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| Function | Method | Outputs | Inputs | Main formula (generic form) | Notes / Context |
|---|---|---|---|---|---|
| Converting module | |||||
c150_c130() |
Convert c150 to c130 orConvert c130 to c150 |
c150c130 |
c130c150 |
c130=a⋅c150+bc150=(c130-b)/a |
The function computes c150 or c130 depending on data availabity |
add_c130_dbh() |
Add or compute c130 and dbh
|
c130dbh |
dbhc130
|
dbh = c130 / πc130 = dbh · π
|
Auto-fills missing c130 or dbh. |
| General & widely applicable volume models | |||||
dagnelie_vc22_1() |
Dagnelie single entry | vc22 |
c130 |
vc22 = a + b·c130 + c·c130² + d·c130³ |
Simplest Dagnelie taper model, relies only on circumference. |
dagnelie_vc22_1g() |
Dagnelie graduaded | vc22 |
c130 hdom |
vc22 = a + b·c130 + c·c130² + d·c130³ + e·hdom + f·c130²·hdom |
Improves accuracy in pure, even-aged stands by adding dominant height. |
dagnelie_vc22_2() |
Dagnelie 2 entry | vc22 |
c130 htot |
vc22 = a + b·c130 + c·c130² + d·c130³ + e·htot + f·c130²·htot |
Most precise Dagnelie model; recommended mainly for high-value trees due to height measurement cost. |
dagnelie_br() |
Dagnelie – Branch volume | vbr |
c130 |
vbr = a + b·c130 + c·c130² + d·c130³ |
Estimates branch volume from circumference only. |
vallet_vta() |
Vallet - Volume above ground | vta |
c130 htot |
*form* = (a + b·c130 + c·c130/htot)·(1 + d·c130²)*vta* = form · (π / 40000) · c130² · htot
|
Explicitly models stem form factor; primarily for French species. |
vallet_vc22() |
Vallet merchantising volume | vc22 |
dbh htot |
vc22 = a·htot/dbh + (b + c·dbh)·π·dbh²·htot / 40000 |
Geometrically adjusted; species-specific coefficients reflecting stem structure. |
| Context-specific methods | |||||
algan_vta_vc22() |
Algan - volume computer(2006) |
vtavc22
|
dbhhtot |
vta = 0.40 · (dbh/100)² · htotvc22 = 0.33 · (dbh/100)² · htot
|
Simplified geometric estimator; mainly used in France for Abies alba. |
bouvard_vta() |
Bouvard - Volume above ground | vta |
dbhhtot |
vta = 0.50 · (dbh/100)² · htot |
Specific to oaks (Quercus sp.), especially in coppice-with-standards regimes. |
rondeux_vc22_vtot() |
Rondeux / Pauwels et al. (2022) |
vtotvc22
|
c130htot |
vtot = a · c130² · htot vc22 = a + b · c130² · htot
|
Wallonia-specific; calibrated for larch (Larix sp.) in small-circumference trees (first thinnings). |
| Biomass / carbon computer | |||||
biomass_calc() – CNPF pathway |
CNPF / France Valley |
bagbbgbtotcarbonCO₂
|
vc22 |
bag = vc22 · feb · densitybbg = exp(−a + b·ln(bag) + c)btot = bag + bbgC = 0.475 · btot
|
feb = 1.30 (conifers)feb = 1.56 (broadleaves)carbon and CO₂ derived from total biomass. |
biomass_calc() – Vallet pathway |
Follow Vallet et al. (2006) |
bagbbgbtotcarbonCO₂
|
vallet_vta |
bag = vta · densitybbg = exp(−a + b·ln(bag) + c)btot = bag + bbg
|
Used when vallet_vta is availableroot biomass is implicitly included. |
| Plot module | |||||
plot_by_class() |
Plot histogram by class of c130 |
vc22vtabtot |
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Class width can be adjusted by the breaks input in the function | |