A late-Holocene multiproxy fire record from a tropical savanna, eastern Arnhem Land, Northern Territory, Australia

Fire has a long history in Australia and is a key driver of vegetation dynamics in the tropical savanna ecosystems that cover one quarter of the country. Fire reconstructions are required to understand ecosystem dynamics over the long term but these data are lacking for the extensive savannas of northern Australia. This paper presents a multiproxy palaeofire record for Marura sinkhole in eastern Arnhem Land, Northern Territory, Australia. The record is constructed by combining optical methods (counts and morphology of macroscopic and microscopic charcoal particles) and chemical methods (quantification of abundance and stable isotope composition of pyrogenic carbon by hydrogen pyrolysis). This novel combination of measurements enables the generation of a record of relative fire intensity to investigate the interplay between natural and anthropogenic influences. The Marura palaeofire record comprises three main phases: 4600–2800 cal BP, 2800–900 cal BP and 900 cal BP to present. Highest fire incidence occurs at ~4600–4000 cal BP, coinciding with regional records of high effective precipitation, and all fire proxies decline from that time to the present. 2800–900 cal BP is characterised by variable fire intensities and aligns with archaeological evidence of occupation at nearby Blue Mud Bay. All fire proxies decline significantly after 900 cal BP. The combination of charcoal and pyrogenic carbon measures is a promising proxy for relative fire intensity in sedimentary records and a useful tool for investigating potential anthropogenic fire regimes.

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Distributional pattern of plant species endemic to the Northern Territory, Australia

Australian Journal of Botany ◽

10.1071/bt05041 ◽

2006 ◽

Vol 54 (7) ◽

pp. 627 ◽

Cited By ~ 32

Author(s):

J. C. Z. Woinarski ◽

C. Hempel ◽

I. Cowie ◽

K. Brennan ◽

R. Kerrigan ◽

...

Keyword(s):

Plant Species ◽

Endemic Species ◽

Fire Regimes ◽

Northern Territory ◽

Distributional Pattern ◽

Endemic Plant ◽

Convex Polygons ◽

Topographic Complexity ◽

Arnhem Land ◽

Endemic Plant Species

The distributions of the 567 plant species considered to be endemic to the Northern Territory, Australia, were collated from a distributional database comprising about 600 000 records. Endemic species comprise a non-random taxonomic subset of all plants known from the Northern Territory. Because of substantial geographic disparity in collecting effort, we analysed geographic patterning of these endemic species by using both (1) actual records only and (2) interpolated ranges (minimum convex polygons). The geographic distribution of the number of Northern Territory endemic plant species was well predicted by a measure of topographic complexity and climate (particularly rainfall). The observed distributional patterning of endemic species was also influenced by survey effort, but this latter influence was substantially reduced by the use of minimum convex polygons. Both analyses revealed that there was a clear aggregation of endemic species in the 32 000 km2 of the sandstone plateau of western Arnhem Land. This ‘hotspot’ has been previously recognised in coarser-scale assessments of national and international centres of plant biodiversity. Our analysis concluded that 172 species are restricted to this plateau, and that the plateau comprised at least 90% of the distribution of a further 25 species. More broadly, 438 plant species are endemic to the northern part of the Northern Territory (the 316 000 km2 north of 16°S), a level of endemism that may match that of Cape York Peninsula and surpasses that of the Kimberley. The core area for Northern Territory endemic plants, the plateau of western Arnhem Land, is currently threatened, particularly by unfavourable fire regimes.

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Isotopic fractionation from deep roots to tall shoots: A forensic analysis of xylem water isotope composition in mature tropical savanna trees

The Science of The Total Environment ◽

10.1016/j.scitotenv.2021.148675 ◽

2021 ◽

pp. 148675

Author(s):

Adriana M. Vega-Grau ◽

Jeffrey McDonnell ◽

Susanne Schmidt ◽

Mark Annandale ◽

John Herbohn

Keyword(s):

Isotope Composition ◽

Isotopic Fractionation ◽

Forensic Analysis ◽

Tropical Savanna ◽

Deep Roots ◽

Water Isotope

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The influence of prescribed fire on the extent of wildfire in savanna landscapes of western Arnhem Land, Australia

International Journal of Wildland Fire ◽

10.1071/wf10079 ◽

2012 ◽

Vol 21 (3) ◽

pp. 297 ◽

Cited By ~ 45

Author(s):

