Dixie L. Smith and Loretta Johnson. 2004. Vegetation-mediated changes in microclimate reduce soil respiration as woodlands expand into grasslands. Ecology 85:3348–3361.

Appendix B. A table showing comparisons of soil respiration studies in woodlands and grasslands. Only a few of these studies were of paired woodlands and grasslands. Recalculations were made for the purpose of comparison. Annual estimates were not possible on all data.

		Original Units	Recalculations
Reference	Vegetation	Soil respiration	g C·m-2·yr-1	kg CO2·m-2·yr-1	moles CO2·m-2·s-1
Craine et al. 1999	Schizachyrium scoparium Michx.	6.5 mol CO2·m-2·s-1	NA	NA	6.5
Knapp et al. 1998	Tallgrass prairie (infrequent burn)	6 kg CO2·m-2·yr-1	1.63	6.0	4.3
Raich and Potter 1995	perennial grasslands	611 g C·m2·yr-1	0.61	2.2	NA
Sawamoto et al 2000	Siberian grassland	79 × 10-6 g CO2·m-2·s-1	NA	NA	1.7
this study	Tallgrass  prairie	6 kg CO2·m-2·yr-1	1.63	6	4.6
this study	Juniper woodland	1.9 kg CO2·m-2·yr-1	0.52	1.9	2.87
Hanson et al. 1993	Oak woodland	0.6-3.9 kg CO2·m-2·yr-1	NA	0.6–3.9	NA
Londo et al. 1999	Texas deciduous	4.95 g CO2·m-2·d-1	NA	NA	1.3
Rayment and Jarvis 2000	Black spruce (boreal)	8.96 mg C·ha-1·yr-1	896	3.29	NA
Kelting et al. 1998	Mature red oak	470 mg CO2·m-2·h-1	NA	NA	2.95
Sawamoto et al. 2000	Siberian tiaga	185 10-6 g CO2·m-2·s-1	NA	NA	4.2
Thierron and Laudelout 1996	Oak-hornbeam (Belgium)	69 Mg CO2·ha-1·yr-1	NA	6.9	NA
Raich and Potter 1995	Needle leaf evergreen	332 g CO2·m-2·yr-1	NA	1.2	NA
Raich and Schlesinger 1992	Temperate deciduous woodland	647 g C·m-2·yr-1	NA	0.65	NA

LITERATURE CITED

Craine, J. M., D. A. Wedin, and F. S. Chapin. 1999. Predominance of ecophysiological controls on soil CO₂ flux in a Minnesota grassland. Plant and Soil 207:77–86.

Hanson, P. J., S. D. Wullschleger, S. A. Bohlman, and D. E. Todd. 1993. Seasonal and topographic patterns of woodland floor CO₂ efflux from an upland oak woodland. Tree Physiology 13:1–15.

Kelting, D. L., J. A. Burger, and G. S. Edwards. 1998. Estimating root respiration, microbial respiration in the rhizosphere, and root-free soil respiration in woodland soils. Soil Biology and Biochemistry 30:961–968.

Knapp, A. K., J. M. Briggs, J. M. Blair, and C. L. Turner. 1998. Patterns and controls of aboveground net primary production in tallgrass prairie. Pages 198–200 in A. K. Knapp, J. M. Briggs, D. C. Harnett, and S. L. Collins, editors. Grassland dynamics: long-term ecological research in tallgrass prairie. Oxford University Press, New York, New York, USA.

Londo, A. J., M. G. Messina, and S. H. Schoenholtz. 1999. Woodland harvesting effects on soil temperature, moisture, and respiration in a bottomland hardwood woodland. Soil Science Society of America Journal 63:637–644.

Raich, J. W., and C. S. Potter. 1995. Global patterns of carbon dioxide emission from soils. Global Biogeochemical Cycles 9:23–36.

Raich, J. W., and W. H. Schlesinger. 1992. The global carbon dioxide flux in soil respiration and its relationship to vegetation and climate. Tellus, Series B: Chemical and Physical Meteorology 44:81–89.

Rayment, M. B., and P. G. Jarvis. 2000. Temporal and spatial variation of soil CO₂ efflux in a Canadian boreal woodland. Soil Biology and Biochemistry 32:35–45.

Sawamoto, T., R. Hatano, T. Yajima, K. Takahashi, and A.P. Isaev. 2000. Soil respiration in Siberian taiga ecosystems with different histories of woodland fire. Soil Science and Plant Nutrition 46:41–42.

 Thierron, V., and H. Laudelout. 1996. Contribution of root respiration to total CO₂ efflux from the soil of a deciduous woodland. Canadian Journal of Forest Research 26:1142–1148.