Resource and Energy Economics 26 (2004) 115–136 An introduction to biodiversity concepts for environmental economists Paul R. Armsworth a,∗ , Bruce E. Kendall b , Frank W. Davis b a Department of Biological Sciences, Stanford University, Stanford, CA 94305-5020, USA b Donald Bren School of Environmental Science and Management, University of California, Santa Barbara, CA, USA Received 3 January 2003 Abstract Biodiversity is a valuable, but poorly understood, natural resource, which is being lost at an accelerating rate as a result of human actions. We present a broad, introductory review of biodiversity concepts. Biodiversity is first defined at the species and community levels. Available methods and approaches for quantifying biodiversity are discussed with specific reference to the spatial scales over which these measures can be applied. Dominant threats to biodiversity are reviewed. Fundamental patterns and processes that underlie ecological production functions are outlined. Differing rationales for biodiversity conservation are given and compared. Finally, the current suite of approaches employed in biodiversity conservation is discussed. Our aim in writing this review is to encourage further, much needed, inter-disciplinary collaboration among economists and ecologists on biodiversity questions. © 2003 Elsevier B.V. All rights reserved. JEL classification: Q2 (Q24) Keywords: Biodiversity; Conservation; Ecosystems; Endangered species; Land-use change 1. What is biodiversity? Somewhere between 3 and 100 million species inhabit the Earth (Heywood, 1995). As a shorthand description of this great variety of life, the term “biodiversity” is a contraction of “biological diversity”, and was first coined by Walter Rosen for the 1986 National Forum on BioDiversity (Wilson, 1988). However, biodiversity refers to more than just an accumulation of species. If that were all that it was, then we might hope to conserve biodiversity in ∗ Corresponding author. Tel.: +1-650-724-0510; fax: +1-650-723-5920. E-mail address: armsworth@stanford.edu (P.R. Armsworth). 0928-7655/$ – see front matter © 2003 Elsevier B.V. All rights reserved. doi:10.1016/j.reseneeco.2003.11.003