Pool |
Balance equation (BE), fluxes (IN and OUT), or other equations |
Equations, variables and parameters
(pools and
processes (in one-year steps) are in terms of tC) |
Above-
ground
woody biomass |
BE |
Above-ground woody biomass = above-ground woody
biomasst-1
+ woody increment – mortality – thinnings - final cuttings
AGWBt
= AGWBt-1 + CAIC – M – TH – FC |
Flux IN
|
current
annual increment of above-ground woody biomass = current annual increment
(of tree volume) * wood density * carbon content of wood
CAIC
= CAI * d * cf
d =
weight of oven-dry biomass / volume of fresh wood (at the stand level),
tdm m-3
cf =
carbon fraction of (oven dry) wood |
|
mortality = above-ground woody biomasst-1 * (density dependent
mortality ratio + density independent mortality ratio)
M =
AGWB t-1 * (ddm + dim)
ddm:
sepcies dependent
dim:
randomly generated
ddm +
dim <= 0,4 |
|
thinnings = above-ground woody biomasst-1 * thinning ratio
TH =
AGWBt-1 * thr
Thr =
species specific, depends on age and yield class |
|
final cuttings = above-ground woody biomasst-1 of stands of rotation age
FC =
AGWBt-1 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 woodt-1 + deadwood increment - decomposition of
(i.e., emission from) decomposable dead wood
DWt =
DWt-1 + 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 - non-decomposable
fraction)
DWI =
[M + TH * (1 – wpTH – fpTH) + FC * (1 – wpFC – fpFC)] * (1-ndf) |
Flux OUT |
emission
due to decomposition of deadwood = dead woodt-i
* (1-exp(-kDW)) + deadwood increment *
(kDW - 1 + exp(-kDW)) / kDW
where kDW = ln(2) / half life time of deadwood
EW = DWt-i *
(1-exp(-kDW)) + DWI * (kDW
- 1 + exp(-kDW) /
kDW |
Flux to SINK |
Non
decomposable dead wood fraction = (M + TH – non-productTH * FC – non-productFC)
* ndf
UWI =
(M + TH – non-productTH * FC – non-productFC) * 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
LLt =
LLt-1 + 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 end-of-year leaf mortality)
=
[(leavest-1 + increment of leaves) * non-living/living +
(leavest-1 + increment of leaves) * non-living/living *
(1-non-living/living) * fraction of leaves dying and falling at the end of
year)] * (1 - non-decomposable fraction)
DLI =
[(LLt-1 + LI) * nll + (LL t-1 +LI) * (1 - nll) *
fdlleaves] * (1-ndf)
fdlleaves: species specific (broadleaves: 1; conifers: <1) |
|
non-living/living biomass ratio = increase of deadwood / aboveground woody
biomass of the previous year
nll =
DWI/AGWBt-1 |
Flux to SINK |
Non
decomposable fraction = amount of leaves that become decomposable dead *
ndf/(1-ndf)
ULI =
DLI * ndf / (1-ndf) |
Dead
leaves |
BE
|
dead
decomposable leaves = dead decomposable leavest-1
+ amount of decomposable leaves that die in year – decomposition of dead
leaves
DLt =
DLt-1 + DLI – EL |
Flux OUT |
emission
due to decomposition of dead leaves = dead leavest-i
* (1-exp(-kDL)) + amount of decomposable leaves that die in
year * (kDL - 1 + exp(-kDL)) / kDL
where kDL = ln(2) / half life time of dead leaves
EL = DLt-i *
(1-exp(-kDL)) + DLI * (kDL - 1 + exp(-kDL)
/ kDL |
Roots
(below ground biomass) |
BE |
Roots at
the end of year = Rootst-1 + increase of root biomass – amount
of decomposable roots that die in year – amount of undecomposable dead
root that die in year
Rt = Rt-1
+ RI – DRI – DRI * ndf / (1-ndf) |
Flux IN |
increase
of root biomass = current annual woody increment * (root-to-shoot ratio)
RI =
CAIC * rts |
|
Decomposable dead roots increment =
= [(Root
biomasst-1 + increase of root biomass ) * (non-living/living) +
(increase of root biomasss ) * (1 - non-living/living) * Fraction of roots
of trees (relative to root increment) that dies at the end of year ] * (1
– non decomposable fraction)
DRI =
[(Rt-1 + RI) * nll + (LI t-1 + LRI) * (1-nll) *
fdlroots] * (1-ndf) |
Flux to SINK |
Non
decomposable dead root biomass increment = decomposable dead roots
increment * ndf/(1-ndf)
URI =
DRI * ndf/(1-ndf) |
Dead
Roots |
BE |
Dead
decomposable roots at the end of year = carbon in dead decomposable rootst-1
+ total decomposable dead roots increment – decomposition of (i.e.,
emission from) decomposable dead roots
DRt =
DRt-1 + DRI – ER |
Flux OUT |
emission
due to decomposition of dead roots = carbon in dead decomposable rootst-i
* (1-exp(-kDR)) + total decomposable dead roots increment * (kDR
- 1 + exp(-kDR)) / kDR where kDR = ln(2)
/ half life time of dead roots
ER = DRt-i *
(1-exp(-kDR)) + DRI * (kDR - 1 + exp(-kDR)
/ kDR |
Wood products |
BE |
Wood
products = Wood productst-1 + wood product increment – wood
products becoming unused
WP =
WPt-1 + 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 sawnwood-based wood products, as in the
IPCC KP Supplement)
WPI =
[FC * used part * (1-fuelwood part) + TH * used part(t) * (1-fuelwood
part(t)] * (1 - lost part) |
|
wood
products becoming unused = wood products increment X years before
WPU =
WPIt-i
X: mean
life time of wood product (species specific) |
Flux OUT |
emission
due to decomposition of wood products = unburnt * (carbon in wood productst-i
* (1-exp(-kWP)) + total decomposable dead roots increment * (kWP
- 1 + exp(-kWP)) / kWP) where kWP = ln(2)
/ half life time of wood products (different for paper, wood based
panels and sawnwood-based wood products, as in the
IPCC KP Supplement)
EUUWP = WPUt-i
* (1-exp(-kWP)) + WPI * (kWP - 1 + exp(-kWP)
/ kWP |
Fuelwood |
BE |
Fuelwood
= fuelwoodt-1 + fuelwood increment from harvest + loss in wood
processing + unused wood products becoming fuelwood – emission from
firewood
FW =
FWt-1 + FWI + LWP + UWPF – EFW |
|
Fuelwood
increment from harvests = fuelwood from clearcut + fuelwood from thinning
FWI =
FC * used part * fuelwood part + TH * used partt * fuelwood
partt |
|
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 unusedt-1 *
unburnt fraction
UWPF
= WPUt-1 * unburnt |
Flux OUT |
emission
from burning firewood = avoiding fossil fuel burning = fuelwood carbont-1
* (1-unburnable fraction)
EFW =
FWt-1 * (1-unburn) |
Flux to Sink |
Unburnable fuelwood = fuelwoodt-1 * unburnable fraction
UFWI
= FWt-1 * unburn |
Soil |
BE |
soil =
soil t-1 + net flux to sink – loss due to afforestation and
regeneration
operations – loss due to afforesting grasslands
S = St-1
+ 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 * time-dependent 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 country-specific 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 |