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1.
Understanding both historic and current fire regimes is indispensable to sustainable forest landscape management. In this paper, we use a spatially explicit landscape simulation model, LANDIS, to simulate historic and current fire regimes in the Great Xing’an Mountains, in northeastern China. We analyzed fire frequency, fire size, fire intensity, and spatial pattern of burnt patches. Our simulated results show that fire frequency under the current fire scenario is lower than under the historic fire scenario; total area burnt is larger with lower fire intensity under the historic fire scenario, and smaller with higher fire intensity under the current fire scenario. We also found most areas were burned by high intensity fires under the current fire scenario, but by low to moderate fires under the historic fire scenario. Burnt patches exhibit a different pattern between the two simulation scenarios. Large patches burnt by high intensity class fires dominate the landscape under the current fire scenario, and under historic fire scenario, patches burnt by low to moderate fire intensity fires have relatively larger size than those burnt by high intensity fires. Based on these simulated results, we suggest that prescribed burning or coarse woody debris reduction should be incorporated into forest management plans in this region, especially on north-facing slopes. Tree planting may be a better management option on these severely burned areas whereas prescribed burning after small area selective cutting, retaining dispersed seed trees, may be a sound forest management alternative in areas except for the severely burned patches. 相似文献
2.
气候变化下森林火灾过火面积预测——以大兴安岭北方森林为例 总被引：1，自引：0，他引：1
利用Delta统计降尺度方法解集HadCM3 IPCC SRES A2a和B2a情景下气候基准时段(1961-1990年)与未来不同时段 (21世纪20年化,2010-2039年;21世纪50年代,2040-2069年;21世纪80年代,2070-2099年)的逐月的最高温度、相对湿度、降水和风速数据,结合历史火灾数据、气象资料以及加拿大火险天气指标系统中SSR指标数值的统计相关性,在假设林火动态对当前及未来气候变化具有相同响应方式的基础上,定量和定性相结合预估未来该区北方森林过火面积的变化趋势。结果表明:历史过火面积与SSR均值呈显著线性相关(r,0.16-0.61),SSR增值能作为过火面积增量指标。HadCM3 IPCC SRES A2a和B2a情景下,21世纪大兴安岭地区森林火灾过火面积相对于1961-1990年气候基准值呈显著增加趋势,其中21世纪80年代该区平均过火面积可能会增加1倍。21世纪该区过火面积呈现强烈的季节特征,夏季防火期和秋季防火期的过火面积增长较快,尤其是夏季防火期,A2a情景下21世纪80年代森林火灾过火面积将会增加1.5倍。图4表1参31。 相似文献
3.
基于2003—2018年的中国森林火灾统计数据,全面分析了森林火灾发生的时空分布格局,定量分析了其统计学规律,旨在为森林火灾预测、管理和风险决策提供基础支撑。分析结果表明,森林火灾的发生具有极强的随机性和离散性,通过森林火灾总次数、火场面积和受害森林面积的平均数来反映森林火灾发生风险将会导致评估结果偏高。森林火灾发生次数较多的为湖南、贵州、广西等省,而森林火场面积和受害森林面积较多的为黑龙江、内蒙古、云南、湖南、广西等省。按照森林火灾发生的格局,运用K均值聚类分析将31省分为4类。 相似文献
4.
《Forest Ecology and Management》2001,141(3):155-163
We compared the fire regimes in Mediterranean pine forests during two periods, 1370–1466 and 1966–1996 A.D. Medieval fire regime was estimated from the ‘claveria’ books of the Tortosa city, which record the city expenditures, including those for fighting fires that were burning in the city forest. We used the amount spent as an estimate of fire magnitude. Current fire regime was estimated for the same area from the local environment agency data bank, which includes date, location and burned area. The mean number of recorded fires per year, which mostly occurred in summer, is not significantly different between the two periods. Time-since-fire distributions of both periods fitted the negative exponential model, and they were not significantly different. The probability of fire occurring within 1-year interval was 0.44 for the 1379–1466 period and 0.46 for the 1966–1996 period. In both cases, small fires were more abundant, although there are some differences in the medieval series, 13% of all documented fires accounted for 47% of the suppression effort, whereas in the 20th century series, one single fire accounted for 88% of the area burned. Analysis of extreme fire also indicates that in the medieval series the largest fire per year needed one or less days of suppression effort in 58% of the years, whereas in the current period, fires were smaller than 1 ha in 78% of the years. We found that fire suppression in the Middle Ages was associated with forest exploitation. Although we cannot compare the two data sets accurately, there is not evidence of differences in fire frequency between the medieval and the current periods. Differences in fire magnitude distributions of both series of records may be explained by the different purposes and technical resources involved in the fire suppression practices. 相似文献
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Characterization of forest fires in Catalonia (north-east Spain) 总被引：1，自引：0，他引：1
The present study analyses the temporal variation in the distribution of the number of fires, area burned and fire sizes in
Catalonia using fire data from 1942 to 2002. The study shows variations in the distribution of fire size over recent decades,
with a significant increase in the number of very large fires. The study also analyses relationships between characteristics
of the forest (altitude, slope, aspect, living fuels and species composition) and the probability of the fire occurrence.
