What is a woodland
Within the Phase 1 Habitat Survey System, a woodland is defined as vegetation primarily consisting of trees that are expected to grow taller than 5m when mature, forming a distinct, though potentially open, canopy. This system specifically requires noting the dominant tree species, the layers beneath the canopy, and mapping distinct blocks of woodland based on the types of trees present. Areas with less than 30% tree cover are generally not considered woodland under this system.
The Phase 1 system categorises woodlands primarily by the composition of their tree canopy. Broadleaved woodland has 10% or less conifer trees. Coniferous woodland has 10% or less broadleaved trees. Mixed woodland has a canopy composed of between 10% and 90% of either broadleaved or conifer trees, with the approximate proportions typically noted.
The Phase 1 system also distinguishes woodlands based on their origin, classifying them as either semi-natural or plantation. Semi-natural woodlands are those that do not appear to originate from planting, with species distribution reflecting natural site conditions, including both ancient and more recent woodlands. Woodland with some planted trees is still considered semi-natural if these make up less than 30% of the canopy. Plantation woodlands are those that have been deliberately planted, with some exceptions being classified as semi-natural.
In habitat surveying, the key distinction lies in tree cover percentage. If the cover of trees is less than 30%, the area is designated as scattered trees rather than as woodland. Even if tree cover is above 30%, if there are significant open areas or rides, it is still considered woodland, but particular attention is paid to the ground flora in such cases.
Beyond the quantifiable definition of the Phase 1 system, woodlands are also understood and differentiated through several other factors. These include their ecological structure (comprising distinct layers like canopy, understorey, field, and ground layers), their historical context (categorised as primary, secondary, or plantation, with ancient woodland being a significant historical designation), their plant composition (identified through systems like the National Vegetation Classification which defines communities based on key species), and comparison to related habitats like scrub and hedgerows.
Woodland is generally differentiated from scrub habitat by the height and growth form of the dominant vegetation. Woodland is defined by trees typically more than 5m high when mature, forming a distinct canopy. Scrub, on the other hand, is generally defined as vegetation dominated by shrubs or bushes, which are usually less than 5m tall.
A hedgerow is distinct from woodland. While sometimes described as a woodland edge habitat, a hedgerow lacks the full structure and extent of a woodland. Hedgerows are typically linear features, often subject to specific management practices like trimming, and are composed of shrubs and trees that form a barrier or boundary, rather than the broader, multi-layered ecosystem of a woodland.
Ancient woodland is a specific historical classification for land that has been continuously wooded since at least 1600 AD. This designation is based on the historical continuity of woodland cover, regardless of whether the current trees are recent growth or original ancient trees.
