Fire regimes and interval-sensitive vegetation in semiarid Gregory National Park, northern Australia

2010 ◽  
Vol 58 (4) ◽  
pp. 300 ◽  
Author(s):  
Jeremy Russell-Smith ◽  
Cameron P. Yates ◽  
Chris Brock ◽  
Vanessa C. Westcott

Few data are available concerning contemporary fire regimes and the responses of fire interval-sensitive vegetation types in semiarid woodland savanna landscapes of northern Australia. For a 10 300 km2 semiarid portion of Gregory National Park, in the present paper we describe (1) components of the contemporary fire regime for 1998–2008, on the basis of assessments derived from Landsat and MODIS imagery, (2) for the same period, the population dynamics, and characteristic fine-fuel loads associated with Acacia shirleyi Maiden (lancewood), an obligate seeder tree species occurring in dense monodominant stands, and (3) the fire responses of woody species, and fine-fuel dynamics, sampled in 41 plots comprising shrubby open-woodland over spinifex hummock grassland. While rain-year (July–June) rainfall was consistently reliable over the study period, annual fire extent fluctuated markedly, with an average of 29% being fire affected, mostly in the latter part of the year under relatively harsh fire-climate conditions. Collectively, such conditions facilitated short fire-return intervals, with 30% of the study area experiencing a repeat fire within 1 year, and 80% experiencing a repeat fire within 3 years. Fine fuels associated with the interior of lancewood thickets were characteristically small (<1 t ha–1). Fine fuels dominated by spinifex (Triodia spp.) were found to accumulate at rates equivalent to those observed under higher-rainfall conditions. Stand boundaries of A. shirleyi faired poorly under prevailing fire regimes over the study period; in 16 plots, juvenile density declined 62%, and adult stem density and basal area declined by 53% and 40%, respectively. Although the maturation (primary juvenile) period of A. shirleyi is incompletely known, assembled growth rate and phenology data indicated that it is typically >10 years. Of 133 woody species sampled, all trees (n = 26), with the exception of A. shirleyi, were resprouters, and 58% of all shrub species (n = 105) were obligate seeders, with observed primary juvenile periods <5 years. Assembled data generally supported observations made from other northern Australian studies concerning the responses of fire-sensitive woody taxa in rugged, sandstone-derived landscapes, and illustrated the enormous challenges facing ecologically sustainable fire management in such settings. Contemporary fire regimes of Gregory National Park are not ecologically sustainable.

2015 ◽  
Vol 24 (5) ◽  
pp. 712 ◽  
Author(s):  
Michael J. Lawes ◽  
Brett P. Murphy ◽  
Alaric Fisher ◽  
John C. Z. Woinarski ◽  
Andrew C. Edwards ◽  
...  

Small mammal (<2 kg) numbers have declined dramatically in northern Australia in recent decades. Fire regimes, characterised by frequent, extensive, late-season wildfires, are implicated in this decline. Here, we compare the effect of fire extent, in conjunction with fire frequency, season and spatial heterogeneity (patchiness) of the burnt area, on mammal declines in Kakadu National Park over a recent decadal period. Fire extent – an index incorporating fire size and fire frequency – was the best predictor of mammal declines, and was superior to the proportion of the surrounding area burnt and fire patchiness. Point-based fire frequency, a commonly used index for characterising fire effects, was a weak predictor of declines. Small-scale burns affected small mammals least of all. Crucially, the most important aspects of fire regimes that are associated with declines are spatial ones; extensive fires (at scales larger than the home ranges of small mammals) are the most detrimental, indicating that small mammals may not easily escape the effects of large and less patchy fires. Notwithstanding considerable management effort, the current fire regime in this large conservation reserve is detrimental to the native mammal fauna, and more targeted management is required to reduce fire size.


2003 ◽  
Vol 12 (4) ◽  
pp. 427 ◽  
Author(s):  
Andrew Edwards ◽  
Rod Kennett ◽  
Owen Price ◽  
Jeremy Russell-Smith ◽  
Greg Spiers ◽  
...  

