Woodland Structure In England

'ReForeSt: Remote Sensing for Forest Management and Structural Diversity' was a Defra funded Forestry R&D project. It used remote sensing to map structural diversity across English woodlands, complement locally derived woodland condition assessments, and test the impacts of forest management on structural diversity. 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:

1. Canopy Height 90th. Raster dataset of canopy height 90th percentile for the National Forestry Inventory 2020 (‘Woodland’ Integrated Forest Types) at 30 m resolution. Data are derived from the Environment Agency’s LiDAR Vegetation Object Model (VOM) which is produced from the National LiDAR Programme (2017-2023). Canopy height is presented in metres as the 90th percentile of VOM values within each 30 m pixel.
2. Canopy Gap Fraction. 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.
3. Foliage Height Diversity. 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. 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. Canopy Height 90th and Canopy Gap Fraction are matched with ‘National_LiDAR_Programme_tile_catalog_VOM_2017_2023.gpkg’ Foliage Height Diversity is matched with ‘National_LiDAR_Programme_tile_catalog_2017_2024.gpkg’ Attribution statement: © Forestry Commission & Environment Agency copyright and/or database right 2026. All rights reserved.