Treeshelters : designing the · Control Brown Brown Brown . Mesh Plain 4 holes 48 holes . Guard 10 mm 10 mm . Base Base . 1.2 m Treeshelters . 14 Height growth (cm) of Beech in Cornwall

1

Treeshelters : designing the

perfect climate? Christian Dupraz, INRA, France

Wuchshüllen in der Forstwirtschaft - (k)ein Ende des Booms?

15 May 2018

2

1985

3

1988-1992

5

1995

6

Various concerns

8

A key observation : Stem diameter

growth unbalanced

9

Well, what’s wrong with

treeshelters ?

10

Early hypotheses about tree growth in treeshelters

• Main Hypothesis: excess of humidity

• Experiments in 1986 and 1987 (Cornwall & Mid England)

• Perforate tubes to increase ventilation, hence decrease humidity within the treeshelters.

• Disappointing : erratic results on growth

11

Experiment 1986 Cornwall

Control Brown Brown Brown Brown White Mesh Plain 12 holes 30 holes 30 holes Plain

Guard 6 mm 6 mm 6 mm

Base Base Length

1.2 m Treeshelters

TUBEX PROPRIETARY 12

First ventilated treeshelters

No significant differences bw treeshelters.

1Year: significant difference bw Control (mesh guard) &

Treeshelters

1986 Cornwall Growth increments of Beech in various treeshelters after 1 and 3

growing seasons.

01020304050

Control

Brown plain tube

Brown perfo 12 holes 6 mm ...

Brown perfo 30 holes 6 mm ...

Brown perfo 30 holes 6 mm l...

White plain tube

Type of treeshelters

Gro

wth

(c

m)

1 Season 3 Seasons

Chart2

ControlControl

Brown plain tubeBrown plain tube

Brown perfo 12 holes 6 mm baseBrown perfo 12 holes 6 mm base

Brown perfo 30 holes 6 mm baseBrown perfo 30 holes 6 mm base

Brown perfo 30 holes 6 mm lengthBrown perfo 30 holes 6 mm length

White plain tubeWhite plain tube

1 Season

3 Seasons


Growth (cm)

Growth increments of Beech in various treeshelters after 1 and 3 growing seasons.

1.6

28

4.7

42

2.8

37

3.2

33

3.8

37

1.9

41

Relative growth

2 seasons5 seasonsSurvival

Control (Mesh guard)1185

Treeshelter3.71.996

Relative growth

Control (Mesh guard)

Treeshelter

Relative

Growth of Beech in treeshelter relative to control (Mesh guard) after 2 and 5 growing seasons.

Survival & Growth in Torridge

Survival (%)Height Increment (cm)Survival (%)Height Increment (cm)

1 Season1 Season3 Seasons3 Seasons

Control1001.69928

Brown plain tube1004.79342

Brown perfo 12 holes 6 mm base992.89237

Brown perfo 30 holes 6 mm base1003.29933

Brown perfo 30 holes 6 mm length1003.89937

White plain tube1001.99241

nsssnsns

Survival & Growth in Torridge

1 Season

3 Seasons

Types of treeshelters

Survival (%)

Survival of Beech in various treeshelters after 1 and 3 growing seasons.

Survival & Growth in Tor + Roc

1 Season

3 Seasons


Growth (cm)


Aphid & growth

Survival (%)Height Increment (cm)

3 Seasons3 Seasons

Control Torridge9914.3

Plain tube9936.8ns not statistically significant

Perfo 4x10mm base9840.8ss statistically significant

Perfo 48x10mm base9953

nsss

Control Rockingham416.3

Plain tube6714.1

Perfo 4 holesx10mm base6519.2


nsns

Aphid & growth

Survival (%)

Survival (%)

Survival (%) of Beech in Cornwall in various treeshelters.

Interactions graph

Survival (%)

Survival (%) of Beech in Mid England in various treeshelters.

Height (cm)

Height growth (cm) of Beech in Cornwall in various treeshelters.

