For discussion:
NPP/GPP relationships and (Sebastiaan Luyssaert)
Phenology, and movie (Lisa Wingate)
Link with remote sensing community (JG)
Direct/diffuse story (JG)
Isotopic fluxes (Denis Loustau)
C flux over lifetime of forests (JG)
Biomass trends (JG & Giorgio Matteucci)
Reichstein et al.
Methodology – TDL set up
13CO and 12CO fluxes
2 2
Soil respiration (µmol 13CO2 m-2 s-1)
Soil respiration (µmol 12CO2 m-2 s-1)
9 0.09
8 0.08
7 0.07
6 0.06
5 0.05
4 0.04
3 0.03
2 0.02
1 0.01
0 0
0 5 10 15 20 25 0 5 10 15 20 25
Time (days) Time (days)
13CO 12CO
2/ 2
chronosequences
Effects of age and management
UK
Italy
France
Sweden
Finland
Magnani et al
Difference between lifetime NEP and maximum NEP
Magnani et al
Carbon uptake and radiation variability
. . .. . . ... .
..
. . .. ..
Aerosols
.
(Haze) Fog
.
.
H
Diffuse Direct
Diffuse
CO2 CO2 CO2
Diffuse
Terpenes/
Pollen
LE/H CO2 CO2
LE/H ? LE/H
LE/H
LE/H
?
LE/H
Rroot Rroot Rroot Rroot & debris Rroot & debris Rroot & debris
How forests (and phytoplankton) contribute to clouds
Lovelock et al (1972)
Kulmala et al (2004) Claeys et al (2004)
Meir, Cox & Grace (2006) Trends in Ecology and Evolution
Zhang & et (submitted)
Slope steeper under
diffuse
Respiration greater
under diffuse regime
Challenge: long term trends in
diffuse:direct and the
consequences it has for fluxes
Penetration of diffuse v direct radiation into spruce
canopy (Urban et al. in press)
Cloudy
100 5
C loudy
4
Sunny
Ln(PPFDTrans )
Sunny
PPFD trans (%)
3
75 2
y = 0.602x + 0.95
R 2 = 0.99
1
y = 0.800x - 0.23
0 R 2 = 0.99
50 -1
0 2 4 6 8
H (m)
25
0
0 25 50 75 100
A LAcum ul (%)
6.2
6
5
H (m)
4
Global & diffuse radiation
yearly mean [Wh/m2]
0
100
150
200
250
50
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
Esk Global
1978
1979
1980
1981
1982
1983
1984
Year
Esk Diffuse
1985
1986
1987
Global & Diffuse Radiation
1988
1989
Eskdalemuir & Bracknell 1965 - 2003
1990
1991
Eskdalemuir & Bracknell
Brack Global
1992
1993
1994
1995
1996
1997
Global & Diffuse Radiation (1965 – 2003)
1998
1999
Brack Diffuse
2000
2001
2002
2003