Cause and effects of a megafire in sedge-heathland in the Tasmanian temperate wilderness

2016 ◽  
Vol 64 (6) ◽  
pp. 513 ◽  
Author(s):  
Ben J. French ◽  
Lynda D. Prior ◽  
Grant J. Williamson ◽  
David M. J. S. Bowman
Keyword(s):  
Prescribed Burning ◽  
Fire Severity ◽  
Stand Age ◽  
Temperate Region ◽  
Early 19Th Century ◽  
European Settlement ◽  
Eucalypt Forest ◽  
Regeneration Response ◽  
Whole Plants ◽  
Aboriginal Burning

The World Heritage wilderness of south-western Tasmania contains a complex vegetation mosaic of eucalypt forest, myrtaceous scrub and fire-sensitive rainforest embedded in highly flammable sedge–heathland. Aboriginal burning shaped this temperate region for millennia, and large, severe wildfires have prevailed since European settlement in the early 19th century. In 2013, the Giblin River fire burnt 45 000 ha of wilderness, most of which was sedge-heathland. We surveyed the fire footprint, and an adjacent management burn, to investigate the drivers of fire severity in sedge-heathland and to assess the regeneration response of woody vegetation and how these were influenced by antecedent fire histories. Analyses based on multi-model inference identified time since fire as the most important driver of sedge-heathland fire severity, as measured by diameter of burnt twigs. Mortality was high for both main stems (98%) and whole plants (91%), with only 16% of dead stems resprouting. Resprouting and seedling establishment were little affected by fire severity. The value of prescribed burning in reducing both the extent and severity of wildfires in the south-western Tasmanian landscape, and in maintaining stand-age heterogeneity, is illustrated by the wildfire having self-extinguished on the boundary of the management burn.

scholarly journals Fire-severity mitigation by prescribed burning assessed from fire-treatment encounters in maritime pine stands

2019 ◽  
Vol 49 (2) ◽  
pp. 205-211 ◽  
Author(s):  
Juncal Espinosa ◽  
Pedro Palheiro ◽  
Carlos Loureiro ◽  
Davide Ascoli ◽  
Assunta Esposito ◽  
...  
Keyword(s):  
Prescribed Burning ◽  
Fire Severity ◽  
Regression Tree ◽  
Stem Bark ◽  
Maritime Pine ◽  
Site Quality ◽  
Stand Age ◽  
Fire Control ◽  
Crown Scorch ◽  
Pine Stands

Maritime pine (Pinus pinaster Ait.) stands are prone to high-intensity fire. Fuel treatments lessen potential fire behaviour and severity, but evidence of their effectiveness when tested by wildfire is extremely scarce in Europe. We assess the longevity of prescribed burning in maritime pine plantations in decreasing fire severity. Heights of crown scorch and stem-bark char were measured in treated and untreated adjacent areas after fire-treatment encounters in Portugal, Italy, and Australia. Treatment effect was quantified as the log-transformed ratio between prescribed-burned and untreated fire-severity data. Linear mixed modelling indicated that for typical wildfire conditions, the effect of prescribed burning in crown scorch height lasts 2–6 years. The persistence of prescribed burning benefits is higher for fire control operations than for fire-severity mitigation. Regression tree analysis of data from one wildfire highlighted the roles of wind direction, topography, and stand height in explaining variability in fire severity. A 4-year interval between prescribed burning treatments in maritime pine stands is recommended in general, depending on site quality and stand age and structure. Improved fuel-consumption prescriptions and monitoring procedures are advisable to foster prescribed-burning effectiveness and its evaluation.

scholarly journals Fire severity and ecosystem resilience – lessons from the Wombat Fire Effects Study (1984-2003)

2012 ◽  
Vol 124 (1) ◽  
pp. 30
Author(s):  
Kevin G. Tolhurst
Keyword(s):  
Prescribed Fire ◽  
Fire Severity ◽  
Fire Effects ◽  
Royal Commission ◽  
Mixed Species ◽  
Terrestrial Mammals ◽  
Low Intensity ◽  
Eucalypt Forest ◽  
Fire Characteristics ◽  
Understorey Plants

The Wombat Fire Effects Study was established to address a number of questions in relation to the effects of repeated low-intensity fires in mixed species eucalypt forest in the foothills of Victoria. This study has now been going for 25 years and has included the study of understorey plants, fuels, bats, terrestrial mammals, reptiles, invertebrates, fungi, birds, soils, tree growth, fire behaviour and weather. This forest system has shown a high resilience to fire that is attributed here to the patchiness and variability in the fire characteristics within a fire and the relatively small proportion of the landscape being affected. A means of comparing the level of “injury” caused by low-intensity prescribed fire with high intensity wildfire is proposed so that the debate about leverage benefits (the reduction in wildfire area compared to the area of planned burning) can be more rational. There are some significant implications for assessing the relative environmental impacts of wildfire compared with the planned burning program being implemented in Victoria since the Victorian Bushfires Royal Commission recommendations (Teague et al. 2010).

