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1.
Javier Madrigal Irma Fernández-Migueláñez Carmen Hernando Mercedes Guijarro Daniel J. Vega-Nieva Eduardo Tolosana 《European Journal of Forest Research》2017,136(1):13-26
The Mediterranean basin is a fire-prone area and is expected to continue being so according to projected climate and socioeconomic changes. Sustainable exploitation of forest biomass could have a positive effect on wildfire hazard mitigation. A modelling approach was used to compare how four different Scenarios for biomass collection for energy use affect fire behaviour and potential burnt area at landscape level under extreme meteorological conditions in a typical Mediterranean Massif. A case study of Pinus halepensis stands in Valencia (Eastern Spain) was conducted. The FARSITE simulator was used to evaluate the burnt area and fire behaviour parameters. Simulations predicted a significant increase in the burnt area and the values of most fire behaviour parameters in a Scenario of rural abandonment, relative to the current situation. Biomass management through thinning reduced canopy bulk density; however, no differences in the values of the main fire behaviour parameters were detected. Thinning and understory clearing, including biomass collection in large shrub fuel model areas, significantly reduces fire hazard. Forest biomass sustainable harvesting for energy is expected to reduce fire hazard if management includes intense modification of fuel models, comprising management of shrub biomass at the landscape level. Strong modification of forest fuel models requires intensive silvicultural treatments. Therefore, forest biomass collection for energy in the Mediterranean basin reduces fire hazard only if both tree and shrub strata are managed at landscape level. 相似文献
2.
Each year, wildland fires burn millions of hectares of forest worldwide. Fire managers need to provide effective methods for mapping fire fuels accurately. Fuel distribution is very important for predicting fire behavior. The overall aim of this project is to model fire behavior using FARSITE (Fire Area Simulator) and investigate differences in modeling outputs using fuel model maps, which differ in accuracy, in east Texas. This simulator model requires as input spatial data themes such as elevation, slope, aspect, surface fuel model, and canopy cover along with separate weather and wind data. Seven fuel models, including grass, brush, and timber models, are identified in the study area. To perform modeling sensitivity analysis, two different fuel model maps were used, one obtained by classifying a QuickBird image and the other obtained by classifying a LIDAR (LIght Detection and Ranging) and QuickBird fused data set. Our previous investigations showed that LIDAR improves the accuracy of fuel mapping by at least 13%. According to our new results, LIDAR-derived variables also provides more detailed information about characteristics of fire. This study will show the importance of using accurate maps of fuel models derived using new LIDAR remote sensing techniques. 相似文献
3.
A. P. Dimitrakopoulos I. D. Mitsopoulos D. I. Raptis 《European Journal of Forest Research》2007,126(4):555-561
Nomographs that calculate the threshold values of surface fire parameters which lead to crown fire initiation were created
by linking two separate fire behavior models: Van Wagner’s crown fire ignition criteria and Byram’s surface fire model. The
nomographs were also based on the existing surface (fuel load, fuel heat content) and canopy (foliar moisture content, live
crown base height) fuel models of Aleppo (Pinus halepensis Mill.) pine forests of Mediterranean Greece. The most important fire parameters for crown fire initiation that are calculated
by the nomographs are the critical flame length and the forward spread rate of the surface fire. These parameters are readily
observable in the field during fires. The nomographs provide a judicious way to assess whether a crown fire is likely to occur
in a conifer forest stand. Although the fire behavior models used had limited testing and are based on certain assumptions,
yet they are widely applied in forestry practice worldwide, as a basis for justified fire prevention and suppression planning. 相似文献
4.
Thomas W. McGinnis Jon E. Keeley Scott L. Stephens Gary B. Roller 《Forest Ecology and Management》2010
Typically, after large stand-replacing fires in mid-elevation Sierra Nevada forests, dense shrub fields occupy sites formerly occupied by mature conifers, until eventually conifers overtop and shade out shrubs. Attempting to reduce fuel loads and expedite forest regeneration in these areas, the USDA Forest Service often disrupts this cycle by the logging of fire-killed trees, replanting of conifers and killing of shrubs. We measured the effects of these treatments on live and dead fuel loads and alien species and modeled potential fire behavior and fire effects on regenerating forests. Sampling occurred in untreated, logged and herbicide-treated stands throughout the Sierra Nevada in four large fire areas 4–21 years after stand-replacing fires. Logging fire-killed trees significantly increased total available dead fuel loads in the short term but did not affect shrub cover, grass and forb cover, alien species cover or alien species richness. Despite the greater available dead fuel loads, fire behavior was not modeled to be different between logged and untreated stands, due to abundant shrub fuels in both logged and untreated stands. In contrast, the herbicide treatment directed at shrubs resulted in extremely low shrub cover, significantly greater alien species richness and significantly greater alien grass and forb cover. Grass and forb cover was strongly correlated with solar radiation on the ground, which may be the primary reason that grass and forb cover was higher in herbicide treated stands with low shrub and tree cover. Repeat burning exacerbated the alien grass problem in some stands. Although modeled surface fire flame lengths and rates of spread were found to be greater in stands dominated by shrubs, compared to low shrub cover conifer plantations, surface fire would still be intense enough to kill most trees, given their small size and low crown heights in the first two decades after planting. 相似文献
5.
