02 Contents Frame

Land evaluation – towards a revised framework
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increasingly becoming a priority objective for national and international environmental 
policies. Biodiversity expresses the variety of nature and helps select priority areas for 
conservation.
Biodiversity can be divided into hierarchical categories – genes, species, and 
ecosystems – that describe different aspects of living systems and are measured in 
different ways. Measures of biodiversity are needed to determine in situ conservation, 
particularly in deciding which combinations of available areas could represent and 
help sustain optimal biodiversity value for the future. Since biodiversity represents the 
total complexity of all life, including not only the great variety of organisms but also 
their varying behaviour and interactions, objective measures of biodiversity always 
relate to particular purposes or applications. Ideally such a measure should reflect the 
genetic diversity as a basis for valuing both species diversity, i.e. richness in different 
genes, and ecosystem diversity, i.e. richness in the different processes to which the 
genes ultimately contribute (Natural History Museum 2003). A popular approach is 
to represent sets of organisms (species richness) that can be defined by an area of land 
or sea, usually divided in nearly equal-area grid cells. In the context of this document, 
biodiversity (genetic, species and ecosystems) is to be seen as a crucial indicator for 
evaluating the sustainability of land resources use and management.
The World Resources Institute also advocates the use of human cultural diversity 
in order to present solutions to the problems of survival in particular environments. 
Cultural diversity is manifested by diversity in language, religious beliefs, land-
management practices, art, music, social structure, crop selection, diet, and many other 
attributes of human society.

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