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HAL Id: hal-02791839

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Submitted on 5 Jun 2020

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Field work: example from case studies

Matieu Henry, Laurent Saint-André, Nicolas Picard

To cite this version:

Matieu Henry, Laurent Saint-André, Nicolas Picard. Field work: example from case studies. Training Workshop on Tree Allometric Equations, May 2014, Colombo, Sri Lanka. pp.47 slides. �hal-02791839�

(2)

Training workshop on tree allometric equations,

Forest Department Sri Lanka, May 20 – 24th 2014

Field work: example

from case studies

Dr. Matieu Henry & Dr. Laurent

Saint- André, & Dr. Nicolas

Picard

(3)

Introduction

Field measurement is the most crucial step for developing tree allometric equations:

-It is preferable to weight all tree components in the fields

-Each time samples are collected it is important to measure the mass before and

after sub-sampling

-It is preferable to profit of the field measurements to measure additional

(4)

When selecting the trees:

© Bruno Locatelli

-

Take pictures of the selected tree;

-

Drawing representing the tree architecture.

-

Mark the trees (paint)

-

Measure the diameter/ circumference

(dbh/c at 1.3m)

>>> To verify the tree selected corresponds

to the sampling scheme;

>>> Allow verification and control once the

tree logged.

(5)

When selecting the trees:

© Bruno Locatelli

Avoid:

Measuring trees that are non representative of the population considered

-

E.g. The top is broken, different architecture

Unless the purpose of the measurement is to assess the impact of an

accident, perturbation

Several factors will influence the sampling:

-

Unexpected events

-

Landscape;

(6)

Basic formula for biomass assessment

© Bruno Locatelli

Dry Tree Biomass

Dry mass/ sample

Green mass/

sample

Fresh Tree

Biomass

(7)

û

Sampling mf & md…

Because, the different organs/ tree

components do not have the same

moisture content,

it is preferable to separate the

different tree components to better

consider those variations within the

tree.

A good compromise must be found

between the targeted accuracy, the

time necessary for the measurements

and the costs .

(8)

The different tree components:

Crown diameter (m) T re e h ei g h t (m ) Lo g h ei g h t (m ) C ro w n h ei g h t (m ) Circumference or diameter (cm) at 1.3m Basal circumference or diameter (cm) T re e vo lu m e (m 3) L og v ol um e (m 3) B ra nc h v ol um e (m 3) Le af v ol um e (m 3) Crown area (m2) Basal area (m2) T Bg Bt Bg L Leaves B B Bark Gross branches: D>7cm L T Trunk-underbark Bt Thin branches: D<7cm S Rb Rb S Stump Large roots Bd Bd Dead branches Rm Rf Rm Rf Medium roots Fine roots F F Fruit/seed

(9)

Case studies

Destructive measurements (Eucalyptus plantation in Congo)

Semi-destructive field measurements for Vitellaria paradoxa parkland in North Cameroon

Destructive measurements for trees in tropical rainforests in Ghana Destructive measurements for root biomass assessment

Conclusion: methodologies have to be adapted to the financial and technical means, the social and biophysical contexts

(10)

2. Destructive measurements

(Eucalyptus plantation in Congo)

Saint-André, L., A. T. M'Bou, et al. (2005). "Age-related equations for above and below ground biomass of a Eucalyptus hybrid in Congo." Forest Ecology and Management 205(1-3): 199-214

Rivoire, M., Genet, A., Didier, S., Nys, C., Legout, A., Longuetaud, F., Cornu, E., Freyburger, C., Motz, A., Bouxiero, N. et Saint-André, L., 2009. Protocole. d’acquisition de données volume-biomasse-minéralomasse, Bure. Rapport technique, INRA, Nancy, France.

In order to be the most cost-efficient you

need to:

-

Prepare the equipment;

-

prepare the field data sheets;

-

Prepare the bags to transport the

samples;

-

Well explain to the different technicians

(11)

Place 5



Place 6 Place 7 Place 1 Place2 Place 3 Place 4

û

û

û

û



(12)

When measuring the tree

dimensions:

-

circumference measured

every 1 – 2 m;

-

indicate where to cut the

tree components along the

tree;

-

measure, tree height,

crown diameter etc.

