Study
Positive interactions in communities
Bertness, Mark D.; Callaway, Ragan
Trends in Ecology & Evolution, 1994
Argues that positive interactions between species — one improving conditions for another without requiring reciprocity — have been systematically under-studied relative to competition, and proposes that their importance should increase with physical stress and with consumer pressure.
- Studied in
- Plantae, Animalia
- Sample size
- synthesis across systems where neighbours improve conditions
Facilitation is widespread, particularly in physically stressful environments, and communities in such settings may be structured as much by amelioration as by competition.
What it means
The authors' reading, and ours. Where they differ, that difference is the point.
How the authors put it
Community ecology built on competition alone misses a class of interaction that dominates under stress.
How NatureHQ reads it
The record that names a gap in the discipline rather than a fact about a species. Ecology spent decades assuming the interaction between neighbouring organisms was competitive, and where two plants grew together the question asked was who was suppressing whom. The stress-gradient prediction is what made the alternative testable: if amelioration matters, its importance should rise as conditions get harsher, and that is a claim that can fail.
- A conceptual synthesis; the prediction it proposes required later testing.
- Facilitation and competition usually operate at once, and separating their net effect is difficult.
What this study is used for on NatureHQ
One study can inform several subjects. Here is everywhere this one is cited.
Published by: Cell PressPublished in a Cell Press journal.
doi.org/10.1016/0169-5347(94)90088-4
Checked against Crossref on 2026-09-28, and they agree on the title, the authors and the year.
NatureHQ summarises research in its own words and does not reproduce published text. Reviewed 2026-09-04.