Secondary woodland is the term given to woodlands that have regrown on abandoned or neglected ground that had previously been used for agriculture, grazing or development of towns, villages, industry and roads. Some secondary woodland have been planted, but the majority have come about through the natural processes of colonisation and succession. Secondary woodlands can be also classed as ancient semi-natural woodland, (ASNW), if they developed before the year 1600.
By the nature of the word secondary, there is an implication that these woodlands are a second rate, poor relation to ancient woodlands. However just because secondary woodlands do not have all the characteristics of an ancient woodland, this does not mean they have no or little value and they can often be just as important for their biodiversity, landscape or social value as many ancient semi natural woodlands.
Secondary Woodlands and Biodiversity
Secondary woodlands can have a rich flora and fauna but many are without the specialist woodland plants and animals characteristic of ancient woodland. Those that have developed adjacent or close to ASNW can act as a site for migration and colonisation of the plants and animals associated with ancient woodland, and with time these secondary woods can develop a more diverse flora and fauna. They can also directly link previously isolated areas of ASNW, or act as stepping stone between isolated ancient semi natural woodlands. Where they are adjacent to ASNW, they can also act to buffer the ancient woodland from the negative impacts of every day life such as the effects of intensive agriculture ( fertiliser and pesticide spray drift) or built developments ( road run off, noise and light pollution).
The process by which a woodland develops naturally, known as succession, is in itself important for biodiversity. This process begins with the colonisation by the initial pioneer trees and moves with time through a scrub and thicket stage on to young woodland. The various stages within this process provide a differing range of habitats, both structurally and in the species that are present at any one stage. This natural establishment of trees, also known as natural regeneration, is a recognised method for establishing new woodland next to, or near, existing woodlands. Some would argue that this is the prefered method of creating new areas of woodland in such situations.
Patches of scrub and secondary woodland in more open habitats such as farmland, downland and heathland also provide important habitat diversity where they add to the mosaic of habitats. However in some of these important semi-natural habitats such as downland and heathland, the unmanaged development of scrub and woodland leads to the loss of these habitats and their associated wildlife. Over the last hundred years much downland and heathland has been lost through the development of scrub and woodland. These are both priority habitats in national and local Biodiversity Action Plans and initiatives such as the Hampshire Heathland Project and the Hampshire Grazing Project spend much of their time removing, and preventing, scrub and secondary woodland developing on these habitats.
Secondary woodland and their Social Value
For those secondary woodlands not fitting the definition of ASNW, ( those that have been in existence since 1600), they can still be up to 400 years old. As well as having time to develop important biological interest, just as with ASNW, there are also often important cultural and historical links. The wood itself marks a change in land use, which itself will reflect changes in the local economy/community. The wood may also contain evidence of that past land use in the form of buildings, foundations, old hedge banks or domestic plant species. The wood will also have had a history of local use since its development.
Where secondary woodlands have developed in urban areas or on the urban fringe these often have a history of use by local people for informal, often uninvited, recreation and play. Such woodlands have more direct value to society than a biologically rich but remote, ancient semi-natural woodland with no public access. Urban woodlands, even very small areas, provide areas for recreation and relaxation and can sometimes be the only accessible 'wild' space for play, learning and adventure that local children may have. Many secondary woodlands are ecologically robust. The fact that they may contain less of the sensitive and specialist species that occur in ASNW means that the woodlands themselves are less sensitive to the pressures of recreational use and as such have a higher carrying capacity in terms of visitor usage before unacceptable ecological damage is done.
The value of secondary woodland is often recognised, as is that of ASNW, through designation as a Site of Importance for Nature Conservation, (SINC).