Australian grassland fire danger using inputs from the GRAZPLAN grassland simulation model

2010 ◽  
Vol 19 (3) ◽  
pp. 338 ◽  
Author(s):  
A. Malcolm Gill ◽  
Karen J. King ◽  
Andrew D. Moore

Assessing and broadcasting the Fire Danger Rating each day of the fire season is an important activity in fire-prone nations. For grasslands in Australia, grass curing and biomass are biological variables that are not usually archived yet as inputs, along with weather data, to the calculation of Grassland Fire Danger Index (GFDI) and potential fire intensity. To assess past changes in the index, the biological inputs for GFDI for Canberra in south-eastern Australia were obtained using a pasture simulator, GRAZPLAN. Shoot biomass (including leaf litter) and grass curing were modelled using three contrasting pasture models (exotic annual, exotic perennial and native perennial) in order to calculate two variants of McArthur’s GFDI Mark 4 (the original and a modified version which includes fuel load); values were either capped at 100 as in the original (the ‘worst possible’ condition) or left open-ended. GFDI, and the potential fire intensity for fires burning with the wind each afternoon during a 54-year period were calculated. The native perennial grass model gave contrasting results to those from the exotic perennial grass model, whereas the annual grass model usually was intermediate in behaviour. GRAZPLAN outputs allow not only retrospective examination, but also provide a basis for predicting potential fire danger and behaviour as a result of climate change.

2002 ◽  
Vol 11 (4) ◽  
pp. 183 ◽  
Author(s):  
J. D. Carlson ◽  
Robert E. Burgan ◽  
David M. Engle ◽  
Justin R. Greenfield

This paper describes the Oklahoma Fire Danger Model, an operational fire danger rating system for the state of Oklahoma (USA) developed through joint efforts of Oklahoma State University, the University of Oklahoma, and the Fire Sciences Laboratory of the USDA Forest Service in Missoula, Montana. The model is an adaptation of the National Fire Danger Rating System (NFDRS) to Oklahoma, but more importantly, represents the first time anywhere that NFDRS has been implemented operationally using hourly weather data from a spatially dense automated weather station network (the Oklahoma Mesonet). Weekly AVHRR satellite imagery is also utilized for live fuel moisture and fuel load calculations. The result is a near-real-time mesoscale fire danger rating system to 1-km resolution whose output is readily available on the World Wide Web (http://agweather.mesonet.ou.edu/models/fire). Examples of output from 25 February 1998 are presented.The Oklahoma Fire Danger Model, in conjunction with other fire-related operational tools, has proven useful to the wildland fire management community in Oklahoma, for both wildfire anticipation and suppression and for prescribed fire activities. Instead of once-per-day NFDRS information at two to three sites, the fire manager now has statewide fire danger information available at 1-km resolution at up to hourly intervals, enabling a quicker response to changing fire weather conditions across the entire state.


2012 ◽  
Vol 21 (6) ◽  
pp. 695 ◽  
Author(s):  
Karen J. King ◽  
Geoffrey J. Cary ◽  
A. Malcolm Gill ◽  
Andrew D. Moore

Climate and fuel characteristics influence fire regimes, and both need to be realistically considered in bushfire projections. Previous south-eastern Australian studies have assumed maximum grassland fuel curing (100%) and average fuel load (4.5 t ha–1). This study is the first to include daily fuel curing and load dynamics, derived from the agricultural pasture growth model GRAZPLAN, in projections of Grassland Fire Danger Index (GFDI) and potential fire-line intensity for future climate–CO2 combinations, and for alternate grasslands in the Canberra, Sydney and Melbourne regions. Climate-change projections were characterised by warmer, drier conditions, with atmospheric CO2 concentrations increasing for longer future timeframes. Projected shifts in GFDI and potential fire-line intensity arising from future climate–CO2 combinations were small compared with initial difference arising from using realistic GRAZPLAN-derived curing and fuel load values (compared with constant curing and fuel load) for grass dynamics, and this has important implications for the interpretation of earlier studies. Nevertheless, future grass curing and GFDI generally increased and fuel load generally decreased. The net effect on modelled future fire-line intensity was minimal because higher fire danger, and hence spread rate, was often largely compensated for by lower fuel load across the range of modelled grassland types and locations.


2007 ◽  
Vol 16 (5) ◽  
pp. 531 ◽  
Author(s):  
Patrice Savadogo ◽  
Didier Zida ◽  
Louis Sawadogo ◽  
Daniel Tiveau ◽  
Mulualem Tigabu ◽  
...  

