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Long-term Ecological Research: Eco-hydrology
Julia JonesGeosciences
Oregon State UniversityH.J. Andrews LTER
How to reconcileworld views?
Ecologists -• vertical fluxes of C, N, water• Biotic interactions with atmosphere and soils
Hydrologists, geomorphologists• horizontal fluxes of water, sediment, organics• Physical interactions - gravity v. resistance
Common to both• Time scales, spatial scales, budgets
What are common questions?
Biotic v. abiotic controls on fluxes of C, N, water?
Land use, climate change and natural disturbance effects and feedbacks?
Reciprocal Mechanisms
Q = P - ET - I - SW - GW
Streamflow = f(precipitation, water use by vegetation, vegetation structure, routing of water)
Photosynthesis and respiration = f(soil moisture and temperature, atmospheric moisture and temperature)
What can LTER contribute?
Up to 70 year records of climate and streamflow in small watersheds (thousands of watershed-years)Multiple sites varying in climate, land use and disturbance historyProcess knowledge to formulate and test ecosystem questions
Eco-hydrology: time scales
Eco-hydrology Mechanisms
Cause ConsequenceDiel ET Habitat
Storm ET, I, SW Disturbance
Season Phenology, climate
Habitat
Succession, climate change
Veg. structure, composition
Habitat
Diel Flows and Riparian Zone
Floods and Vegetation Removal
Q
Time (hours)
Vegetation water use influences antecedent moisture, recession
Unvegetated
Vegetated
Contrasting Forest Typeand Climate Effects on
Streamflow
Forest Soil SnowAndrews Evergreen Deep Yes
Hubbard Brook Deciduous Shallow Yes
Coweeta Deciduous Deep No
Effects of Forest Removal by Season Over Succession
-2
0
2
4
6
8
10
1-Oct 31-Oct
30-Nov
30-Dec
30-Jan
29-Feb
30-Mar
29-Apr
30-May
29-Jun
29-Jul
28-Aug
28-Sep
28-Oct
Abs
olut
e ch
ange
in d
aily
av
erag
e st
ream
flow
(mm
)Andrews Watershed 1 vs.
Watershed 2
Actual ETSnowmelt
-2
0
2
4
6
8
10
1-Oct 31-Oct
30-Nov
30-Dec
30-Jan
29-Feb
30-Mar
29-Apr
30-May
29-Jun
29-Jul
28-Aug
28-Sep
28-Oct
Andrews Watershed 1 vs. Watershed 2
Actual ETSnowmelt
Abs
olut
e ch
ange
in d
aily
av
erag
e st
ream
flow
(mm
)
-2
0
2
4
6
8
10
1-Oct 31-Oct
30-Nov
30-Dec
30-Jan
29-Feb
30-Mar
29-Apr
30-May
29-Jun
29-Jul
28-Aug
28-Sep
28-Oct
1-5 yrs, 1967-71
Andrews Watershed 1 vs. Watershed 2
Abs
olut
e ch
ange
in d
aily
av
erag
e st
ream
flow
(mm
)
Actual ETSnowmelt
-2
0
2
4
6
8
10
1-Oct 31-Oct
30-Nov
30-Dec
30-Jan
29-Feb
30-Mar
29-Apr
30-May
29-Jun
29-Jul
28-Aug
28-Sep
28-Oct
actual ET snowmelt
6-10 yrs, 1972-76
Andrews Watershed 1 vs. Watershed 2
Abs
olut
e ch
ange
in d
aily
av
erag
e st
ream
flow
(mm
)
Actual ETSnowmelt
1-5 yrs, 1967-71
-2
0
2
4
6
8
10
1-Oct 31-Oct
30-Nov
30-Dec
30-Jan
29-Feb
30-Mar
29-Apr
30-May
29-Jun
29-Jul
28-Aug
28-Sep
28-Oct
25-30 yrs, 1992-96
Andrews Watershed 1 vs. Watershed 2
Abs
olut
e ch
ange
in d
aily
av
erag
e st
ream
flow
(mm
)
Actual ETSnowmelt
6-10 yrs, 1972-76
1-5 yrs, 1967-71
-2
0
2
4
6
8
10
1-Oct 31-Oct
30-Nov
30-Dec
30-Jan
29-Feb
