Types of indices
Two main types of indices exist:
- those that quantify landscape
configuration or structure
- those that examine landscape
composition (Haines-Young
and Chopping, 1996)
Landscape configuration refers to the spatial arrangement,
positioning, orientation and complexity of patches - that is to the spatial
characteristics of landscapes.
Landscape configuration is described by indices that measure structural characteristics. Configuration is characterised by the distribution and spatial arrangement of patches, so measures like nearest neighbour, adjacency, connectedness and shape complexity are used to describe it.
Landscape composition refers to the distribution of
species and the number of, and abundance of patch types - it is essentially
aspatial and therefore refers to the non-spatial characteristics of landscapes.
Landscape composition is described by measures of variety
and abundance. These may include calculations of the proportion of each
patch type, patch richness, evenness and diversity (McGarigal
and Marks, 1994). Measures of composition are essentially calculating
diversity so many are drawn from indices of species diversity traditionally
used in community ecology.
This means that the landscape is either described by
its spatial or non-spatial characteristics (Baskent
and Jordan, 1995)
Some indices incorporate both configuration and composition.
