Signed in Rio de Janeiro in 1992, the Convention on Biological Diversity defines biodiversity as « the variability among living organisms from all sources, including terrestrial, marine and other aquatic ecosystems, the ecological complexes and diversity within species, between species and of ecosystems».
In every ecosystem, living creatures including humans interact with one another as well as with the air, water and earth. Due to global warming – which leads to the displacement of species in both space and time (annual blooming seasons, for example) – and the disappearance of certain species, 60% of inter-species interaction has been eliminated (IUCN estimates, 2006). The more species there are in a functional group, the less vulnerable that group; a change in one of its components can affect the entire system. Inversely, saving one particular species requires ensuring that the entire ecosystem...