Introduction: Forest fire is considered as a problem in forest management systems. In mixed forest of sal in Terai (flat area in southernmost east to west belt of Nepal), the fire season starts from mid-March and the fires burn the forests 1-3 times till the end of May. All fires are surface fires.
In clause (b), Section 49 of Forest Act 1993, “starting a fire, or doing anything that may cause a fire accident” in National forest is prohibited. In Clause 1.(b), Section 50 of the Act, any person who commits such an offence shall be punished with a fine of not more than NRs. 10,000, or with imprisonment for a term not exceeding one year, or with both. This is the only one legal provision for fire control but it is still ineffective because it is extremely difficult to identify the offender.
From general observations in the Rautahat district (Terai) in 1995, it was found that about 90 percent of the forested area in the plain was burnt out. This condition is more or less similar in all Terai districts.
Broadleaved stands and mixed stands comprise mostly deciduous forests. Normally, they appear in drier areas such as in Terai, Siwaliks, on mountainous slopes where soils are relatively dry with distinct dry season.
During the dry season (March to May) most tree species in Terai totally shed their leaves. The great amount of dry leaves and small twigs which accumulate on the forest floor accompanied by grass and under-growth species which turn dry during the time serve as fuel for the outbreak of forest fires.
Forest fire problems / constraints: There is no single fire control plan in Nepal yet. There is no proper accounting of fire. In the annual programme of District Forest Offices (Terai) they have some fire control programmes which are insufficient and some which are ineffective. Every year in the dry season (March – May) fires invade the forests and burn uncontrolled. They are due to:
lack of resources;
lack of extension education for the local people;
lack of specific fire control rules and regulations; and
lack of specific fire control organization.
Causes of forest fires: There are no statistics on fire in Nepal yet. By the experience of key persons, an attempts is made to give the general picture of the quantity of fires by individual causes in Figure 1.
Fig.1. Distribution of causes of wildfires in Nepal.
Explanation of some categories: Cattle grazing: burning for stimulation of new grass Illegal wood cutters: burning of stumps to hide evidence NWFPs: collecting non-wood (minor) forest products, e.g. honey, trophies, etc. Torches: burning of wood or rubber, for travelling by night Agricultural burnings: escaped fires
Cattle grazing for new grass and smokers alone share about 45 percent of fires among all known causes of forest fires. Natural causes (e.g. thunderstorms) of fire are not reported. About 64 percent of fires are set by people intentionally, about 32 percent of fires are due to accidental/carelessness, and about 4 percent by unknown causes.
Economic Impact of Forest Fires: When fire burns it has a number of effects which are negative to the economy which will eventually affect the people and the nation as a whole, as described in the following lines: It kills the regeneration. It destroys non-wood forest products (NWFPs). Sometimes it reaches villages causing huge losses in properties and life. Some District Forest Offices (DFOs) of Nepal issue licenses for hunting like DFO, Rautahat. When the forest is burned, the number and kinds of wildlife will be reduced.
There are plenty of fallen and standing dry trees in the forest. At present, this is the main source of royalty from the forestry sector. The fire burns this national property. Sometimes it burns wooden bridges in the forest. It destroys the natural beauty of the forest. It accelerate the consequences of soil erosion.
Ecological Impacts of Forest Fires: Fires disturb ecological cycle and adversely affect the bio-diversity in the particular ecosystem by the following impacts:
Soil nutrients: Some nutrients are volatile and burnt off by a fire and these either evaporate or are leached.
Soil texture: Rises and falls of temperature may change soil texture. It affects the water holding capacity of the soil. Rises of soil temperature may kill the soil micro-organisms.
Repeated fire may change species composition creating fire hardy species.
Fire kills undergrowth and sometimes pole size trees also. It creates a gap in age gradation the in younger age group.
Fire may trap small wild animals and kill them. It may lead wild animals to escape from the site in question. In addition, it kills infants, destroys eggs resulting in a narrower base in the population structure and may lead some species to extinction.
Fire burns and kills most of the microflora and microfauna within the top soil layer which have a function of nutrient recycling. Hence, the nutrient cycle is jeopardised.
