Research in Tropical Ecohydrology
Thomas Giambelluca Geography Department
University of Hawai‘i at Mānoa
Guest Lecture
NREM 680: Ecosystem Ecology Seminar 14 February 2012
Photo: Christopher McLeod
My Research Focus: Ecohydrology and Climatology
• Influence of land-cover change on hydrologic and climatic
processes (China, Thailand, Vietnam, Cambodia, Brazil) • Forest evapotranspiration and cloud-water interception in
Hawai‘i (Maui, Big Island) • Effects of global climate change on high elevation
ecosystems (Maui, Big Island) • Climate and climate change (Hawai‘i)
Land-Cover Change Research:
SE Asia • Deforestation effects on local hydrological processes
(streamflow and soil erosion) • Forest fragmentation effects on hydrological processes
(transpiration and overland flow) • Effects of forest roads on hydological processes
(streamflow and soil erosion) • Effects of land-cover change and climate change on
watershed processes • Impacts of rapidly expanding rubber cultivation on energy,
water, and carbon dynamics
Pang Khum THAILAND
Lisu
Karen
Streamgage
Flux tower
Shifting cultivation
Pang Khum THAILAND
Soil Erosion
Roads
Farming steep slopes
Sediment Delivery
Altered Hydrology
Landscape Fragmentation
Ban Tat Hamlet VIETNAM
CHINA: Nam Ken Field Sites
NASA PROJECT
67 Km2
THAILAND: Mae Sa Field Sites
85 Km2
CHINA: Nam Ken Field Sites
NASA PROJECT
67 Km2
Maite Guardiola found an unusual dip in soil moisture in the dry season at the rubber site.
Water and Carbon Dynamics of Rubber Plantations in Non-Tradition Growing Regions of Southeast Asia
Thomas Giambelluca Ryan Mudd Alan Ziegler Maoyi Huang Wen Liu Michael Nullet Qi Chen Jefferson Fox
University of Hawai‘i at Mānoa University of Hawai‘i at Mānoa
National University of Singapore Battelle Pacific NW National Laboratory
University of Hawai‘i at Mānoa University of Hawai‘i at Mānoa University of Hawai‘i at Mānoa
East-West Center
Traditional and non-traditional rubber-growing regions
Jeff Fox, EWC, 2010
Jeff Fox, EWC, 2010
Jeff Fox, EWC, 2010
Jeff Fox, EWC, 2010
Rubber distribution in 2009 in MMSEA derived from MODIS 250m NDVI time series
Jeff Fox, EWC, 2010
Prior Study
Guardiola-Claramonte M, Troch Ziegler A, Giambelluca TW, Vogler JB, Nullet M (2008)
Local hydrologic effects of introducing non-native vegetation in a tropical catchment. Ecohydrology 1: 13–22, DOI: 10.1002/eco.3.
Guardiola-Claramonte M, Troch Ziegler A, Giambelluca TW, Vogler JB, Nullet M (2008)
Local hydrologic effects of introducing non-native vegetation in a tropical catchment. Ecohydrology 1: 13–22, DOI: 10.1002/eco.3.
Guardiola-Claramonte M, Troch Ziegler A, Giambelluca TW, Vogler JB, Nullet M (2008)
Local hydrologic effects of introducing non-native vegetation in a tropical catchment. Ecohydrology 1: 13–22, DOI: 10.1002/eco.3.
Research Questions Hydrology of Hevea brasiliensis Plantations
• What are the hydrological consequences of conversion of land to rubber plantations in non-traditional rubber growing areas?
• What are the rates of ET in rubber stands, and how does it compare with other land-cover types in the region?
• To what extent are dry-season basin water storage affected by water use of rubber?
