For each date, the 12 category input land cover was reclassified into three categories:
CLEAR’s Landscape Fragmentation Tool was used to identify four forest fragmentation categories using a 300 foot edge width applied to the reclassified land cover:
The analysis is based on the following research:
The forest fragmentation tool classifies forests in four general categories:
|Patch Forest||forest pixels along the edge of an interior gap in a forest that are degraded by "edge effects" (for example the forest immediately surrounding a small house lot in the middle of the forest)|
|Edge Forest||forest pixels along the exterior perimeter of a forest that are degraded by "edge effects" (for example the forest immediately along a major highway or large agricultural field)|
|Perforated Forest||small isolated fragments of forest that are surrounded by non-forest features and completely degraded by "edge effects"|
|Core Forest||forest pixels that are not degraded by "edge effects." The Landscape Fragmentation Tool further divides these by size.|
|Small core||smaller than 250 acres|
|Medium core||between 250 and 500 acres|
|Large core||larger than 500 acres|
Edge effects are abrupt changes in vegetative populations or community structures found at the boundary of two or more different habitats.
NOTE. Core forest sub-categories used in this analysis are based on scientific literature and suggest general thresholds for minimum viable forest patch sizes. The relationship between how viable a forest patch is and patch size is dependent on the species of interest.
The edge width parameter is the distance over which the fragmented land cover type of interest (i.e. forest) can be degraded by the fragmenting land cover types (i.e. development, agricultural fields, etc). The literature indicates that the edge width varies by the species or issue of interest.