|
Forest
The
Mt Gede Pangrango National Park is located in one of the wettest parts of West
Java. The annual rainfall average ranges from
3,000 to 4,200 mm. Relative
humidity is also really high, even though it can range from 30 to 90 %. While it
can get down to 10° C on the high mountain peaks, the average temperature is
18° C. At night times even frost can occur. December to March is the wettest time of
the year, with rain almost every day. However, between May and September, the
"dry season", dry leaves crackle underfoot and there is occasionally a
serious risk of fire, but soil and atmospheric moisture in the forest are
usually sufficient to keep ve-getation green and growing.
The
functioning of Gede-Pangrango's tropical montane forest is very different from
the workings of tropical lowland rain forest. Lowland types recycle nutrients,
with very little input or output to the ecosystem. Mountain ecosystem,
particularly on volcanoes, have a throughput of material: mineral enrichment
from eruptions, and mineral depletion due to erosion and leaching by rain This immense climatic
variety naturally has a great effect on the vegetation of Mt Gede Pangrango
National Park. The forest ecosystems can be grouped into three zones, based on
altitude:
Lower
Montane/SubMontane Forest
It
ranges from 1000 - 1500 m a.s.l. It has the highest diversity of species of the
three forest groups. Large trees form a tall canopy 30 - 40 m above the ground.
Three different tree layers dominate the submontane forest: at a height of 30
-60 m one can find a canopy dominated by huge rasamalas and chestnut trees. In
10 to 20 m height one discovers a layer with Antidesma tetandrum and several
different laurels. The shrubs "Ardisia fuliginosa" and
"Dichrea
febrifuga" build a plant layer at 3 - 5 m height. Further the ground is
covered by a mat of plants, consisting of begonias, fern, epiphytes, orchids,
lianas and herbs.
This
is the forest you experience on first entering the park. Many of the animals and
plants here, including the gibbon and the huge rasamala trees, are lowland
species living close to their upper altitudinal limit. Because such forest is a
mixture of lowland and mountain species, it is sometimes regarded as
a submontane ecosystem. The soils of the lower montane zone are usually deep,
well weathered and rich in organic matter and fine particles such as clays.
These fertile soils are known as latosols, and provide the nutrients to
support the typical luxuriant growth of the submontane forest.
Montane
Forest
It
ranges from 1500 to 2400 m a.s.l. This zone possesses a much lower diversity of
plants, than the submontane forest zone. The dominating tree species is the puspa. Further many conifers grow in this layer. The cooler conditions favor
mosses as the dominant epiphytes. This zone also called "upper montane
forest". The boundary (ecotone) between the lower and upper
montane
vegetation is often sharp. A change has taken place: there are fewer sounds and
it is possible to see deeper into the forest, as views are unhindered by a thick
understorey.
Hikers
who stop to take a rest often feel cold. Cloud hangs over the zone for much of
the time, cooling the air and limiting the amount of sunlight. Such atmospheric
conditions slow growth rates and limit the number of species. Most of the plants
growing at these altitudes are are true montane dwellers., living on temperature
mountain "island" above a "sea" of tropical vegetation. The
canopy of montane forest tends to be of uniform height, often only about 20;
tree trunks are much shorter than those of the submontane forest. Large,
emergent trees are rare, as are buttress roots. Leaves are often small (microphyllic).
Common herbs of the forest floor include genera well known as garden plants:
Begonia isoptera, Impatiens javensis, Lobelia angulata and L. montana.
Subalpine
Forest
Over
2400 m a.s.l. the species diversity continues to decline. This zone is dominated
by smaller tree species. Lichens such as the "beardmoss" cover plants
and rocks. Tiny highland grass, moss tussocks, and clumps of Javanese edelweiss
create the uniqueness of this zone. Besides other high altitude plants, one can
find oak, buttercup, violets, strawberry, and primrose which surprisingly have a
close affinity to those of the Northern Hemisphere. Above the saddle connecting
Gede and Pangrango, a fundamental change in vegetation takes place. Trees are
reduced to a few metres in height. Old trees are gnarled and twisted. In bright
conditions sunlight floods the whole forest, but weather changes are abrupt and
cloud can bring sudden chill and gloom. No wonder subalpine forest is known more
evocatively as elfin woodland.
The
dominant tree in this zone is cantigi Vaccinium
varingiaefolium, a member of the
heather family (ERICACEAE). In common with its European relative, the bilberry,
cantigi produces edible berries. Slender cantigi trunks form low, dense, upland
ericaceous forest from Kandang Badak almost to the summits; a good example is
seen along the crater trail. Young cantigi leaves are responsible for the
attractive red flushes commonly seen adorning the montane forest, and, as with
puspa, this very probably affords protection againts the strong ultraviolet
light of these altitudes.
back
to top
|
