Biodiversity: An Essential Role
Biodiversity is one of the planet’s greatest treasures; for example, the pharmaceutical industry could not survive without the molecules extracted from plants and animals. The same is true of the fibers used in the clothing industry, wood for heating, construction, and paper production, and fats (plant- and animal-based) for the food and cosmetics industries, among others. Biodiversity is the foremost of all natural resources.
It provides the oxygen we breathe, nourishes the livestock we eat, and helps purify the land and water we pollute. Biodiversity therefore makes our land fertile, recycles our organic waste, and even has a positive impact on the climate. Biodiversity thus plays a key role in the environment: pest control, natural elimination of hazardous or toxic waste, and so on. Finally, biodiversity helps promote cultural and spiritual values and is also a symbol of respect for nature.
However, serious threats loom over biodiversity
To be compatible with the preservation of biodiversity, human activities must adapt and cease to harm the development of natural habitats; yet that is exactly what is happening.
Despite its recognized importance, biodiversity faces numerous threats: between 13 and 15 million hectares of forest are lost each year, one in three fish species is threatened with extinction, there are reportedly only 40,000 lions left in Africa and just 6,000 tigers worldwide, compared to about 100,000 a century ago; one-eighth of bird species, one-quarter of mammals, and one-third of fish species are now threatened with extinction. In 100 years, 50 % of the world’s wetlands have disappeared, and since 1965, just over 50 % of the Arctic sea ice has melted.
The loss of biodiversity is now a scientific reality that threatens the diversity of life; this decline is one of the two major environmental challenges of the 21st century, along with climate change.
The main causes of this loss of biodiversity are: habitat destruction and environmental change, excessive harvesting and overexploitation of resources, the introduction of invasive alien species that thrive at the expense of native species, global warming, etc. These phenomena lead to changes in landscape structure (fragmentation or destruction of habitats), in the composition of animal and plant communities (introduction or extinction of species), as well as in the functioning and evolution of populations (changes in selection pressures).
Can humans limit this loss of biodiversity?
While humans have demonstrated their great capacity to harm nature, they are at the same time doing everything they can to limit their harmful actions.
Today, the scientific community, environmentalists, and others are taking action to limit the loss of biodiversity; to this end, conservation measures are being implemented in situ and ex situ.
The first method of preservation (in situ) is the most popular: it requires the creation of protected areas for endangered species (such as gorillas, orangutans, and many other animal and plant species).
The second argument (ex situ), consists of preserving the genetic heritage of species, since every extinction is an irreparable loss.
All life on Earth forms a single, vast system—the biosphere—composed of elements that interact with one another. Thus, all animal and plant species are part of various ecosystems and, as such, are essential links in complex communities of living organisms. They maintain multiple relationships with one another, which often make them interdependent. The disappearance of any one of them leads to a simplification and weakening of the ecosystem, and may even result in the extinction of associated species. As a general rule, the more diverse an ecosystem is, the more productive and stable it is. Ecosystems that are too severely degraded eventually cease to perform their functions or provide the services they offer to human societies.
The reintroduction of a species is one of the most highly valued conservation efforts. It involves introducing a plant or animal species into a region where it previously thrived (before being destroyed by humans or becoming extinct as a result of natural disasters). Reintroduction has proven to be an effective tool for restoring species to their original habitats, provided that the causes of their disappearance—such as persecution, overharvesting, or habitat degradation—have been addressed.
However, in addition to human activity, nature also takes steps to mitigate the disturbances affecting it. Is nature, then, as vulnerable as we think?
Biodiversity, however, seems to be sustaining itself naturally…
Despite numerous human-induced threats, nature is resilient and has significant capacity to recover from degradation; this is referred to as ecological resilience. It is the ability of an ecosystem, a habitat, a population, or a species, to return to normal functioning and development after experiencing a major disruption. Ecological resilience is a form of resistance: the ability of a system (population, ecosystem) to return to (or maintain) a state of dynamic equilibrium after a period of instability caused by an external or internal disturbance.
Although resilient, biodiversity must be protected, as it contributes to the balance and proper functioning of the environment…and of human societies.
Linsey MONPELAT and Pascal SAFFACHE
