Biodiversity and Ecosystem Services

once commented that although science has brought us precise answers to a range of exceedingly difficult questions, such as the number of stars in the universe, the masses of the earth and its neigh-boring planets, the number of genes in a virus, the mass of the electron, etc., we still do not know how many species of living organisms there are on earth – not even to the closest order of magnitude! This fact, which may appear surprising to many, has been a major motivation behind the rising interest in biodiversity the last 20 years. The term biodiversity itself is just as old, starting with a conference called the National Forum on Biodiversity in 1986 (Wilson 1988). Biodiversity is often represented as three hierarchically nested organiza-tion levels: those of genes, species, and habitats. Genetic diversity refers to the level of variability among genes with th