CSS Forums - forest types in pakistan

The following forest types are found in Pakistan.

[B]Littoral and Swamp forests:[/B] These are more or less gregarious forests of low height which occur in the Arabian sea around the coast of Karachi and Pasni in Balochistan. The main species is Avicennia marina (99%). Other species like Rhizophora have disappeared over a period of time due to heavy cutting. According to latest estimates, these forest cover an area of 207,000 ha.

[B]Tropical dry deciduous forests:[/B] These are forests of low or moderate height consisting almost entirely of deciduous species. Their canopy is typically light though it may appear fairly dense and complete during the short rainy season. This type does not occur extensively in Pakistan but there are limited areas in the Rawalpindi foothills carrying this vegetation type, all much adversely affected by close proximity to habitation or cultivation. It is closely similar both in floristic composition and in structure to that developed freely in the adjoining parts of North West India. The chief tree species are Lannea (Kamlai, Kembal) Bombax ceiba (Semal), Sterculia, Flacourtia (Kakoh, Kangu), Mallotus (Kamila, Raiuni) and Acacia catechu (Kath). Common shrubs are Adhatoda (Bankar, Basuti, Bansha), Gymnosporia (Putaki) and Indigofera (Kathi, Kainthi).

[B]Tropical thorn forests:[/B] These are low, open and pronouncedly xerophytic forests in which thorny leguminous species predominate. This type occupies the whole of the Indus plain except the driest parts. The major tree species are Prosopis cineraria (Jhand), Capparis decidua (Karir, Karil), Zizyphus mauritiana (Ber), Tamarix aphylla (Farash) and Salvadora oleoides (Pilu, wan). Among them are a large number of shrubs of all sizes. The tree forest climax is very frequently degraded to a very open, low thorny scrub of Euphorbia (Thor), Zizyphus (Ber), etc. owing to the universally heavy incidence of grazing and other biotic factors. Edaphic variants, especially connected with degree of salinity, shallowness over rock, etc., often occur. A characteristic pioneer vegetation is developed on inland sand dunes and the semi-deserts of the areas of least rainfall.

On the basis of climax vegetation, the whole Indus basin plain with the exception of parts of the districts of Sialkot, Gujrat and Jehlum, consists of tropical thorn forests. Prior to development of irrigation, agriculture and urbanization, the area extended from the foothills of the Himalayas and low-hills in the south-west Punjab plains and Balochistan to the Arabian sea. The climax species of these forests are Salvadora oleoides, Capparis decidua, Tamarix aphylla and Prosopis cineraria, which grow on a wide range of soil textures, from flat deep alluvial soils to heavy clays, loams and sandy loams. The climate varies from semi-arid (250 to 750 mm rainfall) to arid (less than 250 mm rainfall). The summer temperature in this tract is as high as 50°C.

Earlier, these forests merged with riverain forests along the river banks and with scrub forests in the low hills in the north and north-western regions of Pakistan. Together these forests provided an ideal habitat to the wildlife of the area which seasonally migrated according to their needs; during cold winter from the lower hills towards the plains in search of food and shelter, from the flood plains towards the dry areas during floods and towards the rivers during the summer drought. This is no longer the situation. Riverain forests now grow in the forms of disjunct patches over an area of 173,000 ha. Irrigated agriculture is carried over 18.668 million ha. and irrigated tree plantations over an area of 103,000 ha in this tract.

[B]Sub-tropical broad-leaved evergreen forests:[/B] These are xerophtic forests of thorny and small-leafed evergreen species. This type occurs on the foothills and lower slopes of the Himalayas, the Salt Range, Kalachitta and the Sulaiman Range. The typical species are; Olea cuspidata (Kau) and Acacia modesta (Phulai), the two species occurring mixed or pure, and the shrub Dodonaea (Sanatta) which is particularly abundant in the most degraded areas. Total area of these forests is estimated to be 1,191,000 ha.

