Revista de biodiversidad y especies en peligro de extinción

Biodiversity - 2014: Biodiversity conservation and ecological assessments of arid zone plants in Thar Desert of India

Abstract

Sher Mohammed and Pawan K. Kasera

Among the world’s twelve mega-diversity nations, India is an important nation comprising almost all the climatic conditions and ecological zones found in different parts of the world. The Rajasthan desert, i.e. Thar Desert is among the ecologically important regions of India in the diversity of its biological species. The western Indian Thar desert represents a characteristic environment where plants have adapted to arid hostile conditions. Scanty water with erratic rainfall and high temperature has marked effects on the vegetation, but still several plant species are found here, which thrive well despite the inhospitable conditions. The different plant species, which are common in arid environs includes: Aerva persica, Achyranthesaspera, Cleome viscosa, Corchorus depressus, C. tridens, Crotalaria burhia, Heliotropium spp., Leptadenia pyrotechnica, Tephrosia purpurea, Erianthus munja, Prosopis cineraria, Calotropis procera, Tecomella undulata, Ziziphus spp., Citrullus colocynthis, Capparis decidua, Balanities aegytiaca, Maytenus emarginata, Opuntia dillenii, Parkinsonia aculeate, Salvadora oleoides, S. persica, Tamarix spp. Clerodendrum phlomidis, Farsetia hamiltonii, Lycium barbarum, etc. Among grasses, Aristida funiculata, Bracharia ramosa, Cenchrus spp., Chloris virgata, Cynodon dactylon, Dactyloctenium spp., Desmostachya bipinnata, Dicanthium annulatum, Digitaria ascendense, Eleusine compressa, Eragrostis spp., Panicum spp., Tetrapogon tenela, Tragus racemosus, etc. During rainy season a large number of weeds also make their appearance through seeds/underground vegetative parts. Exotic plants like Verbesina enceliodis and Parthenium hysterophorus are very much disturbing the natural biodiversity of Indian desert. Typical desert plants produce different seeds generally after spring season as well as in summer months. As the climate of Indian desert is hostile to plant life, those possessing special adaptations are sustained.

In Indian arid zone, water is the master-limiting factor in determining the vegetation pattern of this region. The growth and development of the plants are handicapped by prolonged rainless periods, which threaten plant life with desiccation and complete destruction. Yet, this region sustains large plant diversity. In context of the Indian desert the conservation of biodiversity is essential not only to maintain the most fragile ecological processes and life-support system but also to ensure the sustainable utilization of the species as well as the ecosystem.

Due to over-exploitation, a good number of taxa have vanished from the arid zone and many have dwindled in number. Tecomella undulata, popularly known as the desert teak due to its hard wood, was once the climax tree, but at present only a few are found in free state. It has totally been wiped out and used in the manufacture of carved furniture. A highly aridityadapted shrub, Calligonum polygonoides grows on the sand dunes and due to its very long surface running roots, it acts as an excellent sand binder. Digging of this shrub along with its extensive root system is a regular vocation. All the nutritious perennial grasses (Lasiurus sindicus & Panicum turgidum) have been over-grazed since centuries and they are being replaced by short-lived annuals, which are poor in quality.