English Abstract Four main natural resources can be distinguished:
chemical elements, energy carriers, environmental resources (air, water,
soil), and bioresources. Within bioresources can be distinguished: biomass
(e.g. stock of wood or fish), and biodiversity. Biodiversity can be
described in terms of genes, species or ecosystems. Although genetic
variety is the most fundamental concept, species are mostly used as a more
practical alternative. The Dutch environmental policy aims for the
protection of 95% of the species. The Dutch policy for nature conservation
selected "aim-species" on criteria as international rareness/distribution
area, national rareness and declining trend. More attention should however
be paid to: - the genetic information value per species (cladistic value), -
the use of risk analysis. The motives of biodiversity consists of -
financial or other utilitarian motives, - more spiritual or religious
motives: . stewardship . esthetic, religious feelings of alliance with
nature, . partnership (between man and nature based on mutual respect).
The main functions are production, carrier, regulation and information.
These functions can be subdived in at least 37 subfunctions. A summary of
concrete and often monetised examples of functions is given to illustrate
and underpin the importance of different functions. An overview of
evaluation methods of biodiversity is given.
