The ancient woodland concept as a practical conservation tool in Great Britain

Summary

In the 1980s the Nature Conservancy Council created an ancient woodland inventory showing all woods in Great Britain (GB) greater than 2 ha that were believed to have had woodland habitat cover continuously from 1600. Subsequently these lists have been maintained as three separate inventories by NCC's successors, English Nature (now Natural England), Countryside Council for Wales and Scottish Natural Heritage. This paper outlines the concept of ancient woodland as it has developed in GB, and how this idea gave rise to the ancient woodland inventories. The criteria used in compiling the inventories are discussed, including the inception dates and the threshold size, and the difference between ancient woodland and parkland. The inventories have been digitised for use with Geographic Information Systems (GIS), which has made them more accessible to planners and nature conservation bodies; however, the digitising process is more precise than the original definition of the boundaries of the ancient woodland. The three different countries have approached this issue slightly differently, taking account of the differing landscapes within which their ancient woodland exists. As the inventory developed, new legislation has also been brought into play to protect ancient woodland further. The inventory currently lacks detailed information concerning the condition or type of wood, beyond its semi-natural or plantation status. Ascertaining, and then maintaining, the condition of ancient woodland in Great Britain will be a major challenge for the future.

Introduction

In Great Britain (GB), ancient woodland is widely understood to be an area that appears to have been wooded continuously since at least 1600 (1750 in Scotland). These areas have all been managed in some way, which sometimes involved temporary clearance of trees by felling. In GB the terms ‘wood’ and ‘woodland’ are more commonly used than ‘forest’ for tree-covered land because ‘forest’ has, for us, become associated with large scale twentieth-century plantations of introduced conifers and also has a separate meaning as an area preserved in medieval times for deer, which might be totally tree-less.

The concept of ancient woodland can be traced back to at least the 19th century (Watkins, 1988), but was actively promulgated in this form about 30 years ago by Peterken (1977) and Rackham (1971), Rackham (1976). Ancient woods were perceived to be particularly important for nature conservation, and were also under threat from agricultural clearance, development and modern forestry methods. Rackham (1976) pessimistically believed that there would be almost no ancient woodland left by the turn of the century (i.e., 2000) except in nature reserves.

“Ancient woodland” includes all primary woodland, the lineal descendants of Britain's primeval woodland, whose wildlife communities, soils and sometimes structure have been least modified by human activities (Peterken, 1983). In places the patterns of their tree and shrub communities preserve the natural composition of Atlantic forests (Rackham, 2006, p. 87). They provide baselines against which to measure the effects of humans on, say, soils, productivity of woodland communities, and food-webs.

Peterken (1983) also noted that the wildlife communities are generally (but not invariably) richer than those of more recent woods. They contain a very high proportion of the rare and vulnerable wildlife species. Many of these species require the stability afforded by the continuity of suitable woodland. Where large, old trees have been present for several centuries they provide refuges for characteristic inhabitants of primeval woodland such as lichens. They are reservoirs from which the wildlife of the countryside has been maintained (and could be restored). Ancient woodland often contains other natural features which rarely survive in an agricultural setting such as streams in their natural watercourses and microtopographical conditions formed under periglacial conditions.

Ancient woodlands may have been managed by traditional methods for centuries and may show evidence of historical land-use (Peterken, 1983; Rackham, 1976). This has also been shown for continental woods: e.g. Ename Wood, Belgium, has records from the 11th century (Veheyen, Bossuyt, Hermy, & Tack, 1999); the structure of forests in the Kuhmo region, Finland (Wallenius, Kuukuvainen, Keikkilä, & Lindholm, 2002) reflects past burning history. This can aid our understanding of the effects of natural versus artificial processes on woodland systems. Woods and veteran (or “culturally modified”) trees may be considered as ancient monuments (Axelsson & Ostlund, 2001; Ericsson, Östlund, & Andersson, 2003) whose value to historians and village community consciousness is arguably as great as that of the older buildings in a parish (Read, 2000). Where traditional management continues or can be revived, ancient woods provide a living demonstration of conservation in the broader sense of a stable enduring relationship between people and nature (Peterken, 1983). Once destroyed, they cannot be recreated.

In the last 30 years awareness of ancient woods and their value has increased immensely, in part through the creation of the ancient woodland inventory, lists of all ancient woods greater than 2 ha on a county by county basis, a not insignificant undertaking; Rackham (1980) thought it would be too big a job to catalogue all ancient woods on a national scale. The inventory project was initiated in 1981 by George Peterken of the Nature Conservancy Council. The inventory has been maintained by its successors, English Nature (now Natural England), Countryside Council for Wales and Scottish Natural Heritage (Kirby, Reid, Isaac, & Thomas, 1998; Roberts, Russell, Walker, & Kirby, 1992; Spencer & Kirby, 1992).

The concept of ancient woodland and the inventory have become powerful tools in conservation policy. However, their future development and use needs to take into account how our understanding of ancient woods has changed since 1981, specifically:

• the likelihood that ancient woods are primary;

• degrees of semi-naturalness;

• where does woodland end and wood-pasture begin;

• how small can an ancient woodland be.

In addition, changes in technology affect how the inventory is maintained, updated and used in relation to other data sets such as registers of protected sites. In this paper we explore these ideas in turn, after a brief review of the methods used to compile the inventory during the 1980s.