|
Share Thread: Facebook Twitter Google+ |
|
LinkBack | Thread Tools | Search this Thread |
#1
|
||||
|
||||
Climate change and forests of Pakistan
Climate change and forests of Pakistan
1. Introduction Pakistan lies between 24° and 37° north latitudes and 61° and 75° east longitudes. It is located in a region where three important mountain ranges meet. The mountain ranges are the Himalaya, Hindukush and Karakorum. The lessor Himalayan ranges and Hindukush ranges extend deep into the country and form huge complex of mountains and plateau. Accordingly 4 out of 10 highest peaks in the world lie in Pakistan. Physiographically, Pakistan can be divided broadly into two main regions namely plains of the Indus River and its tributaries and huge complex of mountains and plateaus lying in north and northwestern boundaries. The plains are more or less level consisting mostly of irrigated agriculture and arid, semi-arid deserts. The mountain complex consists of broad valleys, partly irrigated and high steep and rugged mountains and plateaus. About 60 percent area of Pakistan is covered by mountainous complex (Sardar, 1989). More than 60 percent area of Pakistan is arid and receives less than 250mm rainfall per annum. About 20 percent area is semi-arid where rainfall varies between 250-400 mm per annum. In these zones temperature rises steeply during summer and drops sharply in winter giving rise to great variations in diurnal temperature. Subsequently the arid and semi-arid parts of the country are characterized by low precipitation, extreme temperatures and low humidity. These conditions are inhospitable to good plant growth. There are frequent droughts and the plant growth fluctuates greatly with precipitation (Sardar, 2002). 2. Climate of Pakistan The geographic location and the phsiographic factors are the major causes of diversity in the climate. These factors affect and modify precipitation and temperatures. Based on these factors the climate of the country has been classified into 4 major climatic regions. These include (i) Marine Tropical Coastland, (ii) Sub Tropical Continental Lowlands, (iii) Sub Tropical Continental Highlands and (iv) Sub Tropical Continental Plateau (Desert). (Sheikh and Hafeez, 1977). Khan (1993) has classified the country into 11 distinct as well as over lapping climatic zones. The climate of the Pakistan is diverse and characterized by mild, moist winters and hot, dry summers in the north to semi arid and arid zones in the west and parts of the south. The part of northeastern mountainous and sub mountainous areas receives more than 1700 mm precipitation mostly in summer monsoon. The arid plains of southwest Balochistan receive only about 30 mm during whole year. Thermal regimes indicate extreme diurnal, seasonal and annual variations. Temperature may fall as low as -26°C in the north to as high as 52°C in the central arid plains. In the semi-arid plains, temperature up to 42°C is also recorded at various stations. 3. Extent of forests Pakistan has meager forest resources. The country due to its sharp climatic variations and arid conditions lacks reasonable tree cover. There is hardly 4.28 million hectares or 4.9 percent of total area forest / tree cover. Out of it the productive forests are less than 2% (Amjad et al. 1996). The vegetation type-wise forest cover is given in Table 1. Table 1: Summary of the estimates of forest/tree area (Thousand hectares) Forest Cover/Land Use class NWFP Punjab Sindh Balochistan Northern Areas Azad Kashmir Total 1. Forest/Tree Cover 1.1 Conifer 940 30 - 42 660 241 1913 1.2 Irrigated plantations - 79 23 1 - - 103 1.3 Riverain 13 27 112 20 - 1 173 1.4 Scrub 539 132 - 504 - 16 1191 1.5 Mangrove - - 205 2 - - 207 1.6 Linear plantations 2 14 - - - - 16 1.7 Farmland trees 70 306 54 23 6 7 466 1.8 Miscellaneous planting 120 20 5 - - 10 155 Total Area: 1684 608 399 592 666 275 4224 2. Geographic area 10174 20626 14091 34719 7040 1330 87980 2.1 Percent (%) tree cover 16.6 2.9 2.8 1.7 9.5 20.7 4.8 Source: Forestry Sector Master Plan (FSMP), 1992 4. Forest/Vegetation types The distribution of forests / vegetation types is primarily controlled by the climatic and edaphic factors. Starting from alpine zones in the north to the coastal belt of Arabian Sea in the south there are 11 types in the country. Sheikh and Hafeez (1977) have described in detail the Forest Types of Pakistan. A very brief description is as under: 4.1 Alpine Scrub The deciduous and small leaved shrubs including evergreen junipers and sometimes Rhododendron and Ephedera are found. Dwarf prostrate Salix spp. are also present. A good herbaceous flora is met with. The characteristic generas are Salix, Lonicera, Berberis, Cotoneaster, Juniperous, Rhododendron and Ephedera. This type is located above 3800 meters elevation above sea level (asl). 4.2 Sub Alpine Forests Abies pindro and Pinus wallichiana trees in groups with irregular dense lower storey of broad leaved trees are found. Betula is typically prominent at the higher elevation in depressions. This is the top most tree formation in the Himalayas which is found between 3350-3800 meters elevation asl. 4.3 Dry Temperate Forests The vegetation, as a whole, is xerophytic. The aromatic shrubs namely; Artemisia and some thorny species of Caragana, Prunus and Rosa are pre-dominant. The forests consists of Conifers mostly having Cedrus deodara, Pinus gerardiana and Juniperus macropoda. Quercus ilex, Pinus wallichiana, Pecea smithiana are also present. Broad leaved trees may include Fraxinus and Acer. Shrubs include Daphne, Lonicera, Prunus, Artemisia, Astragalus and Ephedra. 