The Nature Index (NI) is established to get an overview of the state and development of biodiversity within the major ecosystems of Norway. It includes marine, limnic and terrestrial ecosystems. The aim of the index is to measure if Norway manage to halt the loss of biodiversity by the end of 2010. A number of indicators are chosen to represent the state of biodiversity. 125 scientists from various disciplines of research have contributed with data, expert judgements or modeled data for 310 indicators representing different aspects of biological diversity, such as trophic levels, key species and threatened and common species. In order to assemble all the data to an index, a reference value has been estimated for each indicator. The refere...