Strong effects of weak interactions in ecological communities
- 1 March 1999
- journal article
- letter
- Published by Springer Science and Business Media LLC in Nature
- Vol. 398 (6725), 330-334
- https://doi.org/10.1038/18672
Abstract
The loss or removal of individual species can cause dramatic changes in communities1,2,3,4,5. Experiments indicate that in many communities only a few species will have such strong effects, whereas most will have weak effects owing to small per capita effects and/or low abundance3,6,7,8,9,10,11,12,13,14,15,16. But extinction of these ‘weak’ interactors could significantly alter natural communities because they play important stabilizing or ‘noise-dampening’ roles14,15,17,18,19,20,21,22,23. I demonstrate here that some ‘weak’ interactors may also be important by magnifying spatiotemporal variation in community structure. An analysis of published interaction strength data shows that the greatest variation in species effect occurred for the weakest interactions. A field experiment corroborates this and shows how indirect interactions can generate an inverse relationship between the mean and variance of a consumer's impact on its prey. When a species' effects are highly variable in sign and magnitude, they may average to seem weak over broad scales but be strong in local contexts. Thus, what is frequently considered to be ‘noise’ in species interaction data may be a critical part of the signal.Keywords
This publication has 26 references indexed in Scilit:
- The Influence of Island Area on Ecosystem PropertiesScience, 1997
- The Effects of Plant Composition and Diversity on Ecosystem ProcessesScience, 1997
- The value of biodiversityTrends in Ecology & Evolution, 1997
- Keystone Predation and Interaction Strength: Interactive Effects of Predators on Their Main PreyEcological Monographs, 1996
- Variable Predation: Effects of Whelks on a Mid‐Intertidal Successional CommunityEcological Monographs, 1996
- Food Web Complexity and Community DynamicsThe American Naturalist, 1996
- Hatch Density Variation of a Generalist Arthropod Predator: Population Consequenes and Community ImpactEcology, 1994
- Resource Enhancement by Indirect Effects of Grazers: Armored Catfish, Algae, and SedimentEcology, 1990
- Intertidal Landscapes: Disturbance and the Dynamics of PatternEcological Monographs, 1981
- A Note on Trophic Complexity and Community StabilityThe American Naturalist, 1969