Observations and modeling of biomass and soil organic matter dynamics for the grassland biome worldwide

Century is a model of terrestrial biogeochemistry based on relationships between climate, human management (fire, grazing), soil properties, plant productivity, and decomposition. The grassland version of the Century model was tested using observed data from 11 temperate and tropical grasslands around the world. The results show that soil C and N levels can be simulated to within ±25% of the observed values (100 and 75% of the time, respectively) for a diverse set of soils. Peak live biomass and plant production can be simulated within ± 25% of the observed values (57 and 60% of the time, respectively) for burned, fertilized, and irrigated grassland sites where precipitation ranged from 22 to over 150 cm. Live biomass can be generally predicted to within ±50% of the observed values (57% of the time). The model underestimated the live biomass in extremely high plant production years at two of the Russian sites. A comparison of Century model results with statistical models showed that the Century model had slightly higher r2 values than the statistical models. Data and calibrated model results from this study are useful for analysis and description of grassland carbon dynamics, and as a reference point for testing more physiologically based models prediction's of net primary production and biomass. Results indicate that prediction of plant and soil organic matter (C and N) dynamics requires knowledge of climate, soil texture, and N inputs.

[1]  W. Parton,et al.  A general model for soil organic matter dynamics: sensitivity to litter chemistry, texture and management. , 1994 .

[2]  W. Lauenroth.  Grassland Primary Production: North American Grasslands in Perspective , 1979 .

[3]  C. Owensby,et al.  Effects of clipping and supplemental nitrogen and water on loamy upland bluestem range. , 1970 .

[4]  W. E. Larson,et al.  Estimating soil water retention characteristics from particle size distribution, organic matter percent, and bulk density , 1979 .

[5]  J. Lynch,et al.  The turnover of organic carbon and nitrogen in soil. , 1990 .

[6]  T. Bragg,et al.  Woody plant invasion of unburned Kansas bluestem prairie. , 1976 .

[7]  W. Parton,et al.  Analysis of factors controlling soil organic matter levels in Great Plains grasslands , 1987 .

[8]  W. Lauenroth,et al.  Analysis of the Response of a Grassland Ecosystem to Stress , 1979 .

[9]  J. E. Weaver,et al.  Nature and Degree of Recovery of Grassland from the Great Drought of 1933 to 1940 , 1944 .

[10]  W. Parton,et al.  Physiological Responses of Plant Populations to Herbivory and Their Consequences for Ecosystem Nutrient Flow , 1992, The American Naturalist.

[11]  W. Parton,et al.  Simulating regional patterns of soil C, N, and P dynamics in the U.S. central grasslands region , 1989 .

[12]  J. Briggs,et al.  Comparative analysis of temporal and spatial variability in above-ground production in a deciduous forest and prairie , 1989 .

[13]  Edward T. Linacre,et al.  A simple formula for estimating evaporation rates in various climates, using temperature data alone , 1977 .

[14]  C. Owensby,et al.  Long-term effects of annual burning at different dates in ungrazed Kansas tallgrass prairie. , 1984 .

[15]  David S. Schimel,et al.  Texture, climate, and cultivation effects on soil organic matter content in U.S. grassland soils , 1989 .

[16]  William J. Parton,et al.  PREDICTING SOIL TEMPERATURES IN A SHORTGRASS STEPPE , 1984 .

[17]  D. O. Hall,et al.  Climate Change and Productivity of Natural Grasslands , 1991 .

[18]  Donald A. Klein,et al.  Simulation model for the effects of climate change on temperate grassland ecosystems , 1991 .

[19]  W. Parton,et al.  Primary Production of the Central Grassland Region of the United States , 1988 .

[20]  E. K. Christie,et al.  Analysis of Interferences Between C(3) and C(4) Grasses in Relation to Temperature and Soil Nitrogen Supply , 1982 .

[21]  A. McGuire,et al.  Interactions between carbon and nitrogen dynamics in estimating net primary productivity for potential vegetation in North America , 1992 .

[22]  T. B. Kirchner,et al.  TIME-ZERO: The integrated modeling environment , 1989 .

[23]  J. Menaut,et al.  Structure and Primary Productivty of Lamto Savannas, Ivory Coast , 1979 .

[24]  D. J. Lodge,et al.  Hurricane effects on soil organic matter dynamics and forest production in the Luquillo experimental forest, Puerto Rico : results of simulation modeling , 1991 .

[25]  M. Coughenour.  A mechanistic simulation analysis of water use, leaf angles, and grazing in East African graminoids , 1984 .

[26]  J. Anderson,et al.  The Effects of Climate Change on Decomposition Processes in Grassland and Coniferous Forests. , 1991, Ecological applications : a publication of the Ecological Society of America.

[27]  W. Parton,et al.  Grassland biogeochemistry: Links to atmospheric processes , 1990 .

[28]  W. Smith,et al.  Stomatal and photosynthetic responses to variable sunlight , 1990 .

[29]  O. Sala,et al.  Long-Term Forage Production of North American Shortgrass Steppe. , 1992, Ecological applications : a publication of the Ecological Society of America.

[30]  M. Abrams,et al.  A TEN‐YEAR RECORD OF ABOVEGROUND BIOMASS IN A KANSAS TALLGRASS PRAIRIE: EFFECTS OF FIRE AND TOPOGRAPHIC POSITION , 1986 .

[31]  W. Parton,et al.  Dynamics of C, N, P and S in grassland soils: a model , 1988 .

[32]  P. Crutzen,et al.  Estimates of Annual and Regional Releases of CO2 and Other Trace Gases to the Atmosphere from Fires in the Tropics, Based on the FAO Statistics for the Period 1975–1980 , 1990 .