1 Introduction
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To expand the list of land use types2 considered to include forests, permanent crops, and artificial areas (e.g., urban, industrial areas, mineral extraction sites)
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To better link the recommended characterisation factors with the land use nomenclature recommended by the Life Cycle Initiative and currently used by inventory databases, presented in Koellner et al. (2013a), by providing a correspondence table
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To test the characterisation factors recommended by means of case study analyses on relevant production systems, including annual and perennial agriculture and forestry
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To consider the potential update of the characterisation factors based on the revised IPCC (2019) guidelines, with updated management factors affecting the estimation of SOC stocks
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To provide characterisation factors at a smaller geographical scale (e.g., states, ecoregions within a country, or at a more refined resolution scale) than those provided in the guidance (i.e., at a national level).
2 Methodology
2.1 Conceptual model to assess impacts of land occupation and land transformation on soil quality
2.2 Calculation of characterisation factors based on SOC stock
2.2.1 Step 1: setting the scene for the calculation of SOC stock values of land use classes
ID | Land use class | Group | Rule for assigning SOC stock value (for group B classes) |
---|---|---|---|
0 | Unspecified | B | MIN (all classes) |
0.1 | Unspecified, used | B | MIN (all classes, excluded land cover classes) |
0.2 | Unspecified, natural | Land cover (SOC = SOCref) | |
1 | Forest | B | MIN (1.1; 1.2) |
1.1 | Forest, natural | Land cover (SOC = SOCref) | |
1.1.1 | Forest, primary | A | |
1.1.2 | Forest, secondary | A | |
1.2 | Forest, used | B | MIN (1.2.1; 1.2.2) |
1.2.1 | Forest, extensive | A | |
1.2.2 | Forest, intensive | A | |
2 | Wetlands | Land cover (SOC = SOCref) | |
2.1 | Wetlands, coastal | Land cover (SOC = SOCref) | |
2.2 | Wetlands, inland | Land cover (SOC = SOCref) | |
3 | Shrub land | Land cover (SOC = SOCref) | |
4 | Grassland/pasture/meadow | B | MIN (4.1; 4.2) |
4.1 | Grassland | B | MIN (4.1.1; 4.1.2) |
4.1.1 | Grassland, natural | Land cover (SOC = SOCref) | |
4.1.2 | Grassland, for livestock grazing | A | |
4.2 | Pasture/meadow | B | MIN (4.2.1; 4.2.2; 4.2.3) |
4.2.1 | Pasture/meadow, extensive | A | |
4.2.2 | Pasture/meadow, intensive | A | |
4.2.3 | Pasture/meadow severely degraded** | A | |
5 | Agriculture | B | MIN (5.1; 5.2) |
5.1 | Arable | B | MIN (5.1.1; 5.1.2; 5.1.3; 5.1.4) |
5.1.1 | Arable, fallow | A | |
5.1.2 | Arable, non-irrigated | B | MIN (5.1.2.1; 5.1.2.2) |
5.1.2.1 | Arable, non-irrigated, extensive | A | |
5.1.2.2 | Arable, non-irrigated, intensive | A | |
5.1.3 | Arable, irrigated | B | MIN (5.1.3.1; 5.1.3.2) |
5.1.3.1 | Arable, irrigated, extensive | A | |
5.1.3.2 | Arable, irrigated, intensive | A | |
5.1.4 | Arable, flooded crops | A | |
5.1.5 | Arable, greenhouse | B | MIN (5.1.1; 5.1.2; 5.1.3; 5.1.4) |
5.1.6 | Field margins/hedgerows | Excluded | |
5.2 | Permanent crops | B | MIN (5.2.1; 5.2.2) |
5.2.1 | Permanent crops, non-irrigated | B | MIN (5.2.1.1; 5.2.1.2) |
5.2.1.1 | Permanent crops, non-irrigated, extensive | A | |
5.2.1.2 | Permanent crops, non-irrigated, intensive | A | |
5.2.2 | Permanent crops, irrigated | B | MIN (5.2.2.1; 5.2.2.2) |
