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

1. Imprint of nutrient availability on
WUE and Ts- α relationship
Tarek El-Madany1, Mirco Migliavacca1, Jürgen Knauer1, Thomas Wutzler1, Oscar Perez-Priego1,
Javier Pacheco-Labrador1, Tiana Hammer1, Kathrin Henkel1, Olaf Kolle1, Arnaud Carrara², Gerardo
Moreno³, Maria-Pilar Martin-Isabel4, Rosario Gonzales-Cascon5, Markus Reichstein1
ICOS Science Conference
2018-09-12 - Prague
1 Max Planck Institute for Biogeochemistry Department Biogeochemical Integration, Germany
2 Centro de Estudios Ambientales del Mediterráneo (CEAM), Spain
3 Forest Research Group - INDEHESA University of Extremadura, Spain
4Consejo Superior De Investigaciones Cientificas, Spain
5Instituto Nacional de Investigacion y Technologia Agraria Alimentaria Department of Environment, Spain

2. Objectives
Plant
Community
Surface
Properties
Environmental
conditions
Meteo, Soil
LAI, Chl, T
Precipitation, VPD
E, soil type
Nutrient, SWC
Tair
GPP
T
WUE
Ts
α
Nutrient addition ???

3. MaNiP Experimental Site
NT Nitrogen
NPT Nitrogen +
Phosphorous
CT Control
Majadas de Tietar
Footprint model from Kljun et al., (2015)

4. MaNiP Experimental Site
80 %
60 %
20 %
CT
NPT
NT
Footprint climatology
2014-2017
(El-Madany et al. 2018)

5. MTCI
1st P-Fert 2014-11-05 50 kg P/Ha
1st N-Fert 2015-03-16 100 kg N/Ha
2nd P-Fert 2016-03-05 10 kg P/Ha
2nd N-Fert 2016-03-16 20 kg N/Ha
P: triple super phosphate
N: ammonium nitrate
MTCI (2015-04-23)
MERIS Terestrial
Chlorophyl Index
Compact Airborn
Spectrographic Imager
Spatial resolution 1.25 m
(Pachecho-Labrador et al. 2017)
Fertilization - Ecosystem Level
MTCI =1.9 +/- 0.3
MTCI =1.5 +/- 0.3
MTCI =2.0 +/- 0.4

6. Fertilization - Grassland
Pre-fertilization
N concentration
is similar in
grassland
plants
P concentration
is similar in
grassland
plants
Post-fertilization
N concentration
is significantly
higher in NT and
NPT treatments
P concentration
is significantly
higher in NPT
treatment

7. Fertilization - Fluxes
Between tower
differences accounting
for pre-fertilization
period
Season mean +/-
standard error

8. Fertilization - Fluxes
Between tower
differences accounting
for pre-fertilization
period
Season mean +/-
standard error

9. Fertilization – G1 (WUE)
Reduction in G1 during
peak of growing
season
-> increase in WUE
𝐺𝑠 = 𝐺0 + 1.6 1 +
𝐺1
𝑉𝑃𝐷
𝐺𝑃𝑃
𝐶 𝐶𝑂2
Knauer et al., (2018) bigleaf R-package

10. Fertilization – Ts-albedo
Changes in surface
properties change the
relationship between
albedo and surface
temperature
Corner points are
moving based on
precipitation
Fertilization effectData and segmented regressionData driven conceptMeteorology effect

11. Conclusions
WUE
• Nutrient availability changes WUE
• Carbon uptake is increased by fertilization
• LE is increased under N:P imbalance
Surface Temperature
• Changes in greenness and LE can change
albedo and surface temperature
• Nitrogen addition increases biomass growth in
spring and autumn (regreening)
EFPs changed but did only the traits change or the
plant community?

12. http://1920x1080hdwallpapers.com/image/201505/macro/1516/grass-drop-water-dew-sunrise.jpg
Thank you for your attention