title: Climate and landscape drivers of tree decline in a Mediterranean ecoregion.
abstract: Climate change and anthropogenic land use are increasingly affecting the resilience of natural ecosystems. In Mediterranean ecoregions, forests and woodlands have shown progressive declines in health. This study focuses on the decline of an endemic woodland tree species, Eucalyptus wandoo (wandoo), occurring in the biodiversity hotspot of southwest Western Australia. We determined the change in health of wandoo stands between 2002 and 2008 across its geographic and climatic range, and associated this change in health with non-biotic variables focusing on: (1) fragment metrics; (2) topography; (3) soil characteristics; and (4) climate. Only fragment metrics and climate variables were found to be significantly related to the observed change in health. Stands that were small with high perimeter/area ratios were found to be most sensitive to health declines. Recent increases in autumn temperatures and decreases in annual rainfall were negatively affecting health of wandoo most prominently in the low rainfall zone of its climatic range. Together, these results suggest the onset of range contraction for this ecologically important species, which is likely to be exacerbated by projected future changes in climate. Our results emphasize the importance of establishing monitoring programs to identify changes in health and decline trends early to inform management strategies, particularly in the sensitive Mediterranean ecoregions.
authors: State Centre of Excellence for Climate Change, Woodland and Forest Health, School of Environmental Science, Murdoch University 90 South Street, Murdoch, Western Australia, 6150, Australia.
authors: Niels C
authors: NC
authors: Brouwers
authors: Jack
authors: J
authors: Mercer
authors: Tom
authors: T
authors: Lyons
authors: Pieter
authors: P
authors: Poot
authors: Erik
authors: E
authors: Veneklaas
authors: Giles
authors: G
authors: Hardy
keywords: Climate change; Eucalyptus wandoo; die-off; dieback; forest canopy health; fragmentation; southwest Western Australia; tree crown health
references: Ecol Appl. 2011 Jun;21(4):1162-72
references: 21774421
references: Ecol Appl. 2007 Dec;17(8):2145-51
references: 18213958
references: PLoS One. 2009 Jul 29;4(7):e6392
references: 19641600
references: Trends Ecol Evol. 2009 Dec;24(12):694-701
references: 19695735
references: Science. 2009 Mar 6;323(5919):1344-7
references: 19265020
references: Ecol Lett. 2007 Oct;10(10):909-16
references: 17845291
references: Science. 2009 Jan 23;323(5913):521-4
references: 19164752
references: Proc Natl Acad Sci U S A. 2011 Jan 25;108(4):1474-8
references: 21220333