When logging the tree:

-

take necessary precautions;

-

cut the liana;

-

prepare a path to escape.

-

etc

(13)

When cutting the tree

components:

-

3-5 cm disk are collected;

-

Distance between samples

depends on the strategy

adopted.

When separating the

branches and the leaves:

-

Per class of diameters (e.g.

>20, 20-7, 7-4 and <4cm)

-

if difficult to collect all

leaves, use sub-sampling;

-

For the big branches it is

more convenient to use the

same strategy as for the

trunk.

Place 3

(14)

Place 5 Place 6

When collecting samples:

-

At different location to

ensure consideration of the

variation of the moisture

content & wood density ;

-

more than 3 samples for

each tree components;

When weighting the tree

components:

-

to perform quickly (avoid

moisture content loss);

-

Adapt the spring balance

depending on the size of

the samples.

(15)

Place 7

Case 1: small samples

Case 2: wood disk (bigger samples)

1 2 3 4

Samples are located in a paper bag; Dry the sample in the oven;

Weight the fresh sample with and without bag;

2 3 4 5 6 7

Collect a sub-sample Weight the sub-sample

1 2 3 1 2 3 Case 2: Case 1:

Weight the sample

(16)

UN

-REDD

P R O G R A M M E

3. Semi-destructive field measurements for

Vitellaria paradoxa parkland in North

(17)

Geographic localisation: North

Cameroon, precipitaiton

(900-1200mm), dry forest (FAO

ecological zone), tree savannah

Floristic composition: Vitellaria

paradoxa, Combretum spp.,

Terminalia spp.

Social aspects: permanent (Mafa) and

nomad (peuls)

Vitellaria paradoxa: main tree species,

used to make butter (karité), and

fodder during the « soudure »period.

Trees are pruned every four years.

Trees are never cut.

(18)

UN

-REDD

(19)

UN

-REDD

P R O G R A M M E 2. OBJECTIVES

Estimate the biomass (trunk and crowns) of a parkland of Vitellaria paradoxa

Estimate the mean productivity for the wood and leave components

(20)

UN

-REDD

P R O G R A M M E 3. METHOD

(21)

UN

-REDD

P R O G R A M M E 3.2. ANALYSE TREE ARCHITECTURE

(22)

Bfrais non-émondée des grosses branches et du tronc est mesuré à partir du volume et de la masse volumique

Hypothèses: les tronçons sont considérés comme des

cylindres et la masse

volumique est identique dans les compartiments de l ’arbre

Bfrais non-émondée des petites est

calculée à partir de leur

circonférence à la base et en utilisant un tarif de biomasse

Bfrais émondée des branches

émondées mesurée par pesée

(23)

UN

-REDD

P R O G R A M M E 3. 3. MEASURE THE BRANCH FRESH BIOMASS

Spring balance are selected/ the sample size 3. METHOD

(24)

UN

-REDD

P R O G R A M M E 3. 3. MEASURE THE BRANCH FRESH BIOMASS

WITH AND WITHOUT LEAVES

(25)

UN

-REDD

P R O G R A M M E 3. 4. MEASURE THE VOLUME OF THE REMAINING BIOMASS

BE CAREFUL NOT TO FALL!!!

LENGTH AND

CIRCUNFERENCE ARE MEASURE FOR EACH TREE

SEGMENTS 3. METHOD

(26)

UN

-REDD

P R O G R A M M E 5. MEASURE THE MOISTURE CONTENT AND WOOD DENSITY

LEAVES AND WOOD SAMPLES ARE

COLLECTED

DRIED IN OVEN 105 deg C UP TO WEIGHT

STABILIZATION 3. METHOD

(27)

UN

-REDD

P R O G R A M M E 3. 6. DATA ENTRY AND ANALYSIS

Relation entre diamètre à la base (D) et biomasse humide (Mh) des branches émondées pour le

Combretum negricans 0 5 10 15 20 25 0 1 2 3 4 5 6 7 8 D (cm) M h (k g)

