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Fire weather risk differs across rain forest–savanna boundaries in the humid tropics of north-eastern Australia
journal contribution
posted on 2023-05-17, 14:40 authored by Little, JK, Lynda PriorLynda Prior, Grant WilliamsonGrant Williamson, Williams, SE, David BowmanDavid BowmanAlternative stable state theory has been applied to understanding the control by landscape fire activity of pyrophobic tropical rain forest and pyrophytic eucalypt savanna boundaries, which are often separated by tall eucalypt forests.We evaluate the microclimate of three vegetation types across an elevational gradient and their relative fire risk as measured by McArthur’s Forest Fire Danger Index (FFDI). Microclimatic data were collected from rain forest, tall eucalypt forest and savanna sites on eight vegetation boundaries throughout the humid tropics in north Queensland over a 3-year period and were compared with data from a nearby meteorological station. There was a clear annual pattern in daily FFDI with highest values in the austral winter dry season and lowest values in the austral summer wet season. There was a strong association of the meteorological station FFDI values with those from the three vegetation types, albeit they were substantially lower. The rank order of FFDI values among the vegetation types decreased from savanna, tall eucalypt forest, then rain forest, a pattern that was consistent across each transect. Only very rarely would rain forest be flammable, despite being adjacent to highly flammable savannas. These results demonstrate the very strong effect of vegetation type on microclimate and fire risk, compared with the weak effect of elevation, consistent with a fire–vegetation feedback. This study is the first demonstration of how vegetation type influences microclimate and fire risk across a topographically complex tropical forest–savanna gradient.
History
Publication title
Austral EcologyVolume
37Issue
8Pagination
915-925ISSN
1442-9985Department/School
School of Natural SciencesPublisher
Wiley-Blackwell Publishing AsiaPlace of publication
155 Cremorne St, Richmond, VIC 3121 AustraliaRights statement
Copyright 2012 The AuthorsRepository Status
- Restricted