Consequences of season of prescribed burning on two spring-flowering terrestrial orchids and their endophytic fungi

2018 ◽  
Vol 66 (4) ◽  
pp. 298 ◽  
Author(s):  
N. U. Jasinge ◽  
T. Huynh ◽  
A. C. Lawrie
Keyword(s):  
Mycorrhizal Fungi ◽  
Prescribed Burning ◽  
Fire Risk ◽  
Fuel Load ◽  
Prescribed Burn ◽  
Seasonally Dry ◽  
Terrestrial Orchids ◽  
Different Seasons ◽  
Autumn And Winter ◽  
Smoke Water

Prescribed burning is mandated in seasonally dry regions of the world to reduce fuel load and fire risk. This study investigated the effects of prescribed burning at different seasons on two Australian terrestrial orchids (Glossodia major R.Br. and Thelymitra pauciflora R.Br.) and their orchid mycorrhizal fungi (OMF) to find the least damaging season for a burn. Burns were conducted mid-season in autumn, winter, spring and summer. Orchids were enumerated and measured and their OMF isolated during their flowering seasons. The OMF were grouped and identified using their internal transcribed spacer (ITS) regions and tested for sensitivity to smoke water. Orchid numbers decreased by up to 100% after autumn and winter burns but not spring and summer burns. Plant height, leaf and flower dimensions decreased between the two years. Fire reduced success in the isolation of OMF. The relative frequencies of ITS sequences of Serendipita Roberts from G. major (but not of Tulasnella asymmetrica Warcup and P.H.B. Talbot from Th. pauciflora) changed after burns. OMF from G. major were up to 100% inhibited by smoke water, twice the inhibition of the OMF from Th. pauciflora. Prescribed burning during active orchid growth damaged both the orchids and their OMF. The least damaging practical season for a prescribed burn was in late spring, soon after seed dispersal.

scholarly journals Quantitative Analysis of Forest Fires in Southeastern Australia Using SAR Data

2021 ◽  
Vol 13 (12) ◽  
pp. 2386
Author(s):  
Aqil Tariq ◽  
Hong Shu ◽  
Qingting Li ◽  
Orhan Altan ◽  
Mobushir Riaz Khan ◽  
...  
Keyword(s):  
Forest Fires ◽  
Prescribed Burning ◽  
Fire Risk ◽  
Fire Season ◽  
Prescribed Burn ◽  
Backscatter Coefficient ◽  
Prescribed Burns ◽  
Southeastern Australia ◽  
Sar Data ◽  
Sar Imagery

Prescribed burning is a common strategy for minimizing forest fire risk. Fire is introduced under specific environmental conditions, with explicit duration, intensity, and rate of spread. Such conditions deviate from those encountered during the fire season. Prescribed burns mostly affect surface fuels and understory vegetation, an outcome markedly different when compared to wildfires. Data on prescribed burning are crucial for evaluating whether land management targets have been reached. This research developed a methodology to quantify the effects of prescribed burns using multi-temporal Sentinel-1 Synthetic Aperture Radar (SAR) imagery in the forests of southeastern Australia. C-band SAR datasets were specifically used to statistically explore changes in radar backscatter coefficients with the intensity of prescribed burns. Two modeling approaches based on pre- and post-fire ratios were applied for evaluating prescribed burn impacts. The effects of prescribed burns were documented with an overall accuracy of 82.3% using cross-polarized backscatter (VH) SAR data under dry conditions. The VV polarization indicated some potential to detect burned areas under wet conditions. The findings in this study indicate that the C-band SAR backscatter coefficient has the potential to evaluate the effectiveness of prescribed burns due to its sensitivity to changes in vegetation structure.

Characterisation of the fuel and fire environment in southern Ontario’s tallgrass prairie

2015 ◽  
Vol 24 (8) ◽  
pp. 1118 ◽  
Author(s):  
Susan Kidnie ◽  
B. Mike Wotton
Keyword(s):  
Moisture Content ◽  
Tallgrass Prairie ◽  
Prescribed Burning ◽  
Fire Spread ◽  
Fuel Load ◽  
Prairie Restoration ◽  
Prescribed Burn ◽  
Spread Rate ◽  
Prescribed Burns ◽  
Tallgrass Prairie Restoration

Prescribed burning can be an integral part of tallgrass prairie restoration and management. Understanding fire behaviour in this fuel is critical to conducting safe and effective prescribed burns. Our goal was to quantify important physical characteristics of southern Ontario’s tallgrass fuel complex prior to and during prescribed burns and synthesise our findings into useful applications for the prescribed fire community. We found that the average fuel load in tallgrass communities was 0.70 kg m–2. Fuel loads varied from 0.38 to 0.96 kg m–2. Average heat of combustion did not vary by species and was 17 334 kJ kg–1. A moisture content model was developed for fully cured, matted field grass, which was found to successfully predict moisture content of the surface layers of cured tallgrass in spring. We observed 25 head fires in spring-season prescribed burns with spread rates ranging from 4 to 55 m min–1. Flame front residence time averaged 27 s, varying significantly with fuel load but not fire spread rate. A grassland spread rate model from Australia showed the closest agreement with observed spread rates. These results provide prescribed-burn practitioners in Ontario better information to plan and deliver successful burns.