Tower Sites
Jeff Fox, EWC, 2010
Som Sanuk
CRRI
Instruments and Observations Micrometeorological instruments installed at two rubber (Havea brasiliensis) plantations to measure water, energy, and carbon exchange
Som Sanuk, Nong Khai, NE Thailand Trees planted in 1992 Tower installed February 2009
CRRI, Kampong Cham, Cambodia Trees planted in 2004 Tower Installed September 2009
Tower Instrumentation Cambodia Rubber Research Institute
Kampong Cham, Cambodia
3 air temperature sensors (TC wire, Omega) 10 biomass temperature sensors (TC wire, Omega)
3 dimensional sonic anemometer (CSAT3, Campbell Scientific)
infrared gas analyzer (LI-7500, Licor)
PAR sensor (LI-190, Licor)
4 component radiation (NR01, Hukseflux)
Temperature and relative humidity (HMP45, Vaisala)
3 wind speed sensors for wind height profile (014A, Met one)
2 Rain gauges (TI-525, Texas Instruments)
•Wind speed and direction (05106, RM young)
Underground sensors
• 2 soil temperature sensors (20 cm TC probes, Campbell Scientific)
• 4 soil heat flux plates (HFP01, Hukseflux)
• 5 TDR soil moisture probes – 30 cm (CS616, Campbell Scientific)
– 4 cm horizontal – 30 cm vertical – 1 m vertical – 2 m vertical – 3 m vertical
• 5 ADR soil moisture sensors
(Theta Probe, DeltaT) – in 2 stands (2001 and 2004) – 5, 10, 20, 30, and 50 cm all
horizontal
Collaboration with Kumagai Lab of Kyushu University for sap flow measurements
Sap
flux
(kg
m-2
s-1)
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0.02
0.04
0.06
5/19 5/20 5/21 5/22 5/23 5/24 5/25 5/26
Som Sanuk, Thailand
Som Sanuk, Thailand
CRRI
Preliminary Eddy Flux Results from Som Sanuk Annual Mean Diurnal Cycles
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600
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RnetGHLE
Mean Rnet = 124 W m-2
Mean G = 2 W m-2
Mean H = 27 W m-2
Mean ET = 87 W m-2
ECE = 8 W m-2
Rubber Energy BalanceSom Sanuk, NE Thailand
Preliminary Eddy Flux Results from Som Sanuk
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Feb-09 Apr-09 Jun-09 Aug-09 Oct-09 Dec-09 Feb-10 Apr-10
RnetGHLE
Rubber Energy BalanceSom Sanuk, NE Thailand
Seasonal Cycle Related to Leaf Area
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Feb-09 Apr-09 Jun-09 Aug-09 Oct-09 Dec-09 Feb-10 Apr-10
RnetGHLE
Rubber Energy BalanceSom Sanuk, NE Thailand
0.0
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3.5
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4.5
Feb-09 Apr-09 Jun-09 Aug-09 Oct-09 Dec-09 Feb-10 Apr-10
17 yr old
12 yr old
6 yr old
Preliminary Eddy Flux Results from Som Sanuk: Mean Diurnal NEE Cycles
NEE (µmol m-2s-1)
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0 6 12 18 24 30 36 42 48
30-minute Timesteps
NE
E
Jan
Dec
Nov
OctSepAug
JunJul
May
Preliminary Eddy Flux Results from Som Sanuk: Mean Diurnal NEE Cycles
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NEE
Feb 09 Mar 09 Apr 09 May 09 Jun 09 Jul 09 Aug 09 Sep 09 Oct 09 Noc 09 Dec 09 Jan 10 Feb 10 Mar 10
NEE (µmol m-2s-1)
Mean Annual ET: 1100 mm
Site Land Cover LE:Rnet Borneo Tropical rainforest 0.89
Amazon Tropical rainforest 0.86
Som Sanuk Rubber plantation 0.70 Chiang Mai Hill evergreen 0.60
Mato Grosso Transitional forest 0.66
Weimin Ju,Fangmin Zhang, Jingming Chen, Shuanghe Shen, Shaoqiang Wang, Guirui Yu, Xinquan Zhao, Shijie Han, J. Asanuma (2010) Trends of evapotranspiration in East Asia from 1982 to 2006 simulated using a remote sensing-driven ecological model. Presented at HESSS2, 22 June 2010, Tokyo.
Summary • Rubber ET may be higher than forest ET • Seasonal cycle significantly changed with lower Sep-Jan ET
and higher Mar-Jul ET • Question:
– What effect does the altered annual cycle have on basin water storage and river discharge at the start of rain season?
