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1.
Fire is quite a common natural phenomenon closely related to forest hydrology in forest ecosystem. The influence of fire on water is indirectly manifested in that the post fire changes of vegetation, ground cover, soil and environment affect water cycle, water quality and aquatic lives. The effect varies depending upon fire severity and frequency. Light wildland fires or prescribed burnings do not affect hydrology regime significantly but frequent burnings or intense fires can cause changes in hydrology regime similar to that caused clear cutting. 相似文献
2.
During the summer of 2001, survey data were collected from Colorado residents living near public lands (i.e., the wildland urban interface). Data were collected by telephone after mailing respondents a survey. These data include detailed information of respondents' views towards wildfire management and willingness-to-pay (WTP) values for prescribed burning. Results indicate that Colorado residents living near public lands are aware that fire is a natural process in their area and are in favor of using prescribed burning for fire risk reduction. They also are willing-to-pay an annual tax for prescribed fire undertaken on the public lands near their homes. Respondents' support for adopting a fire risk mitigation policy based on prescribed fire depended on perceived fire frequency intervals. The substantial WTP values for prescribed burning indicate that the public living in the wildland urban interface could potentially pay an annual tax, so the burden of wildfire management need no longer predominantly lie in the hands of the general taxpayers. 相似文献
3.
In the majority of US political settings wildland fire is still discussed as a negative force. Lacking from current wildfire discussions are estimates of the spatial extent of fire and their resultant emissions before the influences of Euro-American settlement and this is the focus of this work. We summarize the literature on fire history (fire rotation and fire return intervals) and past Native American burning practices to estimate past fire occurrence by vegetation type. Once past fire intervals were established they were divided into the area of each corresponding vegetation type to arrive at estimates of area burned annually. Finally, the First Order Fire Effects Model was used to estimate emissions. Approximately 1.8 million ha burned annually in California prehistorically (pre 1800). Our estimate of prehistoric annual area burned in California is 88% of the total annual wildfire area in the entire US during a decade (1994–2004) characterized as “extreme” regarding wildfires. The idea that US wildfire area of approximately two million ha annually is extreme is certainly a 20th or 21st century perspective. Skies were likely smoky much of the summer and fall in California during the prehistoric period. Increasing the spatial extent of fire in California is an important management objective. The best methods to significantly increase the area burned is to increase the use of wildland fire use (WFU) and appropriate management response (AMR) suppression fire in remote areas. Political support for increased use of WFU and AMR needs to occur at local, state, and federal levels because increasing the spatial scale of fire will increase smoke and inevitability, a few WFU or AMR fires will escape their predefined boundaries. 相似文献
4.
Natural catastrophes in forests have become more damaging in recent years and are expected to further increase according to climate change scenarios. Currently, governmental measures mostly focus on providing financial support, such as direct payments, to forest owners after disasters. However, in the light of more weather extremes, this could lead to a heavier financial burden for national budgets. Therefore, the current financial support system has to be reconsidered with regard to privatizing foresters' risks. Insurance could play a key role, but in many countries forests are rarely insured. In order to explain insurance coverage, we analyzed foresters' preferences regarding fire and storm insurance, which are expressed as their willingness-to-pay (WTP). Therefore, we measured the risk attitude and conducted a discrete choice experiment with 137 German foresters, using various policy and forest enterprise scenarios. Our results show that most foresters have a very low WTP for insurance, and individual risk attitude was not of significant influence. The WTP was higher for fire than for storm insurance, presumably due to liquidity preservation motives. Policy programs involving unconditional support after disaster reduced the WTP. Instead, subsidized insurance premiums increased the WTP and thus, should be considered to establish an efficient insurance market. 相似文献
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基于GIS平台的林火景观格局研究构想 总被引：1，自引：0，他引：1
现代林火管理需要在整合森林防灭火信息的基础上,对林火发生、发展、蔓延以及可燃物景观格局现状进行系统深入的分析,以期对林分可燃物进行科学合理的空间布局,并实现对林火防区可燃物未来演替格局的预测。通过对相关研究的综述分析,基于地理信息系统(GIS)平台的空间直观模型模拟,是针对把林火作为驱动因子的大时空尺度森林景观变化研究的强有力工具。提出了以林火景观生态格局为核心的研究框架,具体研究成果将直接为林火防区提供灭火策略和灭火指挥辅助决策的数源基础和定量化技术支持。 相似文献
7.
