Title

A Meta-Analysis of Biotic Resistance to Exotic Plant Invasions

Document Type

Article

Journal/Book Title/Conference

Ecology Letters

Volume

7

Issue

10

Publisher

Wiley-Blackwell

Publication Date

2004

First Page

975

Last Page

989

DOI

10.1111/j.1461-0248.2004.00657.x

Abstract

Biotic resistance describes the ability of resident species in a community to reduce the success of exotic invasions. Although resistance is a well-accepted phenomenon, less clear are the processes that contribute most to it, and whether those processes are strong enough to completely repel invaders. Current perceptions of strong, competition-driven biotic resistance stem from classic ecological theory, Elton's formulation of ecological resistance, and the general acceptance of the enemies-release hypothesis. We conducted a meta-analysis of the plant invasions literature to quantify the contribution of resident competitors, diversity, herbivores and soil fungal communities to biotic resistance. Results indicated large negative effects of all factors except fungal communities on invader establishment and performance. Contrary to predictions derived from the natural enemies hypothesis, resident herbivores reduced invasion success as effectively as resident competitors. Although biotic resistance significantly reduced the establishment of individual invaders, we found little evidence that species interactions completely repelled invasions. We conclude that ecological interactions rarely enable communities to resist invasion, but instead constrain the abundance of invasive species once they have successfully established.

Comments

Originally published by Wiley-Blackwell. Publisher's HTML full text and PDF available through remote link.