城市森林火灾成因及预防扑救技术

随着经济发展和人们生活水平的提高,人们更愿意在森林中或靠近森林的地方居住。但伴随而来的是居民用火对森林造成威胁,与此同时,森林火灾也对居民住宅带来隐患。住宅在森林中的出现导致森林火灾的危险性增高,住宅、木棚、院落、车库及其他建筑物分布靠近森林,也给森林火灾的预防和扑救敲响警钟,近年来"家火上山,山火进城"的情况屡有发生,需加强有关研究。       

城市森林规划的现状与发展

分析了城市森林规划在中国发展的背景,通过案例分析,总结比较了英美两国城市森林规划的特点以及中国城市森林规划的特点,从城市森林规划的范围、与城市绿地系统规划的关系、规划对象、内容、方法、城市森林的多功能问题、协调问题、规划实施和规划立法九个方面探讨了中国城市森林规划的发展。       

因地制宜建设特色城市森林——以无锡市城市森林建设总体规划为例

以无锡市城市森林总体规划为例,探讨因地制宜的特色城市森林规划建设战略;以创建特色森林城市为目标,以无锡市自然、文化和城市发展3方面为重要内容,提出依水建林、森林生态建设、森林生态网络建设和森林生态文化景观区建设4大规划战略。       

论城市森林规划的实证性与规范性

从城市森林规划实证性与规范性的概念入手,回顾总结了景观规划设计中的实证性与规范性传统,揭示了二者并重的发展趋势,讨论了基于实证性与规范性的城市森林规划方法;在对城市森林理性过程规划程序及改进方法论述的基础上,提出了兼顾实证性与规范性的城市森林规划双循环结构过程。       

城市森林规划体系探讨

通过对城市森林建设实践需求、城市森林建设总体规划特性的分析,指出了完善城市森林规划体系的必要性,结合环境规划领域中两种传统方法的论述,提出了与城市规划体系相协调的城市森林规划的类型。基于实践,探讨了不同类型城市森林规划的内容。       

杭州森林城市建设总体规划

分析了杭州市自然概况、城市森林现状及城市特色,明确了规划期限、范围、目标及指导思想,提出了基于杭州市自然山水、人文特色的城市森林建设规划,以及重点实施的城市森林建设特色工程。       

中国城市森林建设的理论与实践——绿色江苏的城市森林建设

本文在系统阐述中国城市森林发展的思路、理念、措施等问题基础上,并以江苏为例对城市森林建设规划进行了具体研究,以期为中国城市森林的发展提供帮助。       

城市森林建设中自然和人文景观要素的综合应用——以常熟虞山为例

城市森林是在城市生态系统背景下存在的森林类型,城市森林建设必须关注人类主体在其中的作用。因此,城市森林建设必须在考虑自然规律的基础上,特别强调人文过程。本文在对常熟虞山的自然和人文景观特征进行分析的基础上,结合对植被的调研和城市森林建设实践,就虞山的城市森林建设规划进行探讨,期望为城市森林建设提供借鉴。       

永安市城乡一体化“四绿”工程建设

文中在对永安市"四绿"工程建设现状分析基础上,针对城市绿化与城市发展不相统一,集镇和村庄公共绿地偏少,次干道、巷道绿化绿量不够,道路景观特色不强等问题,提出要按照城市绿地系统规划和绿地系统防灾避险规划要求,加强城市森林建设。       

江西省峡江县城市森林建设规划

以江西省峡江县城市森林为研究对象,通过对城市森林数量、布局等现状的调查和分析,提出了峡江县城市森林建设总体规划目标、总体布局以及建设内容。研究结果表明:按照规划实施,至2020年峡江县城市森林覆盖率将由2010年的60.5%升至68.0%,建成区绿地率由44.6%升至49.7%,建成区绿化覆盖率由49.9%升至53.2%,人均公共绿地面积由12.2m2升至15m2,城市森林生态效益将得到更大发挥,城市生态环境质量将显著提高。该规划的研究成果也将为其他县级城市森林建设规划提供参考。       

槐花黄 举子忙——透视槐树文化与科举制度

文章探讨了槐树文化与中国科举制度之间丰富的文化内涵。槐树（Sophora japonica Linn）．又称国槐,在我国分布广泛,它枝干茂密,淳朴厚重,是人们喜爱的一个乡土树种。     

Study on Forest Fire Occurrence in China

China is not rich in natural forest sources. Owing to natural and historical factors, forest fires have long been frequenting China. Forest fire prevention is the most important of all. Forest fire prevention and controlling have long been held as a very important factor in our ecological plans. Taking china 's special geographical location, topography, climate and the distribution of forest sources into consideration, we have every reason to believe that forest fires in China have their own special environment and occurrence. China suffers forest fire hazards heavily. Forest fires arise occasionally from thunderstruck or self-burning of peat. However, most fires are due to man's fault while inappropriately using fires in production and daily life. Since China is located in the Northern Hemisphere with a vast territory, there is a striking difference in the climate between South China and North China.     

