Chemically mediated interactions between woody plants and browsing mammals.

Bryant, J.P.
Reichardt, P.B.
Clausen, T.P.
Rangeland Ecology & Management / Journal of Range Management Archives
Publication Year: 
A diverse array of secondary metabolites deters feeding by mammals on woody plants. However, not all secondary metabolites are equally deterrent and the potencies of these substances as antifeedants is related to their structures. Although the physiological reason underlying deterrence by secondary metabolites is not well understood, the available evidence indicates that toxicity is more important than digestion inhibition. Resource limitation influences the production of secondary metabolites by woody plants. Species that are adapted to unproductive habitats are more chemically defended than species that are adapted to productive habitats. Resource limitation also affects the phenotypic expression of chemical defense with nutrient stress favoring increased production of carbon-based secondary metabolites and reduced production of nitrogen-containing secondary metabolites. Light stress has the opposite effects on the production of these substances. Herbivory by mammals also affects the chemical defenses of woody plants. In some cases browsing results in increased defense and in others decreased defense. Three circumstances under which browsing by mammals can change the chemical defenses of woody plants are discussed.
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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