Tree canopy, understory, shrub layer, field layer (containing tall shrubs and low shrubs) and ground layer.
However, not all woodlands will have all the layers and it’s unlikely to find them throughout.
Why are woodland layers important?
The different layers of your woodland will provide a variety of habitats, each of which supports different animals and plants. To provide a diverse range of habitats in your woodland, Glorious Woodlands aims to provide maintenance which enhances your woodlands natural systems including the structure of woodland layers. If you are renovating your forest, Glorious Woodlands can design ground level planting. If your woodland is a new design, we will normally concentrate on trees and shrubs as one has to wait for these to mature before the conditions are right for ground level planting to flourish.
The canopy consists of mature trees with a range of heights.
The canopy consists of either single species with various ages and sizes or different species which reach varying heights when mature.
Typically in a mixed wood emergent species will include: elm or beech, with oak or ash as the most dominant.
The understory includes the low growing and immature trees.
Common species for this layer are crab apple, wild cherry, holly, rowan or field maple.
The shrub layer
Similarly to the canopy, the shrub layer includes low-growing plants and shrubs that reach up to about 5m in height, such as hazel, hawthorn or blackthorn.
The field layer often consists of the grasses, ferns, flowering plants and lichens that cover the ground.
The tall herb layer
This might consist of bracken, rose-bay willow-herb and bramble. Contrasting the low herbs of bluebells, dog’s mercury, ramsons and smaller ferns. Coppiced wood provides the lower layer with shoots of the canopy species.
The ground layer
This consists of mosses and liverworts along with seedlings of plants for the taller layers.
This should be in all layers, including snags caught in the canopy, standing dead trees and on the ground. Deadwood is greatly invaluable to species, including invertebrates and nesting birds.
Beneath the ground:
An important layer of your woodland is beneath the soil surface. Beneath the surface is a complex ecosystem of roots, fungi and soil mirco-organisms. Tree roots are shallow, most occur around the top 30cm of soil. Tree roots can grow twice the height of the tree so roots may spread out beyond the outer edge of the canopy. It is estimated that 50% of the entire biomass of a forest exists underground.
One of the important organisms is mycorrhiza fungi. Mycorrhiza converts organic nitrogen to inorganic nitrogen, which offers some degree of pest, disease or drought resistance. In woodlands, mycorrhiza creates nutrients for vital trees, shrubs and other woodland plants. This is vital for self-renewing the fertility of wood. Glorious Woodlands will use mycorrhizal fungi when planting new trees and shrubs. This can add to the success of the planting.
Glorious Woodlands will not introduce this layer until the woodland canopy has closed sufficiently. This is so that grass and other light-demanding plants have been excluded. Weed control measures are essential for tree growth in the early years. Glorious Woodlands will use close planting, effective weed control and possibly thinning to allow your 10-year-old plantation to be a suitable condition for creating a field-layer of plants. Before introducing woodland plants, weeds such as docks and thistle will be cleared.
Glorious Woodlands will target planting in patches which have suitable conditions of shade, lack of competition from other plants and no disturbance from trampling.
As with other aspects of woodland planting, Glorious Woodlands recommends species that are typical of the local area and type of woodland. An effective way to grow woodland flora is from seeds collected locally. With the permission of landowners, small quantities can be gathered from a few sites over several years.
Glorious Woodlands will group the flora species according to whether they are woodland edge plants or tolerant of deeper shade. We will also consider how the species spreads. Seeds will be sown in the autumn to ensure cold treatment, as some woodland species need this in order to germinate. To prepare the ground, we will rake away the recently fallen leaves and lightly rake the soil surface. We will also mark this area to make sure the seeding can be checked.
Glorious Woodlands will plant woodland flora in early early spring. In spring, the soil is warming up but still moist. We will plant in single species groups of five or more plants, these should spread to form a stable clump, they can then seed or spread to new areas.
Glorious Woodlands will weed in the first five seasons to help the plants establish by reducing competition from other plants. Wood chips from thinning can be raked out as a mulch which will rot down and make a good substrate for the germination of woodland plants.
Scrub is one of the most important habitats for biodiversity. It’s used by species such as nightingales and dormice for nesting, foraging and shelter. Opening up canopy gaps and thinning areas helps restore scrub habitats by letting more light reach the shrub layer. As a result, shrub layers should only be cleared when absolutely necessary. Deer particularly enjoy grazing this layer so Glorious Woodlands can implement fencing to keep these areas restricted.