Simulation of prescribed burning strategies in south-west Tasmania, Australia: effects on unplanned fires, fire regimes, and ecological management values

2006 ◽  
Vol 15 (4) ◽  
pp. 527 ◽  
Author(s):  
Karen J. King ◽  
Geoffrey J. Cary ◽  
Ross A. Bradstock ◽  
Joanne Chapman ◽  
Adrian Pyrke ◽  
...  
Keyword(s):  
Prescribed Burning ◽  
Fire Regime ◽  
Fire Risk ◽  
Fire Regimes ◽  
Treatment Level ◽  
Prescribed Burn ◽  
Burn Treatment ◽  
South West ◽  
Trade Offs ◽  
The Mean

Computer simulation modelling provides a useful approach for determining the trade-offs between the extent of prescribed burning and the long-term impacts of unplanned fires on management values. In the present study, FIRESCAPE-SWTAS, a process-based fire regime and vegetation dynamics model, was used in the World Heritage Area of south-west Tasmania, Australia, to investigate the implications of different prescribed burning treatments on identified management objectives. Treatments included annual prescribed burning of different proportions of the most flammable vegetation community, buttongrass moorlands. Additionally, a proposed strategic burning treatment for this landscape was simulated for comparison with these treatments. Simulations identified the nature of the relationships between the prescribed burn treatment level and the fire size distributions, the mean incidence, and the mean annual areas burnt by unplanned fires, with all three parameters declining with increases in treatment level. The study also indicated that strategically located treatment units were able to enhance the reduction in the fire risk to vegetation species susceptible to fire (fire-intolerant species).

The relative importance of fine-scale fuel mosaics on reducing fire risk in south-west Tasmania, Australia

2008 ◽  
Vol 17 (3) ◽  
pp. 421 ◽  
Author(s):  
Karen J. King ◽  
Ross A. Bradstock ◽  
Geoffrey J. Cary ◽  
Joanne Chapman ◽  
Jon B. Marsden-Smedley
Keyword(s):  
Prescribed Burning ◽  
Fire Risk ◽  
Computer Simulation Model ◽  
Treatment Level ◽  
Unit Size ◽  
Prescribed Burn ◽  
Treatment Unit ◽  
South West ◽  
Ecological Values ◽  
In Fire

In many landscapes, an important fire management objective is to reduce the negative impacts from unplanned fires on people, property and ecological values. In Australia, there exists an inherent assumption that high spatial variability in fire ages and hence fuel loads will have negative effects on both the incidence and spread of subsequent fires, and will enhance ecological values. A recent study using the process-based computer simulation model FIRESCAPE-SWTAS predicted several relationships between prescribed burn treatment levels and spatial patterning and management objectives in south-west Tasmania, Australia. The present study extended this investigation to additionally explore the effects of prescribed burning treatment unit size on unplanned fire incidence and area burned both in the general landscape and specifically in fire-intolerant vegetation. Simulation results suggest that treatment level had the greatest influence on modifying fire effects, whereas treatment unit size had the least effect. The model predicted that all three parameters interacted to determine the mean annual area burnt by unplanned fires. In fire-intolerant vegetation, treatment unit size did not influence the incidence of unplanned fires and the area burnt by unplanned fires in these communities. Where significant differences were evident, fire risk was reduced by higher treatment levels, deterministic spatial patterns of burning units, and smaller burning unit sizes.