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.     

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.     

METHODS OF EVALUATING FOREST FIRE HISTORY

Forest fire history can be reconstructed over past centuries across a widevariety of forest types.Fire scars on living tress,and age classes of forest stands,are thetwo sources of information for these reconstructions.Point and area frequencies are usedto reconstruct fire history.Point frequencies are useful in forest types that burn withfrequent,low intensity fire so that many fire-scarred residual trees exist.A true point isa single tree,but more often point estimates are made by combining fire scar records fromseveral adjacent trees.Area frequences are applied where fires are infrequent but ofmoderate to high intensity,so that stand ages are used across wide areas to estimate firereturn interals.Proper selection and application of fire history methods are essential toderiving useful ecological implications from fire history studies.This review evaluates the common methods of determining fire history:what thetechniques are,where they are best applied,and how to interpret them in an ecologicalcontext.E     

The role of fire in forest dynamics in Daxinganling region

Recent fire statistics and preliminary fire history data suggest that fire has been historically responsible for maintaining the vegetative communities up to present in Daxinganling region. Forest types, and even tree species, arc dependent on the degree of fire intensity, fire size, depth of burn and fire frequency. Selected samples of larch, pine, birch and spruce forest were studied in terms of species composition as determined by fire frequency which mainly depends on topography and site conditions. Intervals between fires range between 6 and 170 years.     

我国大兴安岭呼中林区雷击火发生火环境研究

雷击火作为天然火源是一种难以控制的自然现象 ,其形成机理极为复杂。我国大兴安岭林区是雷击火主要发生区 ,对雷击火的研究表明特殊可燃物、干雷暴的天气和较高的地形构成了雷击火发生的火环境。长期干旱 ,可燃物失水严重 ,森林中积累丰富的可燃物 ,雷暴发生后干燥的植被容易引火燃烧 ,起火之后 ,遇上盛行的大风将使火灾迅速蔓延。雷暴 ,特别是干雷暴出现时 ,遇到降水少、地面温度增加 ,相对湿度降低 ,可燃物干燥的情况 ,就很容易引起火灾。森林火灾多发地区 ,雷击火常常也多。大兴安岭纬度越高 ,雷击火越多 ,5 1°N以北海拔 80 0m以上山脉的腹部或山顶的落叶松 -偃松林、樟子松 -偃松林林区为该林区雷击火发生最集中区域。一次干雷暴天气过程 ,可以同时引起多起雷击火 ,它们之间的距离最远可达 1 5 0km。雷击火多发生在 6— 8月 ,雷击火的发生时段主要集中在下午的 1 4时到 1 7时。雷电作为一个随机干扰因子引发森林火灾 ,使得雷击火的预防与扑救变得更加困难。     

Forest Fire History in Viena Karelia,Russia

The history of forest fires was studied in north-west Russia near the Finnish-Russian border on a total of 22 transects within a 3 x 4 km area, 100 m long and 20 m wide, bydendrochronological methods. In total, 25 fires were identified as having occurred in the area between 1400 and 1998. On average, a fire occurred somewhere within the area once every 23 yrs, and once every 13 yrs between 1650 and 1950. The fire frequency (proportion of the area burnt per time unit) broadly followed the changes in the number of fires, but there were also differences. The fire frequency was 1.87% from 1679 to 1872 and 0.40% from 1873 onwards. The mean fire interval was 62 yrs and the median interval 56 yrs. According to the tree-ring width chronology tree growth was significantly lower in the dated fire years than in other years. Forest fire history in north-west Russia is broadly similar to that in many parts of Scandinavia.     

Determination of fire risk to assist fire management for insular areas: the case of a small Greek island

Forest fire risk estimation constitutes an essential process to prevent high-intensity fires which are associated with severe implications to the natural and cultural environment. The primary aim of this research was to determine fire risk levels based on the local features of an island,namely, the impact of fuel structures, slope, aspects, as well as the impact of the road network and inhabited regions. The contribution of all the involved factors to forest fires ignition and behavior highlight certain regions which are highly vulnerable. In addition, the influence of both natural and anthropogenic factors to forest fire phenomena is explored. In this study, natural factors play a dominant role compared to anthropogenic factors. Hence essential preventative measures must focus on specific areas and established immediately. Indicative measures may include: the optimal allocation of watchtowers as well as the spatial optimization of mobile firefighting vehicles;and, forest fuel treatments in areas characterized by extremely high fire risk. The added value of this fire prediction tool is that it is highly flexible and could be adopted elsewhere with the necessary adjustments to local characteristics.     

安康地区森林火灾分析

应用安康地区１０县（市）８年火灾的详细资料，分析得出了安康地区的火源特点、林火的时空规律、主题植被的燃烧性排序等，并提出了相应的森林防火对策。