Publication Details

Category Text Publication
Reference Category Journals
DOI 10.1111/j.1365-2745.2012.02019.x
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Title (Primary) Differences between symmetric and asymmetric facilitation matter: exploring the interplay between modes of positive and negative plant interactions
Author Lin, Y.; Berger, U.; Grimm, V.; Ji, Q.-R.
Source Titel Journal of Ecology
Year 2012
Department OESA
Volume 100
Issue 6
Page From 1482
Page To 1491
Language englisch
Keywords asymmetry; competition; metabolic scaling theory; plant population and community dynamics; plant–plant interaction; self-thinning; spatial pattern; stress-gradient hypothesis; symmetry

  1. Facilitation (positive interaction) has received increasing attention in plant ecology over the last decade. Just as for competition, distinguishing different modes of facilitation (mutualistic, commensal or even antagonistic) may be crucial.
  2. We therefore introduce the new concept of symmetric versus asymmetric facilitation and present a generic individual-based zone-of-influence model. The model simultaneously implements different modes of both facilitation and competition among individual plants via their overlapping zone of influence. Because we consider facilitation modes as a continuum related to environmental context, we integrated this concept with the stress-gradient hypothesis (SGH) by exploring differences in spatial pattern formation in self-thinning plants along a stress gradient in our model.
  3. The interplay among modes of interaction creates distinctly varied spatial patterns along stress gradients. When competition was symmetric, symmetric facilitation (mutualism) consistently led to plant aggregation along stress gradients. However, asymmetric facilitation (commensalism) produces plant aggregation only under more benign conditions but tends to intensify local competition and spatial segregation when conditions are harsh. When competition was completely asymmetric, different modes of facilitation contributed little to spatial aggregation.
  4. Symmetric facilitation significantly increased survival at the severe end of the stress gradient, which supports the claim of the SGH that facilitation should have generally positive net effects on plants under high stress levels. Asymmetric facilitation, however, was found to increase survival only under intermediate stress conditions, which contradicts the current predictions of the SGH.
  5. Synthesis. Our modelling study demonstrates that the interplay between modes of facilitation and competition affects different aspects of plant populations and communities, implying context-dependent outcomes and consequences. The explicit consideration of the modes and mechanisms of interactions (both facilitation and competition) and the nature of stress factors will help to extend the framework of the SGH and foster research on facilitation in plant ecology.

Persistent UFZ Identifier
Lin, Y., Berger, U., Grimm, V., Ji, Q.-R. (2012):
Differences between symmetric and asymmetric facilitation matter: exploring the interplay between modes of positive and negative plant interactions
J. Ecol. 100 (6), 1482 - 1491 10.1111/j.1365-2745.2012.02019.x