@article {KNZ00621, title = {Responses of soil respiration to clipping and grazing in a tallgrass prairie}, journal = {Journal of Environmental Quality}, volume = {27}, year = {1998}, pages = {1539 -1548}, abstract = {Soil-surface CO2 flux (Fs) is an important component in prairie C budgets. Although grazing is common in grasslands, its effects on Fs have not been well documented. Three clipping treatments: (i) early-season clipping (EC); (ii) full-season clipping (FC); and (iii) no clipping (NC); which represented two grazing strategies and a control, were applied to plots in a tallgrass prairie in northeastern Kansas, USA. Measurements of Fs were made with a portable gas-exchange system at weekly to monthly intervals for 1 yr. Concurrent measurements of soil temperature and volumetric soil water content at 0.1 m were obtained with dual-probe heat-capacity sensors. Measurements of Fs also were obtained in grazed pastures. Fs ranged annually from 8.8 {\texttimes} 10-3 mg m-2 S-1 during the winter to 0.51 mg m-2 s-1 during the summer, following the patterns of soil temperature and canopy growth and phenology. Clipping typically reduced Fs 21 to 49\% by the second day after clipping despite higher soil temperatures in clipped plots. Cumulative annual Fs were 4.94, 4.04, and 4.11 kg m-2 yr-1 in NC, EC, and FC treatments, respectively; thus, dipping reduced annual Fs by 17.5\%. Differences in Fs between EC and FC were minimal, suggesting that different grazing strategies had little additional impact on annual Fs. Daily Fs in grazed pastures was 20 to 37\% less than Fs in ungrazed pastures. Results suggest that grazing moderates Fs during the growing season by reducing canopy photosynthesis and slowing translocation of carbon to the rhizosphere.}, keywords = {LTER-KNZ, tallgrass prairie}, doi = {10.2134/jeq1998.00472425002700060034x}, author = {D. Bremer and J.M. Ham and Owensby, C.E. and Alan K. Knapp} }