Thomas Curt Alice SchaffhauserLaurent Borgniet Claire DumasRoland Estève Anne GanteaumeMarielle Jappiot Willy MartinAminata N’Diaye Benjamin Poilvet 《Forest Ecology and Management》2011,261(12):2214-2222
Characterizing the flammability of litter fuels is of major importance for assessing wildland fire ignition hazard. Here we compared the flammability of litter within a mosaic of Quercus suber (cork oak) woodlands and shrublands in a Mediterranean fire-prone area (Maures massif, southeastern France) to test whether the characteristics and the flammability of litter vary with the vegetation types. We tested experimentally the ignitability, the sustainability, the combustibility and the consumability of undisturbed (=non-reconstructed) litter samples with a point-source mode of ignition. Although the frequency of ignition was similar between all the vegetation types, we distinguished four groups having litter of specific composition and flammability: low and sparse shrublands dominated by Cistus species, medium shrublands with cork oak, high Erica shrublands with sparse cork oak woodlands, and mixed mature oak woodlands with Q. suber, Q. ilex and Q. pubescens. As these vegetation types corresponded to a specific range of past fire recurrence, we also tested the effect of the number of fires and the time since the last fire on litter flammability. Litters of plots recurrently burned had low ability to propagate flames and low flame sustainability. We discuss how the recent fire history can modify vegetation and litter flammability, and thus the fire ignition hazard. 相似文献
8.
This paper discusses participatory processes in wildland fire management (WFM). Participation is an essential element of both the European Sustainable Development (SD) Strategy and the White Paper on Governance. Governance and SD have thus become an interconnected challenge to be applied to WFM (as a sub-area in forest policy), amongst other policies. An overspread weakness in WFM is lack of real participa- tion of stakeholders. Absence of (or deficient) participation can seriously impair contribution of this group to WFM in high-risk areas and runs counter governance and the SDS. Further, this weakness might prevent an efficient use of fire as a land management tool (prescribed burning, PB) and as a technique for fighting wildfire (suppression fire, SF). Even though these fire practices have been well known in many different places, they have been increasingly neglected or prohibited over time in Southern Europe. At present, forest and fire fighting administrations are turning their eyes back on them and analyzing the benefits of using fire in relation to preventive and suppressive actions. Therefore, participatory and diffusion mechanisms (the latter adopting the shape of national and international experts’ networks) are required in order to solve the so- called fire paradox: that is, the need to move from a one-dimensional perception of the negative impacts of fire to a more sophisticated one that also stresses its positive effects. Governance, based on broad social participation, and diffusion, through fire networks, are of utmost impor- tance in order, first, to diminish long-standing suspicion amongst differ- ent interests as to the use of fire and, secondly, to diffuse best practices associated with PB and SF. Most importantly, the EU should exercise itsenvironmental leadership so that these new fire practices and sustainable WFM are diffused across the international arena. 相似文献
9.
Johann G. Goldammer 《Agroforestry Systems》1988,6(1-3):235-252
Tropical forest land is increasingly influenced by man-caused wildfires. The vast majority of the forested area burnt and
cleared annually is in the tropics. The use of fire in rural land-use systems is the major cause of the wildfires. Five broad
causative agencies of wildfires are presented, shifting cultivation, grazing, non-wood forest products, migration programs
and the wildland/residential interface. Integrated concepts of prescribed burning and prescribed grazing may offer solutions
to the tropical wildland fire problems. 相似文献
10.
Alexandra D. Syphard Jon E. Keeley Teresa J. Brennan 《Forest Ecology and Management》2011,261(11):2038-2048
Fuel treatment of wildland vegetation is the primary approach advocated for mitigating fire risk at the wildland-urban interface (WUI), but little systematic research has been conducted to understand what role fuel treatments play in controlling large fires, which factors influence this role, or how the role of fuel treatments may vary over space and time. We assembled a spatial database of fuel breaks and fires from the last 30 years in four southern California national forests to better understand which factors are consistently important for fuel breaks in the control of large fires. We also explored which landscape features influence where fires and fuel breaks are most likely to intersect. The relative importance of significant factors explaining fuel break outcome and number of fire and fuel break intersections varied among the forests, which reflects high levels of regional landscape diversity. Nevertheless, several factors were consistently important across all the forests. In general, fuel breaks played an important role in controlling large fires only when they facilitated fire management, primarily by providing access for firefighting activities. Fire weather and fuel break maintenance were also consistently important. Models and maps predicting where fuel breaks and fires are most likely to intersect performed well in the regions where the models were developed, but these models did not extend well to other regions, reflecting how the environmental controls of fire regimes vary even within a single ecoregion. Nevertheless, similar mapping methods could be adopted in different landscapes to help with strategic location of fuel breaks. Strategic location of fuel breaks should also account for access points near communities, where fire protection is most important. 相似文献
11.
