Vegetation Map Animation (IMAGE) University of Washington Caption This animation shows the average amount of wildfire fuels across the country for five different types of vegetation: trees, coarse wood debris, duff (decomposing organic materials on the ground), herbaceous live vegetation and shrubs. Credit Michael Billmire/Michigan Technological University Usage Restrictions Credit required. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.