Diversity of Life
The Earth has a range of variety of life forms that defies the imagination. There could be as many as a trillion species, and only a tiny number of these have been identified and studied. There have been at least 5 great mass extinctions since the beginning of multicellular life. We are currently provoking a sixth.
Biodiversity of an ecosystem is the diversity of species and the richness of these species.
The diversity of life, and the need to maintain it, is instinctive to our concept of a healthy planet. Biodiversity of an ecosystem is therefore both the diversity of species and the richness of these species. Long-term stability of an ecosystem depends on ensuring that the proportions of population numbers reflect the species' respective roles within the ecosystem, determined primarily by their trophic level.
Officially, Biodiversity is defined as the "totality of genes, species, and ecosystems of a region". The types of diversity involved are:
- Taxonomic (species diversity)
- Ecological (diversity of habitats)
- Morphological (intraspecies genetic diversity)
Living Planet Index
The Living Planet Index (LPI) is an indicator of global biodiversity. It is based on trends in the world population of vertebrate species.
The Living Planet Index, a publication on the "health" of more than 3000 species (species) and more than 10,000 populations, published by the WWF (2014) in the "Living Planet Report", is regarded as a measure for the development of biodiversity.
The 2014 report shows the decline in global biodiversity by over 50% between 1970 and 2010. Freshwater species in the rivers and lakes were 76% lost, through fragmentation and pollution of habitats, and invasions of non-endemnic species.
Land degradation losses are 39%, due to changes in land use, the expansion and intensification of agriculture (monocultures, overcrowding, soil erosion, pesticide use, pollutant inputs by fertilizers), shrinkage and degradation of habitats (e.g. deforestation), urbanization and transport axes (fragmentation of habitats).
Marine species: 39% loss, largest in tropical waters and in the southern oceans. Almost 50% of fish stocks in European waters are considered overfished.
According to the Red List of Endangered Species (2015) drawn up by the IUCN (International Union for Conservation of Nature and Natural Resources), 22,000 species are acutely endangered, including 41% of amphibians, 33% of reef-forming corals, and 25% of all marine fish stocks, 25% of mammals and 13% of birds.