Broadleaved Woodlands
About Broadleaved Woodlands
Broadleaved woodlands are made up of deciduous trees, which lose their leaves in the Autumn. Broadleaved trees once covered most of the UK landscape. Deforestation and land-use change have altered the landscape overtime, meaning few of these woodlands remain. Although there are many ancient woodlands across Wales, these are mostly ‘semi-natural’, meaning they have been managed and replanted by humans on ancient woodland sites. Therefore, the trees themselves are unlikely to be ‘ancient’.
Mature semi-natural broadleaved woodlands are often made up of a variety of tree species, with one dominant species such as beech, oak or ash. The main tree species is dependent on conditions such as soil type and water availability.
Trees of varying ages will form a complex woodland structure which has a canopy, understorey, shrub layer and ground layer. The canopy and sub layers provide different habitat characteristics which support a diversity of flora and fauna. Where woodlands are managed successfully, there will be greater light availability in the understorey, allowing shrubs and vegetation to grow. The ground layer plays an important part in decomposition, creating a habitat for fungi, mosses, liverworts and lichen, as well as invertebrates such as wood-boring beetles.Oak Woodlands
Oak woodlands supports more biodiversity than any other native UK woodland. English Oak (Quercus robur) and Sessile oak (Quercus petreae) are both native to the UK. They are mostly found on acidic soils and are a common sight across South Wales. Oak woodlands often have a complex shrub layer of scrub, vegetation, and grasses, characteristic of acidic soils.
Oak flowers provide a food source for squirrels and pollen for invertebrates. Overall, oak supports over 1000 invertebrates, including beetles, flies and caterpillars, which then act as a food source for woodland birds. In the Autumn, acorns provide a food source for invertebrates, many woodland birds and small mammals, such as squirrels and badgers. The cracks and crevices within the bark also provide suitable habitat for nesting birds and roosting bats.
Deadwood, bark and complex root systems provide a home to a diversity of fungi, mosses, liverworts and lichens, including rare species which depend on oak trees.
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- Oak woodland
Beech Woodlands
Beech (Fagus sylvatica) woodlands, which are generally found on drier soils, can also be found across South Wales and are a valuable timber source. Catkins provide pollen for invertebrates and beech nuts provide a food source for woodland birds and small mammals. Beech woodlands are characteristic of tall trees (up to 40 metres) with dense canopies during the spring, creating a shaded ground layer which can appear quite open due to reduced vegetation growth. As a result of these unique habitat characteristics, many plants, fungi and invertebrates are beech woodland specialists. Here are some species to look out for:
- Birds-nest orchid (Neottia nidus-avis)
- Bolete mushrooms (Boletes)
- Chanterelle mushrooms (Cantharellus cibarius)
- Holly (Ilex)
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- Beech woodland (Hensol)
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- Ganoderma applanatum fungus on a beech tree
Ash Woodlands
Ash (Fraxinus) woodlands are a common sight across Wales. The trees are often young, and woodlands have a sparse canopy due to the effects of ash dieback. Trees with greater than 50% canopy loss should be monitored for ecological damage and economic value, as they produce large volumes of spores which spread the fungal disease. Some trees are now considered resistant, meaning mature ash trees are seen on occasion.
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- Ash woodland
The sparse canopy provides greater light availability to the ground layer than other broadleaved woodlands. Therefore, you would expect to find a greater variety of trees and shrubs such as oak, sycamore, lime, hazel and hawthorn. As a result, ash woodlands can appear to be very mixed and can lend themselves to ground flora. Here are some examples to look out for:
- Common bluebells (Hyacinthoides non-scripta)
- Dogs mercury (Mercurialis perennis)
- Wild garlic (Mercurialis perennis)
- Hart’s tongue fern (Asplenium scolopendrium)
- Scaly male fern (Dryopteris affinis)
The range of different trees and shrubs can provide suitable habitat for many woodland birds, invertebrates and mammals, including endangered hazel dormice and bats.