Woodland Structure In England

<p>One of the components was to generate maps of key structural metrics for the whole of England derived from the LiDAR Programme. The following is a description of three output GeoTiff raster maps: &nbsp;</p><p>1) Canopy Height 90th. Raster dataset of canopy height 90th percentile for the National Forestry Inventory (NFI) and Trees Outside Woodlands (TOW) map. The data is derived from the Environment Agency’s LiDAR Vegetation Object Model (VOM) which is produced from the National LiDAR Programme (2017-2023). The 90th percentile of VOM height is calculated at 30 m resolution and the resulting dataset is clipped to the NFI 2020 and TOW V2 datasets.</p><p>2) Canopy Gap Fraction. &nbsp;Raster dataset of canopy gap fraction for the National Forest Inventory 2020 (‘Woodland’ Integrated Forest Types). Data are derived from the Environment Agency’s LiDAR Vegetation Object Model which is produced from the National LiDAR Programme (2017-2023). Canopy gaps are defined as an area larger than 10 m2 where all vegetation is below 2.5 m in height. Canopy gap fraction is calculated as the area of canopy gap divided by the area of woodland with a maximum value of 1.</p><p>3) Foliage Height Diversity. &nbsp;Raster dataset of foliage height diversity for the National Forestry Inventory 2020 (‘Woodland’ Integrated Forest Types) at 30 m resolution. Data are derived from the Environment Agency’s National LiDAR Programme (2017-2024). Foliage height diversity is presented as the ‘number of effective layers’ and uses the Shannon’s Diversity Index to describe how evenly vegetation is distributed across six height layers: 0-1 m, 1-2 m, 2-5 m, 5-8 m, 8-20 m and 20+ m. Scores range from 0 where there is no vegetation to 6 where LiDAR points equally fill all height layers.</p><p>In addition, there are two catalogue files, which are based on the EA’s National LiDAR Programme Catalogue (available under OGL) and provide details on the 5km tiles of the underlying LiDAR survey. These are included because the raster datasets are composites across years, and these catalogue files will help users understand when data for different areas were collected.</p><p>Canopy Height 90th and Canopy Gap Fraction are matched with ‘National_LiDAR_Programme_tile_catalog_VOM_2017_2023.gpkg’<br />Foliage Height Diversity is matched with ‘National_LiDAR_Programme_tile_catalog_2017_2024.gpkg’</p>