Plan For Restoration

Protection measures and restoration interventions should be adequately planned. Drawing up a medium-term management/rest oration plan may be necessary.

A management plan requires information such as an inventory of the standing stock and its condition, including composition, size, and stem quality. An assessment of the regeneration (seedlings, saplings, and advanced growth of marketable or preferred timber and nontimber species) should be considered. Information on nontimber forest products (NTFPs) can be collected as part of this inventory. Important for planning (zonation and mapping purposes) is also the systematic assessment of the physical conditions affecting the restoration work

448 For instance; Carter; 1996; Jackson and Ingles, 1998; and Shell et al., 2002.

449 ITTO, 2002.

(watercourses, topography, soils, vegetation types, etc.).

The advanced regeneration of current and potential commercial or useful tree species should be the first target for interventions. To guide decisions on silvicultural intervention a simple assessment method called diagnostic sampling can be used. Diagnostic sampling is a rapid and inexpensive method intended to estimate the potential productivity of a forest stand and decide whether treatment is necessary or not, and if necessary, whether it can be delayed or not, and what type of treatment should be given. Steps and field procedures for using this method can be found in Hutchinson450 and FAO.451

For monitoring purposes, permanent plots or continuous forest inventory plots should be established in order to provide the necessary baseline data of forest growth and response to the interventions.

Based on the medium-term plan, an annual plan (at the compartment level) is usually done. This is an operational tool for guiding the implementation of the planned activities. It may entail measures for erosion control and/or to protect/enhance biodiversity (of particular vegetation types or species), demarcation of riverine corridors to be retained for hydrological reasons or of wildlife corridors, etc.

3.3. Implement Silvicultural Interventions

Silvicultural interventions are generally necessary to overcome the relative depletion of commercial tree species, to compensate for the slow growth rate, and to ensure a future commercial timber value of the forest.452 Options that can be applied, depending on the condition of the forest stand and the objectives (what major products are expected), include improvement treatments, treatments to stimulate natural regeneration, enrichment planting, and direct planting.

Working with preexisting natural regeneration is the cheapest and safest way to recover the original forest, provided there is plenty of the desirable (e.g., current and potential commercial) species. This is usually the case with forests that have only been lightly degraded through uncontrolled timber exploitation. In more degraded conditions, however, the lack of adequate regeneration or an uneven distribution over the area entails difficult silvicultural work, making it necessary to resort to more costly interventions.

Some examples of interventions are given below. The interested reader will find more detailed information in the various dedicated chapters of this volume (see Section XI, A Selection of Tools that Return Trees to the Landscape).

3.3.1. Improvement Treatments

Improvement treatments (or tending operations) basically aim to provide more space for trees of desirable species. This is done first through the application of an operation called overstorey removal, by which overmature, defective noncommercial individuals (called relics) are removed (usually by poison-girdling) from the upper levels of the forest canopy. A second phase consists of liberation thinning, a treatment that releases young growth from the competition from commercially less desirable species. The prescriptions for liberation may easily be altered to accommodate changes in market demand or alternative management requirements (e.g., maintain keystone food resources for animals).

Timber stand improvement (TSI) is a well-known silvicultural treatment used by preference in dipterocarp forests. Usually conducted 5 to 10 years after logging, it basically involves the cutting or killing of unwanted trees and climbers to improve growing conditions for the remaining trees and species' composition of the stand. A detailed description of procedures is found in Weidelt and Banaag.453

450 Hutchinson, 1991.

451 FAO, 1998.

452 ITTO, 2002.

453 Weidelt and Banaag, 1982.

3.3.2. Treatments to Stimulate Natural Regeneration

The lack of advanced regeneration (or its unsatisfactory spatial distribution), particularly of the desirable species, is a main constraint usually found in more heavily disturbed forests. If the objective is to restore populations of these species, treatments to stimulate their natural regeneration thus become a priority as part of the post-logging interventions.

3.3.3. Enrichment Planting

Enrichment planting (also known as under-planting) is defined as the introduction of valuable species on degraded forests without the elimination of valuable individuals already present. Enrichment of logged-over forests may be appropriate in areas where natural regeneration of desired species is insufficient or soil characteristics are not conducive to other uses, or even when the interest is to introduce high-value species that do not regenerate easily, keystone food species or even fruit trees or other species with commercial or local value.454

3.3.4. Direct Planting

Direct tree planting in logged-over forests is sometimes used for rehabilitating localised areas that were more heavily impacted by harvesting infrastructure (roads, log landings). These patches of trees or shrubs are planted primarily for erosion control (e.g., slope stabilisation). Planting in log landings and other open areas for growing commercial trees is another option.

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