Earth Science: Environmental Exploitation – Loss of Species Diversity
Ninety-nine percent of all species that once lived on Earth have become ex- tinct. Climate change and natural catastrophes used to be the principal reasons for the decimation of biological diversity; it is now usually humankind.
Species diversity provides the foundation for individual ecosystems and thus is the prerequisite for the functioning of the biosphere. It is an immeasurable source of food and medicinal products, and an irreplaceable resource as a gene pool.
Due to the increasing destruction and pollution of natural habitats, over-fishing, hunting, and lucrative trade, humans are destroying the biological multitude of life—and with that the basis of their own livelihood. The public is dismayed when when a well-known species like tiger, whale, or mountain gorilla becomes endangered; however, the majority of other cases are hardly ever noticed by the public.
Apart from the decline of species diversity within habitats, loss of genetic diversity within individual species has also been observed. The decimation of individual populations leads to a reduction in genetic regeneration capacity within a species.
For instance selective deforestation reduces the quality of the genetic material of affected tree species, since only strong, healthy trees are logged and the weaker ones are left behind. Human’s intentional or unintentional introduction of exotic animal and plant species to new habitats plays an important role.
These so-called neozoic species can become a threat to local species and lead to their complete extinction. For instance, in New Zealand the national emblem, the flightless kiwi, is threatened with extinction by introduced rats and feral cats.
Species protection
Throughout the course of evolution the extinction of species has been a natural process. The best known example is the mass die-off of dinosaurs 65 million years ago. However, the majority of species have disappeared only over the last 150 years, and at no time has the extinction rate been as high as it currently is. More than 41,000 species are on the Red List of endangered animal and plant species, which is published regularly by the International Union for the Conservation of Nature (IUCN).
Trade in endangered species has been restricted and prohibited since 1973. The objectives of the Convention on Biological Diversity (CBD), signed in 1992, are both the protection of biological diversity and its sustainable utilization.
BASICS
NOAH’S ARK IN PERMANENT ICE An international seed bank was established on the Norwegian Archipelago Spitsbergen in 2008.
There, in the artic region of permafrost, up to 4.5 million seeds from the most important food plants on Earth are being safely stored in a bunker, where they are protected against climate change, wars, and epidemic plant diseases, and therefore secure a biodiversity for coming generations.