Ecological Archives A025-025-A1

Jelle P. Hilbers, Frank van Langevelde, Herbert H. T. Prins, C. C. Grant, Mike J. S. Peel, Michael B. Coughenour, Henrik J. de Knegt, Rob Slowtow, Izak P. J. Smit, Greg A. Kiker, and Willem F. de Boer. 2015. Modeling elephant-mediated cascading effects of water point closure. Ecological Applications 25:402415. http://dx.doi.org/10.1890/14-0322.1

Appendix A. The SAVANNA model structure and parameters used in this study.

SAVANNA - Model structure

SAVANNA is comprised of several interacting sub-models (Coughenour 1993). These include hydrologic, plant biomass production, plant population dynamics, ungulate herbivory, ungulate spatial distribution, ungulate energy balance and ungulate population dynamics sub-models, which reflect the major processes involved in savanna ecosystem dynamics. Figure S1-1 shows the relational diagram of the sub-models involved in this study. Note that ungulate population sizes were kept at constant values here. For more detailed information on the relational diagrams of the sub-models, the sub-model functions and interactions between sub-models, see Coughenour (1993); Ellis and Coughenour (1998).

FigA1

Fig. A1. A relational diagram of the structure of the SAVANNA model used in this study (modified from Coughenour 1993).


 

Table A1. Parameter values used in this study – Note that in total 1000+ parameters and input maps are needed to run SAVANNA so that only a subset is depicted here (for a complete dataset of parameters used in this study, please contact the corresponding author).

Parameter Description

Buffalo

Impala

Roan

Zebra

Wildebeest

Steenbok

Bushbuck

Kudu

Giraffe

Elephant Bulls

Elephant Cows

Max intake rate (kg/kg/day)

Increaser 1

0.02

0.029

0.029

0.0268

0.0217

0.016

0.018

0.0225

0.021

0.012

0.015

Increaser 2

0.02

0.029

0.029

0.0268

0.0217

0.016

0.018

0.0225

0.021

0.012

0.015

Decreaser

0.02

0.029

0.029

0.0268

0.0217

0.016

0.018

0.0225

0.021

0.012

0.015

Shrub

0

0.029

0.029

0

0

0.016

0.018

0.0225

0.021

0.012

0.015

Fine leaf palatable

0

0.029

0.029

0

0

0.016

0.018

0.0225

0.021

0.012

0.015

Fine leaf unpalatable

0

0

0

0

0

0.016

0.018

0.0225

0.021

0.012

0.015

Broad leaf palatable

0

0.029

0.029

0

0

0.016

0.018

0.0225

0.021

0.012

0.015

Broad leaf unpalatable

0

0

0

0

0

0.016

0.018

0.0225

0.021

0.012

0.015

Mopane

0

0.029

0.029

0

0

0.016

0.018

0.0225

0.021

0.012

0.015

Marula

0

0.029

0.029

0

0

0.016

0.018

0.0225

0.021

0.012

0.015

Wastage fraction (kg/kg/day)

Increaser 1

0.1

0.05

0.05

0.1

0.1

0.02

0.02

0.1

0.02

0.15

0.15

Increaser 2

0.1

0.05

0.05

0.1

0.1

0.02

0.02

0.1

0.02

0.15

0.15

Decreaser

0.1

0.05

0.05

0.1

0.1

0.02

0.02

0.1

0.02

0.15

0.15

Shrub

0.1

0.05

0.05

0.1

0.1

0.02

0.02

0.1

0.02

0.15

0.15

Fine leaf palatable

0.1

0.05

0.05

0

0

0.02

0.02

0.1

0.02

0.15

0.15

Fine leaf unpalatable

0.1

0

0

0

0

0.02

0.02

0.1

0.02

0.15

0.15

Broad leaf palatable

0.1

0.05

0.05

0

0

0.02

0.02

0.1

0.02

0.15

0.15

Broad leaf unpalatable

0.1

0

0

0

0

0.02

0.02

0.1

0.02

0.15

0.15

Mopane

0.1

0.05

0.05

0

0

0.02

0.02

0.1

0.02

0.15

0.15

Marula

0.1

0.05

0.05

0

0

0.02

0.02

0.1

0.02

0.15

0.15

Preferred weights
(Note: higher values= relatively more preferred)

Increaser 1

0.5

0.5

0.5

1

1

0.5

0.1

0.5

0.1

1.5

1.5

Increaser 2

1

1.5

0.5

2

5

1

0.1

0.2

0.1

1.5

1.5

Decreaser

2

0.5

1

2

2

0.5

0.5

0.8

0.1

4

4

Shrub

0

2

2

0

0

2

2

2

0.1

2

3

Fine leaf palatable

0

2

2

0

0

2

2

2

4

4

4

Fine leaf unpalatable

0

0

0

0

0

0.1

0.1

0.1

0.1

0.1

0.1

Broad leaf palatable

0

2

2

0

0

2

3

3

2

4

4

Broad leaf unpalatable

0

0

0

0

0

0.1

0.1

0.1

0.1

1

0.5

Mopane

0

2

2

0

0

2

2

2

1

3

3

Marula

0

2

2

0

0

2

2

2

2

3

3

Tissue Preferred Weigths
(Note: higher values= relatively more preferred)

Pref herb leaf

2

2

2

2

2

2

0.5

1

0.1

4

4

Pref herb stem

1

0.4

1

1

0.3

0.5

0.1

0.1

0.1

1

0.7

Pref herb dead

0.5

0.8

0.8

0.5

0.2

0.5

0.1

0.1

0.1

0.2

0.2

Pref browse leaf

0

2

2

0

0

5

4

3

3

3

3

Pref browse dead

0

1

1

0

0

0.5

1

0.5

0.5

1

1

Pref browse CAG

0

2

2

0

0

2

2

3

2

1

1

Pref browse branch

0

0

0

0

0

0.5

1

1.5

0.5

1

1

Preferred browsing heights on the 6 size classes of woody species
(Note: higher values= relatively more preferred)

