Insights into the diversity of the biodiversity concept

Biodiversity is not a monodimensional but a multidimensional concept. It refers to the variety of life, encompassing levels of complexity from within species to across ecosystems. Biodiversity therefore includes diversity within species (genetic diversity), between species (species diversity), between higher taxonomic units (phyletic diversity), between ecosystems (ecodiversity) and diversity in the functional role of species within ecosystems (functional diversity), from the local (sample) to the global scale. Finally, biodiversity encompasses the proportional distribution of the individuals among the species (heterogeneity diversity or evenness). This complexity of levels and scale makes it impossible to assess the state of diversity using a single measure. Different measures can suggest different conclusions. For example, a given impact can increase α-species diversity and decrease γ-species diversity; patterns of species diversity and diversity measured at higher taxonomic levels are not concordant. It may therefore be naive, risky and/or erroneous to use single measures of diversity for management or conservation purposes.