Carbon and nitrogen dynamics in elk winter ranges.

Author: 
Menezes, R.S.C.
Elliott, E.T.
Valentine, D.W.
Williams, S.A.
Publisher: 
Rangeland Ecology & Management / Journal of Range Management Archives
Publication Year: 
2001
Description: 
Recent increases in elk (Cervus elaphus L.) herbivory and changes in hydrology towards drier conditions have contributed to declines in willow (Salix spp. L.) communities in the winter ranges for elk in Rocky Mountain National Park. In 1994, we constructed 12 large elk exclosures in 2 watersheds of the winter range for elk in the park, and conducted field experiments from 1995 to 1999 to investigate the effects of herbivory and proximity to surface water on the dynamics of C and N. Litterfall biomass averaged 65.6 and 33.0 g m(-2) inside and outside the exclosures, respectively. Elk herbivory increased (P < 0.05) N concentration of willow litter from 1.25 to 1.49%, but there were no differences in losses of C and N from litterbags placed in grazed and ungrazed plots in any of the growing seasons. Carbon losses from litterbags were higher in lower landscape positions (P = 0.001), in comparison to upper landscape positions. Shoot biomass of willow plants fertilized with N averaged 27.3 g and was higher (P < 0.05) than that of unfertilized plants, which averaged 20.2 g, indicating that N availability limits plant growth in our study sites. Elk herbivory had no effect on soil inorganic N availability, even though we estimated that the return of N to the soil in grazed plots could be as much as 265% of the N return in exclosed plots. In the long-term, greater return of N to the soil combined with increased litter quality in the grazed plots could contribute to increases in N cycling rates and availability, and these changes could affect ecosystem structure and function in the winter range for elk in Rocky Mountain National Park.DOI:10.2458/azu_jrm_v54i4_menezes
Document Type: 
Journal Issue/Article
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Rangeland Ecology & Management (formerly the Journal of Range Management) serves as a forum for the presentation and discussion of facts, ideas, and philosophies pertaining to the study, management, ecology, and use of rangelands and their resources. The journal is peer-reviewed and provides international exchange of scholarly research and information among persons interested in rangelands. The Global Rangelands collection includes REM content up to 5 years from the current year. More recent content is available by subscription from BioOne and the Society for Range Management, and may be available at your local university library.
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