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Title: 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

Journal Article · · Bulletin of the Ecological Society of America
OSTI ID:95905

Although grazing mammals are an important component of most grassland ecosystems, previous research on plant responses to elevated CO{sub 2} has rarely considered their effects. In a growth chamber experiment, we tested whether regrowth following simulated grazing was affected by elevated CO{sub 2} and urine hits (40 g/m{sup 2} urea N) in the C{sub 3} grass, Stipa occidentalis, which is common in Yellowstone National Park. Plant response (end of experiment biomass and productivity [biomass + clippings]) to elevated CO{sub 2} depended on whether plants received urine-hits and were clipped: plants only had increased growth in response to CO{sub 2} enrichment if they had received urea and were not clipped. Plants that received the entire grazing treatment (urea and clipping) had biomass and productivity values that were similar to controls. Thus, grazing mammals will tend to dampen the predicted CO{sub 2} effect in grasslands by significantly lowering increases in plant growth response to elevated CO{sub 2} levels.

OSTI ID:
95905
Report Number(s):
CONF-9507129-; ISSN 0012-9623; TRN: 95:004728-0174
Journal Information:
Bulletin of the Ecological Society of America, Vol. 76, Issue 2; Conference: 80. anniversary of the transdisciplinary nature of ecology, Snowbird, UT (United States), 30 Jul - 3 Aug 1995; Other Information: PBD: Jun 1995
Country of Publication:
United States
Language:
English