Appendix E. Scoring of relative importance of threats
We considered each individual threat against each of the six primary soil functions in terms of:
Consequence - What are the medium term (20-25 years) consequences of the threat or issue in relation to the six soil functions?
Extent - Does it impact at the plot, field, regional or Scottish national level?
Reversibility - The extent to which the effects of the threat are naturally attenuated, can be mitigated, remediated or reversed?
Level of uncertainty - How good is our understanding of the issue? How strong is the evidence base and data to support it?
To determine the overall importance of each threat for each function we scored the consequence, extent, uncertainty and reversibility on a simple three point scale. We also used a score of 0 for spatial extent where there was no current evidence of an effect in Scotland.
E1. Criteria for scoring relative importance of threats for different soil functions.
Score | Grade | Definition |
|---|
Criterion a (consequence) |
1 | Low | unlikely to have any significant impact on that function |
2 | Moderate | impacts on the function are significant, but not threatening the operation of the function itself |
3 | High | likely to lead to serious impairment or the loss of that function |
Criterion b (spatial extent) |
0 | Limited | very limited extent or confined to very specific environments |
1 | Local | confined to a limited number of soils or environments or occurring as low frequency events |
2 | Regional | impacts are confined to one major region or soil environment within Scotland ( e.g. arable soils, upland areas) |
3 | National | impacts on almost all soils in Scotland |
Criterion c (uncertainty) |
1 | Low | threat is well characterised, causal factors well understood and quantified where possible, good quantitative data on the soils affected. |
2 | Moderate | causal factors not fully understood, some gaps in our data on soils affected ( e.g. evidence based on more limited research studies rather than on national sample sets or on qualitative information) |
3 | High | poor understanding of the causal factors with no quantification of the effects of these, few data on which to assess current status of soils affected. |
Criterion d (reversibility) |
1 | High | effects of the threat can be easily reversed by simple modifications to management practices or natural attenuation, reversal possible within a season |
2 | Moderate | effects can be reversed but only by significant changes to management practices, technical intervention or by new guidelines or policy, reversal possible within a few years |
3 | Low | effectively irreversible; no economic or technical/management solution, effects can only be reversed by major changes in policy at a national or international level and/or are likely to take many decades |
E2 Detailed scoring of threats
Comparison of threats across all soil functions
| Biomass, food & fibre production | Environmental interactions | Ecosystem support, habitats and biodiversity | Provision of a platform | Provision of raw materials | Protection of cultural heritage | Overall Risk Product | Overall Risk Product | Average Uncertainty |
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Threat | Consequence | Extent | Uncertainty | Reversibility | F1 Sum | Consequence | Extent | Uncertainty | Reversibility |
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Climate change | 2 | 3 | 3 | 3 | 18 | 2 | 3 | 3 | 3 |
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3 Loss of organic matter | 2 | 2 | 2 | 1 | 4 | 3 | 3 | 2 | 3 |
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2 Sealing | 3 | 1 | 2 | 3 | 9 | 3 | 1 | 2 | 3 |
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2 Contamination by atmospheric N,S | 1 | 2 | 1 | 3 | 6 | 2 | 3 | 1 | 3 |
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1 Loss of biodiversity | 2 | 2 | 3 | 2 | 8 | 2 | 3 | 3 | 2 |
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2 Contamination by heavy metals | 2 | 2 | 2 | 2 | 8 | 2 | 2 | 2 | 3 |
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1 Soil erosion | 2 | 1 | 2 | 1 | 2 | 3 | 1 | 2 | 2 |
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2 Soil contamination by land based activities | 1 | 2 | 1 | 1 | 2 | 2 | 2 | 2 | 2 |
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1 Compaction and structure | 2 | 1 | 2 | 1 | 2 | 2 | 1 | 1 | 1 |
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1 Salinisation | 2 | 0 | 1 | 3 | 0 | 2 | 0 | 1 | 3 |
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