I'm not sure why someone would choose green as the color to indicate trees defoilated by mountain pine beetle or western spruce budworm, and gray to show unaffected regions. You just have to use your imagination -- and you might not have imagined the extent of damage from these pests! Click the map below.
|Click the map to go to the USFS web page and see animated sequences |
of maps showing the spread of budworm and beetle over the course
of 24-28 years. Source: USDA Forest Service.
These maps are based on cooperative aerial surveys conducted by Forest Health Protection staffs of the Oregon Department of Forestry, Washington Department of Natural Resources, and the USDA Forest Service Pacific Northwest Region.
Aerial survey data for 1980-2009 are available in both .e00 and shapefile formats. If you have a use for those, you probably already knew that.