Small mammalian herbivore determines vegetation response to patchy nutrient inputs

Joanne L. Denyer, S. E. Hartley, E. A. John

Research output: Contribution to journalArticlepeer-review

Abstract

Nutrient inputs to plant communities are often spatially heterogeneous, for example those deriving from the dung and urine of large grazing animals. The effect of such localised elevation of nutrients on plant growth and composition has been shown to be modified by the grazing of large herbivores. However, there has been little work on interactions between small mammalian herbivores and such patchy nutrient inputs, even though these interactions are potentially of major significance for plant performance and community structure.

We examined the effect of simulated cattle urine deposition on the vegetation structure, above-ground biomass and species composition of chalk grassland within enriched patches. Short-term exclosures were used to determine whether a small herbivore (rabbit) would preferentially graze the vegetation in enriched patches and what impact this interaction would have on the performance of plants in such patches. Rabbit grazing pressure determined whether nutrient inputs had a negative or positive effect on plant biomass. Nutrients increased plant biomass in the absence of grazing, but when exposed to grazing, plants in nutrient-rich patches had more biomass consumed by herbivores than neighbouring plants. Further, nutrients increased the relative palatability of a less preferred forage species (Brachypodium pinnatum), contributing to changes in plant community composition. We conclude that a small herbivore can drive plant responses to patchily distributed nutrients.

Original languageEnglish
Pages (from-to)1186-1192
Number of pages7
JournalOikos
Volume116
Issue number7
DOIs
Publication statusPublished - Jul 2007

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