We describe the rationale, methodology and preliminary results from a major monitoring program in Kakadu National Park, northern Australia. The program aims to assess fire regimes, their impacts upon biodiversity, and the consequences and efficacy of fire management. The program comprises two complementary elements—mapping of fire histories based upon interpretation of satellite imagery, and assessment of vegetation at a large series of permanent monitoring plots. The program commenced formally in 1995, at which time establishment and baseline sampling of vegetation in 134 plots was conducted, with re-sampling proposed at 5-year intervals up to 2010. The monitoring program has an estimated annual cost of about $A140�000 (around 1% of the total annual budget of the Park). Over the period 1995–2000, the mean annual extent of burning was 40.3%, a marginal reduction in extent from the previous 15 years, particularly for late dry season fires in lowland habitats. From the baseline (1995) and subsequent re-sampling (2000) of the vegetation plots, 963 plant taxa have been recorded. The power of the program to detect change in the frequency or abundance of individual species was poor, especially for ground-layer species, largely because of typically substantial variability in abundance across plots and sampling events, and because of the high proportion of species recorded from few samples. Notwithstanding this constraint, five tree species (of 47 recorded from sufficient samples to test), nine shrub species (from 121) and 27 ground-layer species (from 111) showed significant change in abundance between the baseline and subsequent sampling. However when species were grouped into strata and life-form categories, major changes were evident over this 5�year period, particularly with increases in cover of trees and shrubs. Such changes were related to a range of environmental and fire regime parameters of the plots, with increase in woody cover but reduction in cover and species richness of herbs in those plots experiencing lower frequency of fires.


Author(s):  
William Romme ◽  
James Walsh

Whitebark pine (Pinus albicaulis) is a keystone species of upper subalpine ecosystems (Tomback et al. 2001), and is especially important in the high-elevation ecosystems of the northern Rocky Mountains (Arno and Hoff 1989). Its seeds are an essential food source for the endangered grizzly bear (Ursus arctos horribilis), particularly in the autumn, prior to winter denning (Mattson and Jonkel 1990, Mattson and Reinhart 1990, Mattson et al. 1992). In the Greater Yellowstone Ecosystem (GYE), biologists have concluded that the fate of grizzlies is intrinsically linked to the health of the whitebark pine communities found in and around Yellowstone National Park (YNP) (Mattson and Merrill 2002). Over the past century, however, whitebark pine has severely declined throughout much of its range as a result of an introduced fungus, white pine blister rust (Cronartium ribicola) (Hoff and Hagle 1990, Smith and Hoffman 2000, McDonald and Hoff 2001), native pine beetle (Dendroctonus ponderosae) infestations (Bartos and Gibson 1990, Kendall and Keane 2001), and, perhaps in some locations, successional replacement related to fire exclusion and fire suppression (Amo 2001). The most common historical whitebark pine ftre regimes are "stand-replacement", and "mixed­ severity" regimes (Morgan et al. 1994, Arno 2000, Arno and Allison-Bunnell2002). In the GYE, mixed-severity ftre regimes have been documented in whitebark pine forests in the Shoshone National forest NW of Cody, WY (Morgan and Bunting 1990), and in NE Yellowstone National Park (Barrett 1994). In Western Montana and Idaho, mixed fire regimes have been documented in whitebark pine communities in the Bob Marshall Wilderness (Keane et al. 1994), Selway-Bitterroot Wilderness (Brown et al. 1994), and the West Bighole Range (Murray et al.1998). Mattson and Reinhart (1990) found a stand­replacing fire regime on the Mount Washburn Massif, within Yellowstone National Park.


2020 ◽  
Vol 9 (5) ◽  
pp. 333
Author(s):  
Nicole C. Inglis ◽  
Jelena Vukomanovic

Fire management in protected areas faces mounting obstacles as climate change alters disturbance regimes, resources are diverted to fighting wildfires, and more people live along the boundaries of parks. Evidence-based prescribed fire management and improved communication with stakeholders is vital to reducing fire risk while maintaining public trust. Numerous national fire databases document when and where natural, prescribed, and human-caused fires have occurred on public lands in the United States. However, these databases are incongruous and non-standardized, making it difficult to visualize spatiotemporal patterns of fire and engage stakeholders in decision-making. We created interactive decision analytics (“VISTAFiRe”) that transform fire history data into clear visualizations of the spatial and temporal dimensions of fire and its management. We demonstrate the utility of our approach using Big Cypress National Preserve and Everglades National Park as examples of protected areas experiencing fire regime change between 1980 and 2017. Our open source visualizations may be applied to any data from the National Park Service Wildland Fire Events Geodatabase, with flexibility to communicate shifts in fire regimes over time, such as the type of ignition, duration and magnitude, and changes in seasonal occurrence. Application of the tool to Everglades and Big Cypress revealed that natural wildfires are occurring earlier in the wildfire season, while human-caused and prescribed wildfires are becoming less and more common, respectively. These new avenues of stakeholder communication are allowing the National Park Service to devise research plans to prepare for environmental change, guide resource allocation, and support decision-making in a clear and timely manner.


