Location and General Description
This ecoregion represents the alpine scrub and meadows between 3,300 and 3,600 m in the northwestern reaches of the Himalayan Range. The ecoregion extends across northwestern India and northern Pakistan, mostly in the Vale of Kashmir and associated mountains. The vegetation consists of stunted, twisted krummholz, dominated by rhododendron and juniper scrub, interspersed with patches of birch forests. It also includes patches of moist scrub vegetation within some parts of the trans-Himalaya, such as Lahul Valley, the northwestern parts of the Pir Panjal Range, and adjacent areas in Pakistan.
The Himalayas trace their origin to the recent geological past when the collision between the northward drifting Deccan Plateau and the northern Eurasian continent took place. During this, and several subsequent periods of geological upheaval and uplift, the Himalayan Mountains were thrust upward and above the Tibetan Plateau, which represented the bottom of the Tethys Sea before the collision (Wadia 1966). Evidence suggests that this northwest region of the Himalaya is younger than the eastern extent of the mountain range (Gupta 1994).
Because the southwestern monsoon that sweeps in from the Bay of Bengal expends most of its precipitation in the eastern Himalayas, the western Himalayas are drier (Gupta 1994). Therefore, the ecoregion is arid to semi-arid, with little precipitation falling in the winter and spring. Ambient temperature approaches freezing during the winter, but summers are hot. In response to these dry and harsh climatic conditions, the treeline is almost 1,000 m lower in the western Himalayas than in the east.
Aspect is another important determinant of local climatic variation; the north-facing slopes are less exposed to sunlight and therefore are cooler and retain more moisture. But within this general trend, the complex topography also creates rainshadows, resulting in very localized climatic variations.
There are several vegetation types in this ecoregion. Closer to the timberline the vegetation consists of low near-evergreen scrub made up of a stunted birch-rhododendron community. Only five rhododendron species are reported from this belt (Rao 1994), compared to more than sixty species known from the eastern Himalaya. Above this scrub is the alpine meadow, comprising a diverse herb community that includes species of Doronicum, Delphinium, Gentiana, Meconopsis, Pedicularis, Anemone, Aster, Polygonum, Primula, and Mertensia, among others. Scree habitat contains cushion-forming plants such as Caragana, Saxifraga, Draba, and Gypsophila. A high proportion of alpine and sub-alpine herbs in Fumariaceae, Primulaceae, Saxifragaceae, and Scrophulariaceae are endemic and several are endangered (WWF and IUCN 1995).
Little information is available on the biodiversity of this remote and scientifically unexplored area. Although most of the faunal representatives in the high altitudes are small (Mani 1994), the ecoregion contains several large mammals that are important for conservation and can be used as focal species. The snow leopard takes prominence, but a successful and comprehensive conservation program should also include the larger ungulates such as the markhor, Asiatic ibex, blue sheep, and argali that make up this predator's prey species. The ecoregion also represents the southernmost limit for the Asiatic ibex, which prefers drier scrub vegetation on steeper slopes adjacent to the trans-Himalaya. There is a distinct ecological separation between the Asiatic ibex and the Himalayan tahr, which prefer moister scrub and meadow vegetation in the southern slopes of the Greater Himalaya.
The known mammal fauna includes forty-nine species. None of the mammals are considered endemic to the ecoregion, but there are several threatened species, including the snow leopard, serow (Capricornis sumatraensis), markhor, Himalayan tahr, argali, Himalayan musk deer (Moschus chrysogaster), and brown bear (Ursus arctos) (IUCN 2000).
The bird fauna consists of 139 species. None are endemic, but there are several characteristic Himalayan species such as the lammergeier, golden eagle, Himalayan griffon, snow partridge (Lerwa lerwa), Tibetan snowcock (Tetraogallus tibetanus), and Himalayan snowcock (Tetraogallus himalayensis), which should be focal species for conservation efforts.
