1. General Model Information
Name: Vegetation dynamics of grasslands
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,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A newer version of the STEPPE model is under development, and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
Author of the abstract:
II. Technical Information
Operating System(s): UNIX
Programming Language(s): FORTRAN
III. Mathematical Information
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