RELATION BETWEEN THE BRANCH BASAL DIAMETER

AND THE BIOMASS

R² = 93,24 %

Mh = 0,104 * D2,344

3. METHOD

ENTER THE DATA AS SOON AS POSSIBLE

(28)

4.Destructive measurements for trees in

tropical rainforests in Ghana

Boi Tano River forest reserve

Forest concession

Limited access

Henry, M., Besnard, A., Asante, W.A., Eshun, J., Adu-Bredu, S., Valentini, R., Bernoux, M., Saint-André, L., 2010. Wood density, phytomass

variations within and among trees, and allometric equations in a tropical rainforest of Africa Forest Ecology and Management 260, 1375–1388.

(29)

UN

-REDD

P R O G R A M M E 1. CONTEXT

Geographic localisation: Western region, hilly landscape, precipitation (1750-2155mm), moist or wet evergreen forest (FAO ecological zone), dense forest (few logging activities 40 years ago)

Hawthorne, W.D., 1995. Ecologcial Profiles of Ghanaian Forest Trees. Oxford Forestry, Institute, Dept. of Plant Sciences, Forestry Dept., Republic of Ghana, Overseas, Development Admin, Oxford

Floristic composition: >150 tree species per hectare, three main plant functional types (Shade bearer, Pioneer and Non-Pioneer Light Demander)=> existing classification

Social aspects: logging concession (about 140 ha), logging operations focusing on few tree species

Use of the trees: timber

Legal aspects: only trees identified by the Forest Commission and identified in the concession plan can be logged (only commercial trees)

(30)

2. OBJECTIVE

ASSESS FOREST BIOMASS AND CARBON STOCKS

(31)

0 100 200 300 400 500 600 700 800 0 5 10 15 20 25 30 35 40 DBH (cm) T re e st em s (n /h a) Swampy slope upper slope

Boi Tano Forest Reserve 3. METHOD

ANALYSIS OF THE FOREST STRUCTURE IDENTIFY THE FACTOR

INFLUENCING THE FOREST STRUCTURE

IDENTIFY THE MINIMUM AND MAXINUM DIAMETER

FOUND PER PLANT FUNCTIONAL TYPES 3.1. ANALYSIS OF THE FOREST STRUCTURE

(32)

3. METHOD 3.1. SAMPLING STRATEGY

- Three plant functional types (PFT)

- Diameter classes from 2 to 200 cm of diameter - Logging activities and timber demand

- Geographical position and risks Sampling strategy depended on:

Target: Three trees per PFT and per diameter class (10 cm)

Information on the trees to be logged were obtained form the logging company

Trees were georeferenced in order to minimize the transport and facilitate the measurements

Damaged trees close to the road were also considered (mainly for the small trees because trees cannot be logged under a certain minimum diameter, generally around 50 cm of dbh)

(33)

UN

-REDD

P R O G R A M M E 3. METHOD

(34)

UN

-REDD

P R O G R A M M E 3. METHOD

3.3. ESTIMATION OF BIOMASS FOR TREES <20cm of dbh

1. Separation of the different tree compartments (trunk, branches)

2. Trunk and branches are weighted separately

3. Three sample branches were selected to measure separately the wood and the leaves 4. Wood samples (1 stump, 1 middle of the trunk, 3 branches) and leaves samples were collected at different locations

(35)

UN

-REDD

P R O G R A M M E 3. METHOD

3.3. ESTIMATION OF BIOMASS FOR TREES >20cm of dbh

Crown diameter (CD) To ta l h ei gh t ( H ) Diameter at breast height (DBH) Tr un k h ei gh t ( H t) Wood sample (stump) Wood sample (trunk) Wood sample (branches) B ut tr es s H ei gh t ( H b) Buttr ess length (Lb) Width (Wb)

1.Log the trees

2.Design tree architecture (segment of 2m

for the trunk and 1m length for the branches) up to 10cm of DBH.