Johann G. Goldammer 《Agroforestry Systems》1988,6(1):235-252
Tropical forest land is increasingly influenced by man-caused wildfires. The vast majority of the forested area burnt and cleared annually is in the tropics. The use of fire in rural land-use systems is the major cause of the wildfires. Five broad causative agencies of wildfires are presented, shifting cultivation, grazing, non-wood forest products, migration programs and the wildland/residential interface. Integrated concepts of prescribed burning and prescribed grazing may offer solutions to the tropical wildland fire problems. 相似文献
12.
Fire management policy in the United States has evolved to encourage fire managers to address the full range of beneficial and detrimental effects of unplanned ignitions. We developed a probability-based fire risk and benefit simulation approach to support wildland fire management at Sequoia and Kings Canyon National Parks (SEKI) in a manner consistent with the SEKI fire management plan. The approach integrated fire behavior, fire spread probability, and resource values to estimate the spatial distribution of expected fire net benefits for any ignition point in a landscape context. We simulated probabilistic fire footprints from each burnable cell and evaluated them for their potential to provide ecosystem benefits or to require risk mitigation. The expected net benefits of igniting a cell were stored in the ignition cell to provide a landscape-level perspective. We provide results that reflect the fire planning weather conditions of concern to demonstrate how the sensitivity of the results can reflect weather influences. The results provided a preprocessed “playbook” type reference guide to fire management. The results can be quickly accessed and intuitively interpreted and were used to promote interagency cooperation in managing the Tehipite fire on northern SEKI and on the Sierra National Forest. 相似文献
13.
Multi-attribute evaluation of landscape-level fuel management to reduce wildfire risk 总被引：1，自引：0，他引：1
Dan W. Ohlson Trent M. Berry Robert W. Gray Bruce A. Blackwell Brad C. Hawkes 《Forest Policy and Economics》2006,8(8):824-837
This paper provides an example of the practical application of multi-attribute trade-off analysis (MATA) to wildfire management. The MATA approach supports more informed decision-making because it exposes important trade-offs among competing management objectives (requiring value-based choices), helps guide and structure necessary technical judgements, explicitly represents uncertainty (i.e., not just expected outcomes but risk profiles around outcomes) and addresses temporal trade-offs. MATA promotes critical thinking about what analysis is required for decision-making. A MATA approach can be applied for all types of forest and fire management decisions. In this paper, we provide a sample application of MATA to an evaluation of landscape-level fuel treatments for managing wildfire risk. The study area is located in southeastern British Columbia, Canada where historical fire suppression policies and expanding development in wildland urban interface areas have resulted in an increase in both the probability and the consequences of stand replacement fires. We specify management objectives and develop measurable attributes for fire management costs, timber supply, property damage, landscape-level biodiversity, local air quality and climate change. We then simulate the effects on these attributes of four alternative fuel management strategies that include combinations of mechanical treatments and prescribed burning over a 100-year period. The evaluation illustrates the key features of MATA while highlighting the benefits and challenges of implementing the approach. 相似文献
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C. Lampin-Maillet M. Long-FournelA. Ganteaume M. JappiotJ.P. Ferrier 《Forest Ecology and Management》2011,261(12):2200-2213
Each year, forest fires destroy about 500,000 ha of vegetation in Europe, predominantly in the Mediterranean region. Many large fires are linked to the land transformations that have taken place in the Mediterranean region in recent decades that have increased the risk of forest fires. On the one hand, agricultural fallows and orchards are slowly being colonized by vegetation, and on the other hand, the forest is not sufficiently used, both of which result in increased accumulation of fuel. In addition, urbanization combined with forest extension results in new spatial configurations called “wildland-urban interfaces” (WUI). WUI are commonly defined as “areas where urban areas meet and interact with rural lands, wildland vegetation and forests”. Spatial analyses were performed using a WUI typology based on two intertwined elements, the spatial organization of homes and the structure of fuel vegetation. The organization of the land cover in terms of representativeness, complexity or road density was evaluated for each type of WUI. Results showed that there were significant differences between the types of WUI in the study area. Three indicators (i) “fire ignition density”, derived from the distribution of fire ignition points, (ii) “wildfire density”, derived from the distribution of wildfire area and (iii) “burned area ratio”, derived from the proportion of the burned area to the total study area were then compared with each type of WUI. Assuming that the three indicators correspond to important aspects of fire risk, we showed that, at least in the south of France, WUI are at high risk of wildfire, and that of the different types of wildland-urban interfaces, isolated and scattered WUI were the most at risk. Their main land cover characteristics, i.e. low housing and road densities but a high density of country roads, and the availability of burnable vegetation such as forested stands and shrubland (garrigue) explain the high fire risk. Improving our knowledge of relationships between WUI environments and fire risk should increase the efficiency of wildfire prevention: to this end, suitable prevention actions and communication campaigns targeting the types of WUI at the highest risk are recommended. 相似文献
17.
