The term 'biodiversity' was coined in 1985, (abbreviating 'biological diversity') and has been defined in many different ways. Holdgate (1991) regarded it as the 'Total sum of life's variety on Earth, expressed at the genetic, species and ecosystem level' and suggested 3 reasons why it should matter:
All species deserve respect.
The living systems of the planet are our life support mechanism and we do not know the precise role that each species plays.
The economic importance for food, fibre, timber and medicines.
This has been recognized internationally and at the Earth Summit (Rio de Janeiro 1992) 153 countries signed the convention on biological diversity. This convention defined biodiversity as 'The variability of living organisms from all sources including interalia, terrestrial, marine and other aquatic ecosystems and the ecological complexes of which they are part........'
There are 3 main levels of Biodiversity:
Between ecosystems and habitats.
Between species.
Genetic variation within species
In 1994, the UK Biodiversity Action Plan (Cm 2428) was published with the goal of enhancing biological diversity within the UK and to contribute to the conservation of global diversity through all appropriate mechanisms.
Taken from Spedding (1994) Agriculture and the Citizen p 143