Baluchistan xeric woodlands
Climatic and slope variations have given this ecoregion many of world's biomes. The juniper forest of north central Baluchistan is believed to be the most extensive remaining in the world and is home to the distinctive and highly threatened Baluchistan bear and straight-horned markhor. Some individual Juniperus macropoda have been in existence for 2,500 years. Tiger (Panthera tigris virgata), Asiatic cheetah (Aciononyx jubartus venaticus), and Asiatic wild ass (Equus hermionus) have all been extirpated from this ecoregion within the past 400 years.
Location and General Description
This Baluchistan Xeric Woodlands ecoregion spans from the Las Bela Valley and the high barren plateau of Baluchistan from southwest Pakistan to eastern Afghanistan. It extends to the north, cutting through the Trans-Indus Plains of the North-West Frontier Province and through Peshawar, Kohat, and Bannu, ending at the border of Eastern Hindu Kush and the Himalayan Mountains. A maze of ranges, hills, and mountains lie within and around this ecoregion. These include the Sulaiman, Kirthar, Safed Koh, and Pub ranges, Torghar and Kaliphat Waziristan hills, and the Tobakakar, Takhatu, and Zarghun mountains with elevations from 1,000 to 3,000 meters (m). Large passes such as Quetta and Khyber cut through these ranges. Short rivers that originate from the hills of Baluchistan Plateau drain into shallow lakes or are absorbed in the sandy deserts. The submontane plateaus of the north are fed mostly by the tributaries of the Indus and Kabul rivers.
This area is characterized by medium-altitude arid to semiarid scrub forest, and it experiences low rainfall and severe temperature fluctuations. The average annual rainfall is less than 150 millimeters (mm). Temperature is generally high in the summer and can reach up to 40° C. The Baluchistan Plateau reaches temperatures of 45° C. Northerly hot winds called loo blow across the south during the day in the summer, causing dust storms with wind velocities between 60 and 110 miles per hour (mph). The period for the southwest monsoon is from June to September. Winters generally are cold. Soils are classified as gypsum and pedocals that are characterized by high calcium carbonate and low organic matter content. Many of the ridges in the north are made up of uneven limestone filled with lacustrine clays, gravel, or boulder.
The area supports tropical steppe flora (below 1,500 m) and open xeric woodlands (1,500 to 2,000 m). The montane vegetation covers areas of the Baluchistan and Kurram valleys that consist of open woodlands of pistachio (Pistachia atlantica, P. khinjuk), almond (Prunus rosaceae, P. eburnea), barberry (Berberis), honeysuckle bush (Lonicera caprifoliaceae, L. hypoleuca), lycium (Solanaceae), sage or wormwood (Artemesia spp.), and juniper (Juniperus macropoda, J. semiglobosa, and J. seravschanica). The transitional woodland between the subtropical woodlands and the alpine vegetation of sclerophyllus forest supports the olive (Olea cuspidata) accompanied by the shrub varnish leaf (Dodonaea viscosa, Sapindaceae) found on the foothills in Pakistan. The ground layer that dominates areas within the woodlands south of the ecoregion is composed of perennial grasses, tropical shrubs, and Acacia. These include Amygdalus communis, A. kuramica, and Fraxinus xanthoxyloides. The Indus Plain of the immediate vicinity east of the Indus River and north of the ecoregion is heavily degraded because of heavy logging and overgrazing. It supports Tamaricaceae, Gramineae, Leguminosae, and Rhamnaceae communities. These include species such as Tamarix spp., Saccharum spontaneum, Acacia arabica, Savadora oleoides, S. persica, and Ziziphus mauritiana. Thorny small trees and Acacia such as Olea ferruginea, Acacia modesta, and Artemisia maritima, perennial grasses of Poa and Bromus spp., and bulbous plants such as Iris, Tulipa, and Allium spp. are also found on these slopes.
This [[[ecoregion]] is known for its richness rather than its endemism. It has more than 300 bird species. The number of migratory bird species is three times higher than that of restricted-range birds. The majority of migratory bird species are passerines. These include different redstarts (Muscicapidae), swallows (Hirundinidae), larks (Alaudidae), sparrows (Passeridae), common and European goldfinch (Fringillidae), and buntings. Other bird species include bee eaters (Merops spp.) and wheat eaters (Oenanthse spp.), the Egyptian vulture (Neophron percnopterus), Eurasian sparrowhawk (Accipiter nisus), and greater spotted eagle (Aquila clanga), pheasants, doves, and three types of owls. White-cheeked tit (Aegithalos leucogenys) and Brooks's leaf-warbler (Phylloscopus subvirdis) are limited to the juniper woodlands. The Indus valley is rich with migratory and resident waterfowl. The migratory species include ducks (mallard, pintail, shoveler, pochard, and teals), egrets, kingfishers, coots, plovers, sandpipers, and snipes. The marbled teal (Marmaronetta angustirostris) and great Indian bustard (Otis bengalensis) are listed on IUCN's Red List as vulnerable because of fragmentation.
Wild cats such as common leopard (Panthera pardus) and caracal (Caracal caracal) are found on the hills of Baluchistan, whereas the jungle cat (Felis chaus) and leopard cat (Prionailurus bengalensis) are in the northern plains. Antelopes chinkara or Indian gazelle (Gazella bennettii) are found in western Baluchistan, and hog deer (Axis porcinus) are common to the Indus plain and southwest Quetta. The stripped hyena (Hyaena hyaena) and the red fox (Vulpes vulpes) are found in the major hills of Baluchistan.