Fuel characteristics, fire behaviour and temperature were studied in relation to grazing, dominant grass type and wind direction in West African savanna–woodland by lighting 32 prescribed early fires. Grazing significantly reduced the vegetation height, total fuel load, and dead and live fuel fractions whereas plots dominated by perennial grasses had higher values for vegetation height, total fuel load and the quantity of live fuel load. Although fire intensity remained insensitive (P > 0.05) to any of these factors, fuel consumption was significantly (P = 0.021) reduced by grazing, rate of spread was faster in head fire (P = 0.012), and flame length was shorter in head fire than back fire (P = 0.044). The average maximum temperature was higher (P < 0.05) on non-grazed plots, on plots dominated by annual grasses, on plots subjected to head fire, and at the soil surface. Lethal temperature residence time showed a nearly similar trend to fire temperature. Wind speed and total fuel load were best predictors of fire behaviour parameters (R2 ranging from 0.557 to 0.862). It can be concluded that grazing could be used as a management tool to modify fire behaviour, back fire should be carried out during prescribed burning to lower fire severity, and the fire behaviour models can be employed to guide prescribed early fire in the study area.


2011 ◽  
Vol 59 (1) ◽  
pp. 70 ◽  
Author(s):  
Sapphire J. M. McMullan-Fisher ◽  
Tom W. May ◽  
Richard M. Robinson ◽  
Tina L. Bell ◽  
Teresa Lebel ◽  
...  

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.


2004 ◽  
Vol 13 (1) ◽  
pp. 17 ◽  
Author(s):  
S. D. Jones ◽  
M. F. Garvey ◽  
G. J. Hunter

Models of wildfire threat are often used in the management of fire-prone areas for purposes such as planning fire education campaigns and the deployment of fire prevention and suppression resources. While the use of spatial or geographic data is common to all wildfire threat models, the key question arises: Is the accuracy of the spatial data used in wildfire threat models sufficient for the intended decision-making purpose? To help answer this question, a quantitative uncertainty assessment technique was applied to a wildfire threat model used by the Country Fire Authority in Victoria, Australia. The technique simulates known or estimated spatial data error by modifying data values to represent the range of all probable errors present in the input dataset. The wildfire threat model is then run multiple times using these modified ‘error’ layers in order to simulate and observe the effect these errors have on the model outputs. For the model concerned, the results suggest that errors in digital elevation surfaces have only minimal impact upon the outputs, resulting in relatively stable wildfire management decisions. On the other hand inaccuracies in land cover maps (with implied differences in fuel load estimations) result in larger changes in the model outputs, whereas changes in fire weather data can result in highly unstable outputs. Knowledge of these effects can facilitate better wildfire management since any improvements that are to be made to the model’s accuracy can be focussed directly upon the problem datasets.


2006 ◽  
Vol 46 (4) ◽  
pp. 439 ◽  
Author(s):  
W. McG. King ◽  
P. M. Dowling ◽  
D. L. Michalk ◽  
D. R. Kemp ◽  
G. D. Millar ◽  
...  

Temperate perennial grass-based pastures dominate the high rainfall zone of south-eastern Australia and support a major livestock production industry. This area has experienced a recent change in overall pasture condition, however, typified by a reduction in the abundance of perennial grasses and an increasingly prominent winter-annual grass weed component. Improving the condition and productivity of these pastures can be achieved by improved management but this requires better knowledge of the interactions between management options and pasture species composition and of the interaction between pasture vegetation and the complex effects of a heterogeneous landscape. This paper reports the results of an intensive survey of a 60-ha paddock that was designed to identify the species present, determine their patterns of distribution and examine the relationships between pasture vegetation and the environment. The survey of species present in late summer was supplemented by the identification of seedlings that later emerged from extracted soil cores and by soil physical and chemical analyses. Data were analysed using ordination and interpreted with GIS software so that topographic features could be considered. The most frequently identified taxa were Hypochaeris radicata, Austrodanthonia spp. and Bothriochloa spp. (in late summer) and Vulpia spp., Bromus molliformis and Trifolium subterraneum (winter-annual species). Austrodanthonia spp. were commonly found on the drier ridges and more acid soils with lower phosphate levels. These were also the areas dominated in spring by Vulpia spp. and were generally lower in plant species richness overall. The most species-rich areas occurred downslope where soil fertility was higher and less moisture stress was presumably experienced. The measured environmental factors explained a substantial proportion of the variation in the vegetation dataset, which underlined the importance of considering landscape effects in the management of typical tablelands pastures.


2007 ◽  
Vol 58 (12) ◽  
pp. 1167 ◽  
Author(s):  
R. J. Eckard ◽  
D. F. Chapman ◽  
R. E. White

