Access

You are not currently logged in.

Access your personal account or get JSTOR access through your library or other institution:

login

Log in to your personal account or through your institution.

Ungulate Effects on the Functional Species Composition of Plant Communities: Herbivore Selectivity and Plant Tolerance

David J. Augustine and Samuel J. McNaughton
The Journal of Wildlife Management
Vol. 62, No. 4 (Oct., 1998), pp. 1165-1183
Published by: Wiley on behalf of the Wildlife Society
DOI: 10.2307/3801981
Stable URL: http://www.jstor.org/stable/3801981
Page Count: 19
  • Download ($42.00)
  • Subscribe ($19.50)
  • Cite this Item
Ungulate Effects on the Functional Species Composition of Plant Communities: Herbivore Selectivity and Plant Tolerance
Preview not available

Abstract

Large mammalian herbivores not only depend on plant communities for their existence but cause major changes in plant community composition and structure. These changes have direct consequences for ecosystem processes, but recent studies of ungulate-ecosystem relations show widely divergent ungulate effects in different ecosystems. We reviewed studies of ungulate effects on plant community composition to gain insight into potential mechanisms of ungulate-induced changes in both community composition and ecosystem processes. Our analysis of these studies is based on the premise that the effect ungulates exert on plant communities depends on the balance between (1) feeding selectivity of herbivores (i.e., degree to which different plant species or ecotypes experience different levels of tissue loss), and (2) differences among plant species in their ability to recover from tissue loss. A large number of studies clearly show that selective ungulate herbivory leads to the dominance of unpalatable, chemically defended plant species in communities. However, many studies have also demonstrated that intensive long-term herbivory does not lead to the invasion of unpalatable species into the community, and can even increase the dominance of highly palatable species. Our review indicates that high levels of nutrient inputs or recycling and an intermittent temporal pattern of herbivory (often due to migration) are key factors increasing the regrowth capacity of palatable species and hence maintaining their dominance in plant communities supporting abundant herbivores. Key factors limiting ungulate foraging selectivity, again limiting herbivore-induced dominance of slow-growing, unpalatable species, include herding behavior, early growing season and postfire herbivory, asynchronous phenology of palatable versus unpalatable species, and low relative abundance of unpalatable species. Our review indicates differences among ecosystems in the role played by ungulate herbivory result from the relative strength of these factors enhancing plant tolerance to herbivory and limiting foraging selectivity. Anthropogenic changes in these factors (e.g., alteration of migration patterns) therefore have the potential to significantly alter the effects of ungulates on plant communities and ecosystem processes.

Page Thumbnails

  • Thumbnail: Page 
1165
    1165
  • Thumbnail: Page 
1166
    1166
  • Thumbnail: Page 
1167
    1167
  • Thumbnail: Page 
1168
    1168
  • Thumbnail: Page 
1169
    1169
  • Thumbnail: Page 
1170
    1170
  • Thumbnail: Page 
1171
    1171
  • Thumbnail: Page 
1172
    1172
  • Thumbnail: Page 
1173
    1173
  • Thumbnail: Page 
1174
    1174
  • Thumbnail: Page 
1175
    1175
  • Thumbnail: Page 
1176
    1176
  • Thumbnail: Page 
1177
    1177
  • Thumbnail: Page 
1178
    1178
  • Thumbnail: Page 
1179
    1179
  • Thumbnail: Page 
1180
    1180
  • Thumbnail: Page 
1181
    1181
  • Thumbnail: Page 
1182
    1182
  • Thumbnail: Page 
1183
    1183