| Depth of mineral soil | |
| Depth to water table | |
| Soil Kjeldahl nitrogen to 50 cm depth | |
| Soil organic matter to 50 cm depth | |
| Compound Topographic Index (CTI) | |
| Enhanced Vegetation Index (EVI) integrated over the local growing season | |
| Enhanced Vegetation Index (EVI) integrated over the local non-growing season | |
| Fraction of Photosynthetically Active Radiation (FPAR) absorbed by vegetation integrated over the local growing season | |
| Fraction of Photosynthetically Active Radiation (FPAR) absorbed by vegetation integrated over the local non-growing season | |
| Leaf Area Index (LAI) integrated over the local growing season | |
| Leaf Area Index (LAI) integrated over the local non-growing season | |
| Percent tree cover | |
| Percent bare cover | |
| Gross Primary Production (GPP) integrated over the local growing season | |
| Gross Primary Production (GPP) integrated over the local non-growing season | |
| Respiration Index (RI) integrated over the local growing season | |
| Respiration Index (RI) integrated over the local non-growing season | |
| Gross Primary Production (GPP) integrated over the local growing season | |
| Human population density from LandScan 2004 | |