Responses of bat-prey to prescribed burns and mechanical thinning

2021 ◽  
Vol 491 ◽  
pp. 119162
Author(s):  
Aaron P. Tormanen ◽  
Jorista Garrie
2021 ◽  
Author(s):  
Xiao Fu ◽  
Abigail Lidar ◽  
Michael Benjamin Kantar ◽  
Barath Raghavan

Wildfires ravage lands in seasonally-dry regions, imposing high costs on infrastructure maintenance and human habitation at the wildland-urban interface (WUI). Current fire mitigation approaches present upfront costs with uncertain long-term payoffs. Instead, we show that a simple landscape intervention on human-managed wildlands -- buffers of a low-flammability crop species such as banana irrigated using recycled water -- can mitigate wildfires, produce food profitably, and provide additional ecosystem services. Recreating a recent, major fire in simulation, we find that a medium-sized banana buffer decreases fireline intensity by 96%, similar to prescribed burns and mechanical thinning combined, and delays the fire by 316 minutes, enabling safe and effective firefighting. We find that under climate change, despite worsened fires, banana buffers will still have a protective effect. We also find that banana buffers with average yield could produce a profit of $56k USD/hectare through fruit sales, in addition to fire mitigation and other benefits.


Author(s):  
J. Cadoz ◽  
J. Castaing ◽  
J. Philibert

Plastic deformation of alumina has been much studied; basal slip occurs and dislocation structures have been investigated by transmission electron microscopy (T.E.M.) (1). Non basal slip has been observed (2); the prismatic glide system <1010> {1210} has been obtained by compression tests between 1400°C and 1800°C (3). Dislocations with <0110> burgers vector were identified using a 100 kV microscope(4).We describe the dislocation structures after prismatic slip, using high voltage T.E.M. which gives much information.Compression tests were performed at constant strainrate (∿10-4s-1); the maximum deformation reached was 0.03. Thin sections were cut from specimens deformed at 1450°C, either parallel to the glide plane or perpendicular to the glide direction. After mechanical thinning, foils were produced by ion bombardment. Details on experimental techniques can be obtained through reference (3).


Fire Ecology ◽  
2019 ◽  
Vol 15 (1) ◽  
Author(s):  
Valerie S. Densmore ◽  
Emma S. Clingan

Abstract Background Prescribed burning is used to reduce fire hazard in highly flammable vegetation types, including Banksia L.f. woodland that occurs on the Swan Coastal Plain (SCP), Western Australia, Australia. The 2016 census recorded well over 1.9 million people living on the SCP, which also encompasses Perth, the fourth largest city in Australia. Banksia woodland is prone to frequent ignitions that can cause extensive bushfires that consume canopy-stored banksia seeds, a critical food resource for an endangered bird, the Carnaby’s cockatoo (Calyptorynchus latirostris, Carnaby 1948). The time needed for banksias to reach maturity and maximum seed production is several years longer than the typical interval between prescribed burns. We compared prescribed burns to bushfires and unburned sites at three locations in banksia woodland to determine whether low-intensity prescribed burns affect the number of adult banksias and their seed production. Study sites were matched to the same vegetation complex, fire regime, and time-since-fire to isolate fire intensity as a variable. Results Headfire rates of spread and differenced normalized burn ratios indicated that prescribed burning was generally of a much lower intensity than bushfire. The percentage survival of adult banksias and their production of cones and follicles (seeds) did not decrease during the first three years following a prescribed burn. However, survival and seed production were significantly diminished followed high-intensity bushfire. Thus, carrying capacity for Carnaby’s cockatoo was unchanged by prescribed burning but decreased markedly following bushfire in banksia woodland. Conclusions These results suggest that prescribed burning is markedly different from bushfire when considering appropriate fire intervals to conserve canopy habitats in fire-resilient vegetation communities. Therefore, low-intensity prescribed burning represents a viable management tool to reduce the frequency and extent of bushfire impacts on banksia woodland and Carnaby’s cockatoo.


2021 ◽  
Vol 13 (12) ◽  
pp. 2386
Author(s):  
Aqil Tariq ◽  
Hong Shu ◽  
Qingting Li ◽  
Orhan Altan ◽  
Mobushir Riaz Khan ◽  
...  

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.


2003 ◽  
Vol 18 (2) ◽  
pp. 109-114 ◽  
Author(s):  
Steven J. Stein ◽  
Diana N. Kimberling

Abstract Information on the mortality factors affecting naturally seeded conifer seedlings is becoming increasingly important to forest managers for both economic and ecological reasons. Mortality factors affecting ponderosa pine (Pinus ponderosa) seedlings immediately following natural germination and through the following year were monitored in Northern Arizona. The four major mortality factors in temporal order included the failure of roots to establish in the soil (27%), herbivory by lepidopteran larvae (28%), desiccation (30%), and winterkill (10%). These mortality factors were compared among seedlings germinating in three different overstory densities and an experimental water treatment. Seedlings that were experimentally watered experienced greater mortality than natural seedlings due to herbivory (40%), nearly as much mortality due to the failure of roots to establish in the soil (20%), less mortality due to winterkill (5%), and no mortality due to desiccation. The seedling mortality data through time were summarized using survivorship curves and life tables. Our results suggest that managers should consider using prescribed burns to decrease the percentage of seedlings that die from failure of their roots to reach mineral soil and from attack by lepidopteran larvae. West. J. Appl. For. 18(2):109–114.


