + total decomposable dead roots increment * (k_{DR}
 1 + exp(k_{DR})) / k_{DR }where k_{DR} = ln(2)
/ half life time of dead roots
ER = DR_{ti }*
(1exp(k_{DR})) + DRI * (k_{DR}  1 + exp(k_{DR})
/ k_{D}_{R} 
Wood products 
BE 
Wood
products = Wood products_{t1} + wood product increment – wood
products becoming unused
WP =
WP_{t1} + WPI – EUUWP
– UWPF 

wood
products increment = (timber from clearcut + timber from thinnings) * (1 –
lost part)
(the increment, as well as
pools, flux out and other calculations are split into three factions,
using appropriate parameters: paper,
wood based panels and sawnwoodbased wood products, as in the
IPCC KP Supplement)
WPI =
[FC * used part * (1fuelwood part) + TH * used part(t) * (1fuelwood
part(t)] * (1  lost part) 

wood
products becoming unused = wood products increment X years before
WPU =
WPI_{ti}
X: mean
life time of wood product (species specific) 
Flux OUT 
emission
due to decomposition of wood products = unburnt * (carbon in wood products_{ti}
* (1exp(k_{WP})) + total decomposable dead roots increment * (k_{WP}
 1 + exp(k_{WP})) / k_{WP}) where k_{WP} = ln(2)
/ half life time of wood products (different for paper, wood based
panels and sawnwoodbased wood products, as in the
IPCC KP Supplement)
EUUWP = WPU_{ti }
* (1exp(k_{WP})) + WPI * (k_{WP}  1 + exp(k_{WP})
/ k_{WP} 
Fuelwood 
BE 
Fuelwood
= fuelwood_{t1} + fuelwood increment from harvest + loss in wood
processing + unused wood products becoming fuelwood – emission from
firewood
FW =
FW_{t1} + FWI + LWP + UWPF – EFW 

Fuelwood
increment from harvests = fuelwood from clearcut + fuelwood from thinning
FWI =
FC * used part * fuelwood part + TH * used part_{t }* fuelwood
part_{t} 

Loss in
wood processing = wood product increment * lost part / (1 – lost part)
LWP =
WPI * lost part / (1 – lost part) 

Wood
product becoming fuelwood = wood products becoming unused_{t1} *
unburnt fraction
UWPF
= WPU_{t1} * unburnt 
Flux OUT 
emission
from burning firewood = avoiding fossil fuel burning = fuelwood carbon_{t1}
* (1unburnable fraction)
EFW =
FW_{t1} * (1unburn) 
Flux to Sink 
Unburnable fuelwood = fuelwood_{t1} * unburnable fraction
UFWI
= FW_{t1} * unburn 
Soil 
BE 
soil =
soil_{ t1} + net flux to sink – loss due to afforestation and
regeneration
operations – loss due to afforesting grasslands
S = S_{t1}
+ FS – CLO – GAL
(Net flux to sink, which includes soil respiration, and loss due to afforesting grasslands
are only calculated for 75 years after afforestations. After that time,
net flux to sink is supposed to be zero, i.e. transfer of carbon from
other compartments to soil is equal to soil respiration, and no more
losses are supposed to take place due to converting grassland to
forest.) 

carbon
loss due to afforestation operations = afforestation area * area specific
loss
CLO = A
* asl
asl: to be specified by the user 

carbon
loss due to afforesting grasslands = afforestation area * percent of area
of grassland * timedependent difference of carbon stock between
cropland and grassland
GAL = A
* glp * diff_CL_GL
glp: to be specified by the user
diff_CL_GL: values are taken from a countryspecific equation 
Flux to SINK 
Flux to
permanent sink = total amount of dead organic matter becoming
undecomposable and unburnt = undecomposable dead leaves pool +
undecomposable dead roots + undecomposable dead wood + unburnable fraction
of firewood
FS = ULI
+ URI + UWI + UFWI 