1. 1 Amacher, M.C.; O'Dea, C.; Page-Dumroese, D. 2020a. Indicator 4.17: area and percent of forest whose designation or land management focus is the protection of soil and water resources. Washington, DC: U.S. Department of Agriculture, Forest Service, Research and Development. 3 p. https://www.fs.usda.gov/research/inventory/sustainability/. (1 May 2023)
2. 2 Amacher, M.C.; O'Dea, C.; Page-Dumroese, D. 2020b. Indicator 4.18: proportion of forest management activities that meet best management practices or other relevant legislation to protect soil resources. Washington, DC: U.S. Department of Agriculture, Forest Service, Research and Development. 1 p. https://www.fs.usda.gov/research/inventory/sustainability/. (1 May 2023)
3. 3 Amacher, M.C.; O'Dea, C.; Page-Dumroese, D. 2020c. Indicator 4.19: area and percent of forest land with significant soil degradation. Washington, DC: U.S. Department of Agriculture, Forest Service, Research and Development. 4 p. https://www.fs.usda.gov/research/inventory/sustainability/. (1 May 2023)
4. 4 Amacher, M.C.; O'Dea, C.; Page-Dumroese, D. 2020d. Indicator 4.20: proportion of forest management activities that meet best management practices, or other relevant legislation, to protect water related resources such as riparian zones, water quality, quantity, and flow regulation. Washington, DC: U.S. Department of Agriculture, Forest Service, Research and Development. 3 p. https://www.fs.usda.gov/research/inventory/sustainability/. (1 May 2023)
5. 5 Amacher, M.C.; O'Dea, C.; Page-Dumroese, D. 2020e. Indicator 4.21: area and percent of water bodies or stream length in forest areas with significant change in physical, chemical, or biological properties from reference conditions. Washington, DC: U.S. Department of Agriculture, Forest Service, Research and Development. 4 p. https://www.fs.usda.gov/research/inventory/sustainability/. (1 May 2023)