• Further work: – Continued monitoring-both sites – Integrate EC and Sapflux observations – Leaf level measurements – Carbon stocks and budget
Evapotranspiration in Native and Invaded Tropical Montane Cloud Forest in Hawai‘i
Thomas W. Giambelluca John K. DeLay Mami Takahashi Ryan G. Mudd
University of Hawai‘i at Mānoa Maoyi Huang
State University of New York-Buffalo Gregory P. Asner Roberta E. Martin
Carnegie Institution for Science Michael A. Nullet
University of Hawai‘i at Mānoa
Photo: Trade Wind Fruits
Strawberry Guava (Psidium cattleianum)
Photo credit: Michelle Clapper, USGS-BRD, UH
• Grows fast • Invades quickly • Already widespread in Hawai‘i • Difficult to eradicate • High stem density • Smooth bark
Photo: Trade Wind Fruits
• State of Hawai‘i lists 106 highly invasive plant species in the Islands • Many tree species have been found to be invasive
Species Invasion in Hawaiian Forests
Field Study of Invasive Tree Impacts
• Compare Native (Thurston) and Invaded (Ola‘a) Sites • Water and Carbon Dynamics at Stand Level • Transpiration of Different Species • Fog Interception • Rainfall and Fog Water Partitioning
Photo credit: Michelle Clapper, USGS-BRD, UH
Photo: Trade Wind Fruits
Field Sites
• Invaded Forest Site – ‘ōhi‘a forest invaded by
Psidium cattleianum (strawberry guava)
• Native Forest Site – Metrosideros
polymorpha (‘ōhi‘a) – Cibotium spp. (hapu‘u;
tree fern)
Epiphyte Study Master’s Student, Ryan Mudd
Thurston Ola‘a
Biomass (t ha-1) 2.57 0.89
Surface Area per Ground Area (%) 26.5 15.5
Water Storage Capacity (mm) 1.48 0.59
LEinvaded 27% higher
Difference is here. LEnative has lower minimum
Stand-level Comparison Eddy Covariance Measurements
Dry Canopy: LEinvaded 53% higher
Dry Periods
Transpiration enhanced at invaded site.
During dry canopy periods, when physiological control over gas exchange is important, ET is much higher in the invaded stand. Why?
Photo credit: Forest & Kim Starr
Native: ‘Ōhi‘a
Invasive: Guava
We looked to our sapflow measurements for answers.
Sapflow Study PhD Student, John DeLay
Sample period mean sapflow velocities: Native ‘Ōhi‘a 3.3 Native Ilex 3.6 Native Olapa 3.3 Invasive Guava 2.7
Are sapflow velocities higher in guava?
Stand Basal Area
Basal Area-Xylem Area Large ‘Ōhi‘a Small ‘Ōhi‘a Guava
16% Xylem 50% Xylem 100% Xylem
Based on 400-m2 survey areas
Basal Area (cm2) Xylem Area (cm2)
Native Invaded Thurston Invaded ‘Ōhi‘a 19195 4795 3000 2424 Ilex 1760 0 800 0 Guava 0 5392 0 5392 Cheirodendron 0 859 0 859 Total 20955 11046 3800 8675 Sapwood/Basal 0.18 0.79
How about the effects of canopy wetting?
Photo: Trade Wind Fruits
48%56%56%
58%
36%34%
18%
27%
0%
10%
20%
30%
40%
50%
60%
PE Transpiration PE Transpiration
Native Site-‘Ōhi‘a Invaded Site-Guava
Am
ount
Rel
ativ
e to
Dry
Lea
f Con
ditio
ns
Partially Wet Wet
Leaf Wetness Effects
Leaf Wetness Effect (-)
No Leaf Wetness Effect
Canopy Water Balance Study Master’s Students Ryan Mudd and Mami Takahashi
Throughfall Measurements
Stemflow Measurements
Single-Layer Canopy Water Balance Model
Canopy
RF
CWI
IE
FF FF
TF SF
Wet-Canopy Evaporation vs Transpiration
0.00
0.05
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0.25
0:00 3:00 6:00 9:00 12:00 15:00 18:00 21:00 0:00
Wet-Canopy EvapTotal ETTranspiration
Native
52%
48%
Mean Diurnal Cycle June 2007-May 2008
0.00
0.05
0.10
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0.25
0:00 3:00 6:00 9:00 12:00 15:00 18:00 21:00 0:00
Wet-Canopy EvapTotal ETTranspiration
Invaded
36%
64%
Canopy Water Balance: Native vs. Invaded
IE EC ET Total ET Transpiration Native (mm yr-1)
500 1249 961 461
Invaded (mm yr-1)
396 1392 1102 706
Diff -21% +11% +15% +53%
Implications For Regional Water Resources: • Guava invasion has significant
negative impact on ground-water recharge
For Dynamics of Tree Invasion: • High stem density and small
diameter stems favor higher transpiration; improves carbon assimilation and growth?
• Gas exchange uninhibited by leaf wetting
Photo: Trade Wind Fruits
Thank You