SFB 552 “STORMA” – Stability of Rainforest Margins in Indonesia www.storma.de
Promoting sustainable land-use management: water, carbon and nutrient turnover
Dirk Hölscher &
Pak Soekisman
Tadulako University Palu
Bogor Agricultural University
SFB 552 “STORMA” – Stability of Rainforest Margins in Indonesia www.storma.de
Objectives • Present key results • Draw conclusions for agricultural and forest management
Tadulako University Palu
Bogor Agricultural University
Slide 2
SFB 552 “STORMA” – Stability of Rainforest Margins in Indonesia www.storma.de
Land use types & land use gradients
Tadulako University Palu
Bogor Agricultural University
SFB 552 “STORMA” – Stability of Rainforest Margins in Indonesia www.storma.de
Aboveground biomass, premontane natural forests
Hertel et al. 2009 Tadulako University Palu
Bogor Agricultural University
SFB 552 “STORMA” – Stability of Rainforest Margins in Indonesia www.storma.de
Tree cover (%) Steffan-Dewenter et al., 2007 Tadulako University Palu
Bogor Agricultural University
SFB 552 “STORMA” – Stability of Rainforest Margins in Indonesia www.storma.de
Meteorological flux tower in a montane rainforest, Bariri
Tadulako University Palu
Bogor Agricultural University
Slide 6
SFB 552 “STORMA” – Stability of Rainforest Margins in Indonesia www.storma.de
Measured net ecosystem exchange flux Fc, extrapolated respiration flux RE, and the sum of both fluxes Pg (gross photosynthesis) 8
Ecosystem Respiration 1760 g C m-2 year-1 RE
CO2 flux g (C) m-2 d-1
CO2 flux (g (C) m-2 d-1)
6
4
2
0
Net turbulent uptake 970 g C m-2 year-1 -2
Fb
-4
-6
-8
Pg
Gross photosynthesis 2730 g C m-2 year-1
-10
OCT ' 03
JAN ' 04
APR
JUL
OCT
JAN ' 05
MAR
Ibrom et al., 2007 Tadulako University Palu
Bogor Agricultural University
SFB 552 “STORMA” – Stability of Rainforest Margins in Indonesia www.storma.de
CO2 fluxes between the atmosphere: forest vs. cacao
Ibrom et al., 2007 Tadulako University Palu
Bogor Agricultural University
Slide 8
SFB 552 “STORMA” – Stability of Rainforest Margins in Indonesia www.storma.de
Land use types and net ecosystem productivities: scenarios
Olchev et al., 2008 Tadulako University Palu
Bogor Agricultural University
SFB 552 “STORMA” – Stability of Rainforest Margins in Indonesia www.storma.de
Land use types and net ecosystem productivities: model results
Olchev et al., 2008 Tadulako University Palu
Bogor Agricultural University
Slide 10
SFB 552 “STORMA” – Stability of Rainforest Margins in Indonesia www.storma.de
Fluxes of sensible (H) and latent (E) energy: forest vs. cacao
Ibrom et al., 2007
Tadulako University Palu
Bogor Agricultural University
SFB 552 “STORMA” – Stability of Rainforest Margins in Indonesia www.storma.de
Sap flux of cacao and shade trees
Köhler et al. 2009
Tadulako University Palu
Bogor Agricultural University
Slide 12
SFB 552 “STORMA” – Stability of Rainforest Margins in Indonesia www.storma.de
Cacao tree water use vs. canopy gap fraction
Shade trees enhanced water use by cacao trees
(R2adj = 0.39, p = 0.043, n = 9)
Tadulako University Palu
Köhler et al. 2009
Bogor Agricultural University
SFB 552 “STORMA” – Stability of Rainforest Margins in Indonesia www.storma.de
Gumbasa river watershed ³ #
Catchment size:
c
1275 km²
c
/#
c
c c c c ³ #
River discharge
c
c#³
³ #
³ #
c c
c c
R2 = 0.86
/# c
R²=0.83
0
³ # /#
c c
10
auto m atic s tage recorde r
automatic stage recorder stage recorder - Fo restry departm ent stage recorder – Forestry clim ate station station climate climate station STORMA clim ate station - S TOR M A project
20 Kilometers
main irriga tion channel
main irrigation chanel re Li nd u National Parc LoreLoLindu National Park PALU R IVER w atershed Palu river watershed
Gerold & Leemhuis 2008 Gauging stations
Tadulako University Palu
Bogor Agricultural University
SFB 552 “STORMA” – Stability of Rainforest Margins in Indonesia www.storma.de