Owen F. Price ◽

Jeremy Russell-Smith ◽

Felicity Watt

Keyword(s):

Greenhouse Gas Emissions ◽

Greenhouse Gas ◽

Prescribed Fire ◽

Fire History ◽

Prescribed Burning ◽

Landsat Imagery ◽

Fire Regimes ◽

Dry Season ◽

Gas Emissions ◽

Arnhem Land

Fire regimes in many north Australian savanna regions are today characterised by frequent wildfires occurring in the latter part of the 7-month dry season. A fire management program instigated from 2005 over 24 000 km2 of biodiversity-rich Western Arnhem Land aims to reduce the area and severity of late dry-season fires, and associated greenhouse gas emissions, through targeted early dry-season prescribed burning. This study used fire history mapping derived mostly from Landsat imagery over the period 1990–2009 and statistical modelling to quantify the mitigation of late dry-season wildfire through prescribed burning. From 2005, there has been a reduction in mean annual total proportion burnt (from 38 to 30%), and particularly of late dry-season fires (from 29 to 12.5%). The slope of the relationship between the proportion of early-season prescribed fire and subsequent late dry-season wildfire was ~–1. This means that imposing prescribed early dry-season burning can substantially reduce late dry-season fire area, by direct one-to-one replacement. There is some evidence that the spatially strategic program has achieved even better mitigation than this. The observed reduction in late dry-season fire without concomitant increase in overall area burnt has important ecological and greenhouse gas emissions implications. This efficient mitigation of wildfire contrasts markedly with observations reported from temperate fire-prone forested systems.

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The carbon isotope composition of semi-labile and stable pyrogenic carbon in a thermosequence of C3 and C4 derived char

Organic Geochemistry ◽

10.1016/j.orggeochem.2015.01.008 ◽

2015 ◽

Vol 81 ◽

pp. 20-26 ◽

Cited By ~ 6

Author(s):

Christopher M. Wurster ◽

Anna V. McBeath ◽

Michael I. Bird

Keyword(s):

Carbon Isotope ◽

Isotope Composition ◽

Carbon Isotope Composition ◽

Pyrogenic Carbon

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Fire regime impacts on post-fire diurnal land surface temperature change over North American boreal forest

10.5194/egusphere-egu21-10702 ◽

2021 ◽

Author(s):

Jie Zhao ◽

Chao Yue ◽

Philippe Ciais ◽

Xin Hou ◽

Qi Tian

Keyword(s):

Climate Change ◽

Regression Analysis ◽

Land Surface ◽

Fire Regime ◽

Fire Severity ◽

Linear Regression Analysis ◽

Fire Regimes ◽

Fire Intensity ◽

Surface Temperature Change ◽

One Year

Wildfire is the most prevalent natural disturbance in the North American boreal (BNA) forest and can cause post-fire land surface temperature change (&#916;LSTfire) through biophysical processes. Fire regimes, such as fire severity, fire intensity and percentage of burned area (PBA), might affect &#916;LSTfire through their impacts on post-fire vegetation damage. However, the difference of the influence of different fire regimes on the &#916;LSTfire has not been quantified in previous studies, despite ongoing and projected changes in fire regimes in BNA in association with climate change. Here we employed satellite observations and a space-and-time approach to investigate diurnal &#916;LSTfire one year after fire across BNA. We further examined potential impacts of three fire regimes (i.e., fire intensity, fire severity and PBA) and latitude on &#916;LSTfire by simple linear regression analysis and multiple linear regression analysis in a stepwise manner. Our results demonstrated pronounced asymmetry in diurnal &#916;LSTfire, characterized by daytime warming in contrast to nighttime cooling over most BNA. Such diurnal &#916;LSTfire also exhibits a clear latitudinal pattern, with stronger daytime warming and nighttime cooling one year after fire in lower latitudes, whereas in high latitudes fire effects are almost neutral. Among the fire regimes, fire severity accounted for the most (43.65%) of the variation of daytime &#916;LSTfire, followed by PBA (11.6%) and fire intensity (8.5%). The latitude is an important factor affecting the influence of fire regimes on daytime &#916;LSTfire. The sensitivity of fire intensity and PBA impact on daytime &#916;LSTfire decreases with latitude. But only fire severity had a significant effect on nighttime &#916;LSTfire among three fire regimes. Our results highlight important fire regime impacts on daytime &#916;LSTfire, which might play a critical role in catalyzing future boreal climate change through positive feedbacks between fire regime and post-fire surface warming.