 

 

 

 

 

 

 

 

 

 

 

Shrub

1,1,1,1,1,1

1,1,1,1,1,1

1,1,1,1,1,1

1,1,1,1,1,1

1,1,1,1,1,1

1,1,1,1,1,1

1,1,1,1,1,1

1,1,1,1,1,1

1,1,1,1,1,1

1,1,1,1,1,1

1,1,1,1,1,1

Fine leaf palatable

3,3,2.5,1,0,0

3,2.5,2,0.5,0,0

3,3,2.5,1,0,0

3,3,2.5,1,0,0

1,1,1,0,0,0

2,1.5,0.5,0,0,0

1.5,1.5,1,0,0,0

2,2,1.5,1,0,0

1,1.5,3,5,4,3

2,3.5,4,4,3.5,3

2,4,4,4,2,2

Fine leaf unpalatable

3,3,2.5,1,0,0

3,2.5,2,0.5,0,0

3,3,2.5,1,0,0

3,3,2.5,1,0,0

1,1,1,0,0,0

2,1.5,0.5,0,0,0

1.5,1.5,1,0,0,0

2,2,1.5,1,0,0

1,1.5,3,5,4,3

2,3.5,4,4,3.5,3

2,4,4,4,2,2

Broad leaf palatable

2,2,1.75,1.5,1.25,1

3,2.5,2,0.5,0.5,0.5

2,2,1.75,1.5,1.25,1

2,2,1.75,1.5,1.25,1

1,1,1,1,1,0

2,1.5,0.5,0,0,0

2,1.5,1.25,1,0.5,0

1.75,2,1.5,1,0.75,0.75

1,2,4,4,5,5

2,4,3.5,3,3,3

2,4,4,5,4,2.5

Broad leaf unpalatable

2,2,1.75,1.5,1.25,1

3,2.5,2,0.5,0.5,0.5

2,2,1.75,1.5,1.25,1

2,2,1.75,1.5,1.25,1

1,1,1,1,1,0

2,1.5,0.5,0,0,0

2,1.5,1.25,1,0.5,0

1.75,2,1.5,1,0.75,0.75

1,2,4,4,5,5

2,4,3.5,3,3,3

2,4,4,5,4,2.5

Mopane

2,2,1,1,0,0

3,2.5,2,0.5,0,0

2,2,1,1,0,0

2,2,1,1,0,0

1,1,0,0,0,0

2,0.5,0,0,0,0

1.5,1,0.5,0,0,0

1.75,2,1.5,1,0,0

1,1.5,4,5,5,5

2,4,3.5,3,2.5,2.5

2,4,4,3.5,2.5,2

Marula

3,3,2.5,1,0,0

3,2.5,2,0.5,0,0

3,3,2.5,1,0,0

3,3,2.5,1,0,0

1,1,1,0,0,0

2,1.5,0.5,0,0,0

1.5,1.5,1,0,0,0

2,2,1.5,1,0,0

1,1.5,3,5,4,3

2,3.5,4,4,3.5,3

2,4,4,4,2,2

Maximum reach height (m)

2

1.75

2.2

2

1

0.8

1.3

2.2

5.3

6

5.2

Metabolizability of forage
(fraction energy after loss by fermentation gas and urine)

0.767

0.809

0.809

0.821

0.809

0.809

0.809

0.830

0.809

0.797

0.797

Ungrazable biomass (g/m²)

3

1.5

1.5

2.5

3.5

0.2

0.2

0.5

0.5

8

8

Initial condition index (-)

0.70

0.75

0.75

0.70

0.65

0.7

0.7

0.7

0.7

0.65

0.65

Water requirement (kg/day)

21.33

10.

20.

14.4

8.33

0.1

7.5

10.

17.

*

*

Elevations at the min and max pref indices

1000.,2000.

1000.,2000.

1000.,2000.

1000.,2000.

1200.,2000.

1000.,2000.

1000.,2000.

1000.,2000.

1000.,2000.

*

*

Mean steepness of terrain consumer frequently travels (% slope)

6

5

5

3

3

5

5

5

5

*

*

Maximum Herbivore Density (#/km**2)

150.

300.

 500.

500.

2000.

50.

70.

10000.

250.

*

*

Minimum Herbivore Density (#/km**2)

1.

.1

1.

1.

1.

0.04

0.04

1.

.2

*

*

*No parameter values needed as distribution is determined using GPS data and the Mahalanobis distance factor analysis

Literature cited

Coughenour, M. B. 1993. Savanna - landscape and regional ecosystem model: user manual. Colorado State University.

De Knegt, H. J., Van Langevelde, F., Skidmore, A. K., Delsink, A., Slotow, R., Henley, S., Bucini, G., De Boer, W. F., Coughenour, M. B., Grant, C. C., Heitkönig, I.M., Henley, M., Knox, N.M., Kohi, E. M., Mwakiwa, E., Page, B.R., Peel, M., Pretorius, Y., Van Wieren, S.E. & Prins, H. H. 2011. The spatial scaling of habitat selection by African elephants. Journal of Animal Ecology,.80:270-281.

Ellis, J. & Coughenour, M. (1998) The SAVANNA integrated modelling system: an integrated remote sensing, GIS and spatial simulation modelling approach. Drylands: sustainable use of rangelands into the twenty-first century, IFAD Technical Reports, Rome, Italy, pp. 97–106.


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