Over the last several
decades, deforestation and degradation of tropical forests as well as their
wasteful utilization have received increased attention. Forest resources
contribute significantly towards foreign exchange earnings in many countries
and over-exploitation of resources cannot be in their long-term interest. In
the early 1980s, there were many predictions that tropical forests – including those
of Malaysia – would be completely depleted by 2000 (Samsudin and Kasinathan
1989). Although such predictions were overly pessimistic and tropical forests
remain an important land use in the Asia-Pacific region, some countries (e.g.
the Philippines and Thailand) have turned from being exporters to net importers
of timber (Appanah 2000). The
widespread concern regarding forest abuse has triggered numerous forest
assessments and inventories.
Most countries in the
Asia-Pacific region assess the extent of their forest areas on a regular basis.
The area of natural forests is usually known, although area assessments may not
necessarily be completely accurate. In some countries, data on logging are also
available and post-harvesting inventories determine the needs for silvicultural
treatments. However, once forest operators leave forest areas and road
conditions deteriorate, regular inventories cease. As a result, knowledge of
the status of logged-over forest areas is scanty, and the assumption that previously
logged forests will be ready for re-entry is frequently based on inadequate
knowledge of forest stand volumes and composition. In fact, there is a
widespread concern that many production forests are now degraded and will yield,
during the second harvest, substantially lower commercial volumes than during
the first harvest. The knowledge gap is a major concern as wood-based
industries rely on a continuous flow of raw material. In many countries, all
the old-growth (production) forests have been or will soon be exploited and
wood supply will have to rely on logged-over or second-growth (or even third
cycle) or residual forests.
Assessing the status of logged-over forests in terms of expected volumes,
species composition and timber quality thus has high priority.
In Peninsular Malaysia,
information based on preliminary investigations (Yong 1998) and observations
indicate that most residual forest stands have not regenerated according to
assumptions and will not be ready for commercial harvesting on a sustainable
basis at the end of the cutting cycle as expected. The effects of (poor)
harvesting practices and illegal logging on forest conditions remain unclear.
Due to the large extent,
high variability and inaccessibility of many natural forests in the region,
conventional forest inventories are extremely costly. Alternative assessment
tools are needed, which allow for the rapid appraisal of stand conditions. This
report provides an account of a methodology that can be used for assessing
logged-over forests rapidly at the broad management level. For operational
level inventories, the design and intensity of sampling will be different.
