Herbivore effects on plant species density at varying productivity levels

By:  and 



Artificially increasing primary productivity decreases plant species richness in many habitats; herbivory may affect this outcome, but it has rarely been directly addressed in fertilization studies. This experiment was conducted in two Louisiana coastal marshes to examine the effects of nutrient enrichment and sediment addition on herbaceous plant communities with and without vertebrate herbivory. After three growing seasons, fertilization increased community biomass in all plots, but decreased species density (the number of species per unit area) only in plots protected from herbivory. Herbivory alone did not alter species density at either site. At the brackish marsh, herbivory caused a shift in dominance in the fertilized plots from a species that is considered the competitive dominant, but is selectively eaten, to another less palatable species. At the fresh marsh, increased dead biomass in the absence of herbivory and in the fertilized plots probably contributed to the decrease in species density, perhaps by limiting germination of annuals. Our results support those of other fertilization studies in which plant species density decreases with increased biomass, but only in those plots protected from herbivory.

Study Area

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Herbivore effects on plant species density at varying productivity levels
Series title Ecology
DOI 10.1890/0012-9658(1998)079[1586:HEOPSD]2.0.CO;2
Volume 79
Issue 5
Year Published 1998
Language English
Publisher Ecological Society of America
Contributing office(s) National Wetlands Research Center
Description 9 p.
First page 1586
Last page 1594
Country United States
State Louisiana
Other Geospatial Pearl River Basin
Google Analytic Metrics Metrics page