1. General Model Information
Name: Simulating Production and Utilization of Range Land
Main medium: air+terrestrial
Main subject: biogeochemistry, agriculture
Type of model: not specified
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
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.
BLUE GRAMA and
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,
- it is a multipoint model,
- it is designed to allow for direct competition between several species for water and nitrogen, and
- the model has incorporated the impacts of wild and domestic herbivores.
Aboveground processes simulated in the SPUR model:
Belowground processes simulated in the SPUR model:
- Photosynthesis (soil water, nutrient, phenology or leaf age, temperature, solar radiation, leaf water potential)
- Carbon allocation (variable allocation to leaf area ratio, soil water, nutrient, phenology or leaf age, temperature)
- Death (leaf area, soil water, temperature, phenology or leaf age, trampling)
- Germination (soil water, temperature).
Two versions of the model (SPUR I and SPUR II) currently exist.
- Carbon allocation (fixed allocation)
- Root growth (soil water, soil nutrient, root to shoot ratio)
- Death (soil water, soil temperature)
- Uptake (soil nutrient)
- Respiration (soil temperature).
SPUR I contains four components:
- plant growth;
- animal physiology and harvesting (for both domestic and wildlife); and
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:
- Annual grasses are not simulated.
- The model requires fairly detailed parameterization when new plant species
are added to the system
- CBCPM (Colorado Beef Cattle Production Model) is a very detailed genetic
model and may be to complex for many of the range management questions
- The erosion and runoff routines used in SPUR2 many not be valid under all
- Incorporate the
Soil Organic Matter Model into the SPUR2 framework
- Develop and incorporate a grassland burning management option
- Improve the hydrology components of the model
- Update and improve the user interface
- Build SPUR2 into the GRASS Geographic Information System
Decision Support System for Assessing and Managing Rangelands
II. Technical Information
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: email@example.com
download registration form
Programming Language(s): FORTRAN 77
III. Mathematical Information
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).
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Tobias Gabele Wed Aug 21 21:44:50 CEST 2002