Height (cm)

Height growth (cm) of Beech in Mid England in various treeshelters.

Height Inc.

W/o P. Fagi14.7

W/ P. Fagi9.8

Untreated13

Treated11.5

Height Inc.

Height Inc. (cm)

Effect of P. Fagi on the height increment of Beech

Height Inc.

Growth Inc. (cm)

Effect of Permethrin treatment on Beech growth.

Interaction

P.fagi w/ treatment27

P.fagi w/o treatment22.5

No P.fagi w/ treatment31.5

No P.fagi w/o treatment45

Interaction

Interaction parameter

Relationship between P. fagi and the application of Permethrin on Beech.

13

Experiment 1987 Cornwall & Mid-England

Control Brown Brown Brown Mesh Plain 4 holes 48 holes

Guard 10 mm 10 mm

Base Base

1.2 m Treeshelters

14


0

10

20

30

40

50

60

Control Torridge

Plain tube

Perfo 4x10mm base

Perfo 48x10mm base

Heig

ht (c

m)

First Ventilated treeshelters

Good soil

1987 Cornwall and Mid-England– 3 growing seasons

Increased ventilation significantly improved the growth height of Beech.

Control: mesh guard


0

5

10

15

20

25

Control Rockingham

Plain tube

Perfo 4 holesx10mm base

Perfo 48 holesx10mm baseHe

ight

(cm

)

Poor soil

Control: unprotected tree

Chart2

Control Torridge

Plain tube

Perfo 4x10mm base

Perfo 48x10mm base

Height (cm)


14.3

36.8

40.8

53

Relative growth



Treeshelter3.71.996

Relative growth


Treeshelter

Relative


Survical & Growth in Torridge



Control1001.69928


Brown perfo 13 mm992.89237

Brown perfo 30 mm bot1003.29933

Brown perfo 30 mm length1003.89937


nsssnsns


1 Season

3 Seasons


Survival (%)


Survical & Growth in Tor + Roc

1 Season

3 Seasons


Growth (cm)


Aphid & growth


3 Seasons3 Seasons





nsss


Plain tube6714.1



nsns

Aphid & growth

Survival (%)

Survival (%)


Interactions graph

Survival (%)


Height (cm)


Height (cm)


Height Inc.

W/o P. Fagi14.7

W/ P. Fagi9.8

Untreated13

Treated11.5

Height Inc.

Height Inc. (cm)


Height Inc.

Growth Inc. (cm)


Interaction





Interaction



Chart4

Control Rockingham

Plain tube



Height (cm)


6.3

14.1

19.2

17.3

Relative growth



Treeshelter3.71.996

Relative growth


Treeshelter

Relative





Control1001.69928


Brown perfo 13 mm992.89237

Brown perfo 30 mm bot1003.29933

Brown perfo 30 mm length1003.89937


nsssnsns


1 Season

3 Seasons


Survival (%)


Survical & Growth in Tor + Roc

1 Season

3 Seasons


Growth (cm)


Aphid & growth


3 Seasons3 Seasons





nsss


Plain tube6714.1



nsns

Aphid & growth

Survival (%)

Survival (%)


Interactions graph

Survival (%)


Height (cm)


Height (cm)


Height Inc.

W/o P. Fagi14.7

W/ P. Fagi9.8

Untreated13

Treated11.5

Height Inc.

Height Inc. (cm)


Height Inc.

Growth Inc. (cm)


Interaction





Interaction



• But what if….

Height growth was NOT the key issue?

These experiments lack a key combination?

• This was the start of a long investigation

16

A long story .. in 7 papers

Dupraz, C., 1997. Greenhouse effect shelters for seedlings. Part 1. How trees react. Revue Forestiere Francaise (Nancy) 49, 417-432.

Dupraz, C., 1997. Greenhouse effect shelters for seedlings. Part 2 : Increasing their efficiency by optimized

ventilation and greater light exposure. Revue Forestiere Francaise (Nancy) 49, 519-530.