The analysis is based on the overlay of forest cover data and perimeters of forest fires during the period (1986–2002). Of
the analysed variables, altitude affects most the probability of fire occurrence, with higher proportions of burned forest
area at lower altitudes. Stand’s vertical structure is also relevant, with lower proportions of burned area in stands with
mature tree cover without understory. The study helps to analyse the strengths and weaknesses of forest and fire management
policies, especially those related to forest and fuel management at the landscape level. 相似文献
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《Forest Policy and Economics》2002,4(1):43-54
All of the Mediterranean countries face a serious forest fire problem. The main factors that affect the problem of forest fires in Greece are vegetation, climate conditions and most of all, arson (Proceedings of Forest Fires in Greece, Thessaloniki, 1990, p. 97). In Greece, after 1974, the number of forest fires and the total burned areas have risen dramatically. The design of an effective fight and prevention policy is a very important matter, as it can minimize the destruction. This paper describes an expert system that classifies the prefectures of Greece into forest fire risk zones, using a completely new methodology. The concept of fuzzy expected intervals (F.E.I.) was defined by Kandel and Byatt (Proc. IEEE, 66, 1978, 1619) and offered a very good approach towards forest fire risk classification. Fuzzy expected intervals are narrow intervals of values that best describe the forest fire problem in the country or a part of the country for a certain time period. Fuzzy logic was applied to produce a F.E.I. for each prefecture of the country. A successful classification of the prefectures of Greece (in forest fire risk zones) was performed by the expert system by comparing the produced fuzzy expected intervals to each other and by using a supervised machine learning algorithm that assigns a certain weight of forest fire risk to each prefecture (Machine Learning, John Wiley and Sons, 1995). 相似文献
9.
福建林火的发生特点与防治对策探讨 总被引：5，自引：0，他引：5
对福建省近年发生的１９７起森林火灾归纳、分析表明，森林火灾发生频率最高的是生产用火，林火发生以２、３月份最多；上午１０时至下午１８时为林火发生的高峰；预防林火发生，应确定森林防火戒严期，开展火险预测预报，完善防火设施，以利于迅速扑火。 相似文献
10.
《林业研究》2019,(6)
Forest fires are influenced by several factors,including forest location, species type, age and density,date of fire occurrence, temperatures, and wind speeds,among others. This study investigates the quantitative effects of these factors on the degree of forest fire disaster using nonparametric statistical methods to provide a theoretical basis and data support for forest fire management.Data on forest fire damage from 1969 to 2013 was analyzed. The results indicate that different forest locations and types, fire occurrence dates, temperatures, and wind speeds were statistically significant. The eastern regions of the study area experienced the highest fire occurrence,accounting for 85.0% of the total number of fires as well as the largest average forested area burned. April, May, and October had more frequent fires than other months,accounting for 78.9%, while September had the most extensive forested area burned(63.08 ha) and burnt area(106.34 ha). Hardwood mixed forest and oak forest had more frequent fires, accounting for 31.9% and 26.0%,respectively. Hardwood-conifer mixed forest had the most forested area burned(50.18 ha) and burnt area(65.09 ha).Temperatures, wind speeds, and their interaction had significant impacts on forested area burned and area burnt. 相似文献
11.
Abbas Banj Shafiei Moslem Akbarinia Gholamali Jalali Mohsen Hosseini 《Forest Ecology and Management》2010
Most of world's forests of different climates have a history of fire, but with different severities. Fire regimes for broadleaf deciduous forests have return intervals that vary from many decades (or less) to centuries (or more). Iran has a total of 1.2 million ha of temperate forest in the north, where fires burn about 300–400 ha annually. This study focused on the impact of fire on forest structure, tree species quality, and regeneration composition (specially beech) in the Chelir forest of northern Iran. The results showed that forest fires changed the structure and had different effects on tree species composition between burned and control areas. Thin barked species such as oriental beech (Fagus orientalis Lipsky) and coliseum maple (Acer cappadocicum Gled.) have been affected more than those with thick bark, like hornbeam (Carpinus betulus L.) and chestnut-leaved oak (Quercus castaneifolia C.A. Mey). The density of oriental beech regeneration in the unburned area was greater than in the burned area, while the quantity of regeneration of hornbeam, coliseum maple and velvet maple (Acer velutinum Boiss) was higher in burned area. Forest fire had a greater effect on oriental beech quality, and changed regeneration composition in the burned area. Fire prevention activities should be considered as a silvicultural treatment for preserving these valuable forests. 相似文献
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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
15.
