CALIBRATION3-PG – Pinus pinaster

Elemer Briceño

15/07/2008

3-PG - Process-based model

Approach for this model overview

3-PG Description- main characteristics- main modules- structure- inputs and outputs

3-PG Use sites for Pine - why and where has been used- Portuguese case study

15/07/2008

3-PG – Basic structure

Climate data

Initial stand

Site factors

Biomass production

Biomass allocation

Conversion into variables of

interest to forest managers

3-PG

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F F n F F

R R n R R

S S n

W P W

W P W

W P

NPP is partitioned into biomass pools (tDM ha-1): Foliage(WF), Above-ground woody tissue(WS) Roots (WR)

Partitioning rates (F, R and S) depend on growth conditions and stand dbh.

Litter-fall (F) and root-turnover (R) also taken into account. Thus:

3-PG – Biomass allocation (I)

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3-PG – Biomass allocation (II)

Increasing DBH decreases foliage partitioning and increases stem partitioning. Graphs show response when:

pFS(2) = 1, pFS(20) = 0.2

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0 10 20 30

Stem diameter

Ab

ov

e-g

rou

nd

pa

rtit

ion

ing

Stem

Foliage

0.0

0.2

0.4

0.6

0.8

1.0

1.2

0 10 20 30

Stem diameter

Ra

tio

of

folia

ge

:sh

oo

t p

art

itio

nin

g

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Net primaryproduction

H 2O , FR

DBH

F /S

StemFoliageRoots

Stocking

3-PG – Biomass allocation (III)

State v ar iab les

Subs id iary v ar iab les

Climate & s ite Inputs

Los s es

Mater ia l f low s

Inf luenc es

Carbon

W ater

Trees

Ke y to colours & sha pe s

Subs id iary v ar iab les

+

H20 R ain

g C

Soil H20

E T

+

+

+

_

_

+

wS x

Deadtrees

Stocking+

+

_

wS +w S >w S x

_ _

N+

+

__

S tres s

VPD

T

FR

f

+

_

+

_

+

++

+

+

D BH

F /SR

L AIL UE

SL A

+

+

_

NPP

Stem

Foliage

Roots

GPP

CO2

C ,N

Litter

+

• Structure without the module for conversion into variables

of interest to forest managers

3-PG – Structure

• Climate data– Monthly data temperature, radiation, rainfall, VPD– Either observed values either means from several years

• Site and soils– Latitude– Soil texture & maximumASW– Fertility rating

• Stand data– Biomasses: Foliage, Above-ground woody tissue , Roots – N – number of trees per hectare

3-PG – Inputs

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There is a group of outputs useful for foresters and less common in process based models :

V, G, N, MAI, etc.

There is a group of outputs which are common in process based models :

GPP, NPP, allocated biomasses, etc.

3-PG – Outputs

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3-PG – Quick summary

Attribute Comments

Model type Dynamic; process-based & empirical relationships

Time frame Monthly

Processes NPP, biomass allocation, water usage & soil water balance, stem mortality, litterfall & root turnover

Inputs Monthly climate data, soil texture & water capacity, fertility

Outputs Biomass pools, stocking, available soil water, NPP & ET, DBH & standard stand attributes, and others

Strengths Fully dynamic, can be adapted for range of species, provides management-related outputs

Weaknesses Naïve treatment of soil nutrition, allocation based largely on size, poor predictor of canopy development & of mortality

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3-PG - Application

3-PG has been applied to many environments: Australia; New Zealand EUA Brazil; Chile South Africa United Kingdom; Sweden; Portugal; Finland China

3-PG has been applied to many species:

Eucalyptus globulus; E. pilularis; E. grandis; E. delagatensisPicea abies; P. sitchensisPinus radiata; P. taeda; P. patula; P. ponderosa; Pseudostuga menziesii

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3-PG – Application in Portugal (I)

3-PG Calibartion and validation for Eucalyptus globulus in Portugal

1.Initial test with 3-PG validated for Eucalyptus globulus in Australia (Sands & Landsberg 2002) with FER trial data:

Reasonable estimates for Ws and bad estimates for Wf2.SLA, wood density, allometric relationships3.3-PG calibration with FER trial4.Test of calibrated 3-PG with a stocking trial5.Validation with Eucalyptus globulus permanent sample plots

On going research is being carried out with Pinus pinaster.

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3-PG – Application in Portugal (II)

6 scenarios – Eucalyptus plantations in Aveiro region

1. To reduce by 30% the rainfall per year and concentrate the remaining by 15% in November and December2. To reduce by 30% the rainfall per year and concentrate the remaining by 15% in November, December and March3. To rise the mean monthly temperature by 1ºC4. To rise the mean monthly temperature by 3ºC5. To reduce by 30% the rainfall per year and to rise the mean monthly temperature by 1ºC 6. To reduce by 30% the rainfall per year and to rise the mean monthly temperature by 3ºC

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3-PG – Application in Portugal (III)

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3-PG – An overview

Thank you!

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