Criteria 4: Evolutionary History

Criteria 4: Evolutionary History

What does this map show?

Number of monospecific Genera (monG)

Genera (or families) of taxa that contain only a single species may be considered to be of high conservation significance as they often represent faunal groups with ancient evolutionary origins.  Planning units containing one or more such species may therefore also be of high conservation value. This attribute was calculated simply as the number of monospecific genera recorded from a planning unit. Note that this attribute could not be calculated for macroinvertebrates as taxa within this faunal group were identified to family level only.

Number of species endemic to each NASYagg Region (SES)

A simple index of endemism calculated as the number of species present in a single region (NASYagg).  A limitation of this attribute is that it requires an a priori definition of the area of endemism, rather than letting the data define the areas of interest. Note that no macroinvertebrate familes or waterbird species were endemic to a seingle region.

Taxonomic endemism index (TE)

An index of endemism identifying areas where species with restricted ranges are concentrated.  Based on the number of species within a planning unit weighted by the inverse of each species’ distribution range (also known as weighted endemism).  This index ranges from one, where all species in a planning unit have broad geographical ranges, to infinity, with large values indicating the presence of species with range-size rarity (i.e. areas with high endemism) (Rebelo & Siegfried, 1992).

Phylogenetic Endemism index (PE)

Phylogenetic endemism (PE) is a measure of the degree to which elements of evolutionary history are spatially restricted in space.  PE combines the phylogenetic diversity (PD) and taxonomic endemism (TE ) measures to identify areas where substantial components of phylogenetic diversity are restricted (Rouser et al., 2009). To estimate the degree of PE represented by the taxa in a given area, the range size of each branch of the phylogenetic tree (rather than the range of each taxon) is quantified. PE is therefore the sum of branch length ⁄ clade range for each branch on the tree (where a clade is a single branch on the tree  consisting of an organism and all its descendants).

Sample map: 4: Evolutionary History

4: Evolutionary History