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【目的】利用卫星遥感技术研究火后植被恢复过程及影响因子,分析不同火烧强度、不同植被类型的火后归一化植被指数(NDVI)变化特征,研究大兴安岭东南部火后不同植被恢复过程,为在长时间尺度上进行北方林火后植被恢复过程研究与监测提供参考。【方法】基于火烧前后一系列的MODIS数据,利用NDVI和地面调查数据,以2006年大兴安岭松岭特大森林火灾为例,研究不同植被类型在不同强度火烧后的植被恢复过程。根据火烧前后NDVI变化提取过火区;结合地面调查,利用监督分类方法划分火烧强度等级;根据火烧强度分级图和土地覆盖类型图,建立属性数据库,生成火烧强度等级-植被类型图。以2003—2005年同期NDVI最大值为对照,在时间序列上分析植被类型和火烧强度对火后NDVI恢复的影响。根据邻近未过火区的NDVI变化,分析气象因子对NDVI的影响。【结果】轻度、中度和重度火烧区所占比例分别为29%,40%和31%。主要植被类型常绿针叶林、针阔混交林和灌丛的重度火烧部分分别占50%,52%和60%。重度火烧区域所占比例随着坡度增大而升高。在火后NDVI的变化过程中,各森林类型变化趋势相近,灌丛、草地和沼泽的变化趋势相近。【结论】火后NDVI总体呈上升趋势,并呈现明显的年际波动。除草地外其余植被类型在重度火烧后的NDVI值均明显低于中、轻度火烧,但中、轻度火烧的不同植被类型之间差异不明显。森林重度火烧区NDVI在火后第2年达到最低,轻度火烧区火后6年NDVI基本恢复到火前水平。针阔混交林火后盖度的恢复速度较其他森林类型快。火烧强度对森林群落垂直结构的影响显著,森林火烧后灌木层盖度高于未火烧区,且火烧强度越高,这种现象越显著。双因素方差分析显示植被类型和火烧强度对火烧迹地NDVI恢复特征的影响显著,且火烧强度对火后植被恢复的影响更关键,但二者交互影响不显著。未过火区NDVI平均值为0.801 2,波动范围为-3.3%~3.4%,过火区d NDVI的变化约25%是由气象因子引起的,其他主要源于植被变化。d NDVI指标可以很好地反映火烧前后植被指数变化,有较好的时序性和空间可获取性,对火烧迹地恢复过程有指示作用。 相似文献
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以内蒙古大兴安岭寒温带兴安落叶松林3个年份的重度火烧迹地为研究对象,利用样地调查数据,阐述重度火烧迹地森林恢复的重要性,研究其林分结构特征及植物多样性为该迹地森林恢复与重建提供理论依据。采用SPSS及R语言进行分析,研究林分结构以及植物多样性变化情况。结果表明:林地经过重度火干扰后,树种的平均胸径有所增大,其林分胸径分布频率均符合威布尔分布,为单峰形偏左倾分布。火干扰后植被物种多样性与火烧强度和火烧时间紧密相关,重度火烧迹地在不同恢复时间上恢复的植物种类有所不同,植物种的α多样性指数因恢复时间的变化而变得较为复杂,其多样性指数总体上呈先上升后下降的趋势。一段时间内高强度的火干扰有利于森林群落内植物种多样性不断更新与恢复。 相似文献
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大兴安岭北坡火烧迹地森林郁闭度恢复及其影响因子分析 总被引：1，自引：0，他引：1
1987年发生在大兴安岭北坡的特大火灾造成了森林资源的巨大损失,其森林景观恢复一直是人们关注的热点.本研究选取与森林生产力具有密切联系的郁闭度因子作为研究对象,以 ArcView、ArcGIS等地理信息系统软件为研究平台,采用1987年和2000年两期森林资源二类调查数据,对郁闭度、火烧强度、抚育类型、地形因子等进行分级,通过数据叠加,探讨了森林郁闭度格局的恢复状况以及火烧强度、更新类型、地形因子对郁闭度恢复的影响.结果显示:2000年郁闭度等级构成与1987年火前相比发生了明显变化,无林地以及高郁闭度等级比重明显下降,较低郁闭度等级比重显著上升;火烧强度是影响火后恢复的初始因子,火烧强度与郁闭度等级呈负相关;更新措施短期内对郁闭度恢复影响不显著,但可以缩短森林演替的周期,对未来针叶林群落生产力恢复具有重要促进作用;地形因子中坡度对郁闭度恢复影响最为明显,其次为坡位,坡向影响最弱. 相似文献
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分解和火干扰是森林凋落物养分循环的重要生态过程。缓慢的凋落物分解速率会促使凋落物的累积，从而导致林火发生的概率大幅提升。火干扰会在短时间内对凋落物载量、厚度以及自身的化学组成产生较大的影响，同时对凋落物分解也会有较长时期的动态影响，可能需要几年或几十年恢复到火前的分解速率。通过查阅大量相关文献，文中从火干扰对森林凋落物分解的直接影和间接影响出发，阐述火这一干扰因子在森林凋落物分解过程中发挥的作用。并针对目前研究中存在的问题，提出今后的相关研究应从以下3个方面实现突破：1）加强火后不同恢复年限对森林凋落物分解动态变化的影响研究；2）探究火干扰后采取不同的森林恢复方式对凋落物分解的影响；3）了解火后副产物-黑碳在森林凋落物分解过程中的作用。基于这些综述，可为更好地理解和探索火干扰对森林凋落物分解的影响机制提供借鉴，以推动该领域的发展。 相似文献
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火,长期与森林生态系统相互作用,对植物群落的形成,发展和演替起着关键作用。研究林火对加速森林的恢复、缩短复生时间有着重要的作用。一、植物群落被火烧后发生的变化。森林植被,不论是人工的还是天然的一旦被火烧后,植物群落都会发生极大变化,使原来的群落变成另一种类型。但是,这种变化类型的方向却和自然条件的群落由简单到复杂,由低级到高级的自然发展相反。因此,当火对群落的干扰作用继续进行时,即 相似文献
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大兴安岭火烧迹地植被天然恢复效果的评价 总被引：2，自引：0，他引：2
通过对大兴安岭新林林业局宏图林场3个不同火烧恢复时期森林植被恢复的调查,以火烧迹地内生物多样性为研究对象,应用主成分分析方法,对各调查区恢复情况进行分析。研究结果表明：火烧迹地各层物种数随火烧后恢复时间的推移,乔木层与灌木层的变化不是很明显,而草本层变化较大,随着时间的推移物种数逐渐降低;各层的物种多样性随火后恢复时间的推移先增加后减少,之后逐渐处于平稳;各层的物种均匀度随火后恢复时间的推移也是先增加后下降,之后逐渐处于平稳,其中波动变化最大的是灌木层,说明火干扰对灌木层空间分布影响较大。 相似文献
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Andrew M. Barton 《Forest Ecology and Management》1999,120(1-3):143-156
I examined contrasts in response to moderate-intensity fire between two pine species (Pinus leiophylla Schiede and Deppe and P. engelmannii Carr.) and four oak species (Quercus hypoleucoides Camus., Q. arizonica Sarg., Q. emoryi Torr., and Q. rugosa Nee.) in Madrean forests in southeastern Arizona. Stem survival of pines after fire was greater than for oaks, but oaks sprouted more successfully after top-kill than did the only sprouting pine species, P. leiophylla. As a result, post-fire decline and subsequent recovery in oak