Fire burns most of litters on the forest floor. It reduces organic matter leaving ashes in the soil.
Fires in the forest and other vegetation of the tropics and subtropics and the changing tropical land-use have an increasing regional and global impact on the environment. The smoke plumes from tropical biomass fires carry vast amounts of atmospheric pollutants, including CO, NOx, N2O, CH4, non-methane hydrocarbons, and aerosols. Smog-like photochemistry produces ozone concentrations comparable to those found in the industrialised regions.
Findings From a Study
This study was conducted in Manahari in Makwanpur district (inner Terai). The area is situated at an altitude of 300 m a.s.l. The method used was experimental burning in small areas and observations were made in uncontrolled burning areas as well during March – April. Three samples of fuel were randomly collected from the burning area, and the green weight was measured immediately and the samples were sent to laboratory for calculating the oven dry weight. Discussions were held with forestry professionals and rural people to compile their knowledge and experience.
Fires set by cattle grazers for stimulating new grass growth and careless smokers alone account for about 45 percent of all known causes of forest fires. Natural causes (e.g. thunderstorms) of fires are not reported. About 64 percent of fires are caused by people intentionally, about 32 percent by accidentally/carelessness, and about 4 percent by unknown causes. Preventive measures could be the solution for a fire control programme.
The fuels are mostly continuous, and one to four layers of leaves of sal (Shorea robusta) and other species comprise about 95 percent of the volume, of which sal leaves account for about 90 percent. Other surface fuels are twigs and grasses. The volume of the available fuel was found to be 10.7 tonnes oven dry weight per hectare (air dry weight of 11.7 t/ha). The moisture content of the fuels at the time of analysis was found to be 10 percent. The fuel type (i.e. forest cover type) is mixed forest comprising 70 percent sal, 10 percent asna (Terminelia alata), and 20 percent other species. The fuel type pattern is more or less homogeneous with some natural (streams, small rivers, etc.) and cultural ( roads, foot trails, etc.) barriers. The rate of spread of the fire in experimental burnings in Manahari forest area (Terai) in the given conditions was found to be about 0.25 m/min and the form was found to be elliptic. The flame height was found to be about 25 cm.
It is recommended that the Department of Forests of Nepal should immediately prepare a district level Forest Fire Management Plan (FFMP). More than 90 percent of the activities should be based on fire prevention activities and the rest on fire suppression activities, research and accounting of fire.
Within the Forest Department a functional organization should be established. The organization be responsible for fire prevention, human resource development, law enforcement, and fire research. Collection of fire statistics should include:
number of fires and area burned (yearly)
number of fires by each cause
area burned by each cause
fire distribution by forest vegetation zones
size distribution of forest fires
duration of forest fires
monthly distribution of forest fire incidents throughout the year
Because of the limited resources and poor communication infrastructures, prevention activities, which are the most economic way of reducing fire damages and losses, could be the most important function of fire control services for Nepal. The most important elements of fire prevention would be:
Primary school education
Extension programmes – general public education;
Workshops among political leaders and members of administrations;
Enforcement of laws, regulations, rules, and restriction for fires and their communication through sign boards and warning notice boards;
Fuel management – fire line construction and control burning along the firelines and forest tracts and roads; and
Clear demarcation of forests.
This study is entirely focused on the Terai situation. In Terai the main species is sal mixed with asna and other species. The fire season begins in mid-March, and the fires burn the forests 1-3 times till the end of May. All fires are surface fires.
The Department of Forest of Nepal is the responsible governmental organization for fire control. However, due to the lack of resources, lack of specific fire control rules and regulations, lack of extension education for the local people, and lack of a specific fire control organization within the frame of the Department, it is not functioning well with regard to the fire control activities. Preventive measures could be the solution for the fire control programme. That is why local NGOs and other groups should be utilized for extension activities. Village Fire Control Group (VFCG) should be formed and motivated by a responsible organization. Statistical information and research activities are almost nil in Nepal. Such data are most important for fire control planning.
From: Sundar P. Sharma Assistant Planning Officer Address: Department of Soil Conservation Ministry of Forest and Soil Conservation His Majesty’s Government of Nepal P.O.Box 4719 Kathmandu NEPAL