After a forest fire, according to whether it causes losses to trees and the size of the fire area, forest fires can be divided into forest fires (the affected forest area is less than 1 hectare or other woodlands are on fire), general forest fires (the affected forest area is greater than 1 hectare and less than 100 hectare) and major forest fires (the affected forest areas are greater than1hectare and 650 hectares)
Man-made cause is the biggest factor that causes forest fires; Secondly, long-term dry weather may also lead to the continuous rise of ground temperature, and forest materials are easy to cause spontaneous combustion. In addition, lightning strike may also lead to fire.
Since 1950, there have been an average of 13067 forest fires in China, with an affected forest area of 6530 19 hectares and 580 casualties. Among them, before 1988, there were forest fires 15932 in China, with 947238 hectares of forest affected and 788 casualties (including 678 injured and 65438 dead +0 10). After 1988, there were 7,623 forest fires in China, covering an area of 94,002 hectares, with casualties 196 (including injuries 142 and deaths of 54), down by 52.2%, 90. 1% and 75.5% respectively.
Forest fire is a kind of natural disaster with strong suddenness, great destructiveness and great difficulty in disposal and rescue. Forest fire prevention is an important part of China's disaster prevention and mitigation work, an important part of the construction of national emergency system, an important guarantee for social stability and people's living and working in peace and contentment, the foundation and premise for accelerating forestry development and strengthening ecological construction, which is related to forest resources and ecological security, people's life and property safety and the overall situation of reform, development and stability. Simply put, forest fire prevention is to prevent the occurrence and spread of forest fires, that is, to prevent and extinguish forest fires. To prevent the occurrence of forest fires, we must understand the laws of forest fires, adopt the method of combining administration, law and economy, and use scientific and technological means to minimize the number of fires. To put out forest fires, it is necessary to understand the burning law of forest fires, establish a strict emergency mechanism and a strong command system, organize a well-trained firefighting team, and use effective and scientific methods and advanced firefighting equipment to put out fires in time to minimize fire losses.
Fighting forest fires should adhere to the basic principle of "fighting early, fighting small and fighting big". 1988+65438 "Regulations on Forest Fire Prevention" issued by the State Council on June 6th stipulates that the policy of "prevention first, active elimination" shall be implemented in forest fire prevention. Forest fire prevention work shall be under the administrative leadership responsibility system of the people's governments at all levels. All units in the forest area shall, under the leadership of the local people's government, implement the leadership responsibility system of departments and units. It is the duty of every citizen to prevent and extinguish forest fires and protect forest resources.
The Regulations on Forest Fire Prevention was revised and passed at the 36th executive meeting of the State Council on June165438+1October 9, 2008, and came into force on June 65438+1October 2009.
Fire cases caused by smoking and littering unlit cigarette butts are often seen in newspapers. The most typical case is the forest fire in Daxinganling in May. 1987. The fire * * * caused great losses of 691.300 million yuan. Afterwards, it was found out that four of the first five fires in this extraordinarily serious forest fire were caused by human beings, and two of them were ignited by cigarette butts discarded by three "smokers".
Forests are an inseparable part of nature. Where there is forest, there is life. Among many natural factors that affect the forest, fire has the most serious impact and destruction on the forest. Studies show that many forest ecosystems depend on fire, and the history of fire's influence on forests is much longer than that of human beings. From the point of view of energy, forest growth is one of the energy accumulation methods of solar energy conversion, which will release energy when accumulated to a certain extent.
Fire, like water, soil, trees and animals, is a factor in forest ecosystem. Plants in the forest use photosynthesis to convert solar energy into chemical energy, and fire is a process of rapid release of a large amount of energy in the forest, which is a part of the material and energy cycle of the ecosystem. The effects and functions of fire on forests and forest environment are various, sometimes the effects of fire are short-lived and sometimes long-term. The forest environment and microclimate changed after the fire. Because of the bare forest land and direct sunlight, the soil surface temperature increases and the humidity decreases. Forest fire not only changed the forest structure, but also caused the redistribution of other ecological factors, affecting the changes of forest plant communities.
Studies at home and abroad show that the impact of fire on forests can be summarized as harmful and beneficial, and fire has two attributes. Harmful effects generally refer to the harm of forest fires to ecosystems. Forest fire destroyed the balance of forest ecosystem, and it was difficult to recover the forest ecosystem after the fire. For example, high-intensity, large-scale forest fires will cause devastating losses to forest resources and the entire forest ecosystem, and more seriously affect residents' property, transportation, atmospheric environment and people's daily life. Therefore, forest fires not only ruthlessly destroy all kinds of creatures in the forest, but also destroy the terrestrial ecosystem. Moreover, the huge smoke and dust it produces will seriously pollute the atmospheric environment and directly threaten the living conditions of human beings. Putting out forest fires requires a lot of manpower, material resources and financial resources, which will bring huge losses to the lives and property of the country and people, disrupt the regional economic and social development and the production and living order of the people, and directly affect social stability. At present, all countries in the world regard large-scale forest fires as major natural disasters to prevent and control them. From the disaster point of view, forest fire is an out-of-control natural disaster caused by human and natural factors.
Beneficial fire can promote the healthy development of forest ecosystem, such as low-intensity fire and forest fire. Beneficial fire slowly releases the energy of forest ecosystem, promotes nutrient transformation and species renewal of forest ecosystem, is beneficial to the health of forest ecosystem, and the forest is easy to recover after fire. People often use the beneficial effects of fire to set fires in a planned and purposeful way, and fire has become a tool for human beings to manage forests. For example, using planned combustion to reduce combustible materials in forest land, control pests and rodents, and promote natural forest regeneration; Afforestation or fire tending in Yamakaji can also promote shrub growth and improve wildlife habitat. At present, the dual nature of fire is still in the research stage, and there are still many debates at home and abroad. It is worth mentioning that fires are all caused by small fires, so all countries in the world regard putting out small fires in the early stage as the key to forest fire prevention, and the beneficial conclusions and opinions are mostly limited to the investigation and research after the fire.