Effects of C-additions on ecosystem processes in the Serengeti: The role of grazing mammals and implications for global change research
- Syracuse Univ., NY (United States)
Increases in atmospheric CO[sub 2] are predicted to cause an increase in the C:N ratio of plant substrates entering the soil organic matter pool. We experimentally increased soil C:N ratios by adding 40 g C/m[sup 2] as sucrose (metabolic C) or cellulose (structural C) in short-, mid-, and tall-grass plots in the Serengeti Ecosystem, and measured plant productivity, plant nutrient uptake rates, and mineralization rates. Experimental treatments also included fencing to exclude grazing and additions of 40 g N/m[sup 2] as urea to simulate a urine hit from an average-sized ungulate. Productivity was only 60% of controls in C-addition plots, and was similar for sucrose and cellulose. However, this response was not observed in the short-grass site, an area of relatively low rainfall and high fertility. These results support the role of a plant-microbe negative feedback mechanism on plant growth in which increased C to microbes results in increased immobilization, reduced plant uptake, and lowered plant growth.
- OSTI ID:
- 7264615
- Report Number(s):
- CONF-940894-; CODEN: BECLAG
- Journal Information:
- Bulletin of the Ecological Society of America; (United States), Vol. 75:2; Conference: Annual Ecological Society of America (ESA) meeting: science and public policy, Knoxville, TN (United States), 7-11 Aug 1994; ISSN 0012-9623
- Country of Publication:
- United States
- Language:
- English
Similar Records
Effects of elevated CO{sub 2} on plant-grazer interactions: The importance of urine-hits and simulated grazing on the response of a C{sub 3} grass from Yellowstone National Park
Long-term effects of elevated atmospheric CO{sub 2} on below-ground biomass and transformations to soil organic matter in grassland.
Related Subjects
AFRICA
RANGELANDS
CARBON DIOXIDE
BIOLOGICAL EFFECTS
ECOLOGICAL CONCENTRATION
MICROORGANISMS
GROWTH
GRAZING
PRODUCTIVITY
MAMMALS
NITROGEN
SOIL CHEMISTRY
SOILS
WILD ANIMALS
ANIMALS
CARBON COMPOUNDS
CARBON OXIDES
CHALCOGENIDES
CHEMISTRY
ECOSYSTEMS
ELEMENTS
FEEDING
NONMETALS
OXIDES
OXYGEN COMPOUNDS
TERRESTRIAL ECOSYSTEMS
VERTEBRATES
560400* - Other Environmental Pollutant Effects