Facts and Figures
Why we need biodiversity
There are many ecological, economic, social and indeed ethical reasons to conserve and safeguard biodiversity:
- For reasons of social and intergenerational equity, it is our ethical duty to conserve and safeguard biodiversity. This duty is enshrined in the German constitution: “Mindful also of its responsibility toward future generations, the state shall protect the natural bases of life” (Basic Law for the Federal Republic of Germany, Article 20a).
- Plants and animals provide the food we eat. Since agriculture began some 12,000 years ago, about 7,000 species of plant have been cultivated for food. We also obtain many materials and other resources from living organisms (e.g. wood for building and energy).
- Plants and animals have inspired many technical inventions (e.g. bionics). Imitating successful adaptations found in nature can result in lighter yet sturdier structures and help save materials and energy.
- Genetic information or genetic resources can be put to use in food and medicine. Much effort is directed at exploiting this kind of diversity (e.g. by breeding improved strains of farm animals and plant varieties). The entire spectrum of biodiversity must be conserved for these efforts to succeed.
- Every day, we benefit from a wide range of ‘services’ of nature (and hence of biodiversity): fresh clean air, clean water, pollination by insects (e.g. bees) and carbon storage (e.g. forests, bogs, soils and oceans), to name but a few. All these ecosystem services are unpaid, but we cannot afford to do without them.
- The same goes for recreational use of nature. Whether we enjoy them in an evening walk through nearby woodland or on holiday by the sea, nature and the scenic beauty of the landscape are highly important to our wellbeing.
- Climate change, too, makes it important to conserve the greatest possible diversity of species and intact ecosystems so that use can be made of their capacity to adapt to changing conditions.
Where biodiversity is concentrated
Biodiversity is everywhere, but major centres of biodiversity with high densities of species, ecosystems and genetic variability include parts of the tropics, oceans, forests, islands and ancient cultivated landscapes. Every region is therefore home to species and communities of species that are adapted to specific locations and climates and are valuable and in need of protection. Many species and communities still await scientific discovery.
Another important facet of biodiversity under threat today is the diversity of crops and farm animals resulting from thousands of years of selective breeding by mankind. Of the 7,000 plant species cultivated and improved by breeding to provide food over the millennia, only fifteen – alongside eight animal species – provide about 90 percent of human nutrition world-wide today.
How and why biodiversity is endangered
Biodiversity is threatened by mankind in many ways. The main threats include:
- Direct destruction of habitats (e.g. urbanisation and infrastructure building, deforestation, slash-and-burn agriculture, open-cast mining, draining, various fishing practices and industrial farming)
- Overexploitation and degradation (e.g. overgrazing, soil erosion, habitat fragmentation, unsustainable harvesting of timber for firewood, pesticide spraying, ground contamination, water pollution, unsustainable tourism, and unsustainable farming, fishing and hunting practices)
- Land use change: Biodiversity is often adversely affected when ‘extensively’ farmed land is abandoned (e.g. no longer used for grazing) or turned over to a different kind of farming (intensification, e.g. pasture being ploughed up to grow crops).
- Invasive alien species: Deliberate or inadvertent introductions of species outside of their natural range can have severe consequences for their new habitats (e.g. rabbits in Australia and giant hogweed and Himalayan balsam in Germany)
- Climate change: Where the climate changes faster than ecosystems can adapt, the result can be extinctions of isolated populations and species.