Mechanical mastication and prescribed fire in conifer - hardwood chaparral: differing responses of ectomycorrhizae and truffles

2011 ◽  
Vol 20 (7) ◽  
pp. 888 ◽  
Author(s):  
Darlene Southworth ◽  
Jessica Donohue ◽  
Jonathan L. Frank ◽  
Jennifer Gibson
Keyword(s):  
Dna Sequences ◽  
Prescribed Fire ◽  
Prescribed Burning ◽  
Prescribed Burn ◽  
Internal Transcribed Spacer Region ◽  
Prescribed Burns ◽  
Soil Layers ◽  
Seasonally Dry ◽  
Ectomycorrhizal Roots ◽  
Ectomycorrhizal Communities

Fire-prone hardwood–conifer chaparral comprises a significant component of vegetation in seasonally dry areas where prescribed burns of standing vegetation are limited by air-quality restrictions and narrow climatic opportunities for burning. Mechanical mastication is used by land managers to reduce aerial fuels. When burned, the dry masticated slash layer may result in prolonged soil heating, particularly of the upper soil layers, which contain ectomycorrhizal roots and seasonal truffles (hypogeous fungal sporocarps). The purpose of this study was to examine the effects of mechanical mastication followed by prescribed fire on ectomycorrhizae and truffles. We treated blocks with mechanical mastication only, mechanical mastication followed by prescribed fire, prescribed fire only, and no treatment. Five years after the prescribed burn, soils with ectomycorrhizal roots were sampled at the canopy dripline of Pinus attenuata and Quercus kelloggii and surveyed for truffles. Ectomycorrhizae and truffles were described by morphology and by DNA sequences of the internal transcribed spacer region. Ectomycorrhizal communities did not differ among treatments. However, burning reduced the abundance and species richness of truffles in both controls and masticated vegetation. We conclude that prescribed burning of mechanically masticated slash does not harm ectomycorrhizal communities, but does inhibit fruiting of truffles.

scholarly journals Facilitating Prescribed Fire in Northern California through Indigenous Governance and Interagency Partnerships

Fire ◽  
2021 ◽  
Vol 4 (3) ◽  
pp. 37
Author(s):  
Tony Marks-Block ◽  
William Tripp
Keyword(s):  
Political Ecology ◽  
Prescribed Fire ◽  
Prescribed Burning ◽  
Participant Observation ◽  
Fire Suppression ◽  
The United States ◽  
Northern California ◽  
Prescribed Burn ◽  
California Department ◽  
State Regulations

Prescribed burning by Indigenous people was once ubiquitous throughout California. Settler colonialism brought immense investments in fire suppression by the United States Forest Service and the California Department of Forestry and Fire Prevention (CAL FIRE) to protect timber and structures, effectively limiting prescribed burning in California. Despite this, fire-dependent American Indian communities such as the Karuk and Yurok peoples, stalwartly advocate for expanding prescribed burning as a part of their efforts to revitalize their culture and sovereignty. To examine the political ecology of prescribed burning in Northern California, we coupled participant observation of prescribed burning in Karuk and Yurok territories (2015–2019) with 75 surveys and 18 interviews with Indigenous and non-Indigenous fire managers to identify political structures and material conditions that facilitate and constrain prescribed fire expansion. Managers report that interagency partnerships have provided supplemental funding and personnel to enable burning, and that decentralized prescribed burn associations facilitate prescribed fire. However, land dispossession and centralized state regulations undermine Indigenous and local fire governance. Excessive investment in suppression and the underfunding of prescribed fire produces a scarcity of personnel to implement and plan burns. Where Tribes and local communities have established burning infrastructure, authorities should consider the devolution of decision-making and land repatriation to accelerate prescribed fire expansion.

Prescribed Burning for Stand Conversion in Budworm-killed Balsam Fir: An Ontario Case History

1986 ◽  
Vol 62 (2) ◽  
pp. 96-100 ◽  
Author(s):  
D. J. McRae
Keyword(s):  
Fuel Consumption ◽  
Prescribed Burning ◽  
Choristoneura Fumiferana ◽  
Abies Balsamea ◽  
Spruce Budworm ◽  
Fire Spread ◽  
Fire Effects ◽  
Balsam Fir ◽  
Prescribed Burn ◽  
Stand Conversion

Recent spruce budworm (Choristoneura fumiferana [Clem.]) infestations have resulted in widespread areas of balsam fir (Abies balsamea [L.] Mill.) mortality in Ontario, and there is growing interest in reestablishing these areas quickly as productive forests. One technique being used is prescribed fire after a salvage and bulldozer tramping operation. A 445-ha prescribed burn was carried out under moderate fire danger conditions in northern Ontario. The site, which was covered by balsam fir fuel that had been killed by spruce budworm, was tramped to improve fire spread. Weather, fuel consumption, and fire effects are reported. The burn effectively reduced heavy surface fuel loadings and consequently planting on the site was easier. Key words: Prescribed burning, fire, spruce budworm. Choristoneura fumiferana, balsam fir, Abies balsamea, fuel consumption, site preparation, tramping, stand conversion.