Nitrogen (N) fertiliser use on dairy pastures in south-eastern Australia has increased exponentially over the past 15 years. Concurrently, imports of supplementary feed onto dairy farms have increased, adding further nutrients to the system. These trends raise questions about the environmental effects of higher nutrient inputs to dairy farms. To gauge possible effects, annual N balances were calculated from an experiment where N inputs and losses were measured for 3 years from non-irrigated grass/clover pastures receiving either no N fertiliser (Control) or 200 kg N/ha applied annually as ammonium nitrate or urea. Estimated total N inputs, averaged over the 3 years, were 154, 314, and 321 kg N/ha.year for the control, ammonium nitrate, and urea treatments, respectively, while N outputs in meat and milk were 75, 99, and 103 kg N/ha.year, respectively. The corresponding calculated N surplus was 79, 215, and 218 kg N/ha.year for the 3 treatments, respectively, and the ratio of product N/total-N inputs for the 3 treatments ranged from 50% in the control to 32% for both N treatments. Total N losses averaged 56, 102, and 119 kg N/ha.year, leaving a positive N balance of 23, 112, and 99 kg N/ha.year for the control, ammonium nitrate, and urea treatments, respectively. The ratio of product N/total-N inputs or the N surplus may be useful in monitoring the efficiency of conversion of N into animal products and the potential environmental effect at a whole-farm scale. However, additional decision support or modelling tools are required to provide information on specific N losses for a given set of conditions and management inputs. Given the large range in N losses there is opportunity for improving N-use efficiency in dairy pastures through a range of management practices and more tactical use of grain and N fertiliser.


2014 ◽  
Vol 65 (8) ◽  
pp. 767 ◽  
Author(s):  
M. L. Mitchell ◽  
J. M. Virgona ◽  
J. L. Jacobs ◽  
D. R. Kemp

Microlaena (Microlaena stipoides var. stipoides (Labill.) R.Br.) is a C3 perennial grass that is native to areas of south-eastern Australia. In this region, perennial grasses are important for the grazing industries because of their extended growing season and persistence over several years. This series of experiments focused on the population biology of Microlaena by studying the phenology (when seed was set), seed rain (how much seed was produced and where it fell), seed germination, germinable seedbank, seed predation and seedling recruitment in a pasture. Experiments were conducted at Chiltern, in north-eastern Victoria, on an existing native grass pasture dominated by Microlaena. Seed yields were substantial (mean 800 seeds m–2), with seed rain occurring over December–May. Microlaena has two distinct periods of high seed rain, in early summer and in early autumn. Seed predation is high. Within a 24-h period during peak seed production, up to 30% of Microlaena seed was removed from a pasture, primarily by ants. Microlaena seedlings recruited throughout an open paddock; however, seedling density was low (5 seedlings m–2). Microlaena represented only low numbers in the seedbank (0.01–0.05% of total); hence, any seedlings of Microlaena that germinate from the seedbank would face immense competition from other species. Management strategies for Microlaena-dominant pastures need to focus on the maintenance of existing plants.


2020 ◽  
Vol 12 (11) ◽  
pp. 1803 ◽  
Author(s):  
Mahlatse Kganyago ◽  
Lerato Shikwambana

This study analysed the characteristics of the recent (2018–2019) wildfires that occurred in the USA, Brazil, and Australia using Moderate Resolution Imaging Spectroradiometer (MODIS) active fires (AF), fire radiative power (FRP, MW) and burned area (BA) products. Meteorological and environmental parameters were also analysed. The study found various patterns in the spatial distribution of fires, FRP and BA at the three sites, associated with various vegetation compositions, prevailing meteorological and environmental conditions and anthropogenic activities. We found significant fire clusters along the western and eastern coasts of the USA and Australia, respectively, while vastly distributed clusters were found in Brazil. Across all sites, significant fire intensity was recorded over forest cover (FC) and shrublands (SL), attributed to highly combustible tree crown fuel load characterised by leafy canopies and thin branches. In agreement, BA over FC was the highest in the USA and Australia, while Brazil was dominated by the burning of SL, characteristic of fire-tolerant Cerrado. The relatively lower BA over FC in Brazil can be attributed to fuel availability and proximity to highly flammable cover types such as cropland, SL and grasslands rather than fuel flammability. Overall, this study contributes to a better understanding of wildfires in various regions and the underlying environmental and meteorological causal factors, towards better wildfire disaster management strategies and habitat-specific firefighting.


2011 ◽  
Vol 50 (8) ◽  
pp. 1617-1626 ◽  
Author(s):  
Paul Fox-Hughes

AbstractHalf-hourly airport weather observations have been used to construct high-temporal-resolution datasets of McArthur Mark V forest fire danger index (FFDI) values for three locations in Tasmania, Australia, enabling a more complete understanding of the range and diurnal variability of fire weather. Such an understanding is important for fire management and planning to account for the possibility of weather-related fire flare ups—in particular, early in a day and during rapidly changing situations. In addition, climate studies have hitherto generally been able to access only daily or at best 3-hourly weather data to generate fire-weather index values. Comparison of FFDI values calculated from frequent (subhourly) observations with those derived from 3-hourly synoptic observations suggests that large numbers of significant fire-weather events are missed, even by a synoptic observation schedule, and, in particular, by observations made at 1500 LT only, suggesting that many climate studies may underestimate the frequencies of occurrence of fire-weather events. At Hobart, in southeastern Tasmania, only one-half of diurnal FFDI peaks over a critical warning level occur at 1500 LT, with the remainder occurring across a broad range of times. The study reinforces a perception of pronounced differences in the character of fire weather across Tasmania, with differences in diurnal patterns of variability evident between locations, in addition to well-known differences in the ranges of peak values observed.


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