Modeling discharge of the river discharge, Gumbasa watershed: effects of land cover change Discharge (2003):
status 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
16
discharge [mm d-1]
14 12
actual land use land use scenario A1 land use scenario A2
10 8 6 4 2
3 01 /1
1/ 0
3 01 /0
9/ 0
3 01 /0
7/ 0
3 01 /0
5/ 0
3 3/ 0 01 /0
01 /0
1/ 0
3
0
Gerold & Leemhuis 2008 Tadulako University Palu
Bogor Agricultural University
Slide 15
SFB 552 “STORMA” – Stability of Rainforest Margins in Indonesia www.storma.de
Modeled run off components 8
Direct flow
-1
Discharge (mm d )
7
Interflow
6
Base flow
5 4 3 2
1 0 Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
2003
Kleinhans et al. 2004 Tadulako University Palu
Bogor Agricultural University
SFB 552 “STORMA” – Stability of Rainforest Margins in Indonesia www.storma.de
Nutrient balance of maize and agroforest
Dechert et al., 2004 Tadulako University Palu
Bogor Agricultural University
SFB 552 “STORMA” – Stability of Rainforest Margins in Indonesia www.storma.de
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
•
Agroforestry strongly benefits from nitrogen input by N fixing shade trees
Tadulako University Palu
Bogor Agricultural University
SFB 552 “STORMA” – Stability of Rainforest Margins in Indonesia www.storma.de
Implications •
Very important to conserve remaining forests
•
Shade trees positively influence cacao cultivation
Tadulako University Palu
Bogor Agricultural University
SFB 552 “STORMA” – Stability of Rainforest Margins in Indonesia www.storma.de
Drought experiments
Premontane rainforest Cacao/Gliricidia agroforest
Tadulako University Palu
Bogor Agricultural University
SFB 552 “STORMA” – Stability of Rainforest Margins in Indonesia www.storma.de
Cacao-Gliricidia agroforest
Tadulako University Palu
Bogor Agricultural University
SFB 552 “STORMA” – Stability of Rainforest Margins in Indonesia www.storma.de
80% of plot area was covered by plastic panels (March 07- mid April 08);
n=3 roof (treatment) plots, n=3 control plots
M. Köhler
G Moser
Tadulako University Palu
Bogor Agricultural University
SFB 552 “STORMA” – Stability of Rainforest Margins in Indonesia www.storma.de
Soil water content
Tree sap flux
Cacao bean yield Tadulako University Palu
Litterfall Bogor Agricultural University
SFB 552 “STORMA” – Stability of Rainforest Margins in Indonesia www.storma.de
Cacao bean dry mass (kg ha-1 2wk-1)
Cacao yield Roof closure 120
Desiccation period Rewetting period
100 Control 80
-55%, p0.05 20
*
0 March
May
July
Sep
2007
Nov
Jan
March
May
2008
Moser et al. under review Tadulako University Palu
Bogor Agricultural University
July
SFB 552 “STORMA” – Stability of Rainforest Margins in Indonesia www.storma.de
to control ratio Roof Cacao
Soil storage (mm) (mm) storage water Soilwater
Sap flux cacao
Soil water storage and cacao water use 1.2 1.0 0.8 0.6 0.0
-11%, p>0.05 Roof closure
600 500 400
Control Mean±SD, n=3 Roof
300
- 40%, p < 0.05)
0 01Feb07
01Jun07 Tadulako University Palu
01Oct07
01Feb08 Bogor Agricultural University
01Jun08
SFB 552 “STORMA” – Stability of Rainforest Margins in Indonesia www.storma.de
Complementary use of soil water deuterium signal
Plant water
ACacao
Gliricidia
B
Soil water (depth in m)
0.0- 0.1
0.1- 0.3
0.3- 0.5
0.5- 0.7
0.7- 1.0
Cacao -70
Gliricidia -60
-50
δ D (‰)
-40 -70
-60
-50
-40
δ D (‰)
Schwendenmann et al. 2009 Tadulako University Palu
Bogor Agricultural University
SFB 552 “STORMA” – Stability of Rainforest Margins in Indonesia www.storma.de
Water uptake depth cacao and Glricidia Proportion of water uptake from a given soil depth interval (%)
Soil depth interval (cm)
0
20
40
60
80
100
0-30 Cacao Jan 07 Gliricidia Jan 07
30-100
Schwendenmann, unpublished Tadulako University Palu
Bogor Agricultural University
SFB 552 “STORMA” – Stability of Rainforest Margins in Indonesia www.storma.de
Root water potential Cacao
Gliricidia Control
0
Root water potential (bar)
Root water potential (bar)