4.4 Himalayan Moist Temperate Forests Major Conifer species are Pinus wallichiana, Cedrus deodara, Picea smithiana and Abies pindrow, Taxus buccata also occurs. The broad leaved tree species include Quercus, Rhododendron, Acer, Aesculus, Prunus, Ulmus, Fraxinus, Corylus and Alnus. 4.5 Sub Tropical Pine Forests This type consists of pure Pinus roxhurghii. Other species found include Quercus, Rhododendron and Lyonia ovalifolia in depression. Pistacia, Syzygium, Mallotus, Xylosoma, Pyrus and many shrubs are also found. 4.6 Dry Sub Tropical Broad Leaved Forests The characteristic tree species of this type are Olea ferruginea and Acacia modesta. Pistacia and Punica are also met with. The unpalatable shrubs include Dodonaea, Withania and Rhazya and thorny species like Gymnosporia, Monotheca and Carissa are also associated. 4.7 Tropical Dry Deciduous Forests This type is limited to the Himalayan foothills and adjoining Siwalik hills. These are deciduous tree species and include generas like Lannea, Salmalia, Sterculia, Flacouria, mallotus and Acacia. 4.8 Tropical Thorn Forests Acacia and Prosopis are strongly represented tree species of this type. There are several generas of shrubs: notable are Suaeda, Salsola, Haloxvlon. Calotropis and Periploca. Some of the generas of typical desert are Capparis, Zizyphus and Salvadora. 4.9 Irrigated Forests These forests are man-made irrigated plantations. Dalbergia sissoo as upper storey and Morus alba as under storey are grown in Punjab and Acacia arabica in Sindh. Other tree species namely Salmalia and Melia are also planted. 4.10 Indus Innudation (Riverian) Forests This forest type predominantly consists of Acacia arabica with scattered tree species like Populus euphratica and Prosopis spicigera on the drier parts. These forests are mostly found along the bank of Indus River. 4.11 Tropical Littoral and Swamp Forests These tidal forests are found in Indus delta in the southwestern part of the country. The main species are Avicennia officinalis and Bruguiera conjugata. These forests provide habitats to various aquatic animal species and is of economic importance to the country. 5. Climate change impact The indepth and precise information on climate change impact on forests has, so far, not been collected in Pakistan. The GOP, through Hagler Bailly Pakistan (2001) has got prepared a report titled “Pakistan Initial National Communication to the UNFCCC” which evaluates qualitative changes in the forests. The report indicated that there would be a shift in the location of the different biomass under the change in precipitation scenario. Further the cold and temperate conifers may shift towards north pushing against the cold conifers mixed woodlands which in turn will encroach upon the southern and lower edges of the alpine tundra. Further study has revealed that the increase in the size of the biomass of economic values and decrease in size of biomass of degraded vegetation/scrub may occur. There is need that the impact of climate change on forests of Pakistan be scientifically evaluated using standard methodology. This is only possible when the international sponsoring agencies provide financial and technical support to the research organizations in Pakistan. 6. Mitigation/adoption options The Hagler Bailly report (2001) had suggested the following mitigation and adoption options to impede the effect of climate change: 6.1 Mitigation i) Agroforestry practices ii) Plantation on agricultural land iii) Protection of conifer forests iv) Reforestation in conifer forests v) Watershed plantation vi) Reforestation in riverain forests vii) Vegetation improvement on rangelands. 6.2 Adoption i) Control of forest ii) Pest control iii) Change in species and variations iv) Preservation of watershed and rangelands v) Control of wastage vi) Conservation of coastal zone The activities mentioned above, had to be carried out in the existing forests, watershed and rangeland areas, would require large scale plantations with indigenous as well as adapted exotic species to improve cover. There is need to rehabilitate, improve and develop the existing forests to impede the impact of climate change. These activities would require strong technical and financial support of the international sponsoring agencies. Since trees have very long gestation period to establish themselves so the projects covering a period not less than 15 years would be appropriate. |
The Following User Says Thank You to uzma khan youzaf zai For This Useful Post: | ||
ArifAwan (Tuesday, December 10, 2013) |
Thread Tools | Search this Thread |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Pak-Affairs Notes | Predator | Pakistan Affairs | 68 | Friday, December 23, 2022 07:27 PM |
development of pakistan press since 1947 | Janeeta | Journalism & Mass Communication | 15 | Tuesday, May 05, 2020 03:04 AM |
Essays - Officer Academy LHR | uzma khan youzaf zai | Essays | 24 | Sunday, October 18, 2015 12:59 AM |
Required VU sociology Notes by Dr. Anwar | shrd | Sociology | 6 | Saturday, February 23, 2013 11:40 AM |