The graphic on this page shows a summary of nitrogen deposition trends on NWPS-managed wilderness areas. Each wilderness area has a row of cells representing up to 30 years of trends in nitrogen concentration values inside the wilderness boundary. If enough data is available to calculate a trend, the cell for that year is shaded to indicate an increasing, decreasing, or stable trend.

Hover over a cell to show trend information for the available period of record up to that year. Click any trend cell to explore trends at that wilderness.

Trends here are done according to USFS protocol (see 3.4.2 Measure: Deposition of Nitrogen) and are available for wilderness areas managed by the Forest Service, Bureau of Land Management, National Park Service, and Fish and Wildlife Service.