Bergez, J.E., Dupraz, C., 1997. Transpiration rate of Prunus avium L seedlings inside an unventilated tree shelter. Forest Ecology and Management 97, 255-264.

Dupraz, C., Bergez, J.E., 1999. Carbon dioxide limitation of the photosynthesis of Prunus avium L. seedlings

inside an unventilated treeshelter. Forest Ecology and Management 119, 89-97.

Bergez, J.E., Dupraz, C., 2000. Effect of ventilation on growth of Prunus avium seedlings grown in treeshelters. Agricultural and Forest Meteorology 104, 199-214.

Coutand, C., Dupraz, C., Jaouen, G., Ploquin, S., Adam, B., 2008. Mechanical Stimuli Regulate the Allocation of

Biomass in Trees: Demonstration with Young Prunus avium Trees. Ann Bot 101, 1421-1432.

Bergez, J.-E., Dupraz, C., 2009. Radiation and thermal microclimate in tree shelter. Agricultural and Forest Meteorology 149, 179-186.

17 86 87 88 89 90 91 92 93 94 95 96

0

100

200

300

400

500

600

700

TEMOINS ABRIS

HAUT

EUR

(cm)

Long-term experiments on hybrid walnut trees

Standard unventilated brown 1.8 m tall treeshelters

18 86 87 88 89 90 91 92 93 94 95 96

0

100

200

300

400

500

600

700

TEMOINS ABRIS

HAUT

EUR

(cm)

Long-term experiments on hybrid walnut trees

Standard unventilated brown 1.8 m tall treeshelters

Control Treeshelter

Control Treeshelter

Height (cm)

DBH (mm)

Portiragnes experiment, France

19

Key finding 1

Early DBH growth more important than early height growth

20

Impact of treeshelters on the root/shoot balance

20% shift of the total biomass to the aboveground biomass in treeshelters

21

Key finding 2

Root deficit with treeshelters

22

1997

23 Trees in treeshelters… save a lot of water!

24 While their stomata are wide open

25 Tree Leaf temperature very close to air temperature in treeshelters

26 Very small VPD in treeshelters

27

But the key finding is :

CO2r CO2 outside CO2 inside treeshelter

Radiation

Unventilated treeshelter with a wild cherry tree

28

But the key finding is : extremely fast Air CO2 depletion

CO2r CO2 outside CO2 inside treeshelter

Radiation

Unventilated treeshelter with a wild cherry tree

29

Key finding 3

Photosynthesis impeded by lack of CO2

33

Air temperature cooling by the chimney effect

34

Tree transpiration stimulation by the chimney effect

Opening the inlet

35

Improved photosynthesis at low radiation levels in treeshelters

36

Tree photosynthesis stimulation by the chimney effect

37

Key finding 4

When CO2 is back, more light is useful

38

Ventex Equilibre

Treeshelter

39

NSW : No Shelter and wind S : Ventilated Shelter

Prunus avium (cv Monteil)

Roots

Shoots

42

NSW : No Shelter and wind

NSSt : No Shelter + Stake

SB : Shelter + Bending

S : Shelter

0%10%20%30%40%50%60%70%80%90%

100%

NSW SB S NSStBefore treatments

shootroot

Bio

mas

s in

% o

f the

tota

bi

omas

s

Prunus avium (cv Monteil)

43

Key finding 5

Stem swinging and bending by wind is important

The sooner the tree emerges from the shelter, the better. So height growth is important

44

Ventilation failures

• When water stress is too high

• When light availability is too reduced

• When the seedlings emerge from the shelter very early or from the start

45

Light transmission of visible light of 4 twin walled treeshelters

300 400 500 600 700

70

60

50

40

30

20

10

0

No pig Light green

Green

Wavelength (nm)

Beige

Light green colour provides:

• High light transmission close to non pigmented tube (Photosynthesis),

• Good mix of blue and red radiation for the Photo Active Radiation while keeping the tubes green for blending in the fields.

• Red/Far Red =0.94 (Photomorphogenesis).