Nitrogen and phosphorus cycling following prescribed burning in natural and managed Aleppo pine forests

1999 ◽  
Vol 29 (8) ◽  
pp. 1237-1247 ◽  
Author(s):  
D Gillon ◽  
C Houssard ◽  
J C Valette ◽  
E Rigolot
Keyword(s):  
Forest Floor ◽  
Prescribed Burning ◽  
Pinus Halepensis ◽  
Fire Severity ◽  
Nutrient Balance ◽  
Pine Needles ◽  
Aleppo Pine ◽  
Slight Reduction ◽  
Nitrogen And Phosphorus ◽  
Natural Stand

Two prescribed burnings (downhill and uphill fires) were conducted in two stands of Aleppo pine (Pinus halepensis Mill.): a natural stand and a managed stand that was subject to thinning, pruning, and shrub removal. The concentrations of nitrogen (N) and phosphorus (P) in the pine needles and regrowth of the main shrub species, Quercus coccifera L., and the quantities of N and P in the needle fall and in the forest floor were measured during the 6 months following the fires. The concentrations of N and P in the pine needles and leaves of Q. coccifera increased compared with the unburned control after both fires in the natural stand, where there was only a slight reduction in fuel during prescribed burnings and where there was an abundant fall of scorched needles. In contrast, the chemical composition of the foliage was unchanged after the fires in the managed stand, where there was a greater reduction in fuel, and where only small quantities of scorched needles fell. This study showed that first opening prescribed burnings (natural stand) were less severe in terms of nutrient balance than maintenance prescribed burnings (managed stand) and that the forest floor reduction was a good indicator of fire severity.

Heterogeneity in fire severity within early season and late season prescribed burns in a mixed-conifer forest

2006 ◽  
Vol 15 (1) ◽  
pp. 37 ◽  
Author(s):  
Eric E. Knapp ◽  
Jon E. Keeley
Keyword(s):  
Sierra Nevada ◽  
Prescribed Burning ◽  
Fire Severity ◽  
Basal Area ◽  
Conifer Forest ◽  
Fuel Loading ◽  
Early Season ◽  
Late Season ◽  
Fuel Loads ◽  
In Fire

Structural heterogeneity in forests of the Sierra Nevada was historically produced through variation in fire regimes and local environmental factors. The amount of heterogeneity that prescription burning can achieve might now be more limited owing to high fuel loads and increased fuel continuity. Topography, woody fuel loading, and vegetative composition were quantified in plots within replicated early and late season burn units. Two indices of fire severity were evaluated in the same plots after the burns. Scorch height ranged from 2.8 to 25.4 m in early season plots and 3.1 to 38.5 m in late season plots, whereas percentage of ground surface burned ranged from 24 to 96% in early season plots and from 47 to 100% in late season plots. Scorch height was greatest in areas with steeper slopes, higher basal area of live trees, high percentage of basal area composed of pine, and more small woody fuel. Percentage of area burned was greatest in areas with less bare ground and rock cover (more fuel continuity), steeper slopes, and units burned in the fall (lower fuel moisture). Thus topographic and biotic factors still contribute to the abundant heterogeneity in fire severity with prescribed burning, even under the current high fuel loading conditions. Burning areas with high fuel loads in early season when fuels are moister may lead to patterns of heterogeneity in fire effects that more closely approximate the expected patchiness of historical fires.

“Careless fires” and “smoaky weather”: The documentation of prescribed burning in the Peace–Athabasca trading post journals 1818–1899

2011 ◽  
Vol 87 (03) ◽  
pp. 414-419 ◽  
Author(s):  
Theresa Ferguson
Keyword(s):  
Prescribed Burning ◽  
Contextual Analysis ◽  
Prescribed Fires ◽  
Ethnographic Research ◽  
Northern Alberta ◽  
Journal Entries ◽  
Aboriginal Burning

An examination of a series of trade post journals from northern Alberta shows how the recording of prescribed fires was shaped by the foci of these brief journal entries. Contextual analysis of these records informed by previous ethnographic research on local Aboriginal burning suggests 1) that prescribed fires that were both routine and carried out at some distance from the post were not likely to be recorded, and 2) that the Aboriginal “careless fires” that threatened or appeared to threaten post property were in fact prescribed fires.