populations was more marked than for the pines, and the ratio of oaks to pines decreased as a result of fire but increased during recovery. In typical forest stands, most individuals established from 1860 to 1920 at the interface between a period of high fire frequency and the onset of fire exclusion. Ages of Q. hypoleucoides were more clustered than for the pines, suggesting post-fire sprouting rather than long-term top-survival of fire. The results point to contrasts in mechanisms of persistence in this fire-prone ecosystem: fire resistance in the pines versus post-fire sprouting in the oaks. As a result, fire regime controls the balance between the two groups, with moderate-intensity fire favoring the pines and periods of low fire frequency – due to natural causes or anthropogenic fire exclusion – favoring the oaks. The species and community response patterns found in this study may apply generally to other pine-oak communities. 相似文献
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Fires are considered the most important disturbance regime in many ecosystems, including boreal forest. Fires usually reduce the abundances of soil living animals, but the duration of the fire effect and the recovery rate of soil fauna communities after fire are poorly understood. The species-rich group of microarthropods (collembolans, mites and proturans) constitutes an important part of the soil food-web, contributing to important ecosystem services like decomposition and nutrient mobilization. Recovery rates of microarthropods after fire reported in the literature differ considerable between sites and studies. Here, I examine if variation in fire severity can explain part of the variation in recovery of microarthropods after fire observed among studies. To do so, I have chosen studies done in boreal forests and in which the post-fire situation was described in such a way that fire severity (depth of burn) could be estimated. I also selected studies that used real abundance data and that sampled for animals for at least 2 years after fire. 相似文献
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D.W. Johnson J.F. Murphy R.B. Susfalk T.G. Caldwell W.W. Miller R.F. Walker R.F. Powers 《Forest Ecology and Management》2005,220(1-3):155-165
The effects of fire, post-fire salvage logging, and revegetation on nutrient budgets were estimated for a site in the eastern Sierra Nevada Mountains that burned in a wildfire in 1981. Approximately two decades after the fire, the shrub (former fire) ecosystem contained less C and more N than the adjacent forest ecosystem. Reconstruction of pre-fire nutrient budgets suggested that most C was exported in biomass during salvage logging and will not be recovered until forest vegetation occupies the site again. Salvage logging may have resulted in longer-term C sequestration in wood products than would have occurred had the logs been left in the field to decay, however. Reconstructed budgets suggested that most N was lost via volatilization during the fire rather than in post-fire salvage logging (assuming that foliage and O horizons were combusted). Comparisons of the pre-fire and present day N budgets also suggested that the lost N was rapidly replenished in O horizons and mineral soils, probably due to N-fixation by snowbush (Ceanothus velutinus Dougl.), the dominant shrub on the former fire site. There were no significant differences in ecosystem P, K, or S contents and no consistent, significant differences in soil extractable P