Patterns of landscape fire and predicted vegetation response in the North Kimberley region of Western Australia

2003 ◽  
Vol 12 (4) ◽  
pp. 369 ◽  
Author(s):  
Rohan Fisher ◽  
Tom Vigilante ◽  
Cameron Yates ◽  
Jeremy Russell-Smith

The paper reports on the development of a decadal fire history, 1990–1999, derived from Landsat imagery, and associated assessment of landscape-scale patterns, in a remote, sparsely human-populated region of the high rainfall zone of monsoonal north-western Australia. The assembled fire history confirms observations, derived from coarser-scale imagery, that substantial areas of the North Kimberley are burnt each year. The annual mean extent of burning was 31% (albeit involving marked inter-annual variability), with most burning occurring in the latter part of the dry season under relatively severe fire weather conditions. Extent of burning was found to be associated with intensity of landuse; most burning occurred on pastoral lands, particularly in association with more fertile basalt soils. Based on previous modelling studies, predicted effects of contemporary fire regimes include increased development of woody regeneration size-classes, especially on non-basalt substrates. In contrast, on sandstone-derived substrata, fire interval data indicate that longer-lived obligate-seeder shrub species are likely to be suppressed and ultimately displaced by contemporary fire regimes. Such observations are supported by recent evidence of regional collapse of the long-lived obligate seeder tree species, Callitris intratropica. Collectively, assembled data point to the need to undertake a thorough appraisal of the status of regional biota in this remote, ostensibly ecologically intact region.


2009 ◽  
Vol 18 (6) ◽  
pp. 631 ◽  
Author(s):  
Aaron C. Greenville ◽  
Chris R. Dickman ◽  
Glenda M. Wardle ◽  
Mike Letnic

Implementing appropriate fire regimes has become an increasingly important objective for biodiversity conservation programs. Here, we used Landsat imagery from 1972 to 2003 to describe the recent fire history and current wildfire regime of the north-eastern Simpson Desert, Australia, within each of the region’s seven main vegetation classes. We then explored the relationship between antecedent rainfall and El Niño–Southern Oscillation with wildfire area. Wildfires were recorded in 11 years between 1972 and 2003, each differing in size. In 1975, the largest wildfire was recorded, burning 55% (4561 km2) of the study region. Smaller fires in the intervening years burnt areas that had mostly escaped the 1975 fire, until 2002, when 31% (2544 km2) of the study region burnt again. Wildfires burnt disproportionally more spinifex (Triodia basedowii) than any other vegetation class. A total of 49% of the study area has burnt once since 1972 and 20% has burnt twice. Less than 1% has burnt three times and 36% has remained unaffected by wildfire since 1972. The mean minimum fire return interval was 26 years. Two years of cumulative rainfall before a fire event, rainfall during the year of a fire event, and the mean Southern Oscillation Index from June to November in the year before a fire event could together be used to successfully predict wildfire area. We use these findings to describe the current fire regime.



2012 ◽  
Vol 21 (3) ◽  
pp. 297 ◽  
Author(s):  
Owen F. Price ◽  
Jeremy Russell-Smith ◽  
Felicity Watt

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.



1995 ◽  
Vol 2 (2) ◽  
pp. 191 ◽  
Author(s):  
Peter R. Mawson ◽  
John L. Long

Mail surveys were sent to field staff of the Agriculture Protection Board of Western Australia to assess the distribution and status of four species of parrot in the agricultural region of south-west Western Australia in 1970, 1980 and 1990. The surveys indicated that the populations of the Regent Parrot (Polytelis anthopeplus) and the Western Rosella (Platycercus icterotis) have declined in range considerably since 1970. The populations of the Red-capped Parrot (Purpureicephalus spurius) and the Port Lincoln Ringneck (Barnardius zonarius) have suffered little or not at all during the same period. Factors which appear to have contributed to the observed changes in distribution and status include clearing for agriculture, dietary preferences, physiology, habitat requirements, altered fire regimes, grazing by exotic herbivores and reduced winter rainfall. These surveys have shown that species which were formerly considered common and widespread have declined with little comment having been made of these changes. The implications of this are serious, both for these formerly common species and for rarer bird species which have similar ecological requirements. The technique of mail surveys has considerable merit for quickly assessing the status of some species of birds, but will be limited by the expertise of the respondents and the degree to which the species in question can be observed.



