To restore the area, more
silvicultural activities should be done. Silviculture is the practice of
controlling the establishment, growth, composition, health, and quality of
forests to meet diverse needs and values (Savadogo et al., 2010). There are two ways to restore the area, which are
enrichment planting, and Miyawaki method.

Enrichment planting is a
strategy for enhancing natural forests’ economic values to increase their
concentration of economically important, indigenous tree species by planting seeds
or seedlings for future harvest. It is commonly used for increasing the density
of desired tree species in secondary forests often characterized by a
prevalence of low commercial species (Savadogo et al., 2010).

First of all, the area has
to given a thorough site assessment to determine the condition of the area to
ease restoration process. This includes the soil and climatic properties such
as annual average temperature, annual rainfall, number of dry months and wet
months, soil drainage, soil depth, soil pH value, Cation exchange capacity, and
salinity. The next step is to do a re-vegetation plan preparation, where the
unwanted vegetations are cleared to make space for new vegetations. Next is
plant selection, where a suitable species is chosen to be planted at the site.

After that, site
preparation is done to clear space for new tree seedlings. The activities
suitable for the area are bush hogging, and spot cultivation. Spot cultivation
makes rows up and down the slope area without the risk of soil erosion. Maintenance
operations such as slashing and spraying can be carried out safely without
‘side slope’. After the planting process, maintenance and monitoring should be
done on a regular basis to ensure the tree seedlings grow well.

The enrichment planting
method used is line planting method, where the tree seedlings are planted in
lines instead of randomly placed area. The tree seedlings are planted in rows
distance of 3 meters and column distance of 5 to 6 meters. The tree seedlings
are 2 m away from the trail, both on the left side and right side of the trail.
The distance of tree seedlings from the first row to the third row is 3 meters.
This distance is used in the existing secondary forest area.

The second method of
restoration is the Miyawaki method. This is a method conjured by a Japanese
name Akira Miyawaki, a botanist and expert in plant ecology. He is also a
specialist in seeds and the study of natural forests. He is active worldwide as
a specialist in the restoration of natural vegetation on degraded land. Dr.
Miyawaki’s approach is to plant seedlings of as many main trees of the
potential natural vegetation as possible, using mainly canopy tree species
native to the region (Bari, 2017).

“From the day they are
planted, the various species and individual trees undergo a process of natural
selection through competition, resulting in the creation of a diversified
natural forest” – Bari (2017). “Seedlings with extensive root systems are
random planted in densely mixed plantings that match natural forest systems.
The trees reach four meters after five years, eight meters after ten years, and
over 20 meters after 25 years. The result is a diversified forest that is
allowed to grow naturally after three years,” – Mitsubishi Corporation (2017).
According to Dr Miyawaki’s theory of forest regeneration, the best forest
management technique is no management at all.

The first step to Miyawaki
method for restoring tropical forests is to collect seeds and seedlings (just
after germination) from the natural forest, or in this case, from the planting
site. The seeds are then germinated in a nursery. When two to three leaves have
sprouted from the seeds, the seedlings are transferred to pots. The seedlings
are cultivated in pots until their root groups generally fill the containers. After
that, the seedlings are cultivated under nets designed to cut out 60 percent of
the sunlight for one to two months.

After the two months had
passed, the seedlings nurtured one to two months more under 30 to 40 percent
shade. After that, have the seedlings adapted to natural environmental
conditions in the existing forests, or in this case, the planting site. This
goes on for one week to one month. The next step is to plant the seedlings into
the planting site. Maintenance is necessary for one to two years. From the
third year onwards, the trees are entrusted to natural management as nature
will foster the planted seedlings. At this point, the rule is “No management is
the best management”.

The Miyawaki method is
chosen because it is effective even in severe environments and has been used to
restore both temperate woodlands and tropical forests. Unlike commercial
forestry, forest management to cultivate trees as a timber resource, the
Miyawaki method promotes the restoration and recovery of native forests.
Forests offer biodiversity in its most natural form and fulfil the many
functions of natural ecosystems, including the absorption of carbon dioxide and
the protection of soil from erosion. Since the main tree species are selected
from the planting site, the original ecosystem, including small soil animals,
will be surely and quickly restored.