Forests in Pakistan: The forests of Pakistan reflect great physiographic, climatic and edaphic contrasts in the country. Pakistan is an oblong stretch of land between the Arabian sea and Karakoram mountains, lying diagonally between 24° N and 37° N latitudes and 61° E and 75° E longitudes, and covering an area of 87.98 million hectares. Topographically, the country has a continuous massive mountainous tract in the north, the west and south-west and a large fertile plain, the Indus plain. The northern mountain system, comprising the Karakoram, the great Himalayas, and the Hindu-Kush, has enormous mass of snow and glaciers and 100 peaks of over 5,400 m. in elevation. K-2 (8,563 m.) is the second highest peak in the world. The mountain system occupies one third of this part of the country. The western mountain ranges, not so high as in the north, comprise the Sufed Koh and the Sulaiman while the south-western ranges forming a high, dry and cold Balochistan plateau. Characteristically, the mountain slopes are steep, even precipitous, making fragile watershed areas and associated forest vegetation extremely important from hydrological point of view. The valleys are narrow. The mountains are continuously undergoing natural process of erosion. The nature of climate with high intensity rainfall in summer and of soil in the northern regions render these mountains prone to landslides. The Indus plain consists of two features; the alluvial plain and sand-dunal deserts. The country is drained by five rivers; namely, Indus, Jhelum, Chenab, Ravi and Sutlej. Of these Indus arising in snow covered northern mountain ranges flows towards south through the Punjab and Sindh plains into a wide delta before entering Arabian sea. Other rivers join it on the way, together feeding one of the largest irrigation systems in the world. The great river system of Indus in Pakistan derives a part of their water supply from sources which lie in the highlands beyond the Himalayas and the western mountains, and part from countless valleys which lie hidden within the mountain folds. Much of the silt of the alluvial plain is from natural geological erosion of mountains in the north brought down by rivers. Thal desert lies between the rivers Indus and Jhelum, while Cholistan and Thar deserts occur on the south-east of the country. A great variety of parent rock types occur in Pakistan, which exert considerable influence on the properties of the soil. The rocks found in Pakistan can be classified into three major groups, viz. the igneous rocks, the sedimentary rocks and the metamorphic rocks. In the Himalayan regions, the common rock types are metamorphic which are gneisses, schists, slates and phyllites with some quartzite and marble. In the northern part of Indus plain, between Sargodha and Shahkot small outcrops of phyllites and quartzites occur. Granite, syenite, diorite, gabbro, dolerite and peridotite are more common types of igneous rocks, which occur in Dir, Swat, Chitral, Gilgit, Zhob, Chagai, Las Bela and Nagarpark. 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. 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. Of the four forest cover percentage groups (> 70%, 40-69%, 10-39%, 0-9%), Pakistan lies in the last category: 0-9%. Between 1981 and 1990, there had been a 4.3% decrease in forest areas of the Tropical Asia and Oceania, which Pakistan is a part of. During the same period, a 0.6% deforestation had been occurring each year. This is an alarming situation and needs to be stalled and then reversed, if possible. As recognition of the multiple values of forests has grown, so have concerns for their disappearance. In Pakistan, subtropical, temperate, riverain and mangrove forests are being lost because of questionable land use practices and the ever-increasing demand for timber and firewood. As a result, more responsible management approaches are being demanded that can accommodate complex economic and ecological needs. Designation of selected forestlands as national parks, area for agro-forestry practices and the development of plantations and afforestation practices are needs of the hour. Total Forest Area under the control of the Forest Departments (including Azad Kashmir and the Northern Areas) is 4.26 million hectares. The per capita forest area is only 0.037 ha compared to the world average of ONE ha. Main reason for this is that more than 70% land area of Pakistan is Arid and semi-Arid with annual rainfall of 250-500 mm: too low and erratic to sustain natural vegetation and to plan afforestation/regeneration programmes. Forest Areas and Rangelands (in ha.) The following forest types are found in Pakistan: • Littoral and Swamp forests • Tropical dry deciduous forests • Tropical thorn forests • Sub-tropical broad-leaved evergreen forests • Sub-tropical pine forests • Himalayan moist temperate forests • Himalayan dry temperate forests • Sub-alpine forests • Alpine scrub • Littoral and Swamp forests 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. Tropical dry deciduous forests: 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). Tropical thorn forests: 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. Sub-tropical broad-leaved evergreen forests: 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. Sub-tropical alpine forests: 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. Himalayan moist temperate forests: 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. Himalayan dry temperate forests: 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. Sub-alpine forests: 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. Alpine scrub: 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).
Posted on: Tue, 02 Sep 2014 09:44:54 +0000
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