Pakistan Forests
Overall
Pakistan forest resources are limited, covering only 4.8 percent of
total land area, which is far below the optimal standard of 25%, forest
cover for a country. However
scarce, forests of Pakistan are very rich in terms of biodiversity and
present a unique blend of tree, shrub, grass and animal species, living
across various ecological (climatic) zones from sea level in the south,
to high altitude alpine pastures of the north.
Most
of the natural forest resources of Pakistan are concentrated in the
mountainous regions of the north covering Himalaya, Hindukush and
Karakoram ranges, where more than 60% of the country natural forest
resources are found.
The
rest of forestry resource is distributed among the south-western
mountains of Baluchistan, plains of Punjab and Sindh and the coastal
areas of Arabian Sea in the south.
Ecologically Pakistan is distributed into nine ecological zones depending
mainly on moisture availability, temperature, elevation and soil
conditions. The broader classification of ecological zones of Pakistan
consists of Alpine zone, Temperate zone, Sub-Tropical and Tropical zones
and Costal zone. Each ecological zone offers specific environmental,
topographic and climatic conditions required to support particular trees
and plants species.
This
greater variety of climatic conditions of Pakistan is a natural gift
and is greatly enriching its biodiversity of flora and fauna. Based on
the distribution of these specific ecological conditions the forests of Pakistan
are classified into nine major forest types, which, for the sake of
simplicity, can be clustered into five broader groups, as described
below;
Alpine Forests
Alpine
forests of Pakistan are found at very high elevations in the
mountainous regions of Himalaya, Karakoram and Hidukush. The timberline,
or elevation limit of tree growth, is exceptionally high in these
mountains, rising upto 4000 m above sea level.
These
forests are subdivided into Sub Alpine forests, Alpine scrub and Alpine
pastures. The Sub Alpine forests grow to the tree limit and due to
harsh climatic conditions tree density is low and growth is stunted.
Alpine scrubs include shrub formations 1 m to 2 m high extending 150 m or more above the sub-alpine forests. Alpine
pastures are situated above the tree line of 4000 meters, where growing
season is very short and vegetation mainly consists of perennial,
herbaceous plants. These high altitude pastures are found mostly in the
northern districts of Gilgit, Diamer, Chitral and Skardu.
Temperate forests
These
are mostly evergreen natural forests of conifers, growing between
elevations of 1500-4000 meters above sea level in the northern
mountainous regions of Pakistan and Kashmir. Economically coniferous
forests are more important as they are Pakistan’s major sources of
commercial timber.
Ecologically
temperate forests of Pakistan are sub-divided into moist and dry
temperate, depending on the rainfall. In moist temperate zone high summer rainfall occurs where mountain masses stand exposed to the moist southwest winds.
Moist
temperate forests of Pakistan are concentrated in the northern
districts of Muree and Galiat hills, Kaghan valley, Kashmir region,
Allai valley, Siran valley and Swat Valley etc.
On the other hand Dry temperate forests grow at the same altitude, as the moist temperate, but receive little of no summer rains. These
forests are mostly found in the northern districts of Dir, Chitral,
Kohistan, Diamer and Gilgit etc. However some of the dry coniferous forests are also found in the Sulaiman Range of Balochistan where Chilghoza pine and Juniper grow in the extreme dry environment.
Sub-tropical Forests
These
forests are found in the lower reaches of Himalya, Hindukush and
Sulaiman Ranges between 600-1700 m above sea level. These forests are
subdivided into sub tropical broad-leaved forest and sub tropical pine
forests. Broad leaved forests grow in the lower most reaches between
600-1000 m, and consists of drought resistant species. These sub tropical broad leaved forests cover fairly large area of about 1,191,000 ha.
On the other hand Sub-tropical pine forests are found at little higher altitude1000-1700 m, meeting the temperate forests at the upper end. Chir pine (Pinus roxburghii) is the major specie found.
Dry Tropical Forests
Coastal (Mangrove) Forests
These are also known as Mangrove forests
and are found in the Indus delta and coastal areas of Arabian Sea
around the coast of Karachi (Sindh) and Pasni in Balochistan. The main species found is Avicennia marina, which grows in low height. According to estimates, these forests cover an area of 207,000 ha.
No comments:
Post a Comment