2012 ◽  
Vol 21 (8) ◽  
pp. 992 ◽  
Author(s):  
Tom Lewis ◽  
Joanne De Faveri

Wildfire represents a major risk to pine plantations. This risk is particularly great for young plantations (generally less than 10 m in height) where prescribed fire cannot be used to manipulate fuel biomass, and where flammable grasses are abundant in the understorey. We report results from a replicated field experiment designed to determine the effects of two rates of glyphosate (450 g L–1) application, two extents of application (inter-row only and inter-row and row) with applications being applied once or twice, on understorey fine fuel biomass, fuel structure and composition in south-east Queensland, Australia. Two herbicide applications (~9 months apart) were more effective than a once-off treatment for reducing standing biomass, grass continuity, grass height, percentage grass dry weight and the density of shrubs. In addition, the 6-L ha–1 rate of application was more effective than the 3-L ha–1 rate of application in periodically reducing grass continuity and shrub density in the inter-rows and in reducing standing biomass in the tree rows, and application in the inter-rows and rows significantly reduced shrub density relative to the inter-row-only application. Herbicide treatment in the inter-rows and rows is likely to be useful for managing fuels before prescribed fire in young pine plantations because such treatment minimised tree scorch height during prescribed burns. Further, herbicide treatments had no adverse effects on plantation trees, and in some cases tree growth was enhanced by treatments. However, the effectiveness of herbicide treatments in reducing the risk of tree damage or mortality under wildfire conditions remains untested.


2015 ◽  
Vol 24 (8) ◽  
pp. 1118 ◽  
Author(s):  
Susan Kidnie ◽  
B. Mike Wotton

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.


2005 ◽  
Vol 19 (2) ◽  
pp. 319-324 ◽  
Author(s):  
James S. Jacobs ◽  
Roger L. Sheley

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.


FLORESTA ◽  
2013 ◽  
Vol 43 (4) ◽  
pp. 557
Author(s):  
Celso Darci Seger ◽  
Antonio Carlos Batista ◽  
Alexandre França Tetto ◽  
Ronaldo Viana Soares

As queimas controladas constituem práticas de manejo utilizadas em diferentes tipos de vegetação e difundidas em vários países. No entanto, para a realização de tais práticas com segurança e eficiência é fundamental o conhecimento do comportamento do fogo. O objetivo desse trabalho foi caracterizar o comportamento do fogo em queimas controladas de vegetação Estepe Gramíneo-Lenhosa no estado do Paraná. Para isso, foi instalado um experimento no município de Palmeira, onde 20 parcelas foram queimadas, sendo metade a favor e metade contra o vento. A carga de material combustível fino estimada foi de 2,26 kg.m-2, com teor médio de umidade de 50,45%. A quantidade de material consumido pela queima foi de 1,76 kg.m-2, com uma eficiência média de queima de 76,86%. As médias obtidas, a favor e contra o vento, foram respectivamente: velocidade de propagação do fogo de 0,049 e 0,012 m.s-1, altura das chamas de 1,34 e 0,843 m, intensidade do fogo de 210,53 e 50,68 kcal.m-1.s-1 e calor liberado de 4.067,19 e 4.508,92 kcal.m-2. Os resultados permitiram concluir que as queimas controladas em vegetação de campos naturais, realizadas dentro dos critérios estabelecidos de planos de queima, são viáveis e seguras sob o ponto de vista de perigo de incêndios.Palavras chave: Queima prescrita; material combustível; intensidade do fogo; perigo de incêndios. AbstractFire behavior of prescribed burns in grassland on Palmeira county, Paraná, Brazil. The prescribed burns are practices of management used in different types of vegetation and widespread in several countries. However, to carry out such practices safely and effectively is fundamental knowledge of fire behavior. The aim of this study was to characterize the fire behavior in controlled burning of grassland vegetation in Paraná state. For this, an experiment was conducted in Palmeira County, where 20 plots were burned, half in favor and half against the wind. The estimated fine fuel loading was 2.26 kg.m-2, with average moisture content of 50.45%. The fuel consumption by burning was 1.76 kg.m-2 with an average efficiency of burning of 76.86%. The averages, for and against the wind, were: speed of fire spread of 0.049 and 0.012 m.s-1, the flame height of 1.34 m and 0.843, fire intensity of 210.53 and 50.68 kcal.m-1.s-1 and heat released from 4,067.19 and 4,508.92 kcal.m-2. The results show that the controlled burnings of grasslands vegetation, carried out within the established criteria burning plans are feasible and safe from the aspect of fire danger.Keywords: Prescribed burns; fuel loading; fire intensity; fire risk.


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