Ancient Trees in the Landscape

Norfolk's arboreal heritage

Gerry Barnes, Tom Williamson, Tom Williamson

• Publisher: Windgather Press
• Year: 2011
• eBook ISBN: 9781905119592
• Topic: Social Sciences
• Subtopic: Archaeology
• Index: Social Sciences

Ancient Trees in the Landscape is the outcome of many years research into the history of trees in Norfolk, and represents the first detailed, published account of the ancient and traditionally managed trees of any English county. Yet it is far more than a regional survey. It is an exploration of how trees can be studied as part of the landscape. It discusses how accurately trees can be dated; explains why old trees are found in certain contexts and not in others; discusses traditional management practices and how these changed over time; and looks at the various ways in which trees have been used in parks and gardens. Above all, it considers how trees were regarded by people in the past, and how this has affected their survival to the present. Ancient Trees in the Landscape is a fascinating and original study which sets out a new agenda in landscape history. It will be essential reading for countryside managers and conservationists, and for all those interested in landscape history, arboriculture, and the history of the English countryside.

CHAPTER ONE

Ancient Trees in the Landscape

Introduction

This book is about the trees which grow in one particular English county, Norfolk. It is largely – although not exclusively – about the larger, older specimens, and about those which have been managed in the past in ‘traditional’ ways. Yet although it deals in detail with only one, relatively restricted, area of the country, we believe that the work presented here has a wider relevance. While each region of Britain has its own, distinctive, arboricultural history the approaches and methodology adopted in this book can be applied elsewhere, and some of our general conclusions may well hold true for other areas, especially in the south and east of England. This is not, therefore, simply a book about old trees in Norfolk. It is about some of the ways in which we can study old trees.

Many people have written about the history of trees in the British landscape: historical ecologists such as the eminent Oliver Rackham; historical geographers such as Charles Watkins and Stephen Daniels; and landscape historians, especially Richard Muir (Rackham 1976 and 1986a; Petit and Watkins 2003; Muir 2005; Daniels 1988). The Tree Council has done much to draw the public’s attention to the importance of our ‘heritage trees’, in part through the work of the Ancient Tree Forum (Fay 2002). It has sponsored a national volunteer survey (the ‘Ancient Tree Hunt’) (Thomas 2007) and published numerous articles on the subject in Tree News, as well as supporting the publication of Stokes and Rodger’s informative and lavishly produced The Heritage Trees of Britain and Northern Ireland (Stokes and Rodgers 2004).

This book differs from most of those earlier studies in a number of respects. In particular, we are concerned above all with the landscape context of trees: with the questions of how, and why, particular kinds of old tree are found in particular places, what this has contributed to the character of the landscape, and what it can tell us about the ways in which trees were managed and regarded in the past – what trees meant to people in earlier periods. It is thus based on the results of a number of detailed systematic surveys and research projects which have been carried out over the years at the University of East Anglia, studies which – precisely because they have focused on one limited (if geographically diverse) region – allow us to tease out some of the complex links between the trees we see today and wider aspects of human and natural history. These links are perhaps less obvious when the subject is considered on a wider spatial canvas, or when trees are studied in isolation from the surrounding landscape. John White, in the title of one of his important articles on veteran trees, posed the question: ‘What is a veteran tree and where are they all?’ (White 1997). The research presented here attempted to answer a related but slightly different question: ‘Where are all the veteran trees and what are they doing there?’

The most important of the projects whose results are presented in this book was a systematic survey, generously supported by the Heritage Lottery Fund and carried out over a number of years by volunteers, students and the authors themselves, of old trees in the county: broadly defined as all trees which have been pollarded in the past (Figure 1), have a circumference in excess of 4m, or which are noticeably old examples of their particular species. Details of over 5000 such trees were recorded and, while the survey did not aim to discover every example in Norfolk, coverage was fairly even in spatial terms, and the results seem to provide a good indication of the ways in which the age and character of our older trees varies across the county. The results of a number of smaller surveys, carried out by individuals and groups, were also made available to us. These included information collected by the Farming and Wildlife Advisory Group in connection with Higher Level Stewardship schemes, and by members of Norfolk County Council’s countryside team as part of their work; surveys made for the various District Councils in Norfolk of veteran trees in the areas under their jurisdiction; an important survey of the trees found in the county’s churchyards, carried out under the aegis of the Norfolk Wildlife Trust; and a detailed record of all the trees on the National Trust’s Blickling and Felbrigg estates. In addition, during the late 1980s and early 1990s a number of tree surveys were undertaken as part of a wider study of the history of designed landscapes – parks and gardens – in the county, the full results of which have been published elsewhere (Williamson 1998). Although recording the character of the surviving planting formed only a small part of this project – and in only a limited number of cases were park and garden trees recorded in systematic detail – this survey also provided much information about changing fashions in planting and management. The current volume also draws on recent research into the history of orchards in the county, carried out largely by Patsy Dallas, and into the ‘contorted pine rows’ which form so distinctive a feature of the landscape of the sandy district of south-west Norfolk (and north-west Suffolk) known as Breckland. Lastly, we include here some discussion of the preliminary results of a programme of research, likely to continue for several more years, into the history and archaeology of ancient woodland in Norfolk.

