Special Issue in “Hydrological Processes”

Hydrology and Biogeochemistry of Small Amazonian Catchments

Christopher Neill, Alex Krusche, Helmut Elsenbeer,

Jonannes Lehmann and Daniel Markewitz

Contact: cneill@mbl.edu

Submission: September 30, 2004

Carbon, Biogeochemistry, and Hydrology: Dynamics at the Terrestrial-Aquatic Interface

Johannes Lehmann, Mark Johnson, Eduardo Couto, Susan Riha, Luiz Carlos Mattos Rodrigues, Mara Abdo, Evandro Selva, and Erick Fernandes

Cornell UniversityUniversidade Federal do Mato Grosso

Surface origin of nutrient export with streams

Markewitz et al., 2001 Nature 410, 802-805OxisolForest, pasture, field cropsParagominas, Eastern Amazonia

Rapid leaching in microaggregated soil

a)

b)

Sa

ugsp

ann

ung

[h

Pa

]

0

100

200

300 0.1 m0.3 m0.6 m0.9 m1.5 m2.5 m

Uhrzeit [h] 3 5 7 9 11 13 15 17 19 21 23 1

Niede

rsch

la

g [m

m]

048

121620

Stra

hlung

s-

inte

nsitä

t [M

W/m

2]

02004006008001000

38.4mm

-0,1-0,3

-0,6

-0,9

-1,5

-2,5

Tiefe

[m

]

04.1 05.1 06.1 07.1 08.1

Nie

de

rsc

hla

g [m

m]

0

4

8

12

16

20

Strahlung

sinten

sität [M

W/m

2]

0

200

400

600

800

1000

Sa

ugsp

ann

ung

[h

Pa

]

0

20

40

60

800.1 m0.3m0.6 m0.9 m1.5 m2.5 m

Uhrzeit [h] 12 14 16 18 20 22 0 2 4 6 8 10 12

Niede

rsch

la

g [m

m]

048

121620

Stra

hlung

s-

inte

nsitä

t [M

W/m

2]

02004006008001000

48.0mm

c)

Rai

nfal

l [m

m]

Solar R

adiation[M

W m

-2]

010203040507090

110140200300

Suction [hPa]0.1 0.3

0.6

0.9

1.5

2.5

Depth [m

]

Jan 4 Jan 5 Jan 6 Jan 7 Jan 8

Renck, Lehmann 2004 Soil Science 169, 330-341

Xanthic HapludoxManaus

Examining the terrestrial-aquatic interface

0.85 Ha1.69 Ha0.78 Ha0.62 Ha

N0 50 100 Meters

1234 IKONOS Panchromatic Image

(Courtesy EOS-Webster)

Headwater watersheds

1

234

Juruena, Mato Grosso, Brazil

Decreasing solute concentrations with depth

Throughfall: 1.3 ±0.4 mg L-1 (N=109)

Leaching: 1.8 ±0.5 mg L-1 (N=25) (free draining lysimeters at 0.1m depth)

Groundwater: 0.6 ±0.2 mg L-1 (N=16) (piezometers)

Spring: 0.6 ±0.3 mg L-1 (N=61) (grab samples)

Stream: 0.7 ±0.3 mg L-1 (N=127) (grab samples, 50m from spring, similar at 2km)

Total N

organic N 5-20%

Forested Ultisol-OxisolSouthern Amazon, Juruena, MTN=4 watersheds ±SEJohnson et al. Sp. Session 4

Nitrate (kg ha-1 0.1m-1)

0 10 20 30 40

Dep

th (

m)

0.00.2

0.6

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

Nitrate (kg ha-1 0.1m-1)

0 10 20 30 40

Dep

th (

m)

0.00.2

0.6

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

Nitrate retention in acid subsoils

Forested Ultisol-OxisolSouthern Amazon, Juruena, MTN=4 watersheds ±SERodrigues et al. Poster 28.10-p

Nitrate (kg ha-1 0.1m-1)

0 10 20 30 40

Dep

th (

m)

0.00.2

0.6

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

More subsoil nitrate on plateau than close to stream

pH (CaCl2) 3.9-4.5

Spring: 0.7 ±0.7 mg L-1 (N=65) (grab samples)

Decreasing solute concentrations with depth

Throughfall: 6.9 ±2.3 mg L-1 (N=106)

Leaching: 8.4 ±2.7 mg L-1 (N=25) (free draining lysimeters at 0.1m depth)

Groundwater: 1.3 ±1.3 mg L-1 (N=42) (piezometers)

Stream: 2.1 ±1.8 mg L-1 (N=134) (grab samples, 50m from spring)

DOC

Forested Ultisol-OxisolSouthern Amazon, Juruena, MTN=4 watersheds ±SEJohnson et al. Sp. Session 4

Important soil control over hydrological flow paths

Elsenbeer, 2001, Hydrol Proc 15, 1751-1759

Spatial distribution of clay

Soil type control

DOC (mg L-1 ± s.e.)

