Fires in forests are not unnatural. Small and controlled fires in the form of prescribed burning are very useful and essential for good natural forest development and regeneration. As they keep forest floor free from the natural annual buildup of the litter thereby reducing risk of catastrophic forest fire, improving silvicultural opportunities, increasing forage and habitat opportunities for wildlife, enhancing biodiversity etc.
Causes of forest fire
Forest fires are caused by both anthropogenic as well as natural reasons.
| NATURAL | ANTHROPOGENIC | |
| Deliberate causes | Accidental causes | |
| LightningFriction of rolling stoneRubbing of dry bamboo clumpsVolcanic explosion | 1. Shifting Cultivation 2. To flush growth of tendu leaves 3. To have good growth of grass and fodder 4. To settle score with forest department or personal rivalry 5. To clear path by villagers 6. To encroach upon the forest land 7. For concealing illicit felling 8. Tribal traditions / customs | 1. Collection of Non-Timber Forest Produce 2. Burning farm residues 3. Driving away wild animals 4. Throwing burning bidi/ cigarettes 5. Campfires by picnickers 6. Sparks from vehicle - exhaust 7. Sparks from transformers 8. Uncontrolled prescribed burning 9. Resin tapping |
Impact of extensive forest fires
- Biodiversity change: In Himalayas, fires have made the situation less favorable for oaks to grow and favorable for chir pine to grow.
- Reduced soil moisture creates a possibility of forest fire in future.
- Reduce water infiltration due to heat induced chemical and physical changes in upper layer of soil which makes it impervious.
- Enhanced global warming: Due to destruction of forest Carbon sequestration potential and addition of newer emissions such as carbon monoxide, methane hydrocarbons, nitric oxide and nitrous oxide that led to global warming and ozone layer depletion.
- Microclimate change caused by removal of litter and duff, opening of the canopy by killing over storey shrubs and trees and darkening of the soil surface by residual soot and charcoal can increase insulation causing temperature increase.
- Soil erosion: Intense Forest fire always has a direct heating effect on soil at the depth below 7 to 10 cm. As a result, soil of the fire affected area loses its water holding capacity and becomes vulnerable for erosion.
- Flooding: due to water repellent soils and cover loss give rise to higher chances of floods.