Dendrochronology-based fire history of mixed-conifer forests in the San Jacinto Mountains,California
The growing public awareness of the increasing number of large wildfires across forested landscapes, coupled with needs of resource base management has accelerated research into forest reference conditions and the historical role of fire in coniferous ecosystems. This work investigates historical fire regimes of mixed-conifer forests in the San Jacinto Mountains of southern California using fire-scar dendrochronology. As such this is the first reconstruction of fire history in the mixed-conifer forests of southern California using landscape-scale systematic-based fire-scar dendrochronology. The pre-historical fire size, seasonality, and frequency within these forests are reconstructed and demonstrated graphically, employing systematic sampling and Geographical Information System (GIS) reconstruction. A 250 m grid system was overlaid upon a 270 ha sample location, and fire-scar samples were collected from each of the grid intersection points. Fire-scar dendrochronology resulted in a 653 years long chronology, indicating a point mean fire return interval of 5.2 years, and an area wide grand mean fire interval of 32.2 years. The majority of fires occurred within latewood or at the ring boundary. Graphic modelling of fire events indicate three-quarters of all fires sampled were less than 6.25 ha in size, but burned over 50% of the area sampled during the period; only a small portion of fires were larger than 18 ha within the sample area. Use of systematic sampling is an important step in modeling long-term frequency and effects of fire on a landscape level, and is invaluable to the long-term management planning. 相似文献
16.
南方人工林森林火灾发生和危害之评估 总被引：1，自引：0，他引：1
根据全国25省区和南方4省区1999～2001年的森林火灾数据,分析评估了南方人工林发生森林火灾的原因、过程和危害的程度;探讨山火防范和控制,减少危害和投资风险的途径,并以肇庆市国有林场过去10年森林火灾发生情况作验证。人工林森林火灾受气候、地区森林覆盖率和特征、人工林特征、经营管理系统等的综合影响,每年10月至次年2月份为干旱季节,森林火灾发生最为频繁。肇庆国有林场过去10年森林火灾面积比率为0．023％0～4、840％0。通过设立健全的森林防火和控制系统,有效的营林管理,南方人工林发生火灾的面积机率可以最大限度地降低,应可以控制在1％以下。 相似文献
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Long term effects of fire on ectomycorrhizas and soil properties in Nothofagus pumilio forests in Argentina 总被引：1，自引：0，他引：1
The forests of Nothofagus pumilio have historically been affected by forest fires. The effects of fire on certain above and belowground, biotic and abiotic components of these ecosystems have been previously documented, albeit belowground components have received much less attention. It has been suggested that the effects observed in the short-term after a fire usually differ from the longer-term effects. The long-term effects of fire (i.e. >5 years after burning) on belowground components in Nothofagus forests are currently unknown. In the present study we evaluated the long-term effect of fire on ectomycorrhiza (ECM) colonization and morphotype composition in N. pumilio roots, as well as soil chemical properties in temperate forests in Patagonia. Sampling was conducted in three mature monospecific forests. In each, nearby burned and unburned sites were selected. The time since the occurrence of fires differed between areas (i.e. 6-10 years). Within each site, 3 transects of 40 m were established randomly along which 5 samples of roots and soil were collected in spring and autumn. The main results were: (1) in comparison with the unburned site, ECM colonization was lower in the burned site in the area with the shorter time length since fire occurrence and no effects in the other two areas were observed; (2) richness and diversity were not significantly affected by fire but there was a significant effect of season for both parameters, being higher in spring; (3) ECM dominance was significantly higher in the unburned than in the burned site in Tronador, while in Challhuaco the opposite was observed, mainly in autumn; (4) in general carbon, nitrogen and phosphorous decreased while pH increased in the burned sites; (5) ECM colonization positively correlated with NH4+ and phosphorus and negatively with pH but was not significantly correlated with organic matter or any other soil variable. Altogether the results suggest that effects of fire on ectomycorrhiza and soil properties in N. pumilio forests are probably related to the time elapsed since fire occurrence combined with site characteristics. In addition, the direct and indirect effects of fire in these forest systems may persist for more than 10 years. 相似文献
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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
20.
Forest fires caused by natural forces or human activities are one of the major natural risks in Northeast China. The incidence and spatial distribution of these fires vary over time and across the forested areas in Jilin Province, Northeast China. In this study, the incidence and distribution of 6519 forest fires from 1969 to 2013 in the province were investigated. The results indicated that the spatiotemporal distribution of the burnt forest area and the fire frequency varied significantly by month, year, and region. Fire occurrence displayed notable temporal patterns in the years after forest fire prevention measures were strictly implemented by the provincial government. Generally, forest fires in Jilin occurred in months when stubble and straw were burned and human activities were intense during traditional Chinese festivals. Baishan city, Jilin city, and Yanbian were defined as fire-prone regions for their high fire frequency. Yanbian had the highest frequency, and the fires tended to be large with the highest burned area per fire. Yanbian should thus be listed as the key target area by the fire management agency in Jilin Province for better fire prevention. 相似文献