Biodiversity is the variety of the living beings inhabiting our planet and of the ecosystems associated with them. Biological diversity includes at least three different levels:
– Intra-species diversity, ie between individuals of the same species, eg., the variations of colour in the petals of the Iris;
– Inter-species diversity, ie between existing species, eg., the variety of butterflies species that inhabit grasslands;
– Ecosystem diversity, or the variety of physical environments and their biological communities, eg. lakes, rivers, meadows, forests, etc…
The current abundance of life on Earth is the result of 3 and a half billion years of evolution, and also the reservoir from which the evolution derives all the genetic and morphological changes originating new species.
Up to date more than 1.700 ml species have been described, but it is assumed that there may be more than 20.000 ml species: many of them are still waiting to be discovered.
Man is part of biodiversity and depends on it for all the resources needed to live. In fact, biodiversity provides us essential goods like food, water, energy, construction materials, fuel, genetic resources, medicines, etc…
Ensuring the functionality of ecosystems, biodiversity also provides a range of services such as water drainage, climate stability, recycling of air, water and nutrients. Forests and oceans, for example, absorb the byproducts of agricultural and industrial activities slowing the accumulation of carbon dioxide and other greenhouse gases linked to climate change.
Greater biodiversity reduces the risk of extinction of species in case of critical events. Environments characterised by greater genetic heterogeneity are in fact less vulnerable to epidemics and extreme events such as drought, frost and floods.
Finally, biodiversity has an important recreational (think of the growing importance of eco-tourism), cultural, intellectual, aesthetic and spiritual value, as well as an ethical or existential value regardless of its use.
For all these reasons, biodiversity is a universal heritage for mankind, and preserving biodiversity is a top priority for all of us. The consequences of loss of biodiversity concern not only the quality of life, but the possibility of life on Earth.
The loss of biodiversity continues at an alarming rate. Over the past 50 years hundreds of thousands of species have been lost. Between 15,000 and 30,000 species are lost every year, according to some estimations.
Species and environments are at risk of disappearing forever, even before being discovered. The main responsibility for the increasing loss of biodiversity is human activities. Population explosion, industrial development, deforestation, desertification, changes in land use, introduction of alien plants and animals, destruction and fragmentation of habitat, unchecked fishing and hunting, global warming, are all the main factors that have contributed to the decline of more than one quarter of the living forms in different ecosystems of our planet.