Alaska Forest Insect and Disease Damage 1989-2007 by 5th Level Watershed

This dataset depicts total hectares of surveyed forest insect and disease damage summarized by 5th level watershed for each year between 1989 and 2007. Forest insect and disease survey data were obtained from the Alaska Forest Health Monitoring Clearinghouse. The insect and disease survey is conducted annually, and covers roughly 25% of the state each year, with special emphasis on high priority areas for trend monitoring. DRAFT watershed boundaries were obtained from the USGS. These watersheds are currently undergoing quality control and review; some watershed boundaries were unavailable at the time that this dataset was created. Due to incomplete coverage of the state during each year, this dataset should not be used for comparison of absolute trends in the spatial or temporal distribution of insects and disease. However, it is intended to provide the basis for relative comparisons in trends of insects and disease across the state over time. Users should be cautioned that areas with zero hectares of insect and disease damage do not necessarily denote absence of those phenomena; lack of survey in those watersheds would produce the same result.