3.Branches less than 10cm of diameter

are cut and weighted

4.Three branch samples are selected to

measure the leaves separately

5.The trunk and branch volume is

measured (up to 10cm of diameter)

6.The stump is measured

7.Wood (1 stump, 1 middle of the trunk, 3

branches) and leaves (3 branches) samples are collected

(36)

UN

-REDD

P R O G R A M M E 3. METHOD

(37)

UN

-REDD

P R O G R A M M E 3. METHOD

3.4. ANALYSIS OF THE WOOD SAMPLES

Wood samples are collected to analyze the influence of the tree height and trunk diameter on the wood gravity Pith Bark Branch samples Trunk samples

(38)

Prendre des échantillons tous les 2cm Prendre 3 échantillons pour lesbranches

(39)

3. METHOD 3.4. ANALYSIS OF THE WOOD SAMPLES

811 Sub-samples every two cm are analyzed

(40)

Wood density is

influenced by pith to

bark distance and plant

functional types

Distance from the pith (cm)

W oo d de ns it y (M g m -3 ) 0.3 0.35 0.4 0.45 0.5 0.55 0.6 0.65 0.7 0 20 40 60 80 100 4. RESULTS Pioneer Shade bearer Non-Pioneer Light Demander 4.1. WOOD DENSITY

(41)

0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 0 20 40 60 80 100 120

Pith to bark distance (cm)

W D ( M g m -3 ) NPLD P SB

Species with late successional characteristics

Species with early successional characteristics

4. RESULTS 4.1. WOOD DENSITY

(42)

Selection of the best model

using the AIC

Models Number Group X W Z a b c d Sigma2 k RMSE AIC ΔAIC

Y=a+b*X 1 ALL DBH2xHxWD 0.05 0.32 1.79 2344 624 13 NPLD DBH2xH 0.03 0.02 2.08 1846 344 1 DBH2xHxWD 0.05 0.01 2 1911 344 1 P DBH2xWD -4.99 1.64 0.00 2.84 1182 140 3 SB DBH2xHxWD 48.87 0.04 4.03 1.09 34 107 16 Y=a+b*X+c*W 2 ALL DBH2xHxWD CD 0.05 4.06 0.11 1.90 2496 617 6 NPLD DBH2xHxWD CD -9.38 0.05 5.89 0.00 2.67 621 343 0 P DBH2xHxWD CD -5.61 0.04 5.74 0.00 2.41 34 138 1 SB DBH2xHxWD CD 0.04 12.44 2.00 1.11 2496 103 13

Y=a+b*X+c*W+d*Z 3 Not different from model 2

Y=a*Xb 4 ALL DBH2xHxWD 0.08 0.96 0.19 0.93 2880 628 16 NPLD DBH 0.11 2.58 0.03 1.02 1095 345 2 DBH2xHxWD 0.07 0.97 0.00 1.17 2476 346 2 P DBH2xHxWD 0.24 0.86 0.04 0.91 629 147 10 SB DBH2xWD 0.79 1.10 1.77 0.64 90 109 19 Y=a*Xb*Wc 5 ALL DBH2xHxWD CD 0.12 0.82 0.48 0.17 1.83 1517 612 1 NPLD DBH2xHxWD CD 0.11 0.83 0.46 0.00 2.52 1308 368 24 P DBH2xHxWD CD 0.20 0.79 0.39 0.07 1.68 255 142 5 SB DBH WD 0.60 2.22 0.63 2180 - 1296 105 14 Y=a*Xb*Wc+Zd 6 ALL DBH CD WD 0.49 2.04 0.47 1.02 0.17 1.83 1750 611 0 NPLD DBH H CD 0.10 1.77 0.70 0.36 0.02 2.08 1495 344 1 P DBH H CD 0.04 2.77 0.47 -0.92 11.40 0.86 72 137 0 SB DBH CD WD 0.43 2.11 0.35 0.79 358 - 1112 90 0 Y=a+b*X*W 7 ALL DBH2xH WD 0.05 0.32 1.79 2344 624 13 NPLD DBH2xH WD 0.05 0.01 2.23 1911 344 1 P DBH2 WD -4.99 1.64 0.00 2.84 1182 140 3 SB DBH2xH WD 48.87 0.04 4.03 1.09 34 107 16 Y=a+b*X*W+c*X*Z 8 ALL DBH2 WD CD 0.89 0.04 0.04 2.07 3391 625 13 NPLD DBH2 WD CD 0.03 0.25 0.00 2.29 2338 343 0 P DBH H CD 0.10 0.60 0.00 3.93 4021 144 6 SB DBH2 WD CD 0.99 0.04 0.81 1.36 112 107 16

