1. General Model Information

Name: Vegetation dynamics of grasslands

Acronym: STEPPE

Main medium: terrestrial
Main subject: biogeochemistry
Organization level: landscape
Type of model: individual-based,
Main application: research
Keywords: grassland, vegetation dynamics, stochastic, gap


D.P. Coffin

Kevin Swab

Fax :


D.P. Coffin,W.K. Lauenroth and others.


STEPPE is a simulation model that incorporates stochastic processes associated with the recruitment and mortality of individual plants and deterministic processes associated with plant growth. The purpose of the model is to evaluate vegetation dynamics of grasslands using an individual plant-based approach (Coffin and Lauenroth, 1989). A newer version of the STEPPE model is under development, and will be adapted for all North American grasslands.

The model requires species specific life history information, and various efficiency and competition parameters as input. Data used are generally field-collected or from published studies. The model provides information on above-ground biomass density, size structure of plants by species and below ground biomass. The model runs at annual time steps and at small spatial scales (e.g. 0.1 km2).

New STEPPE is linked to a daily time-step, multi-layer soil water model (SOILWAT ).

Author of the abstract:


II. Technical Information

II.1 Executables:

Operating System(s): UNIX

II.2 Source-code:

Programming Language(s): FORTRAN

II.3 Manuals:

II.4 Data:

III. Mathematical Information

III.1 Mathematics

III.2 Quantities

III.2.1 Input

III.2.2 Output

IV. References

Coffin, D.P., and W.K. Lauenroth. 1989. Disturbances in a semiarid grassland: a landscape-level approach. Landscape Ecology 3(1):19-27.
Lauenroth, W.K., D.L. Urban, D.P. Coffin, W.J. Parton,H.H. Shugart, T.B. Kirchner and T.M. Smith. 1993. Modeling vegetation structure-ecosystem processinteractions across sites and ecosystems. Ecol. Mod. 67:49-80.
Coffin D.P.; Urban D.L. 1993. Implications of natural history traits to system-level dynamics: comparisons of a grassland and a forest. Ecological-Modelling.1993, 67: 2-4, 147-178; 71 ref..
Coffin D.P.; Lauenroth W.K. 1994. Successional dynamics of a semiarid grassland: effects of soil texture and disturbance size. Vegetatio.1994, 110: 1, 67-82; 61 ref..
CoffinD.P.; Lauenroth W.K.; Smith T.M. 1994. Transient responses of North-American grasslands to changes in climate. Special issue.The application of patch models of vegetation dynamics to global change issues: papers given at the International Geosphere Biosphere Program workshop held at Apeldoorn, Netherlands, 1994. Climatic-Change. 1996, 34: 2, 269-278; 21 ref..
Humphries H.C.; Coffin D.P.; Lauenroth W.K. 1996. An individual-based model of alpine plant distributions. Ecological-Modelling.1996, 84: 1-3, 99-126; 63 ref..

V. Further information in the World-Wide-Web

VI. Additional remarks

Global change implications: STEPPE can be used in globalchange research to understand grassland dynamics (especially ecologicalcompetition). The newer version may allow research at larger scales. This model can also provide information about which species maypredominate or be lost given changes in water resources due to climatechange or human intervention.

Because it is a spatially-explicit model and examines the growthof semiarid grasslands after disturbance, it could be valuable inthe study of how land use changes affect grassland production onlarge scales.

The original version of STEPPE has been used to examine ecosystem processes across ecological gradients (Laurenroth et al., 1993) ofseveral of the National Science Foundation's Long-term EcologicalResearch (LTER) sites. It has also been linked to the Century model.

Last review of this document by: R. Patzak andT. Gabele : 30. September 1997 -
Status of the document:
last modified by Tobias Gabele Wed Aug 21 21:44:50 CEST 2002

Go back to Register of Ecological Models (R E M)