The Deserts of Pakistan

Abstract

Pakistan is a subtropical country spread over an area of 79.6 million hectares (mha) lying between 24° and 37° N and 61° and 75° E. Most of the area is semiarid to arid, extending over 70 mha (87.94% of its land mass), receiving 250 mm annual rainfall. The deserts of Pakistan cover 11 mha (13.82%) of the land situated in the central and southeastern regions. These areas are broadly separated and are located between 100 and 1000 m above sea level. These deserts are monsoon in type, referring to a wind system marked with seasonal fluctuation in response to temperature variations between continents and oceans. The southeast-directed winds of the Arabian Sea supply heavy summer rains. The aridity is characteristic of a desert, with erratic rainfall occurring in clusters. The most dominant and frequent tree species in the desert habitat include Acacia senegal, Acacia nilotica, Azadirachta indica, Capparis decidua, Prosopis cineraria, Salvadora oleoides, Tamarix aphylla, and Tecomella undulata, with Prosopis cineraria being the most dominant and frequent. Among shrubs, Acacia jacquemontii, Aerva javanica, Calotropis procera, Calligonum polygonoides, Dipterygium glaucum, Euphorbia caducifolia, Fagonia indica, Haloxylon salicornicum, Leptadenia pyrotechnica, and Crotalaria burhia are dominant. Ephemerals are an important component of the desert habitat, here represented mostly by Boerhavia procumbens, Convolvulus prostratus, Gisekia pharnaceoides, Heliotropium strigosum, Indigofera argentea, Indigofera cordifolia, Indigofera linifolia, Limeum indicum, Mollugo cerviana, Senna ialica, and Tephrosia purpurea. Grasses are very prominent inhabitants in deserts, including Aristida spp., Cenchrus biflorus, Cenchrus ciliaris, Eragrostis spp., Panicum turgidum, Pennisetum divisum, Saccharum spontaneum, and Stipagrostis plumosa. Abutilon bidentatum, Abutilon pakistanicum, Alysicarpus monilifer, Alysicarpus tetragonolobus, Caralluma edulis, Cenchrus prieurii, Commiphora wightii, Convolvulus scindicus, Gisekia pharnacioides, Ephedra ciliata, Gynandropsis gynandra, Monsonia heliotropioides, Rhynchosia schimperi, and Tecomella undulata are some of the threatened species that are used by the inhabitants to meet their various socioeconomic needs. Pragmatic conservation measures are required to protect such habitats, because they represent threatened or rare and endemic species that are of economic importance to the local communities and thus are used unsustainably.