Fuel and fire characteristics in savanna - woodland of West Africa in relation to grazing and dominant grass type

2007 ◽  
Vol 16 (5) ◽  
pp. 531 ◽  
Author(s):  
Patrice Savadogo ◽  
Didier Zida ◽  
Louis Sawadogo ◽  
Daniel Tiveau ◽  
Mulualem Tigabu ◽  
...  
Keyword(s):  
Prescribed Burning ◽  
Management Tool ◽  
Fuel Load ◽  
Maximum Temperature ◽  
Fire Intensity ◽  
Fire Behaviour ◽  
Savanna Woodland ◽  
Vegetation Height ◽  
Average Maximum ◽  
Dominant Grass

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.

The Effect of Season of Picloram and Chlorsulfuron Application on Dalmatian Toadflax (Linaria genistifolia) on Prescribed Burns

2005 ◽  
Vol 19 (2) ◽  
pp. 319-324 ◽  
Author(s):  
James S. Jacobs ◽  
Roger L. Sheley
Keyword(s):  
Prescribed Fire ◽  
Prescribed Burning ◽  
Block Design ◽  
Prescribed Burn ◽  
Prescribed Burns ◽  
Randomized Complete Block Design ◽  
Untreated Check ◽  
Dalmatian Toadflax ◽  
Density And Biomass ◽  
Cover Density

Herbicides are an important tool for managing weeds where prescribed fire is used for rangeland improvement. Understanding how the season of herbicide application relates to prescribed burning is important. Our objective was to determine the effect of picloram and chlorsulfuron on Dalmatian toadflax cover, density, and biomass, where these herbicides were applied in the fall before burning or in the spring before or after burning. Six herbicide treatments and an untreated check were applied in a randomized complete block design with four replications to a prescribed burn at two sites infested with Dalmatian toadflax in Montana, United States. Herbicides were applied in the fall preburn, spring preburn, and spring postburn. Site 1 was treated in 1999 and 2000, and site 2 was treated in 2000 and 2001. Cover, biomass, and density of Dalmatian toadflax were sampled in September 2000, 2001, and 2002 at site 1 and September 2001 and 2002 at site 2. At site 1, cover, biomass, and density of Dalmatian toadflax were at least 76% lower compared with the check in both spring-applied picloram treatments, whereas the fall picloram treatment had similar Dalmatian toadflax cover, biomass, and density compared with the check 3 yr after application. By 2002, chlorsulfuron reduced Dalmatian toadflax cover, biomass, and density by at least 79% compared with the check in all timings of application at site 1. At site 2, Dalmatian toadflax cover, biomass, and density were reduced by at least 86% for all picloram and chlorsulfuron treatments in 2002, 2 yr after application. Chlorsulfuron applied in the fall or the spring and picloram applied in the spring effectively suppressed Dalmatian toadflax cover, biomass, and density for up to 3 yr.

scholarly journals Temporal–Spatial Patterns of Relative Humidity and the Urban Dryness Island Effect in Beijing City

2017 ◽  
Vol 56 (8) ◽  
pp. 2221-2237 ◽  
Author(s):  
Ping Yang ◽  
Guoyu Ren ◽  
Wei Hou
Keyword(s):  
Relative Humidity ◽  
Urban Areas ◽  
Late Summer ◽  
Beijing City ◽  
Near Surface ◽  
Suburban Areas ◽  
Island Effect ◽  
Different Seasons ◽  
Autumn And Winter ◽  
Beijing China

AbstractHourly datasets obtained by automatic weather stations in Beijing, China, are developed and employed to analyze the spatial and temporal characteristics of relative humidity (RH) and urban dryness island intensity (UDII) over built-up areas. A total of 36 stations inside the sixth ring road are considered as urban sites, while six stations in suburban belts surrounding the built-up areas are taken as reference sites. Results show that the RH is obviously smaller in urban areas than in suburban areas, indicating the effect of urbanization on near-surface atmospheric moisture and RH. A further analysis of relations between RH and temperature on varied time scales shows that the variations in RH in the urban areas are not due solely to changes in temperature. The annual and seasonal mean UDII are high in central urban areas, with the strongest UDII values occurring in autumn and the weakest values occurring in spring. The diurnal UDII variations are characterized by a steadily strong UDII stage from 2000 to 0800 LT and a minimum at 1500 or 1600 LT. The rapid shifts of UDII from high (low) to low (high) occur during the periods 0800–1600 LT (1600–2000 LT). The occurrence time of the peaks varies among different seasons: the peaks appear at 0700, 2100, 2000, and 0800 LT for spring, summer, autumn, and winter, respectively. Further analysis shows that large UDII values appear in the evenings and early nights in late summer and early to midautumn and that low UDII values mainly occur in the afternoon hours of spring, winter, and late autumn.

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