Promoting sustainable land-use management: water, carbon and nutrient turnover

Tadulako University Palu Bogor Agricultural University

Promoting sustainable land-use management:

water, carbon and nutrient turnover

Tadulako University Palu Bogor Agricultural University

Objectives

•

Present key results

•

Draw conclusions for agricultural and forest

management

Tadulako University Palu Bogor Agricultural University

Aboveground biomass, premontane natural forests

Tadulako University Palu Bogor Agricultural University

Tadulako University Palu Bogor Agricultural University

Slide 6

Meteorological flux tower in

Tadulako University Palu Bogor Agricultural University

CO

2

fl

ux

(g

(

C)

m

-2

d

-1

)

OCT ' 03

JAN ' 04

APR

JUL

OCT

JAN ' 05

MAR

CO

2

fl

ux

(g

(

C)

m

-2

d

-1

)

OCT ' 03

JAN ' 04

APR

JUL

OCT

JAN ' 05

MAR

-10 -8 -6 -4 -2 0 2 4 6 8

R

E

F

b

P

g -10 -8 -6 -4 -2 0 2 4 6 8

R

E

F

b

P

g

Ecosystem Respiration 1760 g C m

-2

year

-1

Net turbulent uptake 970 g C m

-2

year

-1

Gross photosynthesis 2730 g C m

-2

year

-1

-10 -8 -6 -4 -2 0 2 4 6 8

R

E

F

b

P

g -10 -8 -6 -4 -2 0 2 4 6 8

R

E

F

b

P

g

Ecosystem Respiration 1760 g C m

-2

year

-1

Net turbulent uptake 970 g C m

-2

year

-1

Gross photosynthesis 2730 g C m

-2

year

-1

Measured net ecosystem exchange flux F

c

,

extrapolated respiration flux RE, and

the sum of both fluxes Pg (gross photosynthesis)

Tadulako University Palu Bogor Agricultural University

Slide 8

CO

2

fluxes between the atmosphere: forest vs. cacao

Tadulako University Palu Bogor Agricultural University

Land use types and net ecosystem productivities:

scenarios

Tadulako University Palu Bogor Agricultural University

Slide 10

Land use types and net ecosystem productivities:

model results

Tadulako University Palu Bogor Agricultural University

Ibrom et al., 2007

Tadulako University Palu Bogor Agricultural University

Slide 12

Sap flux of cacao and shade trees

Tadulako University Palu Bogor Agricultural University

Cacao tree water use vs. canopy gap fraction

Köhler et al. 2009

(R

2

adj

= 0.39, p = 0.043, n = 9)

Tadulako University Palu Bogor Agricultural University

Gumbasa river watershed

Catchment size:

1275 km²

R²=0.83

c

c

c

c

c

c

#

³

#

³

#

³

#

³

#

³

#

/

#

/

c

c

c

c

c

c

c

c

0

10

20 Kilometers

auto m atic s tage reco rde r

#

³

stag e record er - Fo restry d ep artm ent

#

/

clim ate statio n

c

clim ate statio n - S TOR M A p ro ject

c

main irriga tio n ch an nel Lo re Li nd u Natio n al Parc PALU R IVER w atersh ed

Gauging stations

R

2

= 0.86

automatic stage recorder

stage recorder

–

Forestry

climate station

climate station STORMA

main irrigation chanel

Lore Lindu National

Park

Palu river watershed

Gerold & Leemhuis 2008

Tadulako University Palu Bogor Agricultural University

Modeling discharge of the river discharge, Gumbasa

watershed: effects of land cover change

Slide 15

01

/01

/03

01

/03

/03

01

/05

/03

01

/07

/03

01

/09

/03

01

/11

/03

di

sc

har

ge

[

m

m

d

-1

]

0

2

4

6

8

10

12

14

16

actual land use

land use scenario A1

land use scenario A2

Discharge (2003):

s

tatus quo 2003:

590 mm

land use scenario A1: 838 mm

+ 42%



1200m annual crops

Land use scenario A2: 724 mm

+ 23%



1200m change into cacao

Tadulako University Palu Bogor Agricultural University

0

1

2

3

4

5

6

7

8

Di

s

c

h

a

rge (

m

m

d

-1

)

Direct flow

Interflow

Base flow

Kleinhans et al. 2004

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

2003

Tadulako University Palu Bogor Agricultural University

Nutrient balance of maize and agroforest

Tadulako University Palu Bogor Agricultural University

Summary

land use types & land use gradients

•

High carbon storage in forests of Sulwesi

•

High carbon uptake by forest

•

Shade trees enhance transpiration from agrofrests

•

River discharge change with land cover change suggested

Tadulako University Palu Bogor Agricultural University

Implications

•

Very important to conserve remaining forests

Tadulako University Palu Bogor Agricultural University

Drought experiments

Premontane rainforest

Tadulako University Palu Bogor Agricultural University

Tadulako University Palu Bogor Agricultural University

80% of plot area was covered by plastic panels (March 07- mid April 08);

n=3 roof (treatment) plots, n=3 control plots

G Moser

Tadulako University Palu Bogor Agricultural University

Soil water content

Tree sap flux

Cacao bean

Tadulako University Palu Bogor Agricultural University

Cacao yield

Desiccation period Rewetting period

0

20

40

60

80

100

120

C

a

ca

o

b

e

a

n

d

ry

m

a

s

s

(k

g

h

a

2

w

k

)