>40%clay <20%clay(increasing with depth)

UltisolOxisol

2.2 ±0.5 (N=10)

17.4 ±2.0 (N=25)

1.3 ±0.5 (N=11)

11.5 ±2.3 (N=19)

Surface Runoff

Groundwater

Throughfall: 0.6 ±0.3mg L-1 (N=4)

Leaching: na

Groundwater: na (piezometers)

Spring: 4.1 ±1.2mg L-1 (N=28)(grab samples)

Stream: 2.3 ±0.6 mg L-1 (N=28) (grab samples, 50m from spring)

DIC

Decreasing solute concentrations with depth

Distance from spring (m)

0 20 40 60 80 100 120 140 1602500

CO

2 (

ppm

)

0

5000

10000

15000

20000

25000

30000

35000

y=24489.9/(1+0.1189X)r=0.79

Large losses of CO2 from emergent groundwater

Forested Ultisol-OxisolSouthern Amazon, Juruena, MTN=30(from 4 watersheds)

14

12

10

8

6

4

2 0

CO

2 -Caq (m

g L-1)

pH

4.5 5.0 5.5 6.0 6.5

CO

2 (

ppm

)

0

5000

10000

15000

20000

25000

30000

35000

y=-14098x+89779r2=0.91

Losses of CO2 and pH dynamics

Forested Ultisol-OxisolSouthern Amazon, Juruena, MTN=30(from 4 watersheds)

Distance from spring (m)

0 20 40 60 80 100 120 140 1602500

CO

2 (

ppm

)

0

5000

10000

15000

20000

25000

30000

35000

y=24489.9/(1+0.1189X)r=0.79

Losses of CO2 and Ca dynamics

Forested Ultisol-OxisolSouthern Amazon, Juruena, MTN=30(from 4 watersheds)

14

12

10

8

6

4

2 0

CO

2 -Caq (m

g L-1)C

a (

me

q L

-1)

140

120

100

80

60

40

20 0

CO2

Ca

Large losses of CO2 from emergent groundwater

DOC6.6%

DIC-Alk15.7%

CPOC0.3%

POC0.9%

CO2-C outgas evasion66.0%

CO2-C(aq)10.5%

Solid Phase1.2%

Forested OxisolSouthern Amazon, Juruena, MT(from 1 watershed)

C fluxes as percentage of total, rainy season 2004

Important CO2 evasion at the terrestrial-aquatic interface for

the Amazon Basin

Soil water drainage 1250 mm yr-1 (Richey et al., 2002)

17 mg CO2-C mm-1 (Juruena)

Basin-wide CO2 evasion of terrestrial C from streams:

128 Tg yr-1 at terrestrial-aquatic interface (estimated)

353 Tg yr-1 in large streams (Richey et al., 2002)

Terrestrial sources of CO2 evolution from large streams in the Amazon

Forested OxisolSouthern Amazon, Juruena, MT(from 1 watershed)

20%

33%

47%

Richey et al., 2002

Groundwater DOC

Groundwater CO2

Litterfall

36%

58%

7%

DOC

Groundwater CO2

POC

Sources of CO2 evasion at terrestrial-aquatic interface

DOC CO2

?

SOM CO2

?

Root respiration CO2

?

Sources of CO2

20-Jun 21-Jun 22-Jun 23-Jun 24-Jun 25-Jun 26-Jun

CO

2 (p

pm)

10000

15000

20000

25000

30000

35000

40000 0:00 8:00 16:00 0:00 8:00 16:00 0:00 8:00 16:00 0:00 8:00 16:00 0:00 8:00 16:00 0:00 8:00 16:00 0:00 8:00 16:00

Diurnal fluctuation of CO2 in groundwater seep

Forested UltisolSouthern Amazon, Juruena, MT

Conclusions terrestrial-aquatic interface

• Low leaching of DOC to groundwater and emergence in stream

• Significant in-stream generation of DOC and Ca• No in-stream generation of N• Significant subsoil source of dissolved CO2

• Large CO2 evasion at the terrestrial-aquatic interface with profound impact on stream biogeochemistry

• Root respiration is a likely important source in addition to DOC and SOM

Thank You

• LBA, Cnpq, NASA, UFMT• Rohden Inc., Apolinario Schuler• Cornell Einaudi Center, Department of

Crop and Soil Sciences, Cornell Biogeochemistry Program

• Alex Krusche, Jeff Richey• The entire field team in Juruena: Paulo

Nunes, Benedito, Elielton

Special Session 4

Soil Control on Stream Biogeochemistry

Thursday, 3:30-6:00 p.m.

Sala “Brasilia”

Special Issue in “Hydrological Processes”

Hydrology and Biogeochemistry of Small Amazonian Catchments

Christopher Neill, Alex Krusche, Helmut Elsenbeer, Jonannes Lehmann and Daniel Markewitz

Soil type control

Spatial distribution of clay

Juruena, MT

Month

Jan-04 Feb-04 Mar-04 Apr-04 May-04

Car

bon

loss

es f

rom

wat

ersh

ed (

kg)

0.01

0.1

1

10

100

1000

CO2

Dissolved OC

Particulate OC

Coarse POC

Large losses of CO2 from emergent groundwater

Forested OxisolSouthern Amazon, Juruena, MT(from 1 watershed)

In-stream generation of DOC and N (Ca etc?)

• Explanation of in-stream generation of DOC and N by C and N input via surface flow. Can we show some data on that? Could we show stormflow versus baseflow concentrations (at weir) of particulate C and say that during that period of course a lot of coarse OM stays in the stream (or do we have data for surface particulate surface flow into streams? I think we shouold have particulate flow on surface, but not into streams,- but maybe we should look at that as well as an alternative or additional option).

• Or maybe relationship between coarse C and DOC losses? (we would need to multiply the water amount by the DOC concentration to get at DOC amounts. Coarse C is already ok I guess from Evandro’s data.

In-stream generation of DOC and N (Ca etc?)

• Maybe DOC and N with distance (same period etc as CO2 from previous slide)? Out to the Juruena possible?

• The idea is to show that not much DOC and N is lost from groundwater, but from in-stream generation that ultimately came from surface flow