1. Introduction

Biodiversity is regarded as a scientific concept, a measurable entity, and a social–political construct (Wilson in The diversity of life. Harvard University Press, Cambridge, 1993; Gaston in Biodiversity—a biology of numbers and differences. Blackwell Science, Oxford, 1996). The 34 global hotspots are considered to be the living laboratories for biodiversity. Myers et al. (Nature 403:853–858, 2000) argued that most of the species for example 44 % of all plant species and 35 % of the vertebrate species worldwide can be conserved in hotspots with minimal efforts. The hotspots of biodiversity are important not only for the conservation of animal and plant species but also equally important for about 21 % of people living in the biodiversity hotspots (Conservation International online). Keeping current environmental problems in view, the hotspots play important role in reducing the ecological footprints. The biodiversity-rich areas have been attracting the attention of the researchers and stakeholders for the decades, and detailed database is developed on the biodiversity which would enable to understand the impact of various driving forces on the resources. The welfare of mankind is associated with the biodiversity and its sustainable use not only in the hotspots but all across the ecoregions of the planet earth. Thus, the issues related to the conservation of biodiversity are highly crucial since the sustainable flows of services from the ecosystems are important for the livelihood of the people in various ways. Many areas are rich in biodiversity but not able to qualify for the hotspots because of not having 0.5 % species of plants as endemic to that particular region. Various aspects of ecosystems are based on the variability and complexity of organisms that constitute the biodiversity of a given geographic region and, thus, in the world as a whole (Al-Eisawi in J Arid Environ 54:81–90, 2003). The studies related to biodiversity in semiarid and arid regions have not got much attention as comprehensive database based on the empirical field studies is not available in integrated form.