2009 ◽  
Vol 39 (6) ◽  
pp. 1236-1246 ◽  
Author(s):  
H.M. Poulos ◽  
R.G. Gatewood ◽  
A.E. Camp

While piñon woodlands cover much of arid North America, surprisingly little is known about the role of fire in maintaining piñon forest structure and species composition. The lack of region-specific fire regime data for piñon–juniper woodlands presents a roadblock to managers striving to implement process-based management. This study characterized piñon–juniper fire regimes and forest stand dynamics in Big Bend National Park (BIBE) and the Davis Mountains Preserve of the Nature Conservancy (DMTNC) in west Texas. Mean fire return intervals were 36.5 and 11.2 years for BIBE and DMTNC, respectively. Point fire return intervals were 150 years at BIBE and 75 years at DMTNC. Tree regeneration in west Texas piñon–juniper woodlands occurred historically during favorable climatic conditions following fire years. The presence of multiple fire scars on our fire-scar samples and the multicohort stands of piñon suggested that low intensity fires were common. This study represents one of the few fire-scar-based fire regime studies for piñon–juniper woodlands. Our results differ from other studies in less topographically dissected landscapes that have identified stand-replacing fire as the dominant fire regime for piñon–juniper woodlands. This suggests that mixed-severity fire regimes are typical across southwestern piñon forests, and that topography is an important influence on fire frequency and intensity.


Author(s):  
Stephen Barrett ◽  
Stephen Arno

This study's goal is to document the fire history of the Lamar River drainage, southeast of Soda Butte Creek in the Absaroka Mountains of northeastern Yellowstone National Park (YNP). Elsewhere in YNP investigators have documented very long-interval fire regimes for lodgepole pine forests occurring on rhyolitic derived soils (Romme 1982, Romme and Despain 1989) and short-interval fire regimes for the Douglas-fir/grassland types (Houston 1973). No fire regime information was available for lodgepole pine forests on andesitic derived soils, such as in the Lamar drainage. This study will provide managers with a more complete understanding of YNP natural fire history, and the data will supplement the park's Geographic Information System (GIS) data base. Moreover, most of the study area was severely burned in 1988 and historical tree ring data soon will be lost to attrition of potential sample trees.


2006 ◽  
Vol 15 (3) ◽  
pp. 433 ◽  
Author(s):  
William L. Baker

Reconstructing fire regimes of the past can provide a valuable frame of reference for understanding the impact of human land uses on contemporary fire and forest structure, but methods for reconstructing past fire regimes are under re-evaluation. In the present article, a common method of characterizing surface fire regimes, using composite fire intervals from fire scars, is shown to significantly underestimate the length of the fire rotation and population mean fire interval in Grand Canyon landscapes where these parameters are known. Also, the evidence and interpretation that past high-severity fire was uncommon in ponderosa pine landscapes in Grand Canyon National Park are challenged. Together, these two concerns mean that an alternative characterization of the fire regime, which has very different implications, cannot be excluded. Management aimed at lowering fire risk, as a means of restoration, does not presently have a sound scientific basis, if it uses the composite fire interval as a measure of the fire regime or is based on fire history research that lacks adequate analysis of past high-severity fire.


2011 ◽  
Vol 20 (2) ◽  
pp. 223 ◽  
Author(s):  
Andrea E. Thode ◽  
Jan W. van Wagtendonk ◽  
Jay D. Miller ◽  
James F. Quinn

This paper quantifies current fire severity distributions for 19 different fire-regime types in Yosemite National Park, California, USA. Landsat Thematic Mapper remote sensing data are used to map burn severity for 99 fires (cumulatively over 97 000 ha) that burned in Yosemite over a 20-year period. These maps are used to quantify the frequency distributions of fire severity by fire-regime type. A classification is created for the resultant distributions and they are discussed within the context of four vegetation zones: the foothill shrub and woodland zone; the lower montane forest zone; the upper montane forest zone and the subalpine forest zone. The severity distributions can form a building block from which to discuss current fire regimes across the Sierra Nevada in California. This work establishes a framework for comparing the effects of current fires on our landscapes with our notions of how fires historically burned, and how current fire severity distributions differ from our desired future conditions. As this process is refined, a new set of information will be available to researchers and land managers to help understand how fire regimes have changed from the past and how we might attempt to manage them in the future.