The major mountain ranges around the Sulaiman Range, northeastern Baluchistan, southern Northwest Frontier Province, and small areas in northeastern Afghanistan support the straight-horned or Sulaiman markhor (Capra falconeri jerdoni or C. f. megaceros), flare-horned markhor (C. f. falconeri or C. f. falconeri cashmirensis), Baluchistan black bear (Ursus thibetanus gedrosianus), Afghan urial (Ovis vignei cycloceros), Sind ibex (Capra hircus aegargus), Eurasian wild boar (Sus scrofa), Baluchistan gerbel (Gerbillus nanus), and Hotson's long-tailed hamster (Calomyscus hotsoni). The freshwater Indus River dolphin (Platanista minor) and the terrestrial mammals listed on table 1 are near-endemic species of this ecoregion.
|Table 1. Endemic and Near-Endemic Mammal Species|
|An asterisk signifies that the species' range is limited to this ecoregion.|
The endangered mugger or marsh crocodiles (Crocodylus palustris) are found around the Indus River as well as the High and Dasht rivers of Baluchistan. The crocodile recovery that is being carried by the Sind wildlife department from 1983 to 2000 has helped to recover the population successfully. Other reptiles in the area are leopard gecko (Eublepharis macularius), which is common throughout the ecoregion; the Indian cobra (Naja naja), found in Baluchistan; and the Central Asian cobra (Naja oxiana) from the northwest plains. Other important reptile species include Afghan tortoise (Testudo horsefieldi), rock Agsama lizard (Agama caucasica), and Perisan horned viper (Pseudocerastes persicus). Amphibians such as three species of toads and frogs such as ant frog (Rana cyanphylyctic), R. rudibunda, R. sternostignata, and R. khuli are common in Baluchistan, and the tiger frog (Rana tigrina) is common in the northern plains.
Three species of goitered gazelles, the Chiltan wild goat, and the Afghan urial are considered vulnerable. The Indus River dolphin, the Baluchistan bear, the Suleiman markhor, Hotson's long-tailed hamster, and the Central Asian cobra are classified as endangered.
This ecoregion has lost much of its woodlands because of intensive logging that has occurred over hundreds of years. The Indus Plains to the northeast have been cleared for cultivation. The remaining forest in this area exists in small patches and is highly fragmented. There are four national parks, twelve wildlife sanctuaries, ten game reserves, and one waterfowl sanctuary in this ecoregion. However, the 22 areas listed in table 2 are strictly protected from human impact.
|Table 2. WCMC (1997) Protected Areas That Overlap with the Ecoregion|
|Protected Areas||Area (km2)||IUCN Category|
|Bund Khush Dil Khan||10||UA|
|Surjan, Sumbak, Eri, and Hothiano||390||UA|
|Ecoregion numbers of protected areas that overlap with additional ecoregions are listed in brackets.|
Out of 255,200 km2 total area of the ecoregion, 8,150 km2, or 3.2 percent, is in a protected area system. Less than 0.2 percent of the remaining 4 percent arid subtropical habitat and 0.1 percent of the 3 percent thorn scrub forest of the northern plains is within the protected areas.
The protected area systems support a number of all the restricted species of avian species, but few of them have large enough area to support viable populations.
Types and Severity of Threats
Deforestation for fuel, fodder, charcoal, building materials, commercial logging, and food by natives and the 3 million refugees in the bordering areas of Pakistan and Afghanistan is one of the main threats to the area.
The assignment of large portions of land as rangelands, where some pastures support livestock populations that are three times greater than their carrying capacity, has caused a serious overgrazing problem that led to biodiversity degradation, soil erosion, and desertification.
The construction of dams and barrages on the Indus and Kabul rivers to control floods and store water for irrigation has benefited the wintering waterfowl by expanding the amount of wetland habitat. However, it has interfered with the movement of migratory fish species, severely affecting the habitat of the Indus River dolphin and other fish fauna.
Surface irrigation and seepage from unlined irrigation canals and channels have resulted in the rise of the water table, which in turn is causing land loss through waterlogging and salinization.
The conversion of land for agriculture has caused high fragmentation and destruction of the ground vegetation, which in turn affects the fauna that depend on it. Hunting is controlled in Pakistan. However, permits in game reserves often are given on the basis of influence rather than ecological considerations.
Political instability and the presence of extensive mine fields in Afghanistan have hindered the conservation efforts by causing uncontrolled timber and wood use and hunting of wildlife. No activities have been undertaken in Afghanistan in the field of conservation and protected areas since 1979.
Justification of Ecoregion Delineation
We identified five ecoregions-Sulaiman Range alpine meadows, South Iran Nubo-Sindian desert and semi-desert, Baluchistan Xeric Woodlands, Rajasthan-North Pakistan sandy desert, and East Afghan montane conifer forests-from MacKinnon's Baluchistan subunit. All five of these ecoregions extend westward and have a portion of their ecoregion beyond the limits of this analysis. These ecoregions overlap with numerous Udvardy biogeographic provinces outside the scope of this analysis. These include the Hindu Kush highlands to the north and the Anatolian-Iranian Desert, Iranian Desert, and Caucaso-Iranian highlands to the south and west.
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