Water stress sitesSite name Year

DE-Gri- Grillenburg 2005

DE-Hai- Hainich 2000,2001,2002,2003,2004,2005

ES-LMa-Las Majadas del Tietar 2004,2005

DK-Sor-Soroe 1996,1997,1998,1999,2000,2001, 2002,2003,2004,2005,2006

FI-Kaa-Kaamanen 2000,2001,2002,2003,2004,2005

PT-Esp-Espirra 2002,2003,2004

PT-Mi1-Mitra II (Evora) 2003,2004,2005

PT-Mi2-Mitra IV (Tojal) 2004,2005,2006

FR-Hes -Hesse 1997,1998,1999,2000,2001,2002, 2003,2004,2005,2006

FR-Pue-Puechabon 2000,2001,2002,2003,2004,2005, 2006

FR-LBr-Le Bray 1996,1997,1998,2000,2003,2005, 2006

HU-Bug -Bugac 2002,2003,2004,2005,2006

IT-Cpz-Castelporziano 2000,2001,2002,2003,2004,2005

DE-Tha -Tharandt 1996,1997,1998,1999,2000,2001, 2002,2003,2004,2005

IT-Ro1-Roccarespampani 1 2000,2001,2002,2003,2004,2005, 2006

IT-Ro2 – Roccarespampani 2 2002,2003,2004,2005,2006

USA-Blodgett 1999,2000,2001,2002,2003,2004,2005

USA-Freeman 2004,2005,2006

LAI, SAIPhenologyLeaf physiology

Sunlit

Shaded

1 Canopy Layer

PIXGRO Canopy

Day of Year

-85

-75

-65

-55

-45

0 60 120 180 240 300 360

Day of Year

2003

200x?

Empiricalor

FluxnetSoil

Mat

ric

po

ten

tial

(cm

)ABA

SIGNAL

Separation of COSeparation of CO22 exchange by components exchange by components

of a herbaceous vegetation mosaic and up-scalingof a herbaceous vegetation mosaic and up-scalingvia chamber plus eddy covariance measurements via chamber plus eddy covariance measurements

in the Portuguese montadoin the Portuguese montado

John Tenhunen, Yuelin Li, Heydar Mirzaei, Mir Zaman HussainDepartment of Plant Ecology, University of Bayreuth, Germany

Lukas Siebicke, Thomas FokenDepartment of Micrometeorology, University of Bayreuth, Germany

Joao Banza, Joao PereiraInstituto Superior de Agronomia, Technical University of Lisbon, Portugal

Luis Aires, Casimiro PioCESAM and Department of Environment, University of Aveiro, Portugal

2001-2005

B

Jan.

Feb

.M

ar.

Apr

.M

ayJu

neJu

lyA

ug.

Sep

t.O

ct.

Nov

.D

ec.

Dai

ly a

ver

age

FN

EE (

g m

-2)

-4

-2

0

2

4

Mitra, Portugal

Tem

per

atu

re (

0C

)

0

10

20

30

40

50 1961-1990

Pre

cip

itat

ion

(m

m)

0

20

40

60

80

100

A

March April May

Nit

rog

en (

g m

-2)

0

5

10

15

20

March April May

Gre

en b

iom

ass

(g m

-2)

0

200

400

600Low open siteHigh open siteUnderstory site

Mitra, Portugal 2006

Period of major carbon uptake into the montado system

An example of `open vegetation` - a classical ecosystem typerelated to changing water balance, e.g.,

forest grassland transition, true savanna, desert shrublands,taiga forest limit

Ca.

100

m

E

L

UH

H

B

CA

DOY=99

CO

2 F

lux

(m

ol m

-2 s

-1)

-40

-30

-20

-10

0

10

20

30

DOY=103

-40

-30

-20

-10

0

10

20

30

-10

0

10

20

30

40

Q (mol m-2 s-1)

0 500 1000 1500 2000

FG

PP ( m

ol m

-2 s

-1)

-10

0

10

20

30

40

-10

0

10

20

30

40

DOY=98

-40

-30

-20

-10

0

10

20

30

FNEE

FRE

High open site

Understory site

Low open site

Mitra, Portugal 2006

Time

06:00 09:00 12:00 15:00 18:00

Col 2 vs Col 7

Day of Year

60 80 100 120 140

mo

l C

O2 m

-2 s

-1)

0

5

10

15

Mitra, Portugal 2006

Col 2 vs Col 4

(

)

m

ol

CO

2 m

-2 s

-1)

0

15

30

45 Low open siteHigh open siteUnderstory site

mo

l / m

ol)

0.00

0.04

0.08

Mitra, Portugal 2006

Lowopen site

FN

EE m

easu

red

( m

ol m

-2 s

-1)

-30

-20

-10

0

10

20

30

y = 0.94xR2 = 0.88

A

Understorysite

FNEE modelled (mol m-2 s-1)

-30 -20 -10 0 10 20

FN

EE m

easu

red

( m

ol m

-2 s

-1)

-30

-20

-10

0

10

20

30C

y = 0.99xR2 = 0.75

Highopen site

FN

EE m

easu

red

( m

ol m

-2 s

-1)

-30

-20

-10

0

10

20

30

y = 0.99xR2 = 0.88

B

Day of Year

60 80 100 120 140

To

tal

nig

htt

ime

FR

E,

(g m

-2)

0

1

2

3

4

5

Low open siteHigh open siteUnderstory

Mitra, Portugal 2006

B

Day of Year60 80 100 120 140

To

tal

nig

htt

ime

FR

E,

(g m

-2)

0

1

2

3

4

5

Low open siteEddy site

A C

Day of Year60 80 100 120 140

Dai

ly F

NE

E,

(g m

-2)

-10

-8

-6

-4

-2

0

2

4

Low open siteEddy site

D

Day of Year60 80 100 120 140

Dai

ly F

NE

E,

(g m

-2)

-10

-8

-6

-4

-2

0

2

4

Low open siteHigh open siteUnderstory site

Day of Year

60 80 100 120 140

Dai

ly F

NE

E (

g m

-2)

-4

-2

0

2

4

Herbaceous componentMontado ecosystem

Mitra, Portugal 2006

-8

-6

-4

-2

0

2

60 80 100 120 140

Day of Year

Dai

ly F

NE

E(g

m-2

)

Herbaceous component

Low open site

Tojal grassland

Alentejo, Portugal 2006