Description

Aggregation index (Aggregation metric)

Usage

Arguments

Details

AI = \Bigg[∑\limits_{i=1}^m \Big( \frac{g_{ii}}{max-g_{ii}} \Big) P_{i} \Bigg](100)

where g_{ii} is the number of like adjacencies based on the single-count method and max-g_{ii} is the classwise maximum number of like adjacencies of class i and P_{i} the proportion of landscape compromised of class i.

AI is an 'Aggregation metric'. It equals the number of like adjacencies divided by the theoretical maximum possible number of like adjacencies for that class summed over each class for the entire landscape. The metric is based on he adjacency matrix and the single-count method.

Units

Percent

Range

0 <= AI <= 100

Behaviour

Equals 0 for maximally disaggregated and 100 for maximally aggregated classes.

Value

tibble

References

McGarigal, K., SA Cushman, and E Ene. 2012. FRAGSTATS v4: Spatial Pattern Analysis Program for Categorical and Continuous Maps. Computer software program produced by the authors at the University of Massachusetts, Amherst. Available at the following web site: http://www.umass.edu/landeco/research/fragstats/fragstats.html

He, H. S., DeZonia, B. E., & Mladenoff, D. J. 2000. An aggregation index (AI) to quantify spatial patterns of landscapes. Landscape ecology, 15(7), 591-601.

See Also

lsm_c_ai

Examples