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close this book Reforestation in the Pacific Islands
close this folder 1. Introduction
View the document Objectives of This Manual
View the document What is Forestry?
View the document The Problem of Deforestation
View the document Causes of Deforestation
View the document Basic Uses of Forest Products

Causes of Deforestation

There are many factors influencing the cutting of trees and the depletion of forest resources in the Pacific islands. In recent years, increasing pressure has been placed on forest lands for economic and social as well as political reasons (Plumwood and Routely, 1982). The social, economic, and environmental causes and effects of deforestation are closely interlinked, and any proposed strategy for reversing the trend must consider these linkages.


Illus. 1-1. 1-1 Effects of the Forest Ecosystem

The major causes of deforestation in the South Pacific islands are summarized below.

Human Intervention

The main effect of human intervention in forest areas has been to decrease the extent of the forest and to change the types and quantities of vegetation. When land is intensively cropped and then abandoned, the natural tree cover and soil fertility may never return. Instead, shrub and grass species may become the dominant type of vegetation. Once established, these species are difficult to eradicate. This has already occurred in many islands with the establishment of Imperata grasses.

The high population growth rate in the Pacific islands (3-5%) has contributed to increasing pressure on land and other natural resources. As population increases, the amount of forest land usually declines, because demand for land for food production and other uses intensifies.

Settlement Patterns

Increases in population, as well as migration among and within island regions, have created an ever-increasing demand for land that can be used for- settlement and/or cultivation. As population increases, the size of individual farms or plots usually decreases. Particularly for subsistence farmers, cultivation intensifies as plot size is reduced. This usually results in soil depletion and related problems such as declining crop yields. In many of the south Pacific islands, land ownership is tribal or clan-related. This system can be a major concern in forest management. Additionally, population pressure forces many farmers onto land unsuitable for cultivation.

In some areas, disputes over land ownership may result in misuse of the land or poor land management practices. Without clear title to the land, people tend to be less concerned with proper management.

The construction of roads and expansion of transportation networks into forested areas also lead to the destruction or damage of forest lands. The new roads open marginal lands to migrants, who often lack the skills or incentives to properly manage the land.

Agricultural Practices

Shifting cultivation (swidden agriculture) is a common practice in many regions of the world. In the Pacific islands, shifting cultivation usually occurs on steep, sloping lands; tilling with draft animals, machinery, or by hand takes place on the flat lowlands. In shifting cultivation, farmers intensively crop a given area of land for a few seasons until the productivity of the land and crop yields decline. They then leave the exhausted land fallow (uncultivated) and move on to farm elsewhere. The natural cycle of regeneration of land takes about 25 years; in order for soil fertility to be restored, the land should lie fallow for at least five to ten years. But because of increasing pressures for land, in many areas of the Pacific this "resting" time has been reduced to 4 years or even eliminated entirely.

Slash and burn techniques for clearing forests are associated with shifting cultivation practices. They enable the farmers to quickly and easily prepare new land for cultivation. The combination of shifting cultivation and related practices often leads to deterioration of soil conditions and loss of protective ground cover. These practices can be particularly damaging to the land, causing rapid depletion of soil nutrients and loss in productivity, erosion, landslides, uncontrolled fires, and flooding.

Increased population pressures often lead to the use of margin lands, or fragile areas that are ill-suited for cultivation under normal circumstances. Overgrazing of livestock can also lead to losses in productive

capacity. Animals tend to eat favorable vegetative species, leaving behind hardy weeds. Unmanaged herds tend to compact soil, thus reducing water infiltration, exacerbating runoff, and precluding the establishment of favorable plants.

Monoculture, or single crop systems, may reduce species diversity and resistance to disease and pest infestations. Continuous corn or upland rice cultivation on steep slopes promotes erosion. Unless proper long-term management techniques are applied, intensive cropping of single species can also deplete soil fertility.

Inadequate Forest Management Practices

In many regions, there has been insufficient education, promotion, coordination, and enforcement of proper forest and watershed management practices. Natural mangrove forests on many islands have been destroyed by overcutting and clearing by loggers and farmers. The revegetation of these lands is often not enforced, or is difficult to enforce due to the demand for tillable land. Farmers with poor land management skills receive limited training due to underfunded government programs. In many cases, government bureaus in charge of forestry and agriculture fail to coordinate related programs, thus undermining long-term government objectives. Even where properly conceived programs do exist, enforcement and public support for them may be limited. Environmental education and extension efforts are required to teach officials and farmers the importance of sound management techniques.

Economic Pressures--Demand for Timber, Fuelwood

The demand for timber has increased, in part due to the growth in world market demand and in part to pressure on small- island economies to develop cash-generating activities to pay foreign debts. Between 1963 and 1983 the amount of wood produced for markets increased from 1.8 to 3.0 billion cubic meters. Ten developed countries account for 65 percent of the total value of timber imports.

Over the past 35 years the production of fuelwood has more than tripled. Nearly 1.5 billion people in 63 countries, or about 60 percent of the people who depend on fuelwood as their principle source of energy for cooking and heating, are cutting wood faster than it can grow back. At present consumption rates, the estimated fuelwood deficit will double by the year 2000. (For more information, see Arnold, 1983.)

Natural Disasters

Although typhoons, floods, landslides, fires, and other natural disasters occur naturally, their frequency and impact can be significantly increased when the delicate balance of the ecosystem is disturbed, or when natural protection is lessened.