5.2.2.1 | Permanent crops, irrigated, extensive | A | |
5.2.2.2 | Permanent crops, irrigated, intensive | A | |
6 | Agriculture, mosaic | Excluded | |
7 | Artificial areas | B | MIN (7.1; 7.2; 7.3; 7.4; 7.5; 7.6) |
7.1 | Urban | B | MIN (7.1.1; 7.1.2; 7.1.3; 7.1.4, 7.1.5) |
7.1.1 | Urban/industrial fallow | A | |
7.1.2 | Urban, continuously built | A | |
7.1.3 | Urban, discontinuously built | A | |
7.1.4 | Urban, green areas | A | |
7.1.5 | Urban, sparsely built** | A | |
7.2 | Industrial area | A | |
7.3 | Mineral extraction site | A | |
7.4 | Dump site | A | |
7.5 | Construction site | A | |
7.6 | Traffic area | B | MIN (7.6.1; 7.6.2, 7.6.3) |
7.6.1 | Traffic area, road network | A | |
7.6.2 | Traffic area, rail network | A | |
7.6.3 | Traffic area, rail/road embankment | A | |
8 | Bare area | Land cover (SOC = SOCref) |
ID | Land use class | Basis for SOC stock calculation | Land use category (FLU) | Land use practice (FMG) | Land use intensity (FI) |
---|---|---|---|---|---|
1.1.1 | Forest, primary | IPCC factors | Forest | ||
1.1.2 | Forest, secondary | IPCC factors | Forest | ||
1.2.1 | Forest, extensive | IPCC factors | Forest | ||
1.2.2 | Forest, intensive | IPCC factors | Forest | ||
4.1.2 | Grassland, for livestock grazing | IPCC factors | Grassland | Nominally managed (non-degraded) | |
4.2.1 | Pasture/meadow, extensive | IPCC factors | Grassland | Improved grassland | Medium inputs |
4.2.2 | Pasture/meadow, intensive | IPCC factors | Grassland | High-intensity grazing | |
4.2.3 | Pasture/meadow, severely degraded | IPCC factors | Grassland | Severely degraded | |
5.1.1 | Arable, fallow | IPCC factors | Cropland—set aside | ||
5.1.2.1 | Arable, non-irrigated, extensive | IPCC factors | Cropland—long-term cultivated | Reduced tillage | Medium inputs |
5.1.2.2 | Arable, non-irrigated, intensive | IPCC factors | Cropland—long-term cultivated | Full tillage | Medium inputs |
5.1.3.1 | Arable, irrigated, extensive | IPCC factors | Cropland—long-term cultivated | Reduced tillage | Medium inputs |
5.1.3.2 | Arable, irrigated, intensive | IPCC factors | Cropland—long-term cultivated | Full tillage | Medium inputs |
5.1.4 | Arable, flooded crops | IPCC factors | Cropland—paddy rice | ||
5.2.1.1 | Permanent crops, non-irrigated, extensive | IPCC factors | Perennial/tree crop | No tillage | Medium inputs |
5.2.1.2 | Permanent crops, non-irrigated, intensive | IPCC factors | Perennial/tree crop | Reduced tillage | Medium inputs |
5.2.2.1 | Permanent crops, irrigated, extensive | IPCC factors | Perennial/tree crop | No tillage | Medium inputs |
5.2.2.2 | Permanent crops, irrigated, intensive | IPCC factors | Perennial/tree crop | Reduced tillage | Medium inputs |
7.1.1 | Urban/industrial fallow | 80% sealed area (SOC = 0); 20% severely degraded grassland (4.2.3) | |||
7.1.2 | Urban, continuously built | 90% sealed area (SOC = 0); 10% grassland (4.1.2) | |||
7.1.3 | Urban, discontinuously built | 50% sealed area (SOC = 0); 50% grassland (4.1.2) | |||
7.1.4 | Urban, green areas | IPCC factors | Grassland | Improved grassland | Medium inputs |
7.1.5 | Urban, sparsely built | 30% sealed area (SOC = 0); 70% grassland (4.1.2) | |||
7.2 | Industrial area | 90% sealed area (SOC = 0); 10% severely degraded grassland (4.2.3) | |||
7.3 | Mineral extraction site | SOC = 0 | |||
7.4 | Dump site | SOC = 0 | |||
7.5 | Construction site | SOC = 0 | |||
7.6.1 | Traffic area, road network | SOC = 0 | |||
7.6.2 | Traffic area, rail network | SOC = 0 | |||
7.6.3 | Traffic area, rail/road embankment | 50% sealed area (SOC = 0); 50% nominally managed grassland (4.1.2) |