[B]Sub-tropical pine forests:[/B] These are open inflammable pine forests sometimes with, but often without, a dry evergreen shrub layer and little or no underwood. This type consists of Chir pine (Pinus roxburghii) forests found between 900 m and 1700 m elevation in the Western Himalayas within the range of the south-west summer monsoon. It is the only pine of these forests though there is a small overlap with Pinus wallichiana (Kail, Biar) at the upper limit.

[B]Himalayan moist temperate forests:[/B] The evergreen forests of conifers, locally with some admixture of oak and deciduous broad-leaved trees fall in this category. Their undergrowth is rarely dense, and consists of both evergreen and deciduous species. These forests occur between 1500 m and 3000 m elevation in the Western Himalayas except where the rainfall falls below about 1000 mm in the inner ranges, especially in the extreme north-west.

These forests are divided into a lower and an upper zone, in each of which definite species of conifers and/or oaks dominate. In the lower zone, Cedrus deodara (Deodar, diar), Pinus wallichiana, Picea smithiana and Abies pindrow (Partal) are the main conifer species in order of increasing altitude, with Quercus incana (rin, rinj) at lower altitudes and Q. dilatata above 2130 m. In the upper zone Abies pindrow and Q. semecarpifolia are the dominant tree species. There may be pockets of deciduous broad-leaved trees, mainly edaphically conditioned, in both the zones. Alder (Alnus species) colonizes new gravels and sometimes kail does the same. Degradation forms take the shape of scrub growth and in the higher reaches, parklands and pastures are subjected to heavy grazing.

[B]Himalayan dry temperate forests:[/B] These are open evergreen forest with open scrub undergrowth. Both coniferous and broad-leaved species are present. This type occurs on the inner ranges throughout their length and are mainly represented in the north-west. Dry zone deodar, Pinus gerardiana (Chalghoza) and/or Quercus ilex are the main species. Higher up, blue pine communities occur and in the driest inner tracts, forests of blue pine, Juniperus macropoda (Abhal, Shupa, Shur) and some Picea smithiana (e.g. in Gilgit) are found locally.

[B]Sub-alpine forests: [/B]Evergreen conifers and mainly evergreen broad-leaved trees occur in relatively low open canopy, usually with a deciduous shrubby undergrowth of Viburnum (Guch), Salix (Willow, Bed), etc. The type occurs throughout the Himalayas from about 3,350 m to the timber limit. Abies spectabilis and Betula utilis (Birch, Bhuj) are the typical tree species. High level blue pine may occur on landslips and as a secondary sere on burnt areas or abandoned clearings. Rhododendrons (Bras, Chahan) occur in the understorey but do not form extensive communities as they do in the central and eastern Himalaya. Dwarf junipers are often abundant.

[B]Alpine scrub:[/B] Under this type are included shrub formations 1 m to 2 m high extending 150 m or more above the sub-alpine forests. The characteristic genera are Salix, Lonicera (Phut), Berberis (Sumbul, Sumblue), Cotoneaster with Juniperus and occasionally Rhododendron or Ephedra (Asmania).

[B]Present situation: [/B]Forest area of Pakistan reported in different official documents has varied over the years with administrative and political changes in country as well as with changes in methods of reporting data. Different government departments have been publishing different forest statistics since 1947 when Pakistan was created as an independent country. Most recently, data of land use including forest area have been reported by Forestry Sector Master Plan (FSMP) Project in 1993, with the help of Landsat Satellite Thematic Mapper Images at a scale of 1:250,000 covering the whole of Pakistan. This is presented in Table 1.

The total area of forests in Pakistan is 4.224 million ha which is 4.8% of the total land area. However, it may be mentioned here that the farmland trees and linear planting along roadsides, canalsides and railway sides covering an estimated area of 466,000 ha and 16,000 ha respectively do not constitute forests within the context of legal, ecological or silvicultural/management definition of forests. The situation is also similar, but to a lesser extent, in the case of miscellaneous plantations over an area of 155,000 ha. If the area of these three categories of plantations is excluded from total forest area of 4.224 million ha, then the latter is reduced to 3.587 million ha which is approximately 4.1 % of the total area.