Vachellia nilotica subsp. cupressiformis – status and conservation approach of an endemic agroforestry tree in Rajasthan

Abstract

The arid zone of India is the most fragile ecosystem facing extreme droughts, erratic and high-intensity rainfall, seasonal variations in climatic pattern, abundance of solar energy and high evapotranspiration. The arid region is spread over 38.7 m ha, while the semi-arid region accounts for 34% of the total land area. In recent decades, the semi-arid region has expanded by 10%. The newly formed semi-arid region in North India alone accounts for 4% of reduction in rainfall and increased evapotranspiration have led to increased aridity1. Under such adverse situations, traditional agroforestry plays an important role in providing food, fodder, fruits, fuel, etc. and also provides security to the local people and animals/livestock during extreme drought conditions. The traditional agroforestry system is a permanent feature of a landscape, where farmers without disturbing the natural tree component, integrate crops, grasses and animals. Especially, under arid regions, a clear-cut demarcation in distribution of agroforestry systems based on rainfall gradient can be seen, for example, khejri (Prosopis cineraria)-based agroforestry system performs well under 400 mm rainfall zone; Ziyphus sp. – P. cineraria-based agroforestry system between 200 and 300 mm rainfall and shrub-based system under less than 150 mm rainfall2. Some species are particular and unique to specific zones/areas due to rainfall, soil or other microclimatic factors. Such types of species are not found in other regions and the growth performance of the species is also not assured. One such endemic agroforestry species is Vachellia nilotica subsp. cupressiformis (J. L. Stewart) Ali and Faruqi (Acacia nilotica subsp. cupressiformis), a subspecies of A. nilotica.