Detailed ecosystem geometry methods:

Materials:

1. ecosystem map (vector)

Edge to core ratio steps:

• Calculate geometry (area) of each ecosystem
• Perform a 500m buffer inside each ecosystem (-0.5km)
• Calculate geometry (area) of the new inward buffer for each ecosystem = edge
• Subtract the buffer are from ecosystem total area = core
• Divide edge by core to achieve a ratio
  • Note: some ecosystems may have no cores (edge=ecosystem total area) because they are so small. If this is the case, the highest vulnerability rank should be assigned.
• Assign a numerical rank based on this ratio (scale of 1-5)

Irregularity steps:

• Calculate geometry (area) of each ecosystem
• Calculate geometry (perimeter) of each ecosystem
• Divide this ecosystem total area by pi, and then take the square root of this value (this equals radius, r)
• "Create" a perfect circle with this new r
  • Area(circle) = pi*r^2
• Calculate the perimeter of this circle
  • Perimeter(circle) = 2*pi*r
• Divide the Perimeter(ecosystem) by the Perimeter(circle)
• Use this ratio to assign a numerical rank (scale of 1-5)
  • the higher the P(ecosystem):P(circle) ratio, the higher the rank

Add the Edge:Core ratio and Irregularity ranks together to get Ecosystem geometry (scale of 2-10)

Data sources: UNESCO ecosystem map