Trophic compensation reinforces resistance: herbivory absorbs the increasing effects of multiple disturbances

Disturbance often results in small changes in community structure, but the probability of transitioning to contrasting states increases when multiple disturbances combine. Nevertheless, we have limited insights into the mechanisms that stabilise communities, particularly how perturbations can be abs...

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Bibliographic Details
Published in:Ecology Letters
Main Authors: Ghedini, G., Russell, B., Connell, S.
Other Authors: Mouillot, D.
Format: Article in Journal/Newspaper
Language:English
Published: Wiley 2015
Subjects:
Online Access:http://hdl.handle.net/2440/101398
https://doi.org/10.1111/ele.12405
Description
Summary:Disturbance often results in small changes in community structure, but the probability of transitioning to contrasting states increases when multiple disturbances combine. Nevertheless, we have limited insights into the mechanisms that stabilise communities, particularly how perturbations can be absorbed without restructuring (i.e. resistance). Here, we expand the concept of compensatory dynamics to include countervailing mechanisms that absorb disturbances through trophic interactions. By definition, ‘compensation’ occurs if a specific disturbance stimulates a proportional countervailing response that eliminates its otherwise unchecked effect. We show that the compounding effects of disturbances from local to global scales (i.e. local canopy-loss, eutrophication, ocean acidification) increasingly promote the expansion of weedy species, but that this response is countered by a proportional increase in grazing. Finally, we explore the relatively unrecognised role of compensatory effects, which are likely to maintain the resistance of communities to disturbance more deeply than current thinking allows. Giulia Ghedini, Bayden D. Russell and Sean D. Connell