Defining Woodland

While there is no single, universal definition of what a woodland "actually is", various systems provide specific criteria to help us identify and categorise these habitats.

Defining a Woodland

According to the Phase 1 Habitat Survey System, a woodland is characterised as vegetation dominated by trees that reach over 5m in height at maturity. These trees form a distinct canopy, though it may sometimes be open.

To be classified as woodland rather than "scattered trees," the area must have at least 30% tree cover. If the cover is higher than 30% but contains large open spaces or rides, it is still considered woodland, though special attention is then paid to the ground flora.

The Structure of a Wood

Woodlands are structurally diverse and are typically composed of four distinct layers:

• Canopy: The tallest trees.

• Understorey: Shorter trees or shrubs.

• Herb or Field Layer: Flowering plants, ferns, and grasses.

• Ground Layer: Mosses, lichens, ivy, fungi, and decaying vegetation.

The balance of these layers is often dictated by grazing pressure and how much light penetrates the canopy.

Types of Woodland by Canopy Composition

The Phase 1 system categorises woodlands based on the percentage of tree types found within the canopy:

Woodland Type Canopy Composition

Broadleaved Consists of 10% or less conifer trees.

Coniferous Consists of 10% or less broadleaved trees.

Mixed Consists of between 10% and 90% of either type.

Origin and History: How Woodlands Form

Woodlands are also classified by how they began and how long they have existed.

1. Semi-Natural Woodland

These stands do not obviously originate from planting; their species distribution usually reflects the natural variations of the soil and site. Even if some trees were planted, a wood is still considered semi-natural if those planted trees make up less than 30% of the canopy.

2. Plantation Woodland

This includes all obviously planted woods of any age. This category also encompasses:

• Orchards.

• Arboreta.

• Ornamental tree gardens.

3. Historical Classifications

• Primary Woodland: Land that has been continuously wooded since the last glaciation.

• Secondary Woodland: Woods that grew on previously unwooded land, such as former agricultural fields.

• Ancient Woodland: A specific designation for land that has been continuously wooded since at least 1600 AD.

Woodland vs. Similar Habitats

It is important to distinguish woodland from other vegetative categories:

• Scrub: Dominated by shrubs or bushes usually under 5m tall.

• Hedgerows: Described as "woodland edge habitat without the wood," typically linear and managed.

• NVC Communities: The National Vegetation Classification (NVC) identifies specific communities based on key species, such as NVC W14, a broadleaved woodland dominated by Beech and Bramble