National Forest Inventory GB 2024

The National Forest Inventory (NFI) woodland map covers all forest and woodland area over 0.5 hectare with a minimum of 20% canopy cover, or the potential to achieve it, and a minimum width of 20 metres. This includes areas of new planting, clearfell, windblow and restock. The woodland map excludes all 'tarmac' roads and active railways, and forest roads, rivers and powerlines where the gap in the woodland is greater than 20 meters wide. All woodland (both urban and rural), regardless of ownership, is 0.5 hectare or greater in extent, with the exception of Assumed woodland or Low density areas that can be 0.1 hectare or greater in extent. Also, in the case of woodland areas that cross the countries borders, the minimum size restriction does not apply if the overall area complies with the minimum size. Woodland less than 0.5 hectare in extent, with the expectation of the areas above, will not be described within the dataset but will be included in a separate sample survey of small woodland and tree features. The woodland map is updated on an annual basis and the changes in the woodland boundaries use the Ordnance Survey MasterMap® (OSMM) as a reference where appropriated. The changes in the canopy cover have been identified on: Sentinel 2 imagery taken during spring/summer 2024 or colour aerial orthophotographicimagery available at the time of the assessment; New planting information for the financial year 2023/2024, from grant schemes and the sub-compartment database covering the estate of Forestry England, Forestry and Land Scotland and Natural Resources Wales; Transition areas where the difference between last assessment date (source) and the latest date (source) currently available was greater than 17 years. Woodland areas, greater than 0.5 hectares, are classified as an interpreted forest type (IFT) from aerial photography and satellite imagery. Non-woodland areas, open areas greater than 0.5 hectare completely surrounded by woodland are described according to open area types. IFT categories are Conifer, Broadleaved, Mixed mainly conifer, Mixed mainly broadleaved, Coppice, Coppice with standards, Shrub, Young trees, Felled, Ground prep, Cloud \ shadow, Uncertain, Low density, Assumed woodland, Failed, Windblow. IOA categories are Open water, Grassland, Agricultural land, Urban, Road, River, Powerline, Quarry, Bare area, Windfarm, Other vegetation. For further information regarding the interpreted forest types (IFT) and the interpreted open areas (IOA) please see NFI description of attributes available on www.forestresearch.gov.uk国家森林清查（National Forest Inventory, NFI）林地地图覆盖所有面积不小于0.5公顷、冠层覆盖率至少20%或具备达到该覆盖率潜力，且最小宽度为20米的森林与林地范围。该范围包含新造林、皆伐、风倒及补植区域。此林地地图不包括沥青路面（tarmac）道路、运营中的铁路，以及林地间隙宽度超过20米的林区道路、河流与输电线路。所有林地（包括城市与乡村林地），除权属外，面积需不小于0.5公顷，但假定林地或低密度林地的面积下限可放宽至0.1公顷。对于跨越国界的林地，若整体面积符合最小面积要求，则不受最小尺寸限制。除上述例外情况外，面积不足0.5公顷的林地不会被纳入本数据集，但会纳入小型林地与树木特征的独立抽样调查中。林地地图每年更新一次，林地边界变更在合适情况下以英国地形测量局主地图（Ordnance Survey MasterMap®, OSMM）为参考基准。冠层覆盖变化的识别依据包括：2024年春夏季获取的哨兵2号（Sentinel 2）影像，或评估当期可用的彩色航空正射影像；2023/2024财年来自拨款计划、以及覆盖英格兰林业署、苏格兰林业与土地局、威尔士自然资源局辖区的分区数据库的新造林信息；上次评估数据源与当前最新可用评估数据源间隔超过17年的过渡区域。面积大于0.5公顷的林地会通过航空摄影与卫星影像解译为解译森林类型（Interpreted Forest Type, IFT）。完全被林地环绕、面积大于0.5公顷的非林开阔区域，会按开阔区域类型进行分类。IFT分类项包括：针叶林、阔叶林、针阔混交（以针叶为主）、针阔混交（以阔叶为主）、矮林、矮林伴留植树、灌丛、幼龄林、采伐迹地、整地、云/阴影、不确定、低密度、假定林地、造林失败、风倒。解译开阔区域（Interpreted Open Areas, IOA）分类项包括：开阔水体、草地、农用地、城市区域、道路、河流、输电线路、采石场、裸地、风电场、其他植被。如需了解解译森林类型（IFT）与解译开阔区域（IOA）的详细属性说明，请访问www.forestresearch.gov.uk查阅国家森林清查（NFI）属性描述文档。