FIGURE 1. The distinctive shape of this pollarded oak near Hethersett is particularly clear in the winter snow.

FIGURE 2. Soils and soil districts of Norfolk referred to in the text.

Norfolk is a particularly good area in which to undertake a systematic study of old trees. In spite of some descriptions of the county’s landscape as flat, dull and uninteresting, Norfolk is in fact very varied not only topographically but also in terms of its geology and soils. The only extensive areas of truly level terrain are to be found in the far west of the county – the drained wetlands of Fenland and Marshland – and in the east – the Halvergate Marshes (Figure 2) – although some parts of the boulder-clay plateau running through the centre and south of the county are also flat over several square kilometres of ground. Elsewhere, the land is either gently rolling or – in parts of the north and west especially – positively hilly. The soils are likewise diverse, ranging from silts and peat on the lower ground, through acid sands (most notably in Breckland) and damp boulder clays, to the fertile loams of Flegg and the north-east. But, as we shall see, it was less the intrinsic character of soils and topography, so much as the human landscapes of fields, commons, parks and settlements which these engendered, that have had a determining influence on our legacy of old trees.

FIGURE 3. Some of the principal places in Norfolk referred to in the text.

Types of tree

Trees can be managed in a number of ways. They can be grown as maidens or standards – that is, left to grow in a natural way or with only minimal pruning. Such trees might be primarily ornamental specimens, in gardens or pleasure grounds or scattered across the open turf of a park; or they might be grown primarily for timber (large pieces employed in the construction of buildings and ships), in which case they were usually, in the past, felled when mature, in the case of oaks at between 80 and 100 years of age (Rackham 1986a, 65–7). Timber might be widely dispersed across the landscape, in hedges, parks and pastures; or it might be grouped into woods and plantations. Traditional woods were mainly, however, managed as coppice-with-standards: that is, the majority of trees and shrubs were coppiced, being repeatedly cut down to a stool at or near ground level on a rotation of eight to fifteen years, from which they rapidly regenerated to produce wood in the form of straight poles of the right size and shape for fencing, firewood, tool handles, minor structural elements in buildings and a host of other domestic uses (Rackham 1976; 1986b). Standard trees were also grown in such woods but they were usually quite widely spaced, at least in the period before the nineteenth century, for the shade cast by their canopy tended to inhibit the growth of the coppiced understorey beneath (Barnes 2003). Livestock were rigorously excluded from woods, or allowed in them only at certain times or under close supervision, because they would browse off the regenerating coppices and suppress their regrowth, ultimately destroying them. In other situations, where stock could not be so excluded, wood was produced from pollards. These were, in effect, aerial coppices, raised on a trunk, or bolling, at a height of around 2–3m, and thus out of the reach of browsing animals. Pollards could be grown in hedges or thinly scattered across pasture fields, but they might also be grouped into areas of wood-pasture, in which animals were regularly grazed but wood (and timber) were also produced. As we shall see, the majority of trees more than two centuries old in the Norfolk countryside, as elsewhere in England, are former pollards. Most have not been cropped for many decades – usually for more than a century – but they can still in most cases be easily recognised. A short (c.2–3m) trunk is topped by an area of damaged, calloused bark, from which the main branches of the tree all rise (Figure 4). Pollards may also have been used to provide browse or fodder for livestock, and this may have been the main function of shreds. These were trees from which the side branches were systematically removed to leave a small tuft at the top, a form of management probably adopted to encourage the development of twiggy, epicormic growth down the stem of the tree. Shredding seems to have been common in East Anglia before the seventeenth century, but declined rapidly thereafter. The documentary references available to us make it clear that pollarding was usually carried out in the winter months, when leaves were off the trees; but if trees were being managed as a source of browse it presumably took place during the summer.