2007 ◽  
Vol 13 (3) ◽  
pp. 177 ◽  
Author(s):  
Owen Price ◽  
Bryan Baker

A nine year fire history for the Darwin region was created from Landsat imagery, and examined to describe the fire regime across the region. 43% of the region burned each year, and approximately one quarter of the fires occur in the late dry season, which is lower than most other studied areas. Freehold land, which covers 35% of the greater Darwin region, has 20% long-unburnt land. In contrast, most publicly owned and Aboriginal owned land has very high fire frequency (60-70% per year), and only 5% long unburnt. It seems that much of the Freehold land is managed for fire suppression, while the common land is burnt either to protect the Freehold or by pyromaniacs. Generalized Linear Modelling among a random sample of points revealed that fire frequency is higher among large blocks of savannah vegetation, and at greater distances from mangrove vegetation and roads. This suggests that various kinds of fire break can be used to manage fire in the region. The overall fire frequency in the Darwin region is probably too high and is having a negative impact on wildlife. However, the relatively low proportion of late dry season fires means the regime is probably not as bad as in some other regions. The management of fire is ad-hoc and strongly influenced by tenure. There needs to be a clear statement of regional fire targets and a strategy to achieve these. Continuation of the fire mapping is an essential component of achieving the targets.



2007 ◽  
Vol 29 (1) ◽  
pp. 1 ◽  
Author(s):  
A.N. Start ◽  
A.A.. Burbidge ◽  
N.L. McKenzie ◽  
C. Palmer

The mammalian fauna of the North Kimberley bioregion has been cited as ?intact? because 1970s and 1980s surveys showed that all terrestrial mammal species known at European settlement were extant. This assumption was tested in 2003/4 by re-surveying 16 of the most diverse sites sampled in earlier surveys of three mainland areas and four islands. Most Critical Weight Range species were re-located at many sites and some were found at sites where they were previously unknown. Most differences between early surveys and this survey are probably artifacts of limited survey intensity. However, the region is not exempt from processes associated with decline elsewhere, particularly effects of changed fire regimes and invasion by exotic species, and species of non-rocky habitats may be more vulnerable. Small granivorous rodents were notably scarce.



2008 ◽  
Vol 17 (1) ◽  
pp. 72 ◽  
Author(s):  
Cathy Whitlock ◽  
Jennifer Marlon ◽  
Christy Briles ◽  
Andrea Brunelle ◽  
Colin Long ◽  
...  

Pollen and high-resolution charcoal records from the north-western USA provide an opportunity to examine the linkages among fire, climate, and fuels on multiple temporal and spatial scales. The data suggest that general charcoal levels were low in the late-glacial period and increased steadily through the last 11 000 years with increasing fuel biomass. At local scales, fire occurrence is governed by the interaction of site controls, including vegetation, local climate and fire weather, and topography. At subregional scales, patterns in the long term fire-episode frequency data are apparent: The Coast Range had relatively few fires in the Holocene, whereas the Klamath–Siskiyou region experienced frequent fire episodes. Fire regimes in the northern Rocky Mountains have been strongly governed by millennial- and centennial-scale climate variability and regional differences in summer moisture. At regional scales, sites in present-day summer-dry areas show a period of protracted high fire activity within the early Holocene that is attributed to intensified summer drought in the summer-dry region. Sites in summer-wet areas show the opposite pattern, that fire was lower in frequency than present in the early Holocene as result of strengthened monsoonal circulation then. Higher fire-episode frequency at many sites in the last 2000 years is attributed to greater drought during the Medieval Climate Anomaly and possibly anthropogenic burning. The association between drought, increased fire occurrence, and available fuels evident on several time scales suggests that long-term fire history patterns should be considered in current assessments of historical fire regimes and fuel conditions.



2014 ◽  
Vol 20 (1) ◽  
pp. 57 ◽  
Author(s):  
Barbara A Wilson ◽  
Janine Kuehs ◽  
Leonie E Valentine ◽  
Tracy Sonneman ◽  
Kristen M Wolfe

In Mediterranean ecosystems prescribed burning is commonly employed to reduce the risk or intensity of wildfires. As a consequence, a major challenge for conservation land managers is the development of fire regimes that reduce damaging wildfires and are optimal for biodiversity. The aim of this paper was to develop guidelines for ecological fire regimes using the Banksia woodland on the Gnangara Groundwater System in Western Australia as a case study. Development of the guidelines involved the determination of maximum and minimum fire intervals of key fire response species, analyses of fire history records and estimation of ideal age class distributions at the landscape level. Recommendations included a) adoption of a minimum fire interval of 8–16 years, b) implementation of a burning regime to redress the current skewed distribution (60%: 1–7 years since last fire), c) retention of long-unburnt habitats that are significant for species such as the critically endangered Calyptorhynchus latirostris (Carnaby’s black-cockatoo), and Tarsipes rostratus (honey possum), and d) protection for wetlands that can serve as fire ‘refugia’ for associated species, such as Isoodon obesulus fusciventer (southern brown bandicoot or quenda). The guidelines developed provide a model for the development of ecological burning regimes in other similar ecosystems. The implementation of ecological guidelines normally involves incorporation into fire management planning by fire agencies and often entails complex solutions to conflicting aims. The guidelines are thus valuable for ecologists and land managers, especially in light of an expected significant increase in global fire activity as a consequence of predicted climate change.



