Presented at the 3rd ICOS Science Conference in Prague, Czech Republic, 11-13 Sep 2018.

1. Exotic observational sites: nuisance or critical test beds?
10/5/2018 ICOS Prague 2018
Dan Yakir, Earth & Planetary Sciences
Weizmann Institute of Science, Israel
1

2. 10/5/2018 ICOS Prague 2018 2
…An exotic site: Biosphere II Arizona, USA
No replicates, under glass, artificial ecosystems, etc.,
but a true challenge to your models…

3. 10/5/2018 ICOS Prague 2018 3
Changes in precipitation
(1961-1990 vs 2071-2100):
Large part of ICOS domain
ICOS: in the comfort zone…

4. 10/5/2018 ICOS Prague 2018 4
Living in the future: The driest forest FLUXNET site (not an ICOS site)

5. 10/5/2018 ICOS Prague 2018 5
RS vs ground measurements
LWu
Ra
H
LE
RS Ground
2017

6. 10/5/2018 ICOS Prague 2018 6
The results quantify the interactions of land use and climate on
ecosystem ET, indicating that in dry climates, afforestation impact
on WYe varies significantly across small spatial scales and can reduce
WYe with significant impacts on local hydrology…
2018

7. 10/5/2018 ICOS Prague 2018 7
The results quantify the interactions of land use and climate on
ecosystem ET, indicating that in dry climates, afforestation impact
on WYe varies significantly across small spatial scales and can reduce
WYe with significant impacts on local hydrology…
2018

8. 10/5/2018 ICOS Prague 2018 8
Rn
H
LE
The ‘convector effect’
20152018

9. 10/5/2018 ICOS Prague 2018 9
0 1000 2000 3000 4000 5000
-2
0
2
4
6
8
10
12
Fc(mmolm
-2
s
-1
)
VPD (Pa)
Day105
Day106
Day107
Day108
Day109
April 2001
Heat waves that you can count on…

10. 10/5/2018 ICOS Prague 2018 10
Phenology: “homeostatic-like response across climates
00:00 04:00 08:00 12:00 16:00 20:00 24:00
-0.16
-0.12
-0.08
-0.04
0.00
0.04
-12
-9
-6
-3
0
3
NEE(mgCm
-2
s
-1
)
Time
Mar 2003
Jun 2003
Aug 2003
Oct 2003
Jan 2004
mmolCO2
m
-2
s
-1
0.00
0.25
0.50
0.75
1.00
GPP(relative)
-10.0
-5.0
0.0
5.0
10.0
15.0
20.0
25.0
30.0
35.0
1 2 3 4 5 6 7 8 9 10 11 12
Month of the Year
Airtemperature(degrees)
Yatir (6) El Saler FR-Le Bra(6) NL-Loobo(8) FI-Hyytia(8)
15C 19C17C 15C
DailySeasonal

11. 10/5/2018 ICOS Prague 2018 11
75
85
95
105
115
100
200
300
400
500
600
700
800
900
1000
GPPAnnAv.[mmolm-2s-1
Rain[mma]
Year1999)
30
40
50
60
70
80
90
100
150
200
250
300
350
400
1 2 3 4 5 6 7 8 9 10 11 12 13
GPP[mol/(m2y)]
Rain[mma]
Hydrological year (1 = 2001/02)2001)
Yatir
Hyytiala

12. Flow through (Hyytiälä) vs. storage (Yatir)
Hour
23:00 03:00 07:00 11:00 15:00 19:00 23:00
SF(literhr-1)
0.0
.5
1.0
1.5
2.0
2.5
3.0
Transpiration(mmolm
-2
s
-1
)
0.0
.1
.2
.3
.4
SF dry season
Transpiration dry season
~5 hours offset, ~1.5 l/h
Hour
23:00 03:00 07:00 11:00 15:00 19:00 23:00
SF(literhr-1)
0
1
2
3
4
5
6
Transpiration(mmolm
-2
s
-1
)
0.0
.2
.4
.6
.8
1.0
1.2
1.4
1.6
1.8
SF wet season
Transpiration wet season
~0 hours offset, ~5.5 l/h
Teemu Holtta and Yakir Preisler

13. 10/5/2018 ICOS Prague 2018 13
The approach typically used by biogenic emission models
overestimated monoterpene fluxes at Yatir when temperatures rose
during the heat wave. This result, together with complementary leaf-
level measurements showing that summertime monoterpene fluxes
almost completely ceased at Yatir while being enhanced at Birya,
highlight the interaction of water scarcity and high temperatures that
drive monoterpene emissions from vegetation in such extreme climate
zones and the need to further improve model
performance.
VOC:

14. 10/5/2018 ICOS Prague 2018 14
Conclusions:
Exotic observational sites: nuisance or critical test beds ?

15. 10/5/2018 ICOS Prague 2018 15
Conclusions:
Exotic observational sites: nuisance or critical test beds !---------

16. 10/5/2018 ICOS Prague 2018 16
Thank you on behalf of the team