scholarly journals A framework for testing the influence of Aboriginal burning on grassy ecosystems in lowland, mesic south–eastern Australia

2016 ◽  
Vol 64 (8) ◽  
pp. 626 ◽  
Author(s):  
Paul W. Foreman

The complex interactions among climate, soils, fire and humans in the biogeography of natural grasslands has long been debated in Australia. On the one hand, ecological models assume the primacy of climate and soils. On the other, Aboriginal burning is hypothesised to have altered the entire continent since before the last glacial maximum. The present paper develops a framework to test for the ‘fingerprint’ of Aboriginal burning in lowland, mesic grassy ecosystems of south-eastern Australia, using ecological theory, and the ethno-historical record. It is clear that fire-stick farming was used to promote staple roots in south-eastern Australia and, in some instances, it has been shown to influence grassland–woodland boundaries. The framework comprises the following three evidence lines: (1) archival benchmarking and palaeoecology; (2) phytoecology; and (3) ethnology and archaeology. That fire-stick farming was likely instrumental in grassland formation and maintenance must be supported by evidence that shows that ‘natural’ grasslands exist in climatically–edaphically unexpected places, that fine-scale patterns and dynamics are at least partly due to fire and that the fire regime has been influenced by Aboriginal burning. Application of the framework indicated that widespread Aboriginal burning for staple foods likely extended the area of temperate grasslands and influenced their structure and function.

2020 ◽  
Vol 68 (4) ◽  
pp. 320
Author(s):  
Paul Foreman

The historic influence of human fire and the role of ‘top-down’ vs ‘bottom-up’ drivers on ecosystems globally is highly contested, and our knowledge of regime diversity is poor. This paper uses an early European account as a case study to describe Aboriginal fire history in south-eastern Australia based on links between fire and: grasslands, native foods and culture. The route and observations detailed in Assistant Protector William Thomas’ 1840 account of a journey led by Aborigines to Western Port, Victoria, were overlayed with grass-tree boundaries compiled from historic plans. The narrative provides direct evidence of up to moderate-scale and intensity burns (with minimal fine-scale patchiness), undertaken in the height of the dry season, opportunistically linked to rainfall. The fires targeted open grassy ‘plains’ to maintain and access preferred hunter-gathering grounds. A synthesis of the earliest records supports high frequency anthropogenic burning maintaining alternative vegetation states with dynamic boundaries on elevated alluvial plains and, in places, adjoining swamps. The narrative represents an important primary source for studying traditional society, including the description of a local historic fire regime (‘koyuga burning’). Establishing such a fire regime ‘benchmark’ has the potential to stimulate new interdisciplinary research around the complex processes controlling grass-tree patterns, and build confidence that fire-stick farming was potentially instrumental in grassland formation, and integral to grassland maintenance throughout this region.


2018 ◽  
Vol 27 (7) ◽  
pp. 447 ◽  
Author(s):  
Sarsha Gorissen ◽  
Matthew Greenlees ◽  
Richard Shine

Intense fire is a key threatening process for the endangered Blue Mountains water skink, Eulamprus leuraensis. This species is restricted to isolated, densely vegetated and waterlogged peat swamps in montane south-eastern Australia. We surveyed 11 swamps (5 unburnt, 6 burnt) over 2 years, before and after the intense spring bushfires of 2013, to quantify the fires’ impacts on these skinks, other lizards and the habitat upon which they depend. Trapping revealed no direct effect of fire on E. leuraensis populations, with skinks persisting in all burnt swamps. Fire modified ground vegetation, virtually eliminating live plants and the dense understorey. Despite the conflagration, vegetation regrowth was rapid with swamp habitat largely recovering in just over 1 year post-fire. Fire thus had only a transitory effect on lizard habitat and a non-significant impact on E. leuraensis numbers. Nonetheless, broader-scale analyses suggest a different story: skinks were more abundant in swamps that had experienced a longer time since major fire. Although the ability of this endangered reptile to survive even intense wildfires is encouraging, fire during prolonged dry periods or an intensified fire regime might imperil skink populations.


2014 ◽  
Vol 62 (4) ◽  
pp. 294 ◽  
Author(s):  
David Peacock ◽  
Ian Abbott

Since the European settlement of Australia in 1788, 25 mainland terrestrial mammal species have become extinct, more than on any other continent during this period. To determine if the causal factors are still active, it is necessary to better understand the species and their status preceding these regional extirpations or extinctions, and examine the historical record for clues to the cause(s) of these declines. From an extensive review of historical material, primarily newspaper accounts, we collated >2700 accounts of quolls. We discovered 36 accounts that demonstrate the propensity for quolls to become hyperabundant. The geographical distribution of accounts implies that most refer to Dasyurus viverrinus, but an account from Normanton district (Queensland) likely applies to D. hallucatus. More than 110 accounts demonstrate that disease/parasite epizootics occurred in south-eastern Australia, commencing on mainland Australia possibly in the goldfields region of Victoria in the 1850s, or in south-eastern South Australia and south-western Victoria in the mid to late 1860s, and implicate these as the initial primary factor in the regional extirpation of Australia’s quolls. The loss of D. viverrinus populations in south-eastern Australia was reportedly from population abundances and densities that were sporadically extraordinarily high, hence their loss appears more pronounced than previously suspected. Accounts describing the widespread, rapid and major loss of quolls suggest the possible involvement of several pathogens. Ectoparasites such as Uropsylla tasmanica and ticks appear to be described in detail in some accounts. A few others state comortality of Felis catus and Canis lupus familiaris, suggestive of a disease of either or both of these species, such as Canine Distemper Virus, a morbillivirus with a propensity to be non-host specific, that may have caused the decline of the quolls, perhaps vectored by the reported ectoparasites. We also collated 23 presumed independent accounts of cats negatively impacting quolls, two of which describe significant mortality, and three presumed independent accounts of fox predation. These highlight the capacity of both of these introduced predators to have reduced quoll distribution and abundance.


PLoS ONE ◽  
2020 ◽  
Vol 15 (11) ◽  
pp. e0242484
Author(s):  
Bang Nguyen Tran ◽  
Mihai A. Tanase ◽  
Lauren T. Bennett ◽  
Cristina Aponte

Wildfires have increased in size and frequency in recent decades in many biomes, but have they also become more severe? This question remains under-examined despite fire severity being a critical aspect of fire regimes that indicates fire impacts on ecosystem attributes and associated post-fire recovery. We conducted a retrospective analysis of wildfires larger than 1000 ha in south-eastern Australia to examine the extent and spatial pattern of high-severity burned areas between 1987 and 2017. High-severity maps were generated from Landsat remote sensing imagery. Total and proportional high-severity burned area increased through time. The number of high-severity patches per year remained unchanged but variability in patch size increased, and patches became more aggregated and more irregular in shape. Our results confirm that wildfires in southern Australia have become more severe. This shift in fire regime may have critical consequences for ecosystem dynamics, as fire-adapted temperate forests are more likely to be burned at high severities relative to historical ranges, a trend that seems set to continue under projections of a hotter, drier climate in south-eastern Australia.


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