title: An ecoclimatic framework for evaluating the resilience of vegetation to water deficit.
abstract: The surge in global efforts to understand the causes and consequences of drought on forest ecosystems has tended to focus on specific impacts such as mortality. We propose an ecoclimatic framework that takes a broader view of the ecological relevance of water deficits, linking elements of exposure and resilience to cumulative impacts on a range of ecosystem processes. This ecoclimatic framework is underpinned by two hypotheses: (i) exposure to water deficit can be represented probabilistically and used to estimate exposure thresholds across different vegetation types or ecosystems; and (ii) the cumulative impact of a series of water deficit events is defined by attributes governing the resistance and recovery of the affected processes. We present case studies comprising Pinus edulis and Eucalyptus globulus, tree species with contrasting ecological strategies, which demonstrate how links between exposure and resilience can be examined within our proposed framework. These examples reveal how climatic thresholds can be defined along a continuum of vegetation functional responses to water deficit regimes. The strength of this framework lies in identifying climatic thresholds on vegetation function in the absence of more complete mechanistic understanding, thereby guiding the formulation, application and benchmarking of more detailed modelling.
authors.affiliation: CSIRO Land and Water, 15 College Rd, Sandy Bay, TAS, 7005, Australia.
authors.forename: Patrick J
authors.initials: PJ
authors.lastname: Mitchell
authors.affiliation: CSIRO Land and Water, 15 College Rd, Sandy Bay, TAS, 7005, Australia.
authors.forename: Anthony P
authors.initials: AP
authors.lastname: O'Grady
authors.affiliation: CSIRO Land and Water, 15 College Rd, Sandy Bay, TAS, 7005, Australia.
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Pinkard
authors.affiliation: School of Biological Sciences, University of Tasmania, Private Bag 55, Hobart, TAS, 7005, Australia.
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Brodribb
authors.affiliation: School of Ecosystem and Forest Sciences, The University of Melbourne, 500 Yarra Boulevard, Richmond, VIC, 3121, Australia.
authors.forename: Stefan K
authors.initials: SK
authors.lastname: Arndt
authors.affiliation: Hawkesbury Institute for the Environment, Western Sydney University, Science Rd, Richmond, NSW, 2753, Australia.
authors.forename: Chris J
authors.initials: CJ
authors.lastname: Blackman
authors.affiliation: Hawkesbury Institute for the Environment, Western Sydney University, Science Rd, Richmond, NSW, 2753, Australia.
authors.forename: Remko A
authors.initials: RA
authors.lastname: Duursma
authors.affiliation: Queensland Herbarium, Environmental Protection Agency, Mount Coot-tha Road, Toowong, QLD, 4066, Australia.|School of Biological Sciences, University of Queensland, Chancellors Pl., St Lucia, QLD, 4072, Australia.
authors.forename: Rod J
authors.initials: RJ
authors.lastname: Fensham
authors.affiliation: CSIRO Ecosystem Sciences, Tropical Forest Research Centre, Atherton, QLD, 4883, Australia.
authors.forename: David W
authors.initials: DW
authors.lastname: Hilbert
authors.affiliation: School of Ecosystem and Forest Sciences, The University of Melbourne, 500 Yarra Boulevard, Richmond, VIC, 3121, Australia.
authors.forename: Craig R
authors.initials: CR
authors.lastname: Nitschke
authors.affiliation: Department of Environment, Land, Water and Planning, Victorian Government, Melbourne, VIC, 3000, Australia.
authors.forename: Jaymie
authors.initials: J
authors.lastname: Norris
authors.affiliation: CSIRO Land and Water, Clunies Ross St, Black Mountain, ACT, 2601, Australia.
authors.forename: Stephen H
authors.initials: SH
authors.lastname: Roxburgh
authors.affiliation: Centre of Excellence for Climate Change, Woodland and Forest Health, School of Veterinary and Life Sciences Murdoch University, 90 South St, Murdoch, WA, 6150, Australia.
authors.forename: Katinka X
authors.initials: KX
authors.lastname: Ruthrof
authors.affiliation: Hawkesbury Institute for the Environment, Western Sydney University, Science Rd, Richmond, NSW, 2753, Australia.
authors.forename: David T
authors.initials: DT
authors.lastname: Tissue
mesh_terms: D057231:Climate Change; D055864:Droughts; D005052:Eucalyptus / Q000502:physiology*; D065928:Forests; D028223:Pinus / Q000502:physiology*; D014197:Trees / Q000502:physiology
keywords: climate vulnerability; climatic thresholds; drought mortality; drought resistance; forest ecosystems; plant hydraulics; recruitment; resilience; tree die-off