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Biodiversity: definition and challenges

Definition of biodiversity

The concept of Biodiversity was born in 1992, at the global summit of Rio de Janeiro.
Biodiversity, a contraction of "biological diversity", which refers to the variety and diversity of the living world. In its broadest sense, this word is almost synonymous with "the variety of the living world". Biodiversity is considered at several levels:

  • Diversity of genes (Invisible diversity that is at the origin of biodiversity)

  • Species diversity (Including the human species),

  • et Diversity of ecosystems.

The Convention on Ecological Biodiversity of 5 June 1992 defined the term biodiversity as " lA variability of living organisms from all sources including, inter alia, terrestrial, marine and other aquatic ecosystems and the ecological complexes of which they are a part; This includes diversity within species and between species, as well as ecosystem diversity ».

The number of species on land

1,7 million species have been described, however the estimates range from 3,6 to over 100 million species. Many species therefore remain to be discovered, at a rate which will differ according to the zoological groups. It is estimated that about 50% of vertebrate species are already known, whereas 90% of insects are still to be discovered.

The challenges of biodiversity

A reservoir of resources

Biodiversity is the subject of important issues because it constitutes a Reserves of essential resources for the development and welfare of human societies :
- food resources,
- pharmaceutical resources,
- material resources ...
All these renewable resources are sustainable, but only if they are used in an appropriate way.

The current crisis

Today, the diversity of the living world is experiencing an unprecedented erosion. Species disappear at a much higher rate than the "natural" extinction rate; Many, including some of the most common species, are declining in number and geographical areas are decreasing. It is no exaggeration to speak of a mass extinction crisis, and that - unlike the preceding ones - is indisputably the fact of man, directly or indirectly :
- pollution, fragmentation of ecosystems,
- biological invasions,
- overexploitation,
- climatic changes…
The extent of this crisis is illustrated and mediated by the IUCN (International Union for Conservation of Nature) lists that document the status of endangered and vulnerable species throughout the world. Within this list are more 3600 species of plants, more 3500 species of vertebrates, including 25% of species of mammals.
The consequences of this "erosion" are not limited to a list of maltreated species, as they also lead to the degradation of ecosystems and the functions they play in the living system - the biosphere - and thus the services They give back to humanity.

The ecological footprint

There is currently an emblematic indicator -ecological footprint1  - which attempts to represent these societal-nature interactions and the impacts of our lifestyles on the world around us on biodiversity.

1 Called “Ecological footprint (EE)” the ratio between the flows of renewable natural resources used by man and their renewal capacities. EE is constructed from the final consumption of a country and uses a conversion module to calculate the equivalent of renewable natural resources consumed. The unit of equivalence used is the hectare of ecosystem consumed by an individual (1), city, enterprise or country. This equivalence makes it possible to know how many planets Earth would be necessary if the whole of humanity consumes as a country, this or that individual, and so on.

What can be done to preserve biodiversity?

The human species profoundly modifies its environment. It acts on almost the entire surface of our planet, even on the most uninhabited spaces. Like any living being, man can not live without interacting with other species. Preserving biodiversity is therefore vital. This explains the presence of numerous nature conservation programs and tools, as well as mobilization at all levels (managers, researchers, politicians, elected officials, associations, the general public, companies, etc.).

How is biodiversity protected at the international level?

The planet is full of remarkable natural spaces, some of which are known as hot spots of biodiversity or " hot-spots ", Host a particularly important biodiversity. Many spaces (land and sea) are protected in many ways. In 2007, 110 000 sites about either 18 000 000 km² were protected from around the world, By a group of major international organizations. Among these, Unesco, with its program on humans and the biosphere, " Man and biosphere"(Mab) has the largest coordinated network for biodiversity protection with 535 protected sites in more than 100 countries.
In addition, a set of common environmental and management guidelines and policies have been established at the international level to more effectively protect biodiversity. The Convention on Biological Diversity (CBD) established in April 2002 a strategic plan whose main objective was to stop the erosion of biodiversity in 2010.
The IUCN Red List Identifies all endangered, endangered or extirpated species in the world. International laws prevent their hunting, gathering and trade.

Protecting biodiversity in France

Thanks to its overseas territories, France has a very important natural heritage: it is placed at the 4 world rank for its biodiversity. More than 12% of its surface is protected in 2009 by 46 Regional natural parksNational Parks, 600 biotope stopped and more 100 000 hectares of coasts belonging to Conservatory. In addition, the European Natura 2000 network for environmental protection concerns more than 6,8 million hectares of our territory in 2008. And these numbers are constantly changing.

At the national level, the state has defined various environmental protection policies. These legal texts (laws and regulations) are grouped in the environmental code. They impose respect for ecosystems, limit the discharges of industries and individuals into the environment and the modification of natural spaces.

At the local level, different specific structures intervene at various levels in the management of the environment; Management unions, town halls. The regional directorates for the environment ...) ensure their good ecological quality and the application of regulations (prefectural orders ...). Other targeted actions also contribute to the maintenance of biodiversity.

A public increasingly concerned with biodiversity

Eco-citizenship is a value that is developing gradually with, for example, the development of ecological gestures; The design of products that respect biodiversity (such as the Bio label) and green buildings (HQE label); The development of ecotourism that respects and informs on the protection of ecosystems; The emergence of a "responsible" advertising valuing a reflective consumption and less harmful for our environment; The introduction of eco-taxes for certain polluting products (computers for example), school activities and the inclusion of this theme in the programs. This awareness in France is however recent and requires an increased mobilization of the population.


Faced with the current environmental crisis, man has only one solution: to cooperate with nature. He must moderate his demands and harvest and conserve the living resources of the earth, the only way for him to ensure the continuation of his civilization.
We must change our relationship with nature. In order to change, we must first observe and understand, and then change our behavior, our choices, our practices, our policies. This implies a growing knowledge of the evolution of biodiversity, the biosphere, and the place of man on the planet.

How to measure biodiversity?

The concept of sustainable development as used today was defined in 1983 by the World Commission on Environment and Development (WCED):

« A development that meets the needs of the present generation by preserving for future generations the possibility of satisfying their »

We are only beginning to realize that our way of life is unsustainable for the planet and its inhabitants. The main question now being: How can we, under the best conditions, move to a culture of permanence, both for ourselves and for the biosphere on which we depend? »

That is why, in Rio and in Johannesburg, it was stressed that the economic and social development of mankind depends on the long-term health of the environment - biodiversity Good measure.

Biodiversity indicators

Considering biodiversity as a whole is virtually impossible, which is why specialists are working to define reliable biodiversity indicators.

The general function of a biodiversity indicator is to assess the health status of biodiversity (its viability, sustainability, resilience, productivity, etc.) in order to enable users to make decisions and evaluate them the results.

The concept of indicator of biodiversity is often reduced to that of indicator species (s) (also called bio-indicator). The presence of these species is used to characterize the quality of an environment. The notion of indicator species covers only a small part of the expected functions of a biodiversity indicator. Among the indicators used to assess biodiversity are: functional groups (eg herbivores, carnivores, ...), number Individuals of an environment or diversity in species ...