There is a lack of knowledge to identify and classify forest structures according to the risk of crown fires, especially in
Mediterranean regions. In this study, for the first time, we use real information, obtained after a wildfire that burnt under
extreme meteorological conditions, to classify forest structures of Pinus halepensis into fuel types as a function of crown fire potential. We identified fourteen forest structures which characterize many forest
types in Western Mediterranean areas depending on canopy closure, number of tree layers, percent of each tree layer and overall
tree density. By using the pattern of fire types that burnt the most numerous forest structures, we have identified four fire
hazard groups of forest structures which are considered different fuel types. The first two had the lowest risk of active
crown fires and they differed in the proportion of surface fires and passive crown fires. The third fuel type was the threshold
between structures with low and high extreme fire behavior; while the fourth had a high risk of active crown fires. Firefighters
and forest managers who are demanding this kind of schema, will test and upgrade this classification of fuel types in function
of crown fire potential during future wildfires. 相似文献
6.
INTRODUCTION'Inforn1ahonondvnan1icsofthefoel1oadslslmPOrtantt0bothl1lanagersandresearchersofecologicaleffectsoffire.Theal11ountoffuelconsullledbyfireandthesubsequentpat-ten1ofre-acculnulationoffilel1sln1POrtantf(I)illdeterl11inah0nofthefilelquanhtyftlelpresentatanyh1ne,asweIlasthesteady-stateweightofaccumtIlatedresidues;(2)inpredichngenenyrelease,il1tensityandspreadrateforfirebehaviorforecastandsuppression;(3)illassessingtheeffechvenessofpre-scribedburni11gforftlellnanageme11t,(4)indete… 相似文献
7.
北京市森林可燃物分类研究 总被引：4，自引：0，他引：4
利用北京市土地利用图和Landsat TM影像,采用监督分类方法对可燃物进行分类,获得可燃物分类图,并对各类可燃物的特征进行详细描述.结果表明:可燃物可分6类,即O- 1草地(中低盖度)、O- 2草地(高盖度)、S- 1灌丛、S- 2幼林、C- 1针叶林、M- 1针阔混交林和B- 1阔叶林.由于TM卫星影像分辨率的限制,很难分别出林分垂直结构的差异.这一分类结果,可以满足森林火险等级预报的需要,但对于火行为预报,还需要根据林分燃烧性、林分垂直结构及可燃物分布状态进一步分类.对当前的可燃物分类方法与制图途径以及未来的发展趋势进行讨论. 相似文献
8.
A key challenge in modern wildfire mitigation and forest management is accurate mapping of forest fuels in order to determine spatial fire hazard, plan mitigation efforts, and manage active fires. This study quantified forest fuels of the montane zone of Boulder County, CO, USA in an effort to aid wildfire mitigation planning and provide a metric by which LANDFIRE national fuel maps may be compared. Using data from 196 randomly stratified field plots, pre-existing vegetation maps, and derived variables, predictive classification and regression tree models were created for four fuel parameters necessary for spatial fire simulation with FARSITE (surface fuel model, canopy bulk density, canopy base height, and stand height). These predictive models accounted for 56–62% of the variability in forest fuels and produced fuel maps that predicted 91.4% and 88.2% of the burned area of two historic fires simulated in the FARSITE model. Simulations of areas burned based on LANDFIRE national fuel maps were less accurate, burning 77.7% and 40.3% of the historic fire areas. Our results indicate that fuel mapping efforts that utilize local area information and biotic as well as abiotic predictors will more accurately simulate fire spread rates and reflect the inherent variability of forested environments than do current LANDFIRE data products. 相似文献
9.
