1. General Model Information

Name: Simulating Production and Utilization of Range Land

Acronym: SPUR

Main medium: air+terrestrial
Main subject: biogeochemistry, agriculture
Organization level:
Type of model: not specified
Main application:
Keywords: grassland, rangeland sustainability, climate change, management, watershed, plant growth, herbivores, irrigation, fertilization, seeding, grazing


Dr. Jon D. Hanson
USDA, Agricultural Research Service
Great Plains Systems Research Unit
301 S. Howes, P.O. Box E.
Fort Collins, CO 80522

Phone: (970) 490-8323 or (970)490-8322
Fax: (970) 490-8310
email: jon@mandan.ars.usda.gov

Homepage: http://www.mandan.ars.usda.gov/hanson.htm


Dr. Jon D. Hanson


SPUR (Simulating Production and Utilization of Range Land) is a simulation and process model. Its purpose is to determine and analyze management scenarios as they affect rangeland sustainability and to forecast the effects of climate change on rangelands. ELM , BLUE GRAMA and ROOTS were studied extensively during the construction of this plant growth model.

The model is unique because :

The SPUR plant growth model was designed to be useful in the decision-making process, thus it includes a framework whereby managerial practices, such as irrigation, fertilization, seeding, or grazing systems, can be investigated over long periods of time. The model simulates growth initiation, germination, carbon assimilation, translocation between roots and shoots, decomposition, and nitrogen uptake. SPUR has displayed reasonable dynamics for a two-species, single-site example.

Aboveground processes simulated in the SPUR model:

Belowground processes simulated in the SPUR model: Two versions of the model (SPUR I and SPUR II) currently exist.

SPUR I contains four components:

  1. hydrology;
  2. plant growth;
  3. animal physiology and harvesting (for both domestic and wildlife); and
  4. economics.

Driving variables for the model include daily precipitation, maximum and minimum temperature, solar radiation and wind speeds. SPUR I has been validated by several researchers (Hanson et al., 1992a).

SPUR2 DOS ver. 2.2 is a general grassland ecosystem simulation model designed to determine beef cattle performance and production by simultaneously simulating production of up to 15 plant species on 36 heterogeneous grassland sites. SPUR2 simulates grassland hydrology, nitrogen cycling, and soil organic matter on grazed ecosystems as well as rangeland production under different climatic regimes, environmental conditions, and management alternatives.

Future (or current) Developments:

II. Technical Information

II.1 Executables:

Operating System(s): DOS, MS-Windows, UNIX and VMS Hardware demands: 4MB RAM (DOS) or 8MB RAM (MS-Windows), 20 MB Disk-space Support: The model has been released for public use and is supported by the Great Plains Systems Research Unit. For further copies of the code, documentation, or publications relating to the validation and use of SPUR2, please contact:
Dr. Jon D. Hanson USDA, Agricultural Research Service Great Plains Systems Research Unit 301 S. Howes, P.O. Box E. Fort Collins, CO 80522 COM: (303)490-8323 or (303)490-8322 FAX: (303)490-8310 E-mail: jon@gpsr.colostate.edu

download registration form

II.2 Source-code:

Programming Language(s): FORTRAN 77

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

J.R. Wight (ed.) 1983.SPUR--simulation of production and utilization of rangelands : a rangeland model for management and research.
Washington, D.C. : U.S. Dept. of Agriculture, Agricultural Research Service , no. 1431 (NAL CALL NO: 1 Ag84M no.1431)

Thurow, T.L., Carlson, D.H. and Heitschmidt, R.K. 1993. Estimating the impacts of alternative management practices on rangeland production and ecology using the SPUR model. p - .
in: Robertson, T., English, B.C. and Alexander, R.R. (eds.). Evaluating Natural Resource Use in Agriculture.
Univ. Tennessee Press. Knoxville.

Hanson, J.D., B.B. Baker and R.M. Bourdon. 1992a. The effect of climate change on rangeland livestock production: atheoretical approach. (submitted to Agricultural Systems).

Hanson, J.D., B.B. Baker and R.M. Bourbon. 1992b. SPUR II Model Description and User Guide: GPSR Technical ReportNo. 1. USDA-ARS, Great Plains Systems Research Unit, Ft. Collins, Colorado.
Hanson, J.D.; Dye ,A.J.: Diurnal and seasonal patterns of photosynthesis of honey mesquite.Photosynthetica, (14) 1980, p. 1-7.
Hanson, J.D.; Skiles, J.W.; Parton, W.J.: A multispecies model for spatially heterogeneous rangeland plant communities. Ecological Modelling.
Hanson, J.D.; Parton, W.J.; Innis, G.S.: Plant growth and production of grassland ecosystems - A comparison of modelling approaches. Ecological Modelling (29) 1985, P. 131-144.
Skiles, J.W.; Hanson, J.D.; Parton, W.J.: Simulation of above- and belowground carbon and nitrogen dynamics of Bouteloua gracilis and Agropyron smithii.
in: W.K. Lauenroth; G.V. Skogerboe; M.Flug (Editors):Analysis of ecological systems : State-of-the-Art in Ecological Modelling. Developments in Environmental Modelling,(5) 1983, Elsevier, Amsterdam/Oxford/New York, p. 467-473.

V. Further information in the World-Wide-Web

VI. Additional remarks

Global change implications:SPUR II can be used to studyglobal change because it provides algorithms making photosynthesis sensitive toCO2 changes. Furthermore, it provides inputs based on managementscenarios. Finally, it is one of the few models that examines ecosystemsor watersheds at all levels of interactions, from social (management andeconomics), to physical (soils and atmosphere), and biological (plantand animal).

SPUR I has been used, in conjunction with global circulationmodels (GCMs), to understand the effects of increased CO2 concentrationson the dynamics of grazing rangelands (Hanson et al., 1992b).



Last review of this document by: 13.8.96
Status of the document:
last modified by Tobias Gabele Wed Aug 21 21:44:50 CEST 2002

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