1 Introduction

At the outset it is necessary to know what is meant by the term "degraded forests." A dictionary meaning would be "forests that are characterized by degeneration of structure or function." This is too broad a definition to be workable, however, as it would encompass almost all the forests that are not pristine. Barring a few spots in the world, all forests have been disturbed in some way or the other. Forests where swidden agriculture (defined on page 3) is practiced, where trees are logged or planted, or where local people gather products are degenerating or are at least losing their original character. At the other extreme, mismanagement and maltreatment have turned some forests into wastelands—little more than Bullied hill slopes with sparse vegetation or badlands with grasses predominant. Much of the primary forests have thus been converted into secondary forests or other vegetative forms. The question therefore arises whether all of these should be considered degraded forests.

Another vegetation form that should be considered in defining degraded forest is the extensive grasslands of Southeast Asia. In the recent past, most of these grasslands were forests that have changed radically as a result of mismanagement. Should these grasslands be considered degraded forests?

Strictly speaking, most of these conversion processes should be considered as forest degradation and the resultant land as degraded for
ets. But again, this definition is too wide in that it ignores the difference between the small degenerative changes that accompany forest use in a restrained manner and at the other extreme the large-scale ongoing forest degeneration that results in unrehabilitable wastelands.

For this paper, degraded forests are defined as follows: forests with grossly understocked tree, shrub, grass or cultivation formations that, due to ongoing or comparatively recent biotic interference, have either degenerated or are progressively degenerating in their protective or productive functions but that still retain the potential to revive to become a sustainable economic forest formation.

This definition would include the following major categories of land uses in Asia, which will be the focus of this paper:

· Swidden agriculture areas in moist forests;
· Human-induced extensive Imperata grasslands of Southeast Asia;
· Repeatedly hacked, low-profile hardwood forests of, for example, Bangladesh, China, India, and Nepal; and
· Overlogged forests of South and Southeast Asia.

The objectives of this paper are to define and describe each of the above forest categories, determine its extent in Asia, describe key characteristics, evaluate its impact on the local ecology, analyze why over time more area is added to each category, and to propose economic rehabilitation methods. The rehabilitate

Introduction methods include: (a) policy interventions to prevent the causes that lead to degraded forests; and (b) technical interventions to rehabilitate the areas already degraded. Emerging evidence indicates that forest degradation is often driven by social and political forces that must be dealt with prior to the application of technical strategic. However, although policy
interventions are imperative and will be referred to where appropriate, the paper focusses on technologies for rehabilitation.

The target audience of the paper are those who are involved in the preparation and management of projects dealing with rehabilitation of degraded forests of Asia and elsewhere.