-1

-1

2007

2008

Control

Roof

March

May

July

Sep

Nov

Jan

March

May

July

*

Roof closure

-10%, p>0.05

-55%, p<0.05

Tadulako University Palu Bogor Agricultural University

- 40%, p < 0.05)

01Feb07

01Jun07

01Oct07

01Feb08

01Jun08

S

oi

l

w

ater

sto

rage

(

mm

)

0

300

400

500

600

C

a

c

a

o

0.0

0.6

0.8

1.0

1.2

S

o

il

w

a

te

r

sto

rag

e

(

m

m

)

Roo

f

to c

o

nt

rol

rati

o

Roof closure

S

a

p

flux

ca

ca

o

-11%, p>0.05

Control

Tadulako University Palu Bogor Agricultural University

Complementary use of soil water

deuterium signal

-70

-60

-50

-40

Plant water

0.0- 0.1

0.1- 0.3

0.3- 0.5

0.5- 0.7

0.7- 1.0

S

o

il

w

a

te

r

(d

e

p

th

in

m

)

-70

-60

-50

-40

A

B

Cacao

Gliricidia

D (

‰

)

D (

‰

)

δ

δ

Cacao

Gliricidia

Tadulako University Palu Bogor Agricultural University

0

20

40

60

80

100

0-30

30-100

S

o

il

d

e

p

th

in

te

rv

a

l

(c

m

)

Cacao Jan 07

Gliricidia Jan 07

Proportion of water uptake from a given soil depth interval (%)

Tadulako University Palu Bogor Agricultural University

Root water potential

-14

-12

-10

-8

-6

-4

-2

0

R

o

o

t

w

a

te

r

p

o

te

n

ti

a

l

(b

a

r)

R

C

R

C

R

C

R

C

R

C

Feb 07

July 07

Aug 07

Sep 07

Mar 08

Cacao

Feb 07 Jul 07 Aug 07 Sep 07 Mar 08

-14

-12

-10

-8

-6

-4

-2

0

R

o

o

t

w

a

te

r

p

o

te

n

ti

a

l

(b

a

r)

R

C

R

C

R

C

R

C

R

C

Gliricidia

Moser et al. under review

Osmotic adjustment in cacao

Cacao

Gliricidia

Control

Tadulako University Palu Bogor Agricultural University

CO

2

soil efflux

CO

2

effl

ux

(M

g

C

m

-1

h

-1

)

Experiment period

Period of roof closure

Tadulako University Palu Bogor Agricultural University

CO

2

efflux response to soil moisture

Volumetric water content (m

3

m

-3

)

CO

2

effl

ux

(M

g

C

m

-1

h

-1

)

(Adj R

2

= 0.338, n = 94)

Tadulako University Palu Bogor Agricultural University

cacao drought experiment

•

Cacao yield was little influenced for several months; a strong

(~50%) reduction was observed at the end of the experiment

•

Little response of tree water use to drought

•

Cacao and Glriricidia trees use soil water resources complementary

Tadulako University Palu Bogor Agricultural University

Implications

•

Cacao is a suitable crop even where short dry spells occur

Tadulako University Palu Bogor Agricultural University



(

m

3 m



3 )

10cm control 10cm roof 0 .3 0 .4 0 .5 0 .6 0 .7

Throughfall displacement period



(

m

3 m



3 )

40cm control 40cm roof 0 .3 0 .4 0 .5 0 .6 0 .7  ( m

3 m



3 )

150cm control 150cm roof 0 .3 0 .4 0 .5 0 .6 0 .7

03/2007 06/2007 09/2007 12/2007 03/2008 06/2008 09/2008 12/2008 03/2009 06/2009

Soil moisture

Köhler, unpublished

10 cm

40 cm

150 cm

Roof closure

Tadulako University Palu Bogor Agricultural University

Sap flux: all trees

0.4

0.5

0.6

0.7

0.8

0.9

1.0

J

s

R

a

ti

o

ro

o

f

o

v

e

r

c

o

n

tr

o

l

0

25

50

75

100

125

150

175

200

225

250

275

300

325

350

Day of year 2008

Complete dataset: roof plots devided by control plots

Tadulako University Palu Bogor Agricultural University

0

2

4

6

8

10

S

te

m

w

o

o

d

p

ro

d

u

c

ti

o

n

(M

g

h

a

y

r

)

-1

-1

Control

Roof

Stem wood production (2nd year)

Tadulako University Palu Bogor Agricultural University

CO

2

soil efflux

CO

2

e

ff

lux

(

M

g

C

m

-1

h

-1

)

Experiment period

Period of roof closure

Tadulako University Palu Bogor Agricultural University

CO

2

soil efflux vs. soil moisture

CO

2

effl

ux

(M

g

C

m

-1

h

-1

)

(Adj R

2

= 0.79, n = 93)

Tadulako University Palu Bogor Agricultural University

forest drought experiment

•

Little response in tree sap flux to drought

•

Tree diameter growth was significantly reduced

Tadulako University Palu Bogor Agricultural University

Overall summary

•

Old-growth forest is to be conserved

•

Agroforestry is a promissing option in

post-forest landscapes