2.2.2 Step 2: calculating maps of characterisation factors
2.2.3 Step 3: aggregating characterisation factors at national and global level
2.2.4 Step 4: deriving transformation characterisation factors
2.3 Case study analysis
Unit | Ethanol car | Methane car | Electric car | |
---|---|---|---|---|
Energy use | [MJ/FU] | 35340 | 33480 | |
[kWh/FU] | 3565 | |||
Land occupation for cultivation | [m2y/MJ] | 0.078 | 0.084 | |
[m2y/FU] | 1458 | 1567 | ||
Production plant land occupation | [m2y/MJ] | 0.00002 | 0.0001 | |
[m2y/FU] | 0.86 | 3 | ||
Electricity produced by solar PV | [kWh/m2y] | 220 | ||
Area required for PVs | [m2y/FU] | 16.2 | ||
Land occupation for PV and corridors | [m2y/FU] | 40.5 | ||
Refuelling/recharging land occupation | [m2y/FU] | 0.28 | 0.28 | 0.033 |
3 Results
3.1 Characterisation factors based on SOC stock
ID | Land use class | Global average | Country aggregated characterization factors | ||||
---|---|---|---|---|---|---|---|
Min | 1st quartile | Median | 3rd quartile | Max | |||
1.1.1 | Forest, primary | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 |
1.1.2 | Forest, secondary | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 |
1.2.1 | Forest, extensive | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 |
1.2.2 | Forest, intensive | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 |
4.1.2 | Grassland, for livestock grazing | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 |
4.2.1 | Pasture/meadow, extensive | −6.32 | −17.92 | −8.90 | −7.05 | −4.98 | −1.57 |
4.2.2 | Pasture/meadow, intensive | 4.26 | 0.92 | 3.17 | 4.31 | 5.67 | 12.80 |
4.2.3 | Pasture/meadow severely degraded | 12.78 | 2.77 | 9.50 | 12.94 | 17.01 | 38.40 |
5.1.1 | Arable, fallow | 6.23 | 0.68 | 3.27 | 7.00 | 9.47 | 21.02 |
5.1.2.1 | Arable, non-irrigated, extensive | 10.08 | 0.87 | 5.33 | 7.12 | 11.22 | 31.95 |
5.1.2.2 | Arable, non-irrigated, intensive | 10.74 | 0.78 | 6.20 | 8.43 | 11.45 | 35.18 |
5.1.3.1 | Arable, irrigated, extensive | 10.08 | 0.87 | 5.33 | 7.12 | 11.22 | 31.95 |
5.1.3.2 | Arable, irrigated, intensive | 10.74 | 0.78 | 6.20 | 8.43 | 11.45 | 35.18 |
5.1.4 | Arable, flooded crops | −15.76 | −41.16 | −19.95 | −15.06 | −10.67 | −3.40 |
5.2.1.1 | Permanent crops, non-irrigated, extensive | 6.26 | −7.77 | −4.22 | 0.59 | 8.93 | 25.37 |
5.2.1.2 | Permanent crops, non-irrigated, intensive | 8.16 | −3.53 | −1.78 | 1.82 | 10.57 | 29.60 |
5.2.2.1 | Permanent crops, irrigated, extensive | 6.26 | −7.77 | −4.22 | 0.59 | 8.93 | 25.37 |
5.2.2.2 | Permanent crops, irrigated, intensive | 8.16 | −3.53 | −1.78 | 1.82 | 10.57 | 29.60 |
7.1.1 | Urban/industrial fallow | 43.63 | 7.74 | 25.94 | 35.80 | 49.09 | 110.08 |
7.1.2 | Urban, continuously built | 45.66 | 8.10 | 27.15 | 37.47 | 51.37 | 115.20 |
7.1.3 | Urban, discontinuously built | 25.37 | 4.50 | 15.08 | 20.81 | 28.54 | 64.00 |
7.1.4 | Urban, green areas | −7.34 | −17.92 | −9.02 | −6.80 | −4.46 | −1.53 |
7.1.5 | Urban, sparsely built | 15.22 | 2.70 | 9.05 | 12.49 | 17.12 | 38.40 |
7.2 | Industrial area | 47.18 | 8.37 | 28.05 | 38.71 | 53.08 | 119.04 |
7.3 | Mineral extraction site | 50.73 | 9.00 | 30.16 | 41.63 | 57.08 | 128.00 |
7.4 | Dump site | 50.73 | 9.00 | 30.16 | 41.63 | 57.08 | 128.00 |
7.5 | Construction site | 50.73 | 9.00 | 30.16 | 41.63 | 57.08 | 128.00 |
7.6.1 | Traffic area, road network | 50.73 | 9.00 | 30.16 | 41.63 | 57.08 | 128.00 |
7.6.2 | Traffic area, rail network | 50.73 | 9.00 | 30.16 | 41.63 | 57.08 | 128.00 |
7.6.3 | Traffic area, rail/road embankment | 25.37 | 4.50 | 15.08 | 20.81 | 28.54 | 64.00 |