title: Trophic compensation reinforces resistance: herbivory absorbs the increasing effects of multiple disturbances.
abstract: 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.
authors.affiliation: Southern Seas Ecology Laboratories, School of Biological Sciences and The Environment Institute, DX 650 418, The University of Adelaide, Adelaide, SA, 5005.
authors.forename: Giulia
authors.initials: G
authors.lastname: Ghedini
authors.forename: Bayden D
authors.initials: BD
authors.lastname: Russell
authors.forename: Sean D
authors.initials: SD
authors.lastname: Connell
mesh_terms: D000818:Animals; D044822:Biodiversity; D057231:Climate Change; D017753:Ecosystem; D005068:Eutrophication; D020387:Food Chain; D049851:Gastropoda / Q000502:physiology*; D060434:Herbivory; D044423:Kelp / Q000502:physiology*; D011157:Population Dynamics
keywords: climate change; compensatory; inertia; stressors; top-down