Por Sahotra Sarkar (University of Texas at Austin, USA Presidency University, Kolkata, India).

Abstract: The concept of biodiversity emerged in the 1980s in the context of concerted attempts to conserve aspects of living variety that were then being put at risk primarily through land use and land cover change. Thus, biodiversity always has had a normative element in its conceptualization and, in this sense, differed from older concepts of ecological diversity. However, defining and measuring biodiversity has been contested territory ever since its introduction with no diminution of these controversies in recent years in spite of several attempts at explication. This paper reviews these controversies and develops a framework that distinguishes constituents and surrogates for biodiversity and discusses how they must be defined and assessed for conservation projects.