Prescribed-fire effects on fine-root and tree mortality in old-growth ponderosa pine

1991 ◽  
Vol 21 (5) ◽  
pp. 626-634 ◽  
Author(s):  
D. Michael Swezy ◽  
James K. Agee
Keyword(s):  
Ponderosa Pine ◽  
Tree Mortality ◽  
Prescribed Burning ◽  
Fine Root ◽  
Soil Depth ◽  
Fire Severity ◽  
Dry Weight ◽  
Prescribed Burn ◽  
Old Growth ◽  
Root Dry Weight

Old-growth Pinusponderosa Dougl. stands were surveyed at Crater Lake National Park to investigate potential accelerated mortality of large pines due to prescribed burning. Mortality of P. ponderosa greater than 22 cm diameter at breast height was higher in burned areas (19.5%) than in unburned areas (6.6%), and early-season burns had over 30% mortality. Mortality was associated with fire severity, as measured by scorch height and ground char, season of burning, and tree vigor. Pines of high, moderate, and low vigor were subjected to a prescribed burn in June; half of the trees had debris raked from tree bases as an additional treatment. Lethal heat loads (>60 °C) occurred in >75% of samples at the soil surface and at 5 cm soil depth, with duration exceeding 5 h. Burning reduced fine-root dry weight 50–75% 1 and 5 months after burning; raking and burning reduced fine-root dry weight more than burning alone after 1 month and had similar effects to burning after 5 months. A low-vigor tree that had been raked and burned died by the beginning of the fourth dry season after burning. Present fuel loads may be too high to burn during spring if old-growth P. ponderosa are to be protected.

Fire regime and vegetation change in the transition from Aboriginal to European land management in a Tasmanian eucalypt savanna

2016 ◽  
Vol 64 (5) ◽  
pp. 427 ◽  
Author(s):  
Louise M. Romanin ◽  
Feli Hopf ◽  
Simon G. Haberle ◽  
David M. J. S. Bowman
Keyword(s):  
Vegetation Change ◽  
Fire Regime ◽  
Plantago Lanceolata ◽  
Sediment Cores ◽  
Open Water ◽  
Fire Regimes ◽  
Ecological Impacts ◽  
14C Dating ◽  
Early 19Th Century ◽  
European Settlement

Using pollen and charcoal analysis we examined how vegetation and fire regimes have changed over the last 600 years in the Midlands of Tasmania. Sediment cores from seven lagoons were sampled, with a chronology developed at one site (Diprose Lagoon) using 210Pb and 14C dating. Statistical contrasts of six cores where Pinus served as a marker of European settlement in the early 19th Century and showed significant changes in pollen composition following settlement with (a) influx of ruderal exotic taxa including Plantago lanceolata L., Brassicaceae, Asteraceae (Liguliflorae) and Rumex, (b) increase in pollen of the aquatics Myriophyllum spp. and Cyperaceae, (c) a decline in native herbaceous pollen taxa, including Chenopodiaceae and Asteraceae (Tubuliflorae) and (d) a decline in Allocasuarina and an initial decline and then increase of Poaceae. The presence of Asteraceae (Liguliflorae) in the pre-European period suggests that an important root vegetable Microseris lanceolata (Walp.) Sch.Bip. may have been abundant. Charcoal deposition was low in the pre-European period and significantly increased immediately after European arrival. Collectively, these changes suggest substantial ecological impacts following European settlement including cessation of Aboriginal traditions of fire management, a shift in hydrological conditions from open water lagoons to more ephemeral herb covered lagoons, and increased diversity of alien herbaceous species following pasture establishment.

The interactive effects of surface-burn severity and canopy cover on conifer and broadleaf tree seedling ecophysiology

2014 ◽  
Vol 44 (9) ◽  
pp. 1032-1041 ◽  
Author(s):  
Sheel Bansal ◽  
Till Jochum ◽  
David A. Wardle ◽  
Marie-Charlotte Nilsson
Keyword(s):  
Boreal Forest ◽  
Prescribed Burning ◽  
Fire Severity ◽  
Canopy Structure ◽  
Forest Tree ◽  
Interactive Effects ◽  
Burn Severity ◽  
Tree Seedling ◽  
Clear Cutting ◽  
Surface Burn

Fire has an important role for regeneration of many boreal forest tree species, and this includes both wildfire and prescribed burning following clear-cutting. Depending on the severity, fire can have a variety of effects on above- and below-ground properties that impact tree seedling establishment. Very little is known about the impacts of ground fire severity on post-fire seedling performance, or how the effects of fire severity interact with those of canopy structure. We conducted a full-factorial experiment that manipulated surface-burn severity (no burn; light, medium, or heavy burn; or scarification) and canopy (closed forest or open clear-cut) to reveal their interactive effects on ecophysiological traits of establishing broadleaf and conifer seedlings in a Swedish boreal forest. Medium and heavy surface burns increased seedling growth, photosynthesis, respiration, and foliar N and P concentrations, and these effects were most apparent in open clear-cuts. Growth rates of all species responded similarly to surface-burn treatments, although photosynthesis, foliar P, and specific leaf area were more responsive to burning treatments for broadleaf species than for conifers. Our study demonstrates that the positive impacts of fire on tree seedling physiology are dependent on a minimum severity threshold and are more effective when combined with clear-cutting.

Sign in / Sign up

Export Citation Format

Share Document