FOREST FIRE

 FOREST FIRE

Each year millions of tons forest all around the world are destroyed. The resulting amount of forest loss and degradation is roughly of the same order as that caused by destructive logging and conversion to agriculture. Many animal and plant species are disappearing, the main cause being deforestation and fires, both a result of human activity. A drastic reduction in forests has significant effects on the delicate global ecosystem.

During the last twenty years forest fires have increased in the many countries, taking a heavy toll in lives and property. Southeast Asia is suffering its worst drought in five decades and as a result, hundreds of forest fires - many deliberately started as method of clearing land, are burning out of control. In Italy thousands of hectares of woods are burned. This country is very vulnerable to fire because of the Mediterranean scrub and poor summer rainfall. The burned scrub needs 10-25 years to re-grow.

The Effect of Forest Fires

The immediate impacts of fires can be devastating to human communities and forest ecosystems. In the longer term, they can adversely affect the supply of environmental services necessary for the well-being of local communities, threaten the survival of endangered species, simplify the structure and composition of biologically important forest, and provide conditions suitable for entry of invasive species. However it is also important to understand that the role of fire varies between different types of forest. For example, in tropical dry forest, boreal forests and some types of conifer forests, a certain amount of fire is an essential factor for the maintenance of the forests and their associated plants and animals. Conversely, in tropical moist forest, fire is usually always detrimental. The impact of fires on the forest depends on the scale (the area burnt), frequency, distribution (or patchiness), intensity and seasonality (the season in which fires occur) of the fires. These elements combine to produce what is known as a fire regime. A change in any one of these elements, or the balance between them, will impact on a forest's structure and species composition and its capacity to maintain its full complement of biodiversity and ecological services. For example, increasing the frequency of fires often favours plant species which can quickly regenerate at the expense of slower growing species, thus gradually changing the species composition of the forest and in-turn affecting the animal species which rely on certain plants for food or shelter. In areas that are very regularly burnt, some plant species may never reach sufficient age to produce seed, and will thus eventually become locally extinct. Conversely, decreasing the frequency of fires can result in loss of species that rely on fire to regenerate. Decreasing the frequency of fires also often results in the build-up of more fuel in the forest and thus eventually results in more severe fires, which are more difficult to control and can have serious negative impacts on fire sensitive plant and animal species as well as being a threat to human life and property.

Direct Causes of Forest Fires

All forest fires have a direct cause (an ignition source) – either natural (e.g. lightning) or human. Although the proportion of natural fires compared to human-caused fires varies widely between regions and types of forest, overall the vast majority of forest fires can be attributed to the deliberate or accidental actions of people. People light forest fires for many reasons. Some fires are started for practical and beneficial reasons, some are accidental, others are deliberately lit to cause damage. All of these fires have the potential to be harmful to the forest ecosystem or human communities, depending on both the condition of the forest at the time and how they are managed once they are burning. Just how harmful a forest fire can be is strongly influenced by the amount and condition of fuel available for the fire (leaf litter, bark, leaves and branches).

In most cases forest management practices help shape these factors. Humans are often directly responsible for causing forest fires and influencing their destructive potential by changing the forest conditions, altering the natural fire regime, providing the ignition source of the fire itself and, finally through the management of the fire once it is burning.

Underlying Causes of Forest Fires

In many cases, harmful forest fires are a symptom of the same underlying causes that drive forest loss and degradation, such as perverse economic incentives, ill-defined or inequitable land tenure, failure to enforce laws and regulations, failure to recognize and respect customary law, lack of economic opportunities for rural dwellers living in and around protected areas, and weak or under-resourced government institutions. These factors play a major role in determining how forests are exploited and managed, thus influencing both the likelihood of harmful wildfires to occur and their ultimate destructive potential.