Spatial and temporal distribution of forest fire frequency and forest area burnt in Jilin Province,Northeast China

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.     

黑龙江省1980—2005年森林火灾时空特征

森林火灾是林火失去人为控制,在森林内自然蔓延和扩展,对生态系统和人类带来一定危害和损失的森林起火。森林火灾属世界性、跨国性的重大自然灾害,进入20世纪80—90年代以来,全球气候变暖导致森林火灾有上升的趋势,虽然各国的森林防火费用不断增加,但森林火灾发生的面积并未相     

Historic and current fire regimes in the Great Xing’an Mountains,northeastern China: Implications for long-term forest management

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.     

Fire history and fire–climate relationships along a fire regime gradient in the Santa Fe Municipal Watershed, NM, USA

The Santa Fe municipal watershed provides up to 40% of the city's water and is at high risk of a stand-replacing fire that could threaten the water resource and cause severe ecological damage. Restoration and crown fire hazard reduction in the ponderosa pine (PP) forest is in progress, but the historic role of crown fire in the mixed-conifer/aspen (MC) and spruce-dominated forests is unknown but necessary to guide management here and in similar forests throughout the southwestern United States. The objective of our study was to use dendroecological techniques to reconstruct fire history and fire–climate relationships along an elevation, forest type, and fire regime gradient in the Santa Fe River watershed and provide historical ecological data to guide management. We combined systematic (gridded) sampling of forest age structure with targeted sampling of fire scars, tree-ring growth changes/injuries, and death dates to reconstruct fire occurrence and severity in the 7016 ha study area (elevation 2330–3650 m). Fire scars from 141 trees (at 41 plots) and age structure of 438 trees (from 26 transects) were used to reconstruct 110 unique fire years (1296–2008). The majority (79.0%) of fires burned during the late spring/early summer. Widespread fires that scarred more than 25% of the recording trees were more frequent in PP (mean fire interval (MFI)_25% = 20.8 years) compared to the MC forest (31.6 years). Only 24% of the fires in PP were recorded in the MC forest, but these accounted for a large percent of all MC fires (69%). Fire occurrence was associated with anomalously wet (and usually El Niño) years preceding anomalously dry (and usually La Niña) years both in PP and in the MC forest. Fire in the MC occurred during more severe drought (mean summer Palmer Drought Severity Index; PDSI = −2.59), compared to the adjacent PP forest (PDSI = −1.03). The last fire in the spruce forest (1685) was largely stand-replacing (1200 ha, 93% of sampled area), recorded as fire scars at 68% of plots throughout the MC and PP forests, and burned during a severe, regional drought (PDSI = −6.92). The drought–fire relationship reconstructed in all forest types suggests that if droughts become more frequent and severe, as predicted, the probability of large, severe fire occurrence will increase.     

2003—2018年中国森林火灾时空分布格局研究

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...     

A comparative analysis of spatial, temporal, and ecological characteristics of forest fires in seasonally dry tropical ecosystems in the Western Ghats, India

The Western Ghats in India is one of the 25 global hotspots of biodiversity, and it is the hotspot with the highest human density. This study considers variations in the regional fire regime that are related to vegetation type and past human disturbances in a landscape. Using a combination of remote sensing data and GIS techniques, burnt areas were delineated in three different vegetation types and various metrics of fire size were estimated. Belt transects were enumerated to assess the vegetation characteristics and fire effects in the landscape. Temporal trends suggest increasingly short fire-return intervals in the landscape. In the tropical dry deciduous forest, the mean fire-return interval is 6 years, in the tropical dry thorn forest mean fire-return interval is 10 years, and in the tropical moist deciduous forest mean fire-return interval is 20 years. Tropical dry deciduous forests burned more frequently and had the largest number of fires in any given year as well as the single largest fire (9900 ha). Seventy percent, 56%, and 30% of the tropical moist deciduous forests, tropical dry thorn forests, and tropical dry deciduous forests, respectively have not burned during the 7-year period of study. The model of fire-return interval as a function of distance from park boundary explained 63% of the spatial variation of fire-return interval in the landscape. Forest fires had significant impacts on species diversity and regeneration in the tropical dry deciduous forests. Species diversity declined by 50% and 60% in the moderate and high frequency classes, respectively compared to the low fire frequency class. Sapling density declined by ca. 30% in both moderate and high frequency classes compared to low frequency class. In tropical moist deciduous ecosystems, there were substantial declines in species diversity, tree density, seedling and sapling densities in burned forests compared to the unburned forests. In contrast forest fires in tropical dry thorn forests had a marginal positive effect on ecosystem diversity, structure, and regeneration.     