Y=a+b*X*(c*W+d*Z) 9 not different from model 8

Y=a+b*X

Y=a+b*X+c*W

Y=a+X^b

Y=a+X^b+W^c

Y=a+X^b+W^c+Z^d

Y=a+b*X*W

Y=a+b*X*W+c*X*Z

Y=a+b*X*(c*W+d*Z)

4. RESULTS 4.2. TREE ALLOMETRIC MODEL

(43)

0 10 20 30 40 50 60 70 80 0 50 100 150 200 DBH (cm) A G B ( M g ) Henry et al. (2010) Brown et al. 1989 (DBH) Brown et al. 1989 (DBH & H) IPCC 2006 (DBH)

Brown, 1997

Chave et al. 2005 (DBH & WD) Chave et al. 2005 (DBH & H& WD) 4. RESULTS

(44)

6.

Destructive measurements for root

biomass assessment

Levillain, J., Thongo M’Bou, A., Deleporte, P., Saint-André, L. et Jourdan, C., 2011. Is the simple auger coring method reliable for below-ground standing biomass estimation in Eucalyptus forest plantations? Annals of Botany, 108(1): 221–230.

Sampling method varies depending on the size of the tree roots;

In some ecosystems (e.g. agroforestry), it is preferable to develop ratio/ha

(45)

Etape 1 Etape 2

Etape 3 Etape 4

Situation Initiale

To facilitate sampling of root biomass:

Identify a certain area for sampling: e.g. Voronoï space

Hypothesis: roots entering (other trees) = roots outside (considered tree)

6.

Destructive measurements for root

biomass assessment

Exemple of Voronoï space Designing the Voronoi

diagram

1. Draw the segments

between neighboring trees

2. Draw the perpendicular

bisectors

3. Link the perp. Bisector

to deliminate an area around the tree

4. This area can be

divided into joint triangular

(46)

Left: Sampling methods (Voronoï diagram) (picture: C. Jourdan), right: excavation of big roots / rubber plantation in Thailand

(47)

The methods to develop tree biomass allometric equations depend on 0 100 200 300 400 500 600 700 800 0 5 10 15 20 25 30 35 40 DBH (cm) T re e st em s (n /h a) Swampy slope upper slope

The forest structure The tree architecture Human activities

The technical, time and financial

constraints

Already existing methods and data

Legal and social aspects

(48)

• Saint-André, L., A. T. M'Bou, et al. (2005). "Age-related equations for above and

below ground biomass of a Eucalyptus hybrid in Congo." Forest Ecology and Management 205(1-3): 199-214

• Henry, M., Besnard, A., Asante, W.A., Eshun, J., Adu-Bredu, S., Valentini, R.,

Bernoux, M., Saint-André, L., 2010. Wood density, phytomass variations within and among trees, and allometric equations in a tropical rainforest of Africa Forest Ecology and Management 260, 1375–1388.

• Peltier, R., C. F. Njiti, et al. (2007). "Evaluation du stock de carbone et de la

productivité en bois d'un parc à Karités du Nord-Cameroun." Bois et forêt des tropiques 294(4): 39-50.

• Rivoire, M., Genet, A., Didier, S., Nys, C., Legout, A., Longuetaud, F., Cornu, E.,

Freyburger, C., Motz, A., Bouxiero, N. et Saint-André, L., 2009. Protocole. d’acquisition de données volume-biomasse-minéralomasse, Bure. Rapport technique, INRA, Nancy, France.

• Levillain, J., Thongo M’Bou, A., Deleporte, P., Saint-Andr´e, L. et Jourdan,

• C., 2011. Is the simple auger coring method reliable for below-ground standing

biomass

• estimation in Eucalyptus forest plantations? Annals of Botany, 108(1): 221–230.

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