or S between the shrub and forested plots. Exchangeable K+, Ca2+, and Mg2+ were consistently and significantly greater in shrub than in adjacent forested soils, however, and the differences were much larger than could be accounted for by estimated ash inputs. In the case of Ca, even the combustion of all aboveground organic matter could not account for more than a fraction of the difference in exchangeable pools. We speculate that the apparent large increased in soil and ecosystem Ca content resulted from either the release of Ca from non-exchangeable forms in the soil or the rapid uptake and recycling of Ca by post-fire vegetation. 相似文献
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C. Puerta-Pi?ero L. Brotons L. Coll J. R. González-Olabarría 《European Journal of Forest Research》2012,131(3):835-844
Ecological processes within forests provide vital ecosystem services to society, most of which depend on the persistence of
tree cover that can be altered after the impact of a disturbance. The aim of the present study was to examine the role of
seed dispersal and resprouting that mediate resilience to large fires and evaluate the economic costs that these ecological
functions provide. We used field data from 412 plots of the Spanish National Forest Inventory providing information on pre-
and post-fire conditions of Mediterranean Pinus spp. and Quercus spp.-dominated forests. Then, we determined the need for restoration (N
Rest) and estimated the minimum pre-fire densities needed to ensure adequate post-fire cover. Economic valuations were assessed
through three different scenarios (Sc) of possible human-management actions aimed at ensuring proper post-fire tree cover:
Sc. 1) a pre-fire management scenario evaluating the costs of planting Quercus spp. seedlings in the understory, mimicking the whole dispersal function; Sc. 2) a pre-fire scenario in which enrichment
plantations increased the densities of natural oaks; and Sc. 3) a post-fire scenario where the restoration is done through
planting pines within the burned area. Approximately 90% of the burned area (371 out of 412 plots) was able to recover after
fire supporting the view that Mediterranean forests are resilient to fire. This resilience was primarily mediated by biotic
seed dispersal and posterior resprouting of tree species. These ecological functions saved between 626 and 1,326 €/ha compared
to the human-management actions. Ensuring key ecological processes within forests increases forest resilience and recovery
after fire leading to a generally significant saving of economic resources. In a perspective of increased future impact of
disturbances and decrease availability of economic resources for forest management, the implications of the present study
can be far reaching and extended to other forest planning exercises. 相似文献
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遥感技术在火监测中的应用研究综述 总被引：1，自引：0，他引：1
火是地球表面频繁发生的异变现象,也是森林、灌丛、草地等生态系统中植被演替的主要动力。植被火烧释放出来的大量气溶胶颗粒物以及各种痕量气体,会引发大气环境和全球碳循环过程的深刻改变。遥感卫星能够监测和记录全球地表信息,尤其适用于地表异变现象特别强烈的火灾事件。遥感技术在野火识别和监测中的应用主要为了实现以下4个目的:1）火点精确地理位置判定;2）在燃火线的范围制图和火场发展趋势判定;3）火烧强度评价;4）火烧迹地植被恢复监测与评价。文中总结了遥感卫星技术和数据在火险评价与制图、火点识别、火烧面积统计以及火烧迹地植被恢复评价中的应用和贡献。 相似文献
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森林地下火特征及防控措施 总被引：3，自引：1，他引：2
森林地下火在燃烧时观测不到火焰,传播速度较慢,燃烧时间长,难以察觉,但在燃烧过程中会产生大量颗粒物和大气污染物,严重危害生态环境和人体健康,造成严重的经济损失。结合国内外研究成果,文中阐述了森林地下火产生的原因、地下火特征及其对环境的危害,并将森林地下火防控先进技术设备与实际工作相结合,提出了构建"空中-地面-地下"多重监测系统和保障消防水源与重视火后管理的森林地下火综合防控措施,旨在为森林防火部门的地下火预防、监测、扑救等工作提供技术支持。 相似文献