Fire frequency variation in south-eastern Tasmanian dry eucalypt forest 1740–2004 from fire scars

Abstract

An understanding of fire history is important in determining appropriate fire management regimes for biodiversity conservation in fire-prone ecosystems, such as the dry eucalypt forests of temperate Australia. We tested whether ring counts and evidence of fire in the stumps of felled eucalypts could be used to construct fire chronologies in the dry forests of south-eastern Tasmania. Given that the dates of fires derived from this method were consistent with other evidence of fire years, we constructed chronologies for 13 sites in the region. We applied a conversion factor for fires per decade per site based on the relationship between fire detection and sample size for all sites. Between 17 40 and 1819 when indigenous people were managing the region, decadal fire frequency averaged 0. 7. Between 1820 and 1849 fires were very infrequent in the region, with a mean decadal fire frequency of 0.4. An upward transition to a higher fire frequency took place between the 1840s and 1850s. Between 1850 and 1909 decadal fire frequency varied between 0.8 and 1.2 then sharply increased again. Between 1910 and 1989 it varied between 1.3 and 1.7. Extensive fire years were strongly related to annual precipitation <0.75 standard deviations below the mean. Variation in annual precipitation, however, could not explain the sharp transitions in decadal fire frequency that took place in 1820, 1850, 191 0 and 1990 and the constancy of fire frequency between these dates. The relationships of these transitions to land use changes are described.

Organic soils provide evidence of spatial variation in human‐induced vegetation change following European occupation of Tasmania

“…A coincidence of change in land use with fire regime change and vegetation change has been observed elsewhere. In eastern Tasmania, fires became very infrequent with the disruption and destruction of Tasmanian Aboriginal land use between the beginning of the Black War in 1826 and the mid-1830s (von Platen et al, 2011). Between 1850 and 1990, fires were more frequent than under indigenous management (von Platen et al, 2011).…”

“…In eastern Tasmania, fires became very infrequent with the disruption and destruction of Tasmanian Aboriginal land use between the beginning of the Black War in 1826 and the mid-1830s (von Platen et al, 2011). Between 1850 and 1990, fires were more frequent than under indigenous management (von Platen et al, 2011). In New Zealand, there was a massive loss of forest associated with burning after the invasions of both Maori and Pakeha (Wardle, 1991;McGlone & Wilmshurst, 1999).…”

“…The removal of populations of hunter-gatherers from the Tasmanian mainland, as a whole, occurred in the 1830s (Plomley, 1966). There was an immediate reduction in the incidence of fire (Fletcher & Thomas, 2010b;von Platen et al, 2011). While historical and pollen records suggest that the coast became less used by people (Macphail et al, 1999;Fletcher & Thomas, 2010b), the interior of western Tasmania soon became a 'trampled wilderness' (Gowlland & Gowlland, 1976).…”

Fire regime and vegetation change in the transition from Aboriginal to European land management in a Tasmanian eucalypt savanna

“…Broadly, there are two different approaches to reconstruction of past environments: environmental history, stemming from the humanities; and historical ecology from the sciences (Bowman 2002). The former relies on interpretation of historical documents and images Bowman 2002;Butzer and Helgren 2005;Mactaggart et al 2007;Gammage 2008) and the latter, environmental reconstructions using a range of proxies, the most important being dendrochronology (Banks 1982;von Platen et al 2011) and pollen and charcoal in sediments (Swetnam et al 1999;Whitlock and Larsen 2001;Turner and Plater 2004;Higuera et al 2005;Black et al 2007). These approaches are not mutually exclusive, indeed sometimes they motivate and inform each other, and can be effectively merged to provide more robust reconstructions of vegetation cover (Fensham 1989;Batek et al 1999;Benson and Howell 2002;Lunt 2002).…”

Incorporating governance influences into social-ecological system models: a case study involving biodiversity conservation

“…Lowland grassland ecosystems and associated species are well adapted to frequent low level burning events, but are likely to be adversely affected by frequent high intensity fires (Lunt et al 2012). A study of the nearby Eastern Tiers showed that fire events have become less frequent in recent decades, and this has been driven in part by changing community attitudes to fires and the need to ensure protection of assets, including forest plantations (von Platen et al 2011).…”