Comparative Analyses of Carbon Dynamics in Native and Cultivated Ecosystems

Abstract

Plant productivity, litter decomposition rates, and soil organic matter accumulation for winter wheat and for unbroken tallgrass prairie in Central Missouri were analyzed and compared. As measured in this 3-yr study, annual production of dry matter above- and belowground for the cultivated system averaged slightly higher than that for the natural vegetation burned every 3-4 yr. Prairie was characterized by greater year-to-year fluctuation of productivity, which in some years exceeded productivity of the cultivated system. More litter and structural biomass older than 1 yr occurred in the prairie, reflecting the perennial nature of the root system. Principal pathways of carbon transfer in both ecosystems were modeled, and mean residence time in major storage compartments estimated. Combined CO losses from above- and belowground litter decay, expressed as a percentage of total soil respiration, were twice as great under wheat as for native prairie. A relatively greater fraction of net primary production was available for synthesis of soil organic matter in native prairie. Under equilibrium conditions, decomposition constants for this compartment, however, were similar. Contrasts in community structure and phenology, seasonal dynamics of litter decay, and levels of soil disturbance are suggested influences affecting transfer and storage characteristics.

Seasonal dynamics of soil CO2 efflux in a conventional tilled wheat field of the Loess Plateau, China

“…Additionally, it has been reported that the annual SCE values in wheat fields were 640 g C m À2 in Missouri, United States (Buyanovsky et al 1987) and 579 g C m À2 in the Tibetan Plateau (Shi et al 2006). The annual SCE in this study (891.89 g C m À2 in 2006 and 865.08 g C m À2 in 2007) was slightly higher than those values.…”

“…The annual SCE in this study (891.89 g C m À2 in 2006 and 865.08 g C m À2 in 2007) was slightly higher than those values. This difference in SCE might have been due to higher residue input (about 5.7 t ha À1 in our study vs 3.9 t ha À1 in Missouri; Buyanovsky et al 1987) and differences in climate (temperate climate in our study vs alpine climate in the study conducted by Shi et al 2006). In a recent report, the average SCE in wheat fields near our site measured by an Li-8100 in 2008 was 2.1 lmol m À2 s À1 from March to June (Gao et al 2009).…”

Soil temperature and biotic factors drive the seasonal variation of soil respiration in a maize (Zea mays L.) agricultural ecosystem

“…The current study does not contradict the general positive response of SR to temperature, but indicates that temperature is not necessarily the single most important factor. Soil respiration is a net flux derived from several different processes, and changes occurring in any single process can be masked by opposite changes in another (Buyanovsky and Wagner 1995). During the growing season, NPP and biomass changed rapidly on several days (Fig.…”

Soil organic matter dynamics under grain farming in Northern Kazakhstan

“…Farahani et al 1998). Unfortunately, it has often been reported that such agricultural practices on Chernozem soils had accelerated organic matter decomposition (Buyanovsky et al 1987;Srivastava and Meyer 1998;Mikhailova et al 2000;Karbozova-Saljnikov et al 2004).…”