Resistance scale
Resistance indicates whether a receptor can absorb disturbance or stress without changing character (adapted from Holling, 1973; Tillin et al., 2010; Tillin & Tyler-Walters, 2014a&b).
Resistance (rank) |
Description |
---|---|
None |
Key functional, key structural, characterizing species severely decline and/or physico-chemical parameters are also affected e.g., the removal of habitats causing a change in habitat type. A severe decline or reduction relates to the loss of 75% of the extent, density or abundance of the selected species or habitat component e.g., loss of 75% substratum (where this can be sensibly applied). |
Low |
Significant mortality of key and characterizing species with some effects on physico-chemical character of habitat. A significant decline or reduction relates to the loss of 25-75% of the extent, density, or abundance of the selected species or habitat component e.g., loss of 25-75% of substratum. |
Medium |
Some mortality of species (can be significant where these are not key structural, key functional or characterizing species) without change to habitats relates to the loss of <25% of the species or habitat component. |
High |
No significant effects on the physico-chemical character of the habitat and no effect on the population viability of key or characterizing species but may affect feeding, respiration and reproduction rates. |