Planting new woodland
It is important to recognise the correlation between a woodland’s structural diversity and the resulting diversity of species that will occupy it. Mature oak trees, for example, are well known for the tremendous variety of bird and invertebrate species they can support. But in the early years of the plantation (up to 25-30 years), it is the community of trees and the structural complexity they provide that will determine their success.
Natural regeneration of shrubs and other cover is likely to be very limited, particularly on arable sites. It is possible that some bramble and other shrubs may creep into the planting, but the intention should be to establish adequate shrub and medium height species, equivalent to at least 20% of the planting from the outset. Pheasants and warblers will benefit if these species are biased to the edges of the woodland. These areas should be carefully protected and maintained so they are well established before closure of the hardwood canopy.
The conifer is now generally derided in new woodland planting, particulaly in the lowlands. Despite this, its use as a nurse crop and as a means of providing physical diversity and shelter can often be invaluable.
With the decline of many farm and woodland birds, there is good evidence that the key to habitat improvement does not simply rest on the establishment of more woodlands. The specific need is for the establishment of structurally diverse woodland with shrubby edges and open species on which some of our fastest declining woodland birds are dependent.