A review of dipterocarps - Center for International Forestry Research

Plantations 163
entire seedlings lifted from the soil and stripped
seedlings where leaves were reduced to about one third
their length. The percentage of trees surviving after one
year was highest for entire seedlings planted in cultivated
patches (58%). The lowest survival was found for stripped
seedlings planted in notches (19.8%). Bare-root stock
requires some moisture-preserving techniques to keep
roots moist during transport and storage prior to planting
(e.g., Strong 1939, Rayos 1940). A detailed description
of the planting technique for bare-root stock is given by
Agpaoa et al. (1976). Sometimes the planting stock is
root and/or shoot-pruned or stripped partially or totally
of leaves to initially reduce transpiration to facilitate
establishment. Root pruning was generally beneficial
(e.g., Walton 1938, Sasaki 1980a). Stripped seedlings
of Shorea talura could be stored for several months
without losing vigour and capacity for cutting propagation
(Sasaki 1980a). Landon (1948b) found that stripping
leaves of Dryobalanops aromatica was unsuccessful.
Wildings are either lifted with a ball of earth or are forestpulled.
They can be either directly planted or they are
kept in a temporary nursery under light shade for 3 to 6
months to recover before they are planted. Normal
practice is to keep wildings for some months in a nursery
until they have recovered. Very low survival rates were
achieved by Lantion (1938) with forest-pulled wildings
that were planted into the forest without a recovery
period. Wildings of Dipterocarpus grandiflorus and
Shorea teysmanniana were pulled from the forest,
stored for three days (partly mud-puddled and partly not)
and then planted. The average survival for mud-puddled
wildings was 9.5% and for wildings not mud-puddled
2.9%. Palmiotto (1993) described a direct transplanting
trial in the understorey and a gap using wildings of Shorea
hopeifolia, S. johorensis, S. leprosula, S. parvifolia,
S. parvistipulata and S. pinanga. Transplanting appeared
to have a negative effect on survival. Survival in the
understorey was between 8 and 58% and in the gap
between 3 and 50%. Recovery in the nursery is important,
if a high survival percentage after transplanting into the
field is to be achieved (e.g., Capellan 1961, Moura-Costa
1995).
There are clear indicators of the need to fertilise
initially, e.g., (1) sites where deficiency symptoms occur,
(2) sites with top soil removed, (3) sites carrying
vegetation indicating poor soil conditions, and (4) sites
with strong weed competition. It is, at present, still too
early to formulate valid fertiliser regimes. Less certain
are the fertilising requirements of the newly planted
seedlings. Nutrient deficiencies will occur, especially,
in plantation establishment on areas that have suffered
degradation to some extent (e.g., clear-felled areas and
secondary forest). Moura-Costa (1993) reported
fertilisation in the context of large-scale enrichment
plantings with rock phosphate (100 g) applied to the
planting hole. On an experimental scale, the effect of
additional fertiliser application on the establishment of
dipterocarps is being studied. Yap and Moura-Costa
(1994) reported on the effect of nitrogen fertilisation,
soil texture and other factors on biomass production of
Dryobalanops lanceolata seedlings. Nussbaum et al.
(1995) reported a combined experiment of soil-working
and fertilisation of tree seedlings of Dryobalanops
lanceolata and Shorea leprosula. The treatments were:
(1) planting into compacted soil; (2) planting into
compacted soil + fertilisation (100 g of rock phosphate
placed in the planting hole and 40 g of granular 12:12:17
N:P:K + micronutrients placed in a ring of about 10 cm
from the seedling just below the soil surface); (3)
planting into compacted soil + mulching (pieces of bark
which had been stripped from felled trees 1 year earlier
were used to cover the plot); (4) planting of seedlings
into cultivated plots (soil in the whole plot turned over
and broken up to a depth of 30 cm 2 to 3 weeks before
planting); (5) planting into cultivated plots + fertilisation;
(6) planting into cultivated plots + mulching; and (7)
planting into planting holes with soil replaced with topsoil
from undisturbed forests. After 6 months of observation
best diameter growth was found in treatments (2), (5)
and (7). Crown diameter was also largest in these three
treatments. Seedlings responded strongly to fertiliser
application, while (with exception of soil replacement)
response to soil working (plot cultivation or mulching)
was less distinct.
Sowing
Although not a widely used technique for establishment
of even aged stands, sowing has been tried in the past. It
has been applied on an operational scale in India (e.g.,
Chakravarti 1948) and Pakistan (e.g., Amam 1970). Gill
(1970) found sowing of Shorea leprosula promising in
the context of enrichment operations. Some of the finest
Dryobalanops aromatica stands in Malaysia were
established by broadcast sowing into high forest (Watson
1935). The results of direct sowing trials are not
conclusive. Shaded, cool and moist microsites seem to
be essential for successful germination and survival.