46

Tin > Tout Insolation

Insulation No convection

RHin > RHout VPD* decrease as moisture increases in the tube due to transpiration, no convection.

Summer Day time

Standard Ventilated

Tin = Tout

Convection

RHin = RHout

Moisture equilibrium

47

Transpiration of a tree

5 8 11 14 17 20 Time (H)

Sun

Transpiration Outside Ventex Standard

Ventex

Controlled flow

CO2 > 300 ppm

Chimney Holes

48

Temperature due to air flow

Outside Ventex

Standard

0 4 8 12 16 20 24 Time (H)

30

25

20

15

10

5

Tem

pera

ture

(oC

)

Dupraz C., Bergez J.E., Amelioration de protections individuelles d’arbres a effet de serre. Patent 9204295.1, February 1992 See also USA study: B. R. Swistock, K.A. Mecum, W.L. Sharpe, Summer temperatures insode ventilated and unventilated brown plasic treeshelters in Pennsylvania, NJAF, 1999, 16(1), 7-10.

Air flow increases with sunlight.

Tree is in good harmony with Heat / moisture / CO2

49

Standard Over ventilated

Minimum CO2

Excess H2O

Optimum CO2

Good H2O

Maximum CO2

Low H2O

Ventilated

CO2

H2O CO2

50

Ventex and walnut tree

Standard TS

Control

Tubex Ventex

1 year

2 year

3 year

Stem growth in diameter (1/10 mm) Ventex

Montoidre (Allier) 100 0 100

51

Ventex and red oak

Stem growth in diameter 50 40 30

3rd year emergence

(0.1 mm)

Standard TS

Control

Tubex Ventex

52

New Beech Shelters

White

Ventex

Light

green Transparent Upper

Ventilated White

• Early Diameter growth is more important than early height growth

• CO2 is more important than humidity

• Light is required when CO2 is available

• Stem movement is the ultimate challenge

Take home messages

• Never use unventilated shelters if the tree canopy spends more than 2 growing seasons fully inside the shelter

• With unventilated shelters, • the short term positive impact on height growth is

deceptive. • the long term impact on DBH growth is negative.

Take home message

TUBEX PROPRIETARY 57

Vielen Dank für Ihre Aufmerksamkeit

http://context.reverso.net/traduction/allemand-francais/vielen+Dank+f%C3%BCr+Ihre+Aufmerksamkeit

58

https://agroforestry2019.cirad.fr/

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Foliennummer 1Foliennummer 2Foliennummer 3Foliennummer 4Foliennummer 5Foliennummer 6Foliennummer 7Foliennummer 8Foliennummer 9Early hypotheses about tree growth in treesheltersExperiment 1986 CornwallFirst ventilated treesheltersExperiment 1987 Cornwall & Mid-EnglandFirst Ventilated treesheltersFoliennummer 15Foliennummer 16Foliennummer 17Foliennummer 18Foliennummer 19Foliennummer 20Foliennummer 21Foliennummer 22Foliennummer 23Foliennummer 24Foliennummer 25Foliennummer 26Foliennummer 27Foliennummer 28Foliennummer 29Foliennummer 30Foliennummer 31Foliennummer 32Foliennummer 33Foliennummer 34Foliennummer 35Foliennummer 36Foliennummer 37Foliennummer 38Foliennummer 39Foliennummer 40Foliennummer 41Foliennummer 42Foliennummer 43Ventilation failuresLight transmission of visible light of 4 twin walled treesheltersFoliennummer 46Transpiration of a treeTemperature due to air flowFoliennummer 49Ventex and walnut treeVentex and red oakNew Beech SheltersFoliennummer 53Foliennummer 54Foliennummer 55Foliennummer 56Foliennummer 57Foliennummer 58

Documents

Treeshelters : designing the · Control Brown Brown Brown . Mesh Plain 4 holes 48 holes . Guard 10 mm 10 mm . Base Base . 1.2 m Treeshelters . 14 Height growth (cm) of Beech in Cornwall