Summary
In previous papers we have described and verified a primary production model of the desert shrub Larrea tridentata. Here we address the validation phase of the evaluation of this model. Two versions of the model which differ in the priority scheme used for allocating carbon to reproductive or vegetative organs were compared on the basis of their usefulness and reliability over a range of soil-moisture conditions. Over an entire growing season when soil-moisture conditions were near “normal” both versions of the model were adequate predictors of total above-ground vegetative growth and one was an adequate predictor of reproductive growth as well. A more detailed analysis revealed that the versions varied in the range of soil-moisture conditions over which they were adequate and that neither was adequate when soil-moisture had remained high for extended periods. The validation process has revealed some likely areas for model improvement to increase adequacy.
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References
Bamberg SA, Vollmer AT, Kleinkopf GE, Akerman TL (1976) A comparison of seasonal primary production of Mojave Desert shrubs during wet and dry years. Amer Midl Nat 95:398–405
Barbour MS, Cunningham GL, Oechel WC, Bamberg, SA (1977) Growth and development, form and function. In: TJ Mabry, JH Hunziker, DR Difeo (eds), Creosote bush. Biology and chemistry of Larrea in new world deserts. Dowden, Hutchinson & Ross. Stroudsburg, Pennsylvania p 48–91
Beatley JC (1974) Effects of rainfall and temperature on the distribution and behavior of Larrea tridentata (creosote bush) in the Mojave Desert of Nevada. Ecology 55:245–261
Campos-Lopez E, Mabry TJ, Fernandez-Tavizon S, (eds) (1979) Larrea Centro de Investigacion en Quimica Aplicada Saltillo, Mexico. 411 pp
Caswell H (1976) The validation problem. In: BC Patten (ed), Systems Analysis and Simulation in Ecology, Vol 4 Academic Press New York p 313–325
Canningham GL, Reynolds JF (1978) A simulation model of primary production and carbon allocation in the Creosote bush (Larrea tridentata [DC] Cov.). Ecology 59:37–52
Cunningham GL, Syvertsen JP, Reynolds JF, Willson JM (1979) Some effects of soil-moisture availability on above-ground production and reproductive allocation in Larrea tridentata (DC) Cov. Oecologia 40:113–123
Fischer RA, Turner NC (1978) Plant productivity in the arid and semiarid zones. Ann Rev Plant Physiol 29:277–317
Goodall DW (1972) Building and testing ecosystem models. In: JNR Jeffer S (ed), Mathematical models in ecology. Blackwell Scientific Publications Oxford p 173–194
Mabry TJ, Hunziker JH, Difeo DR (eds) (1977) Creosote bush. Biology and chemistry of Larrea in new world deserts. Dowden, Hutchinson and Ross Stroudsburg, PA pp 284
Mankin JB, O'Neill R, Shugart HH, Rust BW (1975) The importance of validation in ecosystem analysis. In: G Innis (ed), The future of systems ecology. Simulation Councils of America La Jolla, California p 63–71
Mihran GA (1973) Some practical aspects of the verification and validation of simulation models. Oper Res Quart 23:17–29
Noy-Meir I (1973) Desert ecosystems: environment and producers. Ann Rev Ecol Syst 4:25–51
Odening WR, Strain BR, Oechel WC (1974) The effect of decreasing soil water potential on net CO2 exchange in intact desert shrubs. Ecology 55:1086–1095
Oechel WC, Strain BR, Odening WR (1972) Tissue water potential, photosynthesis, 14C-labeled photosynthate utilization and growth in the desert shrub Larrea divaricata Cav. Ecol Monogr 42:127–141
Patten BC (1971) A primer for ecological modeling and simulation with analog and digital computers. In: BC Patten (ed), Systems analysis and simulation in ecology, Vol. 1 Academic Press New York p 3–121
Reynolds JF, Cunningham GL, Syvertsen JP (1979) A net CO2 exchange model for Larrea tridentata. Photosynthetica 13:279–286
Reynolds JF, Strain BR, Cunningham GL, Knoerr KR (1980) Predicting primary productivity for forest and desert ecosystem models. In: JD Hesketh, JW Jones (eds), Predicting photosynthesis for ecosystem models, Vol II CRC Press Boca Raton, FL p 169–207
Reynolds JF, Cunningham GL (1979) Modeling primary production in Larrea tridentata (DC) Cov. In: E Campos-Lopez, TJ Mabry, S Fernandez-Tavizon (eds), Larrea Centro de Investigacion en Quimica Aplicada Saltillo, Mexico. p 181–215
Rosenzweig ML (1968) Net primary production of terrestrial communities: prediction from climatological data. Amer Natural 102:67–74
Steel RGD, Torrie JH (1960) Principles and procedures of statistics Graw-Hill New York 481 pp
Swartzman G (1979) Evaluation of ecological simulation models. In: GP Patil, M Rosenzweig (eds). Contemporary quantitative ecology and related ecometrics, International Cooperative Publishing House Fairland, MD
Timmermann BN (1977) Practical uses of Larrea In: TJ Mabry, JH Hunziker, DR Difeo (eds). Creosote bush. Biology and chemistry of Larrea in new world deserts. Dowden, Hutchinson and Ross Stroudsburg, PA p 252–256
van Horn RL (1971) Validation of simulation results. Manage Sci 17:247–258
van Keulen H (1974) Evaluation of models. In: Proceedings 1st International Congress of Ecology, The Hague, The Netherlands. Centre for Agricultural Publication and Documentation Wageningen
Webb W, Szarek S, Lavenroth W, Kinerson R, Smith M (1978) Primary productivity and water use in native forest, grassland and desert ecosystems. Ecology 59:1239–1247
Wiegert RG (1975) Simulation models of ecosystems. Ann Rev Ecol Syst 6:311–338
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Reynolds, J.F., Cunningham, G.L. Validation of a primary production model of the desert shrub Larrea tridentata using soil-moisture augmentation experiments. Oecologia 51, 357–363 (1981). https://doi.org/10.1007/BF00540906
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DOI: https://doi.org/10.1007/BF00540906