The dry season in French Guiana is not enough to impact Parkia nitida Miq. (Fabaceae) secondary growth

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The dry season in French Guiana is not enough to impact

Parkia nitida Miq. (Fabaceae) secondary growth

Hélène MOREL1 2_{, Stéphane PONTON}3_{, Jacques BEAUCHENE}2_{, Bernard THIBAUT}4

WSUFEM 2015, TERVUREN 26-29 May 2015

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In tr od uc tio n

What methods to study tree growth ?

0 Time 20 Ht , D 130 , … Growth monitoring Permanent plot 20 years 2

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In tr od uc tio n

What methods to study tree growth ?

0 Time 20 Ht , D 130 , … Growth monitoring Permanent plot 20 years 0 Time 20 Ht , D 130 , … _{Retrospective analyses} Anatomical markers 1 month 3

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In tr od uc tio n

Retrospective analyses

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In tr od uc tio n

Retrospective analyses

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In tr od uc tio n

French Guiana climate

0 100 200 300 400 500 20 22 24 26 28 30 32 34 Tmin Tmax 2 4 6 8 10 12 1 3 5 7 9 11 Pr ec ip ita tio n (m m ) Tem per at ur e (° C) Month 6

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In tr od uc tio n

Dendrochronology in tropical rain forest

● Hard, because many species do not show

clear annual growth ring ...

● …but not impossible (Jacoby, 1989, Sass et al.,

1995, Lisi et al., 2008, Zuidema et al. 2012, …)

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O bj ect iv es

OBJECTIVES

(1) Identify annual growth rings.

(2) Know if the secondary growth is synchronous and

homogeneous intra-tree and intra-species.

(3) Identify the influence (or not) of climate on secondary

growth in French Guiana.

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M at er ial s an d me th od s

Parkia nitida

An emergent annual deciduous tree of Amazonian basin

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Parkia nitida: Visibility of growth rings?

► Visibility of growth rings

► Availability and accessibility of the resource

► High growth rates

1.00 mm 1.00 mm

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M at er ial s an d me th od s & R es ul ts

In branches: Relationship between primary and secondary growth

(Heuret et al. 2002; Zalamea et al. 2008; Nicolini et al. 2012)

GU n+1

GU n

Growth stop

Parkia nitida: Annual growth rings?

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Parkia nitida: Annual growth rings?

GU n GU n-4 GU n-3 GU n-2 GU n-1 N growth ring N+1 growth rings N+2 growth rings N+3 growth rings N+4 growth rings

In branches: Relationship between primary and secondary growth

(Heuret et al. 2002; Zalamea et al. 2008; Nicolini et al. 2012)

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Growth unit n = n growth ring in Parkia nitida

0 0,5 1 1,5 2 2,5 3 3,5 4 4,5 1 3 5 7 9 Gr ow th ri ng s w id th (mm)

Growth ring rank

UC10 UC9 UC8 UC7 UC6 UC5 UC4 UC3 UC2 UC1

► The same for PN4, PN7, PN8 et PN9

Parkia nitida 10

Parkia nitida: Annual growth rings?

GU 10 GU 9 GU 8 GU 7 GU 6 GU 5 GU 4 GU 3 GU 2 GU 1 13

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In the trunk: Mariaux’s wound (Mariaux, 1967)

1 mm

Growth rings formation around July-August

Parkia nitida: Annual growth rings?

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Parkia nitida: Synchronous and homogeneous growth?

20 trees * 4 discs

Elementary dated

chronologies (by rays)

Chronologies by discs

(average of n-rays)

Individual chronologies

Mean chronology

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Resul

ts

Intra-discs growth homogeneity

Gr owt h ring wid th (m m ) Years

Parkia nitida 6 – 8 rays at 1m30

0 2 4 6 8 10 12 1970 1980 1990 2000 2010 16

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Resul

ts

Intra-discs growth homogeneity

Intra-discs mean similarity index 80.1 % (+/- 9.0 %) 81.5 % (+/- 10.7 %) 79.9 % (+/- 9.5 %) 82.3 % (+/- 10.9 %) 17

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Resul

ts

Parkia nitida 10

• 1m30, ○ middle-trunk, □ base of crown, crown

La rg eu r d es c er nes (m m ) Mean similarity index 79.7 % (+/-12.8) 2010 0 5 10 15 2005 2000 1995 1990 1985

Intra-trees growth homogeneity

Gr owt h ring wid th (m m ) Years 18

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Resul ts 1 2 3 4 5 6 7 8 9 10 12 14 16 18 20 0 10 20 30 40 50 60 70 80 90 100 11 13 15 17 19 Sim ila rit y inde x (%)

Trees of Parkia nitida

1m30 Heights • Middle-trunk Base of crown Crown

Inter-trees growth homogeneity

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Resul

ts

Meteorological data

• Data from the meteorological station of Sinnamary - Temperature (°C)

- Precipitation (mm) • Annual variables

- From 1st_{august of the year n-1 to 31 july of the year n}

• Package bootRes in R software (Zang & Biondi 2012)

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Resul

ts

No influence of climate on secondary growth

Coe ffi ci en t of th e re sp on se fu nc tion -0.5 -0.4 -0.3 -0.2 -0.1 0.0 0.1 0.2 0.3 0.4 a o d F A J a o d F A J a o d F A J Monthly

precipitation Number of rainy day temperature Mean

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Co

ncl

us

io

n

Homogeneous growth but no climatic influence

► Annual growth rings

► Synchronous and homogeneous growth

in Parkia nitida

► No influence of tested factors

(1) Identify annual growth rings

(2) Know if the secondary growth is homogeneous and

synchronous intra-tree and intra-species

(3) Identify the influence (or not) of climate on secondary

growth in French Guiana.

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Di ffi cu lti es a nd P er sp ect iv

es ► Others statistical analysis (others parameters, others methods)

Difficulties and Perspectives

► Growth ring visibility but not always obvious ► Fast growing but short-lived

► Species long life but low resource availability

► Relationship between features years and major climate events (El Niño, drought)

► Others species

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Thank you for your attention !