30-Mar
29-Apr
30-May
29-Jun
29-Jul 28-Aug
28-Sep
Hubbard Brook Watershed 2 vs. Watershed 3
Abs
olut
e ch
ange
in d
aily
av
erag
e st
ream
flow
(mm
)
Actual ETSnowmelt
-2
0
2
4
6
8
10
1-Oct 31-Oct
30-Nov
30-Dec
30-Jan
29-Feb
30-Mar
29-Apr
30-May
29-Jun
29-Jul 28-Aug
28-Sep
Hubbard Brook Watershed 2 vs. Watershed 3
Abs
olut
e ch
ange
in d
aily
av
erag
e st
ream
flow
(mm
)
Actual ETSnowmelt
-2
0
2
4
6
8
10
1-Oct 31-Oct
30-Nov
30-Dec
30-Jan
29-Feb
30-Mar
29-Apr
30-May
29-Jun
29-Jul
28-Aug
28-Sep
Hubbard Brook Watershed 2 vs. Watershed 3
Abs
olut
e ch
ange
in d
aily
av
erag
e st
ream
flow
(mm
)
1-5 yrs, 1965-69
Actual ETSnowmelt
-2
0
2
4
6
8
10
1-Oct 31-Oct
30-Nov
30-Dec
30-Jan
29-Feb
30-Mar
29-Apr
30-May
29-Jun
29-Jul
28-Aug
28-Sep
Hubbard Brook Watershed 2 vs. Watershed 3
Abs
olut
e ch
ange
in d
aily
av
erag
e st
ream
flow
(mm
)
1-5 yrs, 1965-69
Actual ETSnowmelt
6-10 yrs, 1970-74
-2
0
2
4
6
8
10
1-Oct 31-Oct
30-Nov
30-Dec
30-Jan
29-Feb
30-Mar
29-Apr
30-May
29-Jun
29-Jul
28-Aug
28-Sep
25-30 yrs, 1989-94
Hubbard Brook Watershed 2 vs. Watershed 3
Abs
olut
e ch
ange
in d
aily
av
erag
e st
ream
flow
(mm
)
1-5 yrs, 1965-69
Actual ETSnowmelt
6-10 yrs, 1970-74
-2
0
2
4
6
8
10
1-Oct 31-Oct
30-Nov
30-Dec
30-Jan 29-Feb
30-Mar
29-Apr
30-May
29-Jun 29-Jul 28-Aug
28-Sep
Coweeta Watershed 7 vs. Watershed 2
Abs
olut
e ch
ange
in d
aily
av
erag
e st
ream
flow
(mm
)
Actual ETSnowmelt (none)
-2
0
2
4
6
8
10
1-Oct 31-Oct
30-Nov
30-Dec
30-Jan 29-Feb
30-Mar
29-Apr
30-May
29-Jun
29-Jul 28-Aug
28-Sep
Coweeta Watershed 7 vs. Watershed 2
Abs
olut
e ch
ange
in d
aily
av
erag
e st
ream
flow
(mm
)
Actual ETSnowmelt (none)
-2
0
2
4
6
8
10
1-Oct 31-Oct
30-Nov
30-Dec
30-Jan 29-Feb
30-Mar
29-Apr
30-May
29-Jun
29-Jul 28-Aug
28-Sep
Coweeta Watershed 7 vs. Watershed 2
Abs
olut
e ch
ange
in d
aily
av
erag
e st
ream
flow
(mm
)
Actual ETSnowmelt (none)
1-5 yrs, 1965-69
-2
0
2
4
6
8
10
1-Oct 31-Oct
30-Nov
30-Dec
30-Jan 29-Feb
30-Mar
29-Apr
30-May
29-Jun
29-Jul 28-Aug
28-Sep
Coweeta Watershed 7 vs. Watershed 2
Abs
olut
e ch
ange
in d
aily
av
erag
e st
ream
flow
(mm
)
Actual ETSnowmelt (none)
6-10 yrs, 1970-741-5 yrs, 1965-69
-2
0
2
4
6
8
10
1-Oct 31-Oct
30-Nov
30-Dec
30-Jan 29-Feb
30-Mar
29-Apr
30-May
29-Jun
29-Jul 28-Aug
28-Sep
25-30 yrs, 1989-94
Coweeta Watershed 7 vs. Watershed 2
Abs
olut
e ch
ange
in d
aily
av
erag
e st
ream
flow
(mm
)
Actual ETSnowmelt (none)
6-10 yrs, 1970-741-5 yrs, 1965-69
Evidence for Climate Variability and Ecosystem Response
Ann
ual P
reci
pita
tion
(cm
)
Andrews Coweeta Hubbard Brook
Run
off R
atio
(%)
Precipitation vs. Runoff: Long-term Trends
Next Steps
Centralized data access: • Clim-DB, Hydro-DB
More sites, new sitesNew questions, new techniquesIntegrate modeling, process studies
AcknowledgementsNSF LTER grants • Andrews, Coweeta, Hubbard Brook, Luquillo
U.S. Forest Service support • Andrews, Coweeta, Hubbard Brook, Luquillo
NSF award 1996-98 for LTER intersite hydrology comparisonsColleagues • Andrews, Coweeta, Hubbard Brook, Luquillo,
Harvard Forest LTERs