• Alm Bergvall Ulrika
• Rautio Pasi
• Kesti Kari
• Tuomi Juha
• Leimar Olof

Oecologia

• Publish Date: Mar 2006
• ISSN: 0029-8549
• Volume: 147
• Issue: 2
• Pages: 253-60
• Medium: Print
• Language: English
• Citation (JAMA): Alm Bergvall Ulrika, Rautio Pasi, Kesti Kari, et al. Associational Effects of Plant Defences in Relation to Within- and Between-patch Food Choice by a Mammalian Herbivore: Neighbour Contrast Susceptibility and Defence.. Oecologia Mar 2006;147:253-60

Abstract

A basic idea of plant defences is that a plant should gain protection from its own defence. In addition, there is evidence that defence traits of the neighbouring plants can influence the degree of protection of an individual plant. These associational effects depend in part on the spatial scale of herbivore selectivity. A strong between-patch selectivity together with a weak within-patch selectivity leads to a situation where a palatable plant could avoid being grazed by growing in a patch with unpalatable plants, which is referred to as associational defence. Quite different associational effects will come about if the herbivore instead is unselective between patches and selective within a patch. We studied these effects in a manipulative experiment where we followed the food choice of fallow deer when they encountered two patches of overall different quality. One of the two patches consisted of pellets with low-tannin concentration in seven out of eight buckets and with high concentration in the remaining bucket. The other patch instead had seven high- and one low-tannin bucket. We performed the experiment both with individuals one at a time and with a group of 16-17 deer. We found that the deer were unselective between patches, but selective within a patch, and that the single low-tannin bucket among seven high-tannin buckets was used more than a low-tannin bucket among other low-tannin buckets. This corresponds to a situation where a palatable plant that grows among unpalatable plants is attacked more than if it was growing among its own kind, and for this effect we suggest the term neighbour contrast susceptibility, which is the opposite of associational defence. We also found that the high-tannin bucket in the less defended patch was less used than the high-tannin buckets in the other patch, which corresponds to neighbour contrast defence. The neighbour contrast susceptibility was present both for individual and group foraging, but the strength of the effect was somewhat weaker for groups due to weaker within-patch selectivity.

This abstract is part of PubMed, a service of the U.S. National Library of Medicine. PubMed includes more than 17 million citations from MEDLINE and other life science journals for biomedical articles. See Copyright and Disclaimers.

Linked medical terms appearing on this page are added by Healia to help readers find more information and are not part of the original PubMed document.

The data herein was last updated on July 8th, 2008 and may not reflect the most current and accurate data available from NLM.