Being the great enemy to forests, forest fire destroys all kinds of forest resources, damages forest ecosystems, jeopardizes the safety of human life and property in forest areas, impairs the social stability of forest areas and pollutes the air. All of which lead to the continuous deterioration of ecological environments and seriously threatens the human living environment. Forest fire has become a major problem in global forest development. It has been an issue of global concern to prevent forest fires and reduce the losses of forest resources.
General Situation of Forest Fire in China
China suffers from frequent forest fires. From the founding of New China till the year 1987, an average of 15,800 forest fires damaged a total forest area of 940,000 ha per year. During this period, the average Annual Occurrence Rate or Fire Frequency (=number of fires on 100,000 ha of forest land) of forest fire was 13.9 and the Damage Rate (=burned forest area compared to the total forest area of China) is 0.85%. During the recent ten years, however, forest fire has been greatly reduced. There has been a decrease of 52.7% in the frequency of forest fires and a decrease of 94.3% in damaged forest area compared to 1987. The average annual occurrence rate of forest fires is 6.3, and the Damage Rate is below 0.1%.
For many years a great deal of labour, material resources and funds have been put into China’s fire control work, and construction in every aspect has been obviously improved. However, along with the development of forestry, more and more people are involved in activities within forest areas increasing the potential trouble. In addition, the great expansion of forest plantation areas achieved through the recent development of the afforestation movement has made the forest fire control task more arduous. The ecological environment issue has become increasingly severe leading to the necessity of strengthening forest fire control work. The task of forest fire control has yet a long way to go.
Fig.1. Forest fire brigade is getting ready for combating wildfires in the Daxinganling mountain region, Heilongjiang Province, North-East China. Photo: J.G.Goldammer.
Fig.2. Map of the large forest fire in the Daxinganling mountain region, Heilongjiang Province, which occurred in May 1987. At that time a total land area of 1.3 million hectares was affected by fire (grey shaded area). Source: Archive of the Fire Ecology Research Group, Max Planck Institute for Chemistry.
Fig.3. The consequences of large wildfires can be seen everywhere in the mountain boreal forest of Daxinganling. The light colour of trees indicate fire scars caused by high-intensity stand replacement fires; the dark trees are partially or non-damaged coniferous species. Photo: J.G.Goldammer.
General Situation of the Construction of Firebreaks with Retardant Species in China
“Retardant Species Firebreaks” belong to biological retardant engineering hich is part of the forest fire retardant network. For the establishment of the firebreak, we will take into consideration the difference in combustibility and fire resistance between plant (arbor or shrub) individuals and colonies and the difference in mutual influence and mutual action between plants and environment. The fire resistibility of the plant itself is brought into full play, and those species with better fire resistibility are used in proper proportion to form the forest belt in order to improve the ability of fire resistance for the forest itself, prevent fire spread and reduce fire losses accordingly. The fire retardant effect achieved by the above-mentioned firebreak can be divided into two types. One is to use those species with better fire resistibility to prevent fire from expanding. For example, in South China, species like Schima superba, Michelia macclurei, Myrica rubra and Camellia oleifera are used, and in North China, Fraxinus mandshurica, Populus spp. and Eleutherococcus senticosus are used to build firebreaks. The other type is to plant Larix gmelinii of high density in the forest areas of Northeast China. The result is a change to the fire environment with little sunshine, low temperatures and relative high humidity inside the forest which will therefore separate the fire.
There are several advantages to the construction of retardant species firebreaks. First, it closely combines forest fire control together with afforestation, so that forest fire control work is brought into the whole procedure of afforestation. In this way, passive defence has been turned into early prevention, which reflects in a real way the policy of stressing prevention during fire control. Second, it closely combines present work together with long-term targets. The establishment of a retardant species firebreak will result in long-term benefits and is a radical measure taken for the permanent control of fire. The third advantage is that it closely combines social benefits, ecological benefits and economic benefits together. The establishment of the firebreak will effectively prevent the spread of forest fire, contribute to the improvement of forest species and stand, prevent the expansion of forest insects and disease, while at the same time increasing certain economic income. The construction of a retardant species firebreak in China was started by the end of the 1950s in some forest areas of South China where certain species with fire resistibility such as Schima superba and Camellia oleifera are used to build firebreaks. This activity was gradually promoted during the 1960s and 1970s in forest areas of both North and South China, and many good experiences have been achieved all over China, such as in the provinces of Fujian, Guangdong, Guangxi, Jiangxi, Zhejiang and Hunan in the south, and Heilongjiang, Jilin, Liaoning and Inner Mongolia in the north. Great development has been achieved in the construction of retardant species firebreaks along with the strengthening of basic facilities construction of forest fire control in China. At present, the retardant species firebreak with a total length of 339,000 kilometres has already been built in China, of which 170,000 kilometres of the firebreak has already been brought into full play in preventing forest fires.
Main Measures for the Construction of Retardant Species Firebreaks in China
Being one of the forest fire retardant engineering projects, the construction of retardant species firebreak is an effective method to prevent fire spread and has a very important position and role in the construction of basic facilities of forest fire control in China. To further promote the work, an on-site meeting on “Engineering Construction of National Retardant Species Firebreaks” was held by the Ministry of Forestry of China in July 1995. As a result, plans had been made in line with local conditions; funds had been raised in a wide range; input had been increased; and scientific research had been enhanced, so that the firebreak would be built in a more scientific and standard way. Currently, based on the principle of overall optimization, it has been initially planned that within the next 15 years, a total length of one million-kilometres firebreaks will be built. Therefore, together with another isolation strip, the length of an isolation strip per ha will reach 30 metres by the year 2010 in China. The efforts after 10 years, 20 years or an even longer period, will create a Green Great Wall of fire control within the 130 million ha of forest area in China. By then, the ability to control forest fires, especially big fires will be greatly improved.
From: Guang Chengxiang Deputy Director, Forest Fire Control Office Address: Ministry of Forestry No.18 Hepingli Dongije Beijing 100714 People’s Republic of China