J.J. Hollis S. Matthews R.D. Ottmar S.J. Prichard A. Slijepcevic N.D. Burrows B. Ward K.G. Tolhurst W.R. Anderson J.S. Gould 《Forest Ecology and Management》2010
Five models for the consumption of coarse woody debris or woody fuels with a diameter larger than 0.6 cm were assessed for application in Australian southern eucalypt forest fires including: CONSUME models for (1) activity fuels, (2) natural western woody and (3) natural southern woody fuels, (4) the BURNUP model and (5) the recommendation by the Australian National Carbon Accounting System which assumes 50% woody fuel consumption. These models were assessed using field data collected as part of the woody fuel consumption project (WFCP) in south-west Western Australia and northern-central Victoria. Three additional datasets were also sourced to increase variability in forest type, fuel complex and fire characteristics. These datasets comprised data from south-west Western Australia collected as part of Project Aquarius, the Warra Long Term Ecological Research site in Tasmania and Tumbarumba in south-eastern New South Wales. Combined the dataset represents a range of fire behaviour characteristic of prescribed burning conditions with a maximum fireline intensity of almost 4000 kW m−1. 相似文献
10.
11.
Successful management of forest fire risk in the Northeastern China boreal forest ecosystem often involves trade-offs between fire dynamics, fire hazard reduction, and fiscal input. We used the LANDIS model to study the effects of alternative fuel reduction strategies on fire dynamics and analyzed cost effectiveness for each fuel reduction strategy based on cost–benefit theory. Five levels of fuel treatment area (2, 4, 6, 8, and 10% for each decade) and two fuel treatment types (prescribed burning [PB] and mechanical treatments in combination with prescribed fire [PR]) under current fire suppression simulated by LANDIS were compared in a 5 × 2 factorial design over a 300-year period. The results showed that PR scenarios are more effective at reducing the occurrence and burn area of catastrophic fires than PB scenarios. In addition, area burned by high intensity fire can be tremendously reduced by increasing low intensity fires with a higher level of treatment area under the various PR scenarios. The cost effectiveness of alternative fuel reduction strategies is strongly dependent on treatment area. In general, PB scenarios will be more cost effective in larger treatment areas and PR scenarios in smaller. We recommend mechanical treatments in combination with prescribed fire, with 4% of landscape treated in each decade (PR04) to be the optimal fuel reduction strategy in the study area based on risk control and cost efficiency analysis. However, the most challenging work in China is to make local forest policy makers and land managers accept the ecological function of fire on forest ecosystems. 相似文献
12.
13.
在“被动扑救森林火灾”向“以预防为主”的森林火灾预防机制转变过程中,通过对寅街镇20年来森林火灾发生规律、起火原因、地域和时间分布进行分析,指出93％属人为野外用火引起,森林火灾造成的经济损失主要为非生产性用火中故意纵火、外区烧入、上坟等造成的,野外火源是导致寅街镇森林火灾的主要原因。提出落实责任,加强宣传,完善巡查力度,实施计划烧除,抓好森林火灾保险,严格火源管理等寅街镇森林火灾预防对策及加强野外火源管理的_几点建议。 相似文献
14.
Emulating natural forest disturbance is an increasingly popular forest management paradigm that is considered a means of achieving forest sustainability. Adopting this goal requires a sound understanding of natural disturbances at scales that correspond to management policies and strategies. In boreal forest landscapes driven by periodic stand-replacing fires this requires knowledge of fire regime characteristics, especially their spatial and temporal variability as well as stochasticity. The major goal of this study was to demonstrate the utility of fire regime simulation modeling to explore the variability of fire regime characteristics, with respect to formulating and assessing forest management strategies. We conducted a modeling experiment in a boreal forest landscape of northwestern Ontario, Canada, to examine its long-term fire regime in relation to forest policies on harvest size distribution. We used BFOLDS, a spatially explicit fire regime model that simulates individual fire events mechanistically in response to fire weather, fuel patterns, and terrain. The fire regimes in four large eco-regions were modeled for a 200-year period under three fire-weather (cold, normal, and warm) scenarios, with replications. We found that fire size distribution in all eco-regions followed power law under all weather scenarios, but their slopes and intercepts varied among eco-regions and fire weather scenarios. Warming fire weather increased burn rates and fire numbers in all eco-regions, albeit to different degrees. Overall, the variability among eco-regions was higher than the variability among fire weather scenarios, and among replicates. Comparisons of simulated fire size classes with those from an 86-year long fire history showed that empirical data cannot capture the variability that could be revealed by simulation modeling. We also show that fire size distribution is spatially heterogeneous within eco-regions, and provide several suggestions for forest policy directions with respect to forest harvest size distributions and harvest rates, based on the variability of fire regime characteristics. An assessment of present forest policies of emulating natural disturbances that guide forest harvest sizes showed that these are incongruent with simulated fire size distributions under all scenarios with one exception. Overall, this study illustrates the value of scenario simulation modeling to explore and quantify the variability of forest fire regime, for use in forest policies and strategies that attempt to emulate natural disturbance. 相似文献
15.
