干旱区生态环境知识资源中心

Commiphora wightii (Arnott) Bhand., commonly known as ’Guggal’, is an important medicinal plant that has been categorized as threatened but International Union for Conservation of Nature (IUCN) has put it under data deficient (DD) category. Consequently, placing it in ’Data Deficient’ category of IUCN requires detailed information on its spatial distribution and other related aspects. Hence we report here the results of our appraisal of Guggal in Rajasthan, using remote sensing and ground truthing. A base map of Guggal was prepared using Geographical Information System (GIS) open source software Quantum GIS, SAGA. Landsat ETM+ and ASTER GDEM (Advanced Space borne Thermal Emission and Reflection Radiometer Global Digital Elevation Model) Satellite Data were used. By clipping Aster GDEM Data with district boundary it was then provided color range to get elevation information. A digital elevation model of Rajasthan physiography was developed from ASTER and GDEM Data that has 30 m resolution. GIS layers of area of occurrences for Guggal plant and elevation were created. This map along with topographic sheets of 1:50000 were used for field traversing and ground truthing in 35 expeditions from 2009 to 2012. From the ground data, GPS data of longitude, latitude and altitude of each survey points were used in creating GIS layers in a 3D elevation map as also Guggal distribution and density map in 20 districts of Rajasthan. Results revealed that Guggal predominantly occurs in hilly and piedmonts zone. Its density was low in southeast Rajasthan (2-5 plants/ha) compared to western Rajasthan (8-10 plants/ha. In view of better vigour and survival in native sites in western Rajasthan’s bioclimatic conditions, its ex-situ and in-situ conservation will be more successful in the districts of Jaisalmer, Barmer, Jalore and Jodhpur than in other areas.