title: Feedbacks and landscape-level vegetation dynamics.
abstract: Alternative stable-state theory (ASS) is widely accepted as explaining landscape-level vegetation dynamics, such as switches between forest and grassland. This theory argues that webs of feedbacks stabilise vegetation composition and structure, and that abrupt state shifts can occur if stabilising feedbacks are weakened. However, it is difficult to identify stabilising feedback loops and the disturbance thresholds beyond which state changes occur. Here, we argue that doing this requires a synthetic approach blending observation, experimentation, simulation, conceptual models, and narratives. Using forest boundaries and large mammal extinctions, we illustrate how a multifaceted research program can advance understanding of feedback-driven ecosystem change. Our integrative approach has applicability to other complex macroecological systems controlled by numerous feedbacks where controlled experimentation is impossible.
authors.affiliation: School of Biological Sciences, University of Tasmania, Hobart, Tasmania 7001, Australia. Electronic address: david.bowman@utas.edu.au.
authors.forename: David M J S
authors.initials: DM
authors.lastname: Bowman
authors.affiliation: School of Environment, University of Auckland, Private Bag 92019, Auckland, New Zealand; School of Biological Sciences, University of Auckland, Private Bag 92019, Auckland, New Zealand.
authors.forename: George L W
authors.initials: GL
authors.lastname: Perry
authors.affiliation: Department of Physics, Brown University, Providence, RI 02912-1843, USA.
authors.forename: J B
authors.initials: JB
authors.lastname: Marston
mesh_terms: D000818:Animals; D017753:Ecosystem; D053476:Extinction, Biological; D005246:Feedback; D005390:Fires; D065928:Forests; D060434:Herbivory; D008322:Mammals; D008962:Models, Theoretical
keywords: causality; ecosystem dynamics; explanation; feedbacks; fire; landscape ecology; macroecology; megafauna; modelling; savanna boundary