Because of its high elevation and harsh climate, as well as its lack of commercially valuable timber trees, the ecoregion's habitat is relatively stable. There are fifteen protected areas that cover 4,500 km2 (10 percent) of the ecoregion (table 1). Two of these-Siachu Tuan Nalla Wildlife Sanctuary and Pin Valley-are large, the latter exceeding 1,000 km2. Three other protected areas-Great Himalayan (690 km2), Kistar (1,260 km2), and Rupti Bhabha (850 km2)-that overlap with adjacent ecoregions are also large. But most of the others are small, with the average area of the protected areas being only 300 km2.
Table 1. WCMC (1997) Protected Areas That Overlap with the Ecoregion.
Protected Area Area (km2) IUCN Category
Chitral Gol National Park 110 II
Gahriat Gol GR 140
Parit Gol GR 140
Baltal 150 IV
Siachu Tuan Nalla WS 880
Manali WS 100 IV
Pin Valley 1,190 II
Kanawar 80 IV
Great Himalayan (east) 200 II
Great Himalayan (west) [IM0502] 320 II
Kugti WS [IM0502] 160 IV
Tundah WS [IM0502] 180 IV
Kistar National Park [IM0403], [IM0502] 320 II
Overa-Aru [IM0403], [IM0502] 180 IV
Rupti Bhabha [IM0403], [IM0502] 350 IV
Ecoregion numbers of protected areas that overlap with additional ecoregions are listed in brackets.
Types and Severity of Threats
The threats to the natural habitat in this ecoregion stem largely from overgrazing by domestic livestock and fuelwood collection. Already, all lands that can support agriculture (i.e., alluvial fans and valleys) have been cleared and cultivated (Schaller 1977). Commercial harvest of wild medicinal herbs in many areas of western Himalayas also is a major threat.
Justification of Ecoregion Delineation
In a previous analysis of conservation units in the Indo-Malayan region, MacKinnon (1997) divided the Himalayan Range into four subunits along the longitudinal axis: the Northwest Himalayas (I2a), West Nepal (I2b), Central Himalayas (I2c), and Eastern Himalayas (I2d). We used MacKinnon's (1997) vegetation map to extract the alpine scrub and meadows in biounit 12d into a separate ecoregion-Northwestern Himalayan Alpine Shrub and Meadows [PA1012]-as per our rules for defining ecoregions (i.e., represent ecosystems of regional extent within separate ecoregions). We used a digital map of the vegetation provided by MacKinnon (1997), aided by a DEM (USGS) to define the boundaries of the ecoregion. All the Himalayan ecoregions are part of Udvardy's Himalayan highlands biogeographic province.
Birdlife International. 2000. Threatened birds of the world. Barcelona & Cambridge, UK.
Carlquist, Sherwin. 1980. Hawaii: A Natural History – Geology, Climate, Native Flora and Fauna Above the Shoreline. Pacific Tropical Botanical Garden, Honolulu, Hawaii.
Conant, S., C.C. Christensen, P. Conant, W.C. Gagné, and M.L. Goff. 1994. The unique terrestrial biota of the Northwestern Hawaiian Islands. Pages 378-390 in E. Alison Kay, editor. A Natural History of the Hawaiian Islands. University of Hawai’i Press, Honolulu, Hawaii.
Morin, M., and S. Conant. 1998. Laysan Island Restoration Plan. Honolulu, Hawaii.
Mueller-Dombois, D. and F.R. Fosberg. 1998. Chapter 9: Northern Polynesia: The Hawaiian Islands. Pages 461- 577 in D. Mueller-Dombois and F.R. Fosberg, editors. Vegetation of the Tropical Pacific Islands. Springer-Verlag New York, Inc.
Stattersfield, A.J., M.J. Crosby, A.J. Long, and D.C. Wege. 1998. Endemic bird areas of the world: priorities for biodiversity conservation. BirdLife Conservation Series No. 7. BirdLife International. Cambridge, UK.
Van Balgooy, P.H. Hovenkamp, and P.C. Van Welzen. 1996. Phytogeography of the Pacific – floristic and historical distribution patterns in plants. Pages 191-213 in Keast, A. and S.E. Miller, editors. The origin and evolution of Pacific island biotas, New Guinea to Eastern Polynesia: Patterns and processes. SPB Academic Publishing, Amsterdam.
Prepared by: Gopal S. Rawat and Eric D. Wikramanayake, with contributions from Pralad Yonzon
Reviewed by: In process