What is biodiversity?
The Convention on biological diversity defines biodiversity as the variability of living organisms of all origins, including among others, the earth, marine and other aquatic ecosystems and the ecological complexes they are a part of. This definition involves the concepts of diversity within and between species, and the diversity of ecosystems themselves.
These three interdependent concepts of biodiversity – genetical or intraspecific, specific or interspecific and ecosystemic, condition the sustainability of the ecosystems and the living beings that populate them by allowing them to survive normally to the changes of their environment.
- The first concept accounts for the genetical variability within species and allows them to adapt to the changes in their environment. It is one of the motors of evolution and the creation of new species. It is that very same variability that allows some individuals of a species to colonize new habitats.
- The second concept, the interspecific diversity, refers the number of living species. We generally think of this concept when speaking of “biodiversity” because it is the simplest to apprehend. Its depletion translates into the accelerated loss of living species (extinction crisis), generally due to brutal or very large-scaled modifications in the environment. The extinction of the dinosaurs is certainly the most popular, even though the scale of the one we are living today could appear more serious given its direct impact on humans.
- The third one, the ecosystemic diversity, assesses the diversity of the different ecosystems present on Earth. The ecosystems are constituted by:
- The living beings (including humans) that form the biocenosis
- The surrounding environment, the biotope, in which they live.
The concept of ecosystem explores the interactions between biotope and biocenosis, but also in-between species. The ecosystemic diversity is essential given that its depletion has a direct impact on interspecific diversity for the species that only live in certain habitats that suffer great disturbances. For example, many species living in coral reeves are in great danger because of the modification of water temperature due to global warming.
Why protect biodiversity?
Resulting in 3.5 billion years of evolution, the richness of the ecosystems supplies humanity with essential services.
First and foremost, the balance of biodiversity generates vital primary resources such as fresh water, aliments, or wood, and ensures the diversity of genetical identities. Balanced ecosystems then have a regulating function, regarding temperatures, climatic conditions, the management of waste and water but also pollination, crucial for the reproduction of vegetal species. They guarantee a safe habitat for migrating species, ensuring the viability of their genetical identity. Finally, the richness of ecosystems ensures humanity many immaterial advantages, cultural, spiritual and aesthetic.
Today, the depletion of biodiversity is a major source of preoccupation. We have entered a new era, the Anthropocene, and it is the first time for our planet that the major factor of environmental change is the action of humans.
OECD experts foresee that by 2050, the MSA (Mean Species Abundance) indicator will decrease by 10%. The ever-growing encroachment of human activities on the ecosystems but also air and water contamination and global warming resulting of those activities have dangerously weakened biodiversity. One third of soft water vegetal species have disappeared and this tendency will be more and more accurate if actions are not taken to stop the phenomenon. Humans will be victims of the depletion of species variety, especially the poor and indigenous populations that directly withdraw their lifestyle from the services rendered by their ecosystems.
The UN’s 17 Sustainable development goals detail the many actions fields for which humans now have to commit in order to correct their impact and thus limit the effects of natural habitats depletion.