Landscape Ecology - Ecological Systems - page 190

Table 11.3 Some commonly used landscape metrics [ 4 , 52 ]
Landscape metric Abbreviation Description

Patch shape index PSI A measure for the complexity of the shape of a given patch:

PSI

2

P

¼

p
where P is the perimeter of a patch, and A is the area of the patch. PSI = 1 for
circles; PSI = 1.1283 for squares; and PSI = 1.1968 for a rectangle (2 L by L).
1/D is called “compactness” (see Forman [ 4 ]).

A p

Perimeter/area ratio PAR A measure of the complexity of the shape of a patch:

PAR = P/A
where P is the perimeter of a patch, and A is the area of the patch.

Number of patches NP The total number of patches in the landscape.

Patch density PD The number of patches per square kilometer (i.e., 100 ha).

Total edge TE The sum of the lengths of all edge segments (unit: meter).

Edge density ED The total length of all edge segments per hectare for the class or landscape of

consideration (unit: m/ha).

Patch richness PR The number of different patch types in the landscape.

Patch richness density PRD The number of patch types per square kilometer (or 100 ha).

Shannon's diversity index SHDI A measure of patch diversity in a landscape that is determined by both the

number of different patch types and the proportional distribution of area
among patch types:

¼ P

m

H p i ln pðÞ

where m is the total number of patch types and p i is the proportion of the
landscape area occupied by patch type i .

i¼ 1