森林防火隔离带技术的变革与优势 总被引：2，自引：0，他引：2
以消减可燃物的方式预防和阻隔森林火灾是林火管理工作的核心。传统阻隔技术向遮荫型防隔火技术的演变已成为近10余年西方多林国家林火管理工作的重要走向。从林火的特点和蔓延基本规律出发, 遮荫型防火隔离带技术通过局部消减可燃物载量和规则化可燃物分布, 显著降低其可能形成的林火强度, 使大多数火灾自行熄灭。该项技术的实施不受区域和气候条件限制; 与传统全光式防火隔离带和生物防火林带相比, 不但工作量较小, 对林分植被和生态环境的干扰也较小。该项技术实现了偶发性林火的防控、森林健康及生态维护的有机结合, 以此替代传统防火隔离带技术效益显著。针对遮荫型防隔火技术的进一步研究工作应包括不同稀化程度林带潜在火行为和其防隔火效能的量化评估、林地局部可燃物稀化的高效作业机具以及伴随该项技术实施产生的大量生物质副产品的有效利用问题。 相似文献
18.
The shapes of landscapes are fundamental to ecosystem processes at various spatial scales. Topographic roughness index (TRI) is a measure of variability in the landscape surface and a proxy of the potential of disturbances to propagate across the earth's surface, such as a wildland fire burning across a landscape. We describe the significance of TRI, present methods for calculation, and demonstrate the utility of the index in a fire frequency prediction model. The model was used to show how the relationships between topography, fire, and humans changed during the period of AD 1620–1850 for a study area (5180 km2) in Missouri, USA. The model predicted historic mean fire return intervals from TRI and two human population variables. The model explained 46% of the variation in mean fire return intervals and demonstrated that topographic roughness was most important in controlling fire frequency during the period AD 1620–1780 when human population density was lowest (<0.35 humans/km2). Due to increases in human population, mean fire return intervals were shortened by up to one-fourth of their original length and the landscape became more homogeneous with respect to fire frequency despite topographic roughness. The use of TRIs in wildland fire research aid in quantifying and visualizing topographic variability and could be applicable to multiple scales and ecosystem processes. 相似文献
19.
Public compensation for windstorm damage reduces incentives for risk management investments 总被引：1，自引：0，他引：1
Governments of some European countries compensate landowners for windstorm damage to forests. We analyze the impact of such programmes on non-industrial private forest owner decisions to purchase an insurance policy for windstorm coverage and other natural events and/or invest in risk-reducing forest management activities. We develop a theoretical model to predict demand for an insurance policy or risk-reducing forest management activity, and improve upon previous efforts by varying the damage losses proportional to timber stand value. We characterize the comparative static effects on risk management investments of variations in the price of insurance, landowner risk attitude, timber stand value, and presence or absence of public compensation. Then we discuss public policy implications and analyze some alternative approaches. We conclude that providing public financial assistance to non-industrial private forest owners after damage-causing events may reduce their incentive to purchase insurance or invest in protective forest management activities. 相似文献
20.
针对东北林区贮木场的特点,应用层次分析法对其贮木场火灾危险等级的评定进行了研究。结果表明:贮木场的企业状况、气象条件和人为影响是贮木场火灾发生发展的主要影响因素。其中贮木场的单位木材储存量、单位木材生产人数、设备使用时长以及防火检查力度等因素对其火灾发生发展的影响最大。用层次分析法得出了东北林区贮木场火灾危险等级评定指数模型,并制定出贮木场火灾危险等级的评定表。东北林区各贮木场可依据评定表,并结合自身实情,对火灾危险等级进行测报。 相似文献