Summary
The Forest Service Forest Health Protection staff conducts aerial surveys to collect data and map the extent and severity of tree mortality. The surveys are compiled and finalized across the summer months, but prediction of the mortality earlier in the year, such as April, would be highly useful because there would be more time to assign personnel and contracting for its management. Forest Service scientists developed forecasts of bark beetle location and intensity for California 6 months prior to the completion of aerial survey. Historical aerial survey data and weather variables known to influence bark beetle success, such as precipitation, maximum minimum winter temperature, and growing degree days were used in the predictions. Comparison of the 2015 forecast with the 2015 survey data showed only 2 percent of the forecast fell outside the expected range of mortality.