WANG Mingyu SHU Lifu Tian XiaoruiInstitute of Forest Protection. Chinese Academy of ForestryForest Fire Office. National Forestry Bureau Beijins . P.R..China. 《中国林业科技(英文版)》2003,(2)
In recent years, especially in the summer of 2002, the most serious forest fires occurred in the Daxingan Mountain of Heilongjiang province and Inner Mongolia. There has been long time serious forest fire environment in summer in Daxingan Mountain. The grass in the forest is scorched for long time drought and the moisture content of litter and turf layer decrease rapidly. The accumulation and dryness of fuel build the summer forest fire environment, which are major caused by Meteorological environment. Human are lack of the right recognition of summer fires, and can not achieve the goal of detecting and fighting in time. Also summer fires have the tendency to increase in some areas of the world and human have to pay much more attention to how to prevent and control summer fires. 相似文献
16.
Daniele Castagneri Assunta Esposito Giovanni Bovio Stefano Mazzoleni Umberto Seneca Ambra Elena Catalanotti Davide Ascoli 《Annals of Forest Science》2013,70(8):863-871
? Context
Prescribed burning is increasingly recommended to control encroaching shrublands in the Mediterranean area.? Aims
The aims of this paper are to analyze the fuel structural characteristics of Spartium junceum and how they influence fire behaviour during prescribed burning.? Methods
Two winter–spring prescribed burns were conducted in 2009 and 2011. Fuel load and structure of S. junceum shrubs were assessed using the Cube Method, and shrub 3-D models were built using the FIRE PARADOX FUEL MANAGER software. Allometric equations to estimate S. junceum fuel load were developed. During burning, thermocouples measured temperature variations, which were then analyzed relative to fuel characteristics.? Results
Fuel load components and distribution were strictly related to shrub height; in tall shrubs, most of the fine fuel was more than 1.5 m aboveground. Due to fuel vertical discontinuity, not all shrubs were burned in the fires, but wind increased fire sustainment and fuel consumption. Maximum temperatures (over 800 °C) and residence times were positively related to fuel load.? Conclusion
S. junceum tall shrublands represent high hazard formations due to their elevated fuel load, mostly in fine fuel fractions. Vertical discontinuity among fuel strata limits fire propagation in mild weather conditions. Winter–spring prescribed burning cannot eliminate S. junceum shrublands, but do create shrub cover discontinuity. As S. junceum has fire-adapted morphological traits, a single burn is insufficient to control it. 相似文献17.
Francesc Montané Pere Casals Marc Taull Bernard Lambert Mark R. T. Dale 《Annals of Forest Science》2009,66(6):612-612
18.
TIAN Xiaorui SHU Lifu WANG MingyuResearch Institute of Forest Ecology Environment Protection Chinese Academy of ForestryBeijing P.R. China 《中国林业科技(英文版)》2003,(2)
The paper described the natural conditions and forest types in Northwestern Region of China. Most forests in the region are distributed in subalpine areas. It is important to protect the existent forests in the region for maintaining ecological balance. According to the statistics results of 1991~2000, the paper analyzes the forest fires distribution and fire severity. Annually the numbers of forest fires range from 52 to 240. The incidence rate of forest fires in Northwestern Region is under 0.33 per ten thousand ha. There are 0.67-64.4 ha burned area per ten thousand ha forest. The main reasons for forest fires lie in the dry weather conditions, many firebrands, and high fuel loading. The strategies of fire management in the region are to stress the fire education in forest regions, strength the firebrands' management, emphasize the fuel management, and improve the fire monitoring and fire control ability. 相似文献
19.
The variation of fuel loads after a fire for three forest types,phododendron--Larix gmelinii forest,herb--Larix gmelinii forest andherb--Betula platyphlla forest, in the northern forest area of Daxing’anling region was discussed. The dynamic models were developed by gray theory
for estimating the fuels loads of arbor, shrub, herbs, grass, litter, and semi-decomposed litter, inflammable fuel and the
total fuels in each forest type. After a fire, the inflammable fuel loads inphododendron-Lxirix gmelinii forest and in the herb- -Betula platyphlla fores was estimated at 10.958 t/hm2 and 10.473 t/hm2 respectively, by 13 years later, and that was 12.297 t/hm2 inherb--Larix gmelinii forest by 7 years later. It was predicated that a big fire may occur after 10 years based on inflammable fuel biomass accumulated. 相似文献
20.
根据玛可河林区近7年森林火灾资料分析,选择着火时间、地点、原因、地类和面积等因素进行相关分析,得出如下结论:森林火灾主要集中在冬、春两季;冬季降水量少,气候干燥,易发生森林火灾,春季正是春耕生产季节,生产性火源和人为火源并重,易发生森林火灾;从火灾空间分布分析,班前地区森林火灾次数最多,其次是王柔和友谊桥地区;从地类分析,牧草地发生火灾面积最大,其次是灌木林地和阔叶林地,有林地较少。 相似文献