Carbon exchange rates in grazed and ungrazed pastures of Wyoming.

摘要: The influence of cattle grazing on carbon cycling in the mixed grass prairie was investigated by measuring CO(2) exchange rate pastures with a 13 year history heavy or light and an ungrazed exclosure at High Plains Grasslands Research Station near Cheyenne, Wyo. In 1995, 1996 1997 closed system chamber, which covered 1 m(2) ground, used every 3 weeks from April to October measure midday rate. Green vegetation index (similar leaf area index), soil respiration rate, species composition, water content, temperature, air temperature were also measured relate rates treatments. Treatment differences varied among years, but overall early season (mid mid June) grazed higher (up 2.5 X) than exclosure. Higher associated earlier spring green-up pastures, as green index. As growing progressed, increased all more so exclosure, resulting occasionally 2 compared late season. Seasonal treatment not nor there substantial change composition due grazing. We hypothesize that may be better penetration warmer microclimate surface because less litter standing dead pastures. When measurements averaged over entire season, no difference between heavily grazed, lightly this ecosystem. DOI:10.2458/azu_jrm_v53i2_lecain