0 -2 -4 -6 -8 -10
Roof
-12 -14
Cacao R
C
Feb 07
-2 -4 -6 -8 -10 -12 -14
R
C
July 07
R
C
Aug 07
R
C
Sep 07
R
C
Mar 08
Gliricidia R
C
R
C
R
C
R
C
R
C
Feb 07 Jul 07 Aug 07 Sep 07 Mar 08
Osmotic adjustment in cacao Moser et al. under review Tadulako University Palu
Bogor Agricultural University
SFB 552 “STORMA” – Stability of Rainforest Margins in Indonesia www.storma.de
CO2 soil efflux
CO2 efflux (Mg C m-1 h-1)
Period of roof closure
Experiment period
Van Straaten, unpublished Tadulako University Palu
Bogor Agricultural University
SFB 552 “STORMA” – Stability of Rainforest Margins in Indonesia www.storma.de
CO2 efflux (Mg C m-1 h-1)
CO2 efflux response to soil moisture
(Adj R2 = 0.338, n = 94) Van Straaten, unpublished Volumetric water content (m3 m-3)
Tadulako University Palu
Bogor Agricultural University
SFB 552 “STORMA” – Stability of Rainforest Margins in Indonesia www.storma.de
Summary 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
•
Small effects of drought on soil CO2 efflux
Tadulako University Palu
Bogor Agricultural University
SFB 552 “STORMA” – Stability of Rainforest Margins in Indonesia www.storma.de
Implications •
Cacao is a suitable crop even where short dry spells occur
•
Shade trees: no negative effect on cacao tree performance
Tadulako University Palu
Bogor Agricultural University
SFB 552 “STORMA” – Stability of Rainforest Margins in Indonesia www.storma.de
Forest
Tadulako University Palu
Bogor Agricultural University
SFB 552 “STORMA” – Stability of Rainforest Margins in Indonesia www.storma.de
0.7
vol. soil water content Pono ( )
Soil moisture
Throughfall displacement period
0.5 0.3
0.4
3
3
(m m )
0.6
Roof closure
10 cm
0.5
TS
0.3
0.4
3
3
(m m )
0.6
0.7
10cm control 10cm roof
40 cm
0.5
TS
0.3
0.4
3
3
(m m )
0.6
0.7
40cm control 40cm roof
150cm control 150cm roof
06/2007 03/2007 06/2007
150 cm
09/2007 12/2007
03/2008 06/2008 06/2008 09/2008
Tadulako University Palu
Köhler, unpublished 12/2008 03/20096/2009 06/2009
Bogor Agricultural University
70
SFB 552 “STORMA” – Stability of Rainforest Margins in Indonesia
60
Rainfall (mm)
www.storma.de
50 40
Sap flux: all trees
30 20 10
1.1
Js Ratio roof over control
Complete dataset: roof plots devided by control plots 1.0 0.9 0.8 0.7 0.6 0.5 0.4 0
25
50
75
100
125
150
175
200
225
250
275
300
325
Day of year 2008
Schuldt, unpublished Tadulako University Palu
Bogor Agricultural University
350
SFB 552 “STORMA” – Stability of Rainforest Margins in Indonesia www.storma.de
Stem wood production (Mg ha-1 yr-1)
Stem wood production (2nd year)
10 8 6 4 2 0 Control
Tadulako University Palu
Roof
Moser, unpublished
Bogor Agricultural University
SFB 552 “STORMA” – Stability of Rainforest Margins in Indonesia www.storma.de
CO2 soil efflux CO2 efflux (Mg C m-1 h-1)
Period of roof closure
Experiment period
Van Straaten, unpublished Tadulako University Palu
Bogor Agricultural University
SFB 552 “STORMA” – Stability of Rainforest Margins in Indonesia www.storma.de
CO2 efflux (Mg C m-1 h-1)
CO2 soil efflux vs. soil moisture
(Adj R2 = 0.79, n = 93)
Van Straaten, unpublished Tadulako University Palu
Bogor Agricultural University
SFB 552 “STORMA” – Stability of Rainforest Margins in Indonesia www.storma.de
Summary forest drought experiment •
Little response in tree sap flux to drought
•
Tree diameter growth was significantly reduced
•
Strong effect of drought on soil CO2 efflux
Tadulako University Palu
Bogor Agricultural University
SFB 552 “STORMA” – Stability of Rainforest Margins in Indonesia www.storma.de
Overall summary • Old-growth forest is to be conserved • Agroforestry is a promissing option in postforest landscapes • Shade trees play a central role in cacao cultivation
Tadulako University Palu
Bogor Agricultural University
SFB 552 “STORMA” – Stability of Rainforest Margins in Indonesia www.storma.de
Tadulako University Palu
Bogor Agricultural University
Slide 41