Analysis of the seasonal characteristics of forest fires in South Korea using the multivariate analysis approach

For efficient forest fire management, special precautions are required in dry and strong-wind seasons vulnerable to severe forest fires. To extract the seasonal characteristics of forest fires in South Korea, the statistics over the past 16 years, 1991 through 2005, were investigated. The daily records of the number of fire occurrences, the total area burned and the average burned area per occurrence were examined to identify the seasonal patterns of forest fires using cluster analysis and principal component analysis; the risk of daily fires was also assessed using the ordered logit model. As a result, the fire patterns were classified into five clusters and a general danger index for forest fires was derived from the first principal component, showing relatively large-scaled fire regimes in spring, and frequent small-scaled fire regimes in autumn and winter. In connection with the ordered logit model, the probability for the five ranks of forest fire risk was calculated and the threshold for high-risk fires was detected. As an implementation of the results above, the proper forest fire precautionary period in South Korea was estimated, and consequently October 21 through May 17 was recognized as a dry season at a high risk of forest fires. This period began 10 days earlier in autumn and extended into midwinter (late December and January) as opposed to the existing precautionary period, indicating the need of more cautious forest fire management earlier in autumn and continuing through midwinter.     

Forest Fires and Prevention Strategies in Northwestern Region of China

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.     

中国南方冰雪灾害对森林火灾火发生短期影响分析——以湖南为例

以湖南省为研究区域,分析冰雪后短期内(3月份)卫星热点的空间分布特征、与受害程度的空间关系,森林火灾发生的特点和扑火人员伤亡情况,以及气象因素对火发生的影响.结果表明:处于受害区确认为森林火灾的卫星热点占总数的61.00%.2008年3月份火灾次数和过火面积异常增高,共发生火灾3 097起,过火面积23 227.68 hm2,火灾次数超过1999-2007年3月份火灾次数的总和,且是1999-2007年3月份火灾次数总和的120.65%,3月份平均火灾次数的10.86倍.过火面积是1999-2007年3月份总和的88.40%,3月份平均过火面积的4.69倍.人员伤亡40人,是1999-2007年3月份人员伤亡总和的72.73%,平均伤亡人数的6.56倍.冰雪灾害后,2008年3月火灾次数、过火面积和人员伤亡人数的异常增高已经超出了气温和降水对火发生正常影响的范围.     

Characterization of forest fires in Catalonia (north-east Spain)

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.     

基于地理加权回归模型与林火遥感数据估算森林年龄

【目的】通过地理加权回归(GWR)模型估算非干扰林龄,利用遥感数据和林火发生历史数据,获取过火区域信息,进而对林火烈度分级,讨论林火烈度与森林类型的交互作用,估算干扰林龄,最终获得黑龙江省森林年龄的空间分布。【方法】以黑龙江森林为研究区域,基于研究区域的多光谱数据结合地面森林资源清查数据,通过逐步回归方法提取了包括遥感因子绿度指数(Greeness)、湿度指数(Wetness)、林分平均胸径(ADBH)、林分平均树高(ASH)及海拔(Altitude)在内的5个显著因子作为自变量,采用GWR模型建立非干扰林龄估算模型。采用全局Moran I来描述模型残差的空间自相关性。绘制研究区非干扰林龄空间分布图并探究林龄的空间分布状态。[JP+1]结合林火位置与面积记录对多光谱数据目视解译提取过火区域,根据dNBR将过火区域火烈度分级。将火烈度图与植被类型图叠加分析,讨论不同森林类型在不同火烈度下的演替情况。定义干扰林龄时,未发生树种更替的森林林龄不变,树种发生更替的森林在林火发生年将其林龄归为0,并在新的优势树种萌发时从1开始累加,以此类推干扰后森林的林龄。【结果】黑龙江省非干扰森林平均林龄为48年,标准差为16年。GWR模型的 Radj^2 为0.68,RMSE为16.171 7。使用Moran I来检验模型的残差,发现GWR模型可很好地消除残差的空间自相关性。研究区林龄整体空间分布状态不均匀,大兴安岭地区林龄普遍高于黑龙江林区。黑龙江省2000―2010年林火主要发生在大兴安岭及小兴安岭地区,根据dNBR将已提取的过火区域林火烈度分为:未过火、轻度过火、中度过火和重度过火4类,总过火面积为527 932 hm^2,其中重度29 157 hm^2、中度180 268 hm^2、轻度318 507 hm^2。兴安落叶松林和蒙古栎林在整个研究区中过火面积最大,分别占总过火面积的28.63%和47.23%。根据不同森林类型在不同火烈度下的演替情况,估算干扰森林的林龄并绘制干扰林龄空间分布图。【结论】 GWR模型能较有效地估算黑龙江省非干扰林龄,成功地降低了残差的空间自相关性。在估算林龄的过程中加入林火干扰因素,以获取更真实的林龄空间分布数据,可为黑龙江地区森林NPP、NEP以及森林碳储量、森林生物量等相关研究提供数据支持。     

