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Submitted on 5 Jun 2020
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Tapping another water source: below ground competition between lianas and trees
Hannes de Deurwaerder, Pedro Hervé-Fernández, Clement Stahl, Damien Bonal, Pascal Boeckx, Hans Verbeeck
To cite this version:
Hannes de Deurwaerder, Pedro Hervé-Fernández, Clement Stahl, Damien Bonal, Pascal Boeckx, et al.. Tapping another water source: below ground competition between lianas and trees. EGU General Assembly 2016, Apr 2016, Vienne, Austria. 20 p. �hal-02796283�
Tapping another source: below ground
water competition between lianas & trees
H. De Deurwaerder
P. Hervé‐Fernández
C. Stahl
D. Bonal
P. Boeckx
H. Verbeeck
Framework
Setup Results Conclusion• Land‐cover change • Forest fragmentation
• Atmospheric CO2 increase
Framework
Setup Results ConclusionHYPOTHESIS:
“There is strong below ground competition for the same water resources between lianas and trees”
x
O
x
H
Framework
Setup Results ConclusionFramework
Setup Results ConclusionDual isotope‐based studies: δ18O & δ2H
δ 2 H δ18O Precipitation Streams Ground water Ocean Evaporated water
Framework
Setup Results Conclusion δ 2 H δ18O ‐15 ‐1 ‐1 ‐60 OceanFramework
Setup Results Conclusion δ 2 H δ18O ‐15 ‐1 ‐1 ‐60 Enrichment of heavier watermolecules
(1,1H
2180, 1,2H2180)
Soil evaporation line More strongly
bound water
Literature states:
Framework
Setup Results Conclusion No fr actiona tion δ 2 H δ18O ‐15 ‐1 ‐1Soil evaporation line
Soil evaporation Isotopic signature water taken up
by roots =
Isotopic signature xylem
Dual isotope‐based studies: δ18O & δ2H
Diapositive 8
H7 3XWVRLOZDWHUILJXUHVPRUHDQG
Framework
Setup Results Conclusion δ 2 H δ18O Water sourceOur hypothesis
Soil evaporation line
‐15 ‐1
‐1
‐60
LIANAS
TREES
Framework
Setup
Results Conclusion 10 Period: Oct. 2015 Catchments: White Sand (Sand) Oxysol (Clay) Soil samples: 6 soil cores per catchment
0.1‐0.2‐0.3‐0.45‐0.6‐0.9‐1.2‐1.8m Tree samples:
cored xylem samples Liana samples:
δ 2 H [in ‰, VS M O W ]
Framework Setup
Results
ConclusionFramework Setup
Results
Conclusion δ 2 H [in ‰, VS M O W ] δ18O [in ‰, VSMOW]Lianas
Trees
Lianas
Trees
Framework Setup
Results
ConclusionSLEL = 2.8
Diapositive 13
H5 5YDOXHVELMOLMQHQ
Framework Setup
Results
Conclusion δ 2 H [in ‰, VS M O W ]Lianas
Trees
Stream
Lianas
Trees
Stream
Framework Setup
Results
Conclusion δ 2 H [in ‰, VS M O W ] Projected δ2H a a b a b a b bFramework Setup
Results
ConclusionPlausible explanation lies in seasonal replenishment of water compartments
Suzini data δ 2 H [in ‰, VS M O W ] Rain fa ll [mm/mon th] Year: 1995
Framework Setup
Results
Conclusion a a a a All water evaporatedBacktracking extractable range
Framework Setup
Results
Conclusion19
Framework Setup Results
Conclusion
Lianas and trees tap different precipitation water
source, with lianas tapping heavier water
Different isotopic singature in lianas and trees might be linked to seasonaly replenishment of specific water compartments
Trees seem to have a broader extractable range (mobile‐static water)
Æprobably linked to the interaction with mycorrhizae
Dual isotope study is a usefull and easy practice in ecohydrology studies and understanding
Framework Setup Results Conclusion