2003 ◽  
Vol 12 (4) ◽  
pp. 283 ◽  
Author(s):  
Jeremy Russell-Smith ◽  
Cameron Yates ◽  
Andrew Edwards ◽  
Grant E. Allan ◽  
Garry D. Cook ◽  
...  

Considerable research has been undertaken over the past two decades to apply remote sensing to the study of fire regimes across the savannas of northern Australia. This work has focused on two spatial scales of imagery resolution: coarse-resolution NOAA-AVHRR imagery for savanna-wide assessments both of the daily distribution of fires ('hot spots'), and cumulative mapping of burnt areas ('fire-scars') over the annual cycle; and fine-resolution Landsat imagery for undertaking detailed assessments of regional fire regimes. Importantly, substantial effort has been given to the validation of fire mapping products at both scales of resolution. At the savanna-wide scale, fire mapping activities have established that: (1) contrary to recent perception, from a national perspective the great majority of burning in any one year typically occurs in the tropical savannas; (2) the distribution of burning across the savannas is very uneven, occurring mostly in sparsely settled, higher rainfall, northern coastal and subcoastal regions (north-west Kimberley, Top End of the Northern Territory, around the Gulf of Carpentaria) across a variety of major land uses (pastoral, conservation, indigenous); whereas (3) limited burning is undertaken in regions with productive soils supporting more intensive pastoral management, particularly in Queensland; and (4) on a seasonal basis, most burning occurs in the latter half of the dry season, typically as uncontrolled wildfire. Decadal fine-resolution fire histories have also been assembled from multi-scene Landsat imagery for a number of fire-prone large properties (e.g. Kakadu and Nitmiluk National Parks) and local regions (e.g. Sturt Plateau and Victoria River District, Northern Territory). These studies have facilitated more refined description of various fire regime parameters (fire extent, seasonality, frequency, interval, patchiness) and, as dealt with elsewhere in this special issue, associated ecological assessments. This paper focuses firstly on the patterning of contemporary fire regimes across the savanna landscapes of northern Australia, and then addresses the implications of these data for our understanding of changes in fire regime since Aboriginal occupancy, and implications of contemporary patterns on biodiversity and emerging greenhouse issues.


2020 ◽  
Author(s):  
Ramesh Glückler ◽  
Ulrike Herzschuh ◽  
Stefan Kruse ◽  
Andrei Andreev ◽  
Stuart Andrew Vyse ◽  
...  

Abstract. Wildfires, as a key disturbance in forest ecosystems, are shaping the world’s boreal landscapes. Changes in fire regimes are closely linked to a wide array of environmental factors, such as vegetation composition, climate change, and human activity. Arctic and boreal regions and, in particular, Siberian boreal forests are experiencing rising air and ground temperatures with the subsequent degradation of permafrost soils, leading to shifts in tree cover and species composition. Compared to the boreal zones of North America or Europe, little is known about how such environmental changes might influence long-term fire regimes in Russia. The larch-dominated eastern Siberian deciduous boreal forests differ markedly from the composition of other boreal forests, yet data about past fire regimes remain sparse. Here, we present a high-resolution macroscopic charcoal record from lacustrine sediments of Lake Khamra (SW Yakutia, Siberia) spanning the last c. 2200 years, including information about charcoal particle sizes and morphotypes. Our results reveal a phase of increased charcoal accumulation between 600–900 CE, indicative of relatively high amounts of burnt biomass and high fire frequencies. This is followed by an almost 900-year-long period of low charcoal accumulation without significant peaks, likely corresponding to cooler climate conditions. After 1750 CE fire frequencies and the relative amount of biomass burnt start to increase again, coinciding with a warming climate and increased anthropogenic land development after Russian colonisation. In the 20th century, total charcoal accumulation decreases again to very low levels, despite higher fire frequency, potentially reflecting a change in fire management strategies and/or a shift of the fire regime towards more frequent, but smaller fires. A similar pattern for different charcoal morphotypes and comparison to a pollen and non-pollen palynomorph record from the same sediment core indicate that broad-scale changes in vegetation composition were probably not a major driver of recorded fire regime changes. Instead, the fire regime of the last two millennia at Lake Khamra seems to be controlled mainly by a combination of short-term climate variability and anthropogenic fire ignition and suppression.


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