2016 ◽  
Vol 64 (3) ◽  
pp. 198 ◽  
Author(s):  
Rosemary Hohnen ◽  
Katherine Tuft ◽  
Sarah Legge ◽  
Naomi Walters ◽  
Lucy Johanson ◽  
...  

Mammalian species in northern Australia are declining. The resources that many species from this region require to persist in the landscape remain poorly understood. We examined habitat selection and diet of the scaly-tailed possum (Wyulda squamicaudata, hereafter called Wyulda) in the north-west Kimberley, Western Australia, in relation to variation in complexity of rocky habitat, habitat heterogeneity, and recent fire history. We fitted GPS tags to 23 Wyulda between January 2013 and February 2014 and analysed step selection between GPS fixes to describe habitat choice. We assessed diet by microscopic analysis of plant fragments from 47 faecal samples. Individual Wyulda preferentially foraged in locations with high rock complexity and high habitat heterogeneity in a wide variety of habitats, but denned exclusively in complex rock piles. They used savannas of a range of post-fire ages, including recently burnt (1–2 months after fire) and long unburnt (>24 months after fire). They were highly frugivorous with, on average, 77% of plant fragments per scat sample identified as fruit epidermal layers. Overall, rock complexity appears to be an important landscape attribute for Wyulda, as it may provide den sites and protect fire-sensitive landscape features such as fruiting trees and habitat heterogeneity.



Fire ◽  
2018 ◽  
Vol 1 (3) ◽  
pp. 51
Author(s):  
Megan Ladbrook ◽  
Eddie J. B. van Etten ◽  
William D. Stock

This study investigates the fire regime for the arid Carnarvon Basin region of Western Australia using remotely sensed imagery. A fire history database was constructed from satellite images to characterise the general fire regime and determine any effect of vegetation types and pre-fire weather and climate. The study area was divided into two sections (northern and southern) due to their inherently different vegetation and climate. A total of 23.8% (15,646 km2) of the study area was burnt during the 39-year study period. Heathland vegetation (54%) burnt the most extensively in the southern study area, and hummock grasslands (68%) in the northern. A single, unusually large fire in 2012 followed exceptional rains in the previous 12 months and accounted for 55% of the total burnt area. This fire burnt mainly through Acacia shrublands and woodlands rather than hummock grasslands, as normally experienced in the northern study area. Antecedent rainfall and fire weather were found to be the main meteorological factors driving fire size. Both study areas showed a moderate to strong correlation between fire size and increased pre-fire rainfall in the year preceding the fire. Predicted future changes in climate may lead to more frequent and higher intensity fires.



Koedoe ◽  
2008 ◽  
Vol 50 (1) ◽  
Author(s):  
Greg G. Forsyth ◽  
Brian W. Van Wilgen

This paper provides an assessment of fire regimes in the Table Mountain National Park over the past four decades. We compiled a GIS database of all fires between 1970 and 2007 and analysed the fire regime in terms of the frequency, season and size of fires and the relationship between fire occurrence and fire weather. Most fires (90.5% of area burnt) occurred in summer and autumn, the ecologically acceptable season for fires. However, mean fire return intervals declined by 18.1 years, from 31.6 to 13.5 years, between the first and last decades of the record respectively. The area subjected to short (≤ six years) intervals between fires covered > 16% of the park in the last two decades of the record, compared to ~ 4% in the first two decades. A relatively small number of large fires dominated in terms of area burnt. Of the 373 fires recorded, 40 fires > 300 ha burnt 75% of the area, while 216 fires < 25 ha burnt 3.4% of the area. Fires occurred under a wide range of weather conditions, but large fires were restricted to periods of high fire danger. Prescribed burning was a relatively unimportant cause of fires, and most (> 85%) of the area burnt in wildfires. Areas subjected to short fire return intervals should be considered for management interventions. These could include the re-establishment of extirpated fire-sensitive species, the clearing of invasive alien plants and increased precautions for the prevention or rapid suppression of future accidental fires.



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