基于地理加权回归模型与林火遥感数据估算森林年龄

【目的】通过地理加权回归(GWR)模型估算非干扰林龄,利用遥感数据和林火发生历史数据,获取过火区域信息,进而对林火烈度分级,讨论林火烈度与森林类型的交互作用,估算干扰林龄,最终获得黑龙江省森林年龄的空间分布。【方法】以黑龙江森林为研究区域,基于研究区域的多光谱数据结合地面森林资源清查数据,通过逐步回归方法提取了包括遥感因子绿度指数(Greeness)、湿度指数(Wetness)、林分平均胸径(ADBH)、林分平均树高(ASH)及海拔(Altitude)在内的5个显著因子作为自变量,采用GWR模型建立非干扰林龄估算模型。采用全局Moran I来描述模型残差的空间自相关性。绘制研究区非干扰林龄空间分布图并探究林龄的空间分布状态。[JP+1]结合林火位置与面积记录对多光谱数据目视解译提取过火区域,根据dNBR将过火区域火烈度分级。将火烈度图与植被类型图叠加分析,讨论不同森林类型在不同火烈度下的演替情况。定义干扰林龄时,未发生树种更替的森林林龄不变,树种发生更替的森林在林火发生年将其林龄归为0,并在新的优势树种萌发时从1开始累加,以此类推干扰后森林的林龄。【结果】黑龙江省非干扰森林平均林龄为48年,标准差为16年。GWR模型的 Radj^2 为0.68,RMSE为16.171 7。使用Moran I来检验模型的残差,发现GWR模型可很好地消除残差的空间自相关性。研究区林龄整体空间分布状态不均匀,大兴安岭地区林龄普遍高于黑龙江林区。黑龙江省2000―2010年林火主要发生在大兴安岭及小兴安岭地区,根据dNBR将已提取的过火区域林火烈度分为:未过火、轻度过火、中度过火和重度过火4类,总过火面积为527 932 hm^2,其中重度29 157 hm^2、中度180 268 hm^2、轻度318 507 hm^2。兴安落叶松林和蒙古栎林在整个研究区中过火面积最大,分别占总过火面积的28.63%和47.23%。根据不同森林类型在不同火烈度下的演替情况,估算干扰森林的林龄并绘制干扰林龄空间分布图。【结论】 GWR模型能较有效地估算黑龙江省非干扰林龄,成功地降低了残差的空间自相关性。在估算林龄的过程中加入林火干扰因素,以获取更真实的林龄空间分布数据,可为黑龙江地区森林NPP、NEP以及森林碳储量、森林生物量等相关研究提供数据支持。     

黑龙江省林火规律研究Ⅱ.林火动态与格局影响因素的分析

本文对在大尺度 (5 0 0km2 以上 )上影响黑龙江省林火的因素及其影响途径进行了分析。结果表明 ,年林火次数 (人为火次数 )与林业人口正相关 ,林火面积与人口无关。干燥度的空间差异对林火燃烧率格局有正向影响。林火特征与气候因子之间没有线性关系。黑龙江省林火次数和面积对年均温和降水量的响应可归纳为旋转的单叶双曲面和双叶抛物面两种模式。林火特征的周期与年均温、年降水量的周期关系很大。黑龙江省森林类型对林火次数、面积的影响在省级区划尺度上不显著的。较高的管理水平显著减少林火。林火次数、面积与了望塔数量、消防车数量及通讯覆盖率等无线性关系     

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.     

Forest fire effects in beech dominated mountain forest of Iran

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.     

内蒙古大兴安岭林火与气象因子关系研究

基于内蒙古大兴安岭1990—2019年森林火灾历史档案和同期气象因子的数据,对该地区林火与气象因子间的相关性进行了研究。结果表明,林火发生与气象因子间的关系密切。林火发生次数随着温度的升高和降水的减少呈上升趋势;研究区日均相对湿度范围在58%~62%,火灾发生次数最多;林火发生次数与日照时数、日均温、日最高温间均呈显著正相关;过火面积与日均相对湿度间呈显著负相关,与日照时数间呈显著正相关。     

Forest fuel mapping and evaluation of LANDFIRE fuel maps in Boulder County,Colorado, USA

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.     

The effects of wildfires on wood-eating beetles in deciduous forests on the southern slope of the Swiss Alps

The effect of fires on Cerambycidae, Buprestidae and Lucanidae were studied at 23 sites within a chestnut forest in southern Switzerland. We compared six unburnt sites, two freshly burnt sites, eight sites which burned once at different times in the last 30 years, and seven sites where fires occurred repeatedly in the last 30 years. The diversity and the species composition of the three xylobiont families were related to various ecological variables at two levels of spatial scale, a small scale of 0.25 ha and a large scale of 6.25 ha. These variables were: fire frequency, time since the last fire, clear cutting after the fire, forest structure, amount of dead wood, and habitat mosaic. The fire does not have a direct effect on the xylobiont beetles community at small scale; however, fire has an indirect effect by maintaining a relatively open forest structure. The mosaic of forest areas burnt with different frequencies and at different times was an important factor influencing species richness and species composition at the large spatial scale.Data presented here supports the strategy to conserve the diversity and includes species composition of xylobiont fauna in deciduous forests: (i) at small spatial scale, to maintain highly structured and relatively open stands with large amounts of dead wood and big oak trees; (ii) at large spatial scale, to favour a mosaic of different forest habitats and successional stages. A forest offering a good structural diversity is important for maintaining landscape complexity and thus a high species richness of xylophagous beetles.     

Land cover analysis in wildland-urban interfaces according to wildfire risk: A case study in the South of France

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.