Model estimates of CO2 emissions from soil in response to global warming

Carbon dioxide and methane fluxes by a forest soil under laboratory-controlled moisture and temperature conditions

“…This represents an increase of 8.9% over the current GWE emissions during typical summer soil conditions. Clearly other factors must be considered in producing ®nal estimates as illustrated by Jenkinson et al (1991) and Lloyd and Taylor (1994), but our results indicate that single-factor equations used to predict exchanges in¯uxes of greenhouse gases between soils and the atmosphere may be insu cient to predict changes in trace gas¯uxes, and that inclusion of both moisture and temperature in models of trace gas¯uxes can increase the accuracy of trace T = temperature (8C); W = % water-holding capacity. Mineral soil = 0±10 cm depth.…”

Transient climate change and net ecosystem production of the terrestrial biosphere

“…Future changes in atmospheric CO2 concentration and climate are likely to affect net primary production and the carbon storage of terrestrial ecosystems [Gates, 1985;Houghton and Woodwell, 1989;Melillo et al, 1990;Jenkinson et al, 1991 ]. A number of modeling studies have applied ecosystem models to examine the equilibrium responses of net primary production and carbon storage of the terrestrial biosphere to elevated atmospheric CO2 concentration and the doubled CO2 equilibrium climate changes predicted by atmospheric general circulation models at the scales of the globe [Melillo et ].…”

Comparison of Fractionation Methods for Soil Organic Matter 14C Analysis

“…The first models the observed increase of 14C during the 30 yr since the end of atmospheric weapons testing, using additional constraints derived from knowledge of carbon inputs to the system (O'Brien and Stout 1978;Harkness, Harrison and Bacon 1986;Balesdent 1987;Scharpenseel et al 1989;Trumbore, Vogel and Southon 1989;Vitorello et al 1989;Jenkinson, Adams and Wild 1991;Harrison, Broecker and Bonani 1993;Trumbore 1993;Townsend, Vitousek and Trumbore 1995;Trumbore, Chadwick and Amundson 1996). The second relies on physical and/or chemical fractionation methods to separate SOM into pools that turn over on different time scales (Paul et a1.1964;Campbell et a1.1967;Scharpenseel, Ronzani and Pietig 1968;Mattel and Paul 1974;Goh et a1.1976;Goh, Stout and Rafter 1977;Anderson and Paul 1984;Goh, Stout and O'Brien 1984;Scharpenseel et al 1989;Trumbore, Vogel and Southon 1989;Trumbore, Bonani and Wolfli 1990;Scharpenseel and BeckerHeidmann 1992).…”

“…Models describing the dynamics of accumulation and turnover of organic carbon generally recognize components of soil organic matter (SOM) that turn over on annual (active), decadal (slow) and centennial to millennial (passive) time scales (Jenkinson and Raynor 1977;O'Brien and Stout 1978;Parton et al 1987;Jenkinson, Adams and Wild 1991;Potter et al 1993;Townsend, Vitousek and Trumbore 1995;Schimel et al 1994). Although these concepts have proven useful in explaining the magnitude and timing of changes in SOM following a perturbation such as land clearing for cultivation (Parton et a1.1987;Cambardella and Elliott 1993;Davidson and Ackerman 1993;Schimel et al 1994), no recognized method now exists for determining how to apportion SOM into compartments that turn over on different time scales.…”