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Fungi and fire in Australian ecosystems: a review of current knowledge, management implications and future directions

Australian Journal of Botany ◽

10.1071/bt10059 ◽

2011 ◽

Vol 59 (1) ◽

pp. 70 ◽

Cited By ~ 37

Author(s):

Sapphire J. M. McMullan-Fisher ◽

Tom W. May ◽

Richard M. Robinson ◽

Tina L. Bell ◽

Teresa Lebel ◽

...

Keyword(s):

Fungal Community ◽

Large Scale ◽

Current Knowledge ◽

Vegetation Type ◽

Fire Regimes ◽

Trophic Group ◽

Fire Intensity ◽

Specific Information ◽

Eastern Australia ◽

Essential Components

Fungi are essential components of all ecosystems in roles including symbiotic partners, decomposers and nutrient cyclers and as a source of food for vertebrates and invertebrates. Fire changes the environment in which fungi live by affecting soil structure, nutrient availability, organic and inorganic substrates and other biotic components with which fungi interact, particularly mycophagous animals. We review the literature on fire and fungi in Australia, collating studies that include sites with different time since fire or different fire regimes. The studies used a variety of methods for survey and identification of fungi and focussed on different groups of fungi, with an emphasis on fruit-bodies of epigeal macrofungi and a lack of studies on microfungi in soil or plant tissues. There was a lack of replication of fire treatment effects in some studies. Nevertheless, most studies reported some consequence of fire on the fungal community. Studies on fire and fungi were concentrated in eucalypt forest in south-west and south-eastern Australia, and were lacking for ecosystems such as grasslands and tropical savannahs. The effects of fire on fungi are highly variable and depend on factors such as soil and vegetation type and variation in fire intensity and history, including the length of time between fires. There is a post-fire flush of fruit-bodies of pyrophilous macrofungi, but there are also fungi that prefer long unburnt vegetation. The few studies that tested the effect of fire regimes in relation to the intervals between burns did not yield consistent results. The functional roles of fungi in ecosystems and the interactions of fire with these functions are explained and discussed. Responses of fungi to fire are reviewed for each fungal trophic group, and also in relation to interactions between fungi and vertebrates and invertebrates. Recommendations are made to include monitoring of fungi in large-scale fire management research programs and to integrate the use of morphological and molecular methods of identification. Preliminary results suggest that fire mosaics promote heterogeneity in the fungal community. Management of substrates could assist in preserving fungal diversity in the absence of specific information on fungi.

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A new species of the genus Microlestodes Baehr from Arnhem Land, Northern Territory, Australia (Insecta: Coieoptera: Carabidae: Lebiini)

The Beagle : Records of the Museums and Art Galleries of the Northern Territory ◽

10.5962/p.287465 ◽

2010 ◽

Vol 26 ◽

pp. 103-107

Author(s):

Martin Baehr

Keyword(s):

New Species ◽

Northern Territory ◽

Arnhem Land ◽

A New Species

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Influence of prescribed burning on fruit production in Proteaceae

Pacific Conservation Biology ◽

10.1071/pc100046 ◽

2010 ◽

Vol 16 (1) ◽

pp. 46 ◽

Cited By ~ 2

Author(s):

T. D. Penman ◽

S. H. Penman

Keyword(s):

Community Structure ◽

Reproductive Output ◽

Prescribed Burning ◽

Fire Regimes ◽

Fruit Production ◽

Management Tool ◽

Fire Intensity ◽

Term Study ◽

Long Term Study

Prescribed burning is applied worldwide as a forest management tool. It is broadly accepted that altered fire regimes can directly impact upon community structure and composition, but little is known about the indirect effects of altered fire regimes on the mechanisms that produce community-level changes such as changes to the reproductive output of individual plants, hence populations. We examined the reproductive output of four species of Proteaceae within a long term study site where disturbance histories for the last twenty years have been accurately recorded on 216 plots. Frequent fire was found to increase woody fruit production in Banksia marginata, but had no apparent effect on B. serrata, Hakea eriantha or H. sericea. Results of this study vary from a similar study which examined the effect of wildfires. The differences observed are likely to reflect the differing impacts of fire intensity on these species. Indirect changes in fruit production may result in changes in reproductive success of species which in turn may affect vegetation community structure and faunal habitat.

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