FIGURE 4. An old oak pollard in the park at Heydon in north Norfolk.

Our interest is primarily with old trees, but this raises some tricky questions of definition. Many common tree species in Norfolk, as elsewhere, were traditionally managed in such a way that they always remained, in effect, as low shrubs or bushes. Ash, for example, is relatively rare as an ancient tree, but many thousands of ancient stools, kept low for centuries (and often to this day) by regular coppicing, exist within the understorey of traditional woods or as part of hedges. We discuss some examples of ancient coppices and similar features in the course of this book, but our main focus is firmly on trees, whether maidens or old pollards: that is, on specimens with a fully formed trunk or bolling.

Because our interest is in both ancient trees and trees managed in traditional ways, the surveyors whose data provides the basis for much that is written here were, as already intimated, asked to record three main kinds of tree. Firstly, they noted all large specimens, roughly defined as any tree with a girth (or circumference), measured at waist height, of 4m or more. Secondly, they were asked to record all trees, regardless of size, which appeared to have been managed in the past by pollarding or shredding – what we term throughout this book ‘traditionally managed’ trees. Lastly, they were asked to note trees which, while smaller in girth than 4m, could nevertheless be regarded as of ‘veteran’ status.

FIGURE 5. A veteran elder in a hedge at Wymondham in south Norfolk. Trees do not have to be ancient to be of ‘veteran’ status: veterans are simply examples which are old for their particular species.

Veteran trees and biodiversity

We have already had cause to use the term ‘veteran’, which perhaps requires some explanation. It was coined and is principally employed not by landscape historians but by natural historians and arboriculturalists. In essence, a veteran tree is one which is not necessarily very ancient in terms of years, but which is an old example of its particular species (White 1997; 1998). While a veteran oak will thus be several centuries old, a silver birch will seldom live for more than a century and a half, making an example a hundred years old a ‘veteran’ specimen. A veteran elder might be younger still, perhaps no more than forty or fifty years of age (Figure 5). Whatever their species, however, veteran trees are of crucial importance because they provide a range of habitats, not otherwise generally available, for a wide variety of plants and animals. They contain rotten wood, cavities, cracks and crevices which are home to rare lichens, fungi and beetles, and even to larger fauna, such as owls and bats (Briggs 1998; Kirby and Drake 1993; Orange 1994; Read and Frater 1999; Read 2000; Rose 1991) (Figure 6). They are particularly important because the natural environment of England, before human intervention, included substantial areas of wooded ground within which numerous trees grew old, died, fell and rotted, in contrast to their usual fate in later centuries, when they were often felled at economic maturity or cleared away and tidied up if brought down by natural causes.

FIGURE 6. Veteran trees usually have numerous cavities and hollows which provide homes for owls, bats and a range of other vertebrates.

Interest in veteran trees has grown steadily from the last decades of the twentieth century, fuelled in part by the books of writers such as Thomas Pakenham but more generally by an awareness of the importance of such trees as habitats (e.g. Morton 1998; Muir 2005; Pakenham 1996; Stokes and Rodgers 2004). English Nature’s Veteran Tree Initiative was launched in 1996 and, while this came to an end in 2000, interest in the subject was maintained though the ‘Lowland wood-pasture and parkland habitat action plan’. As a consequence of these initiatives the importance of ancient trees for biodiversity is now much more widely recognised by landowners, land agents and farmers, although poor management decisions about them are still sometimes made (as detailed in Green 2001, 166, and Green 2002).

A number of organisms are peculiarly associated with old trees, including a range of fungi which live off and destroy the old dead wood, degrading it in a variety of ways at cellular level to produce different kinds of decay. These can broadly be divided into white rot, in which the cellulose, lignin and hemicellulose in the wood is broken down; red and brown rot, in which the lignin remains intact but the cellulose is degraded (leading to the eventual formation of thick humus wood mould); and soft rot, in which cellulose, hemicellulose and lignin are all broken down, together with the cell walls. All these different forms of rot themselves provide habitats for a wide range of invertebrates, many extremely rare. At the same time, the fungal mycelia and fruiting bodies provide food (and often a habitat) for invertebrates and – by eventually leading to the hollowing of the trunk – for a number of vertebrates.

Invertebrates associated with ancient trees generally exhibit poor mobility: some are poor flyers, others are completely wingless. They are also, with a few notable exceptions, poor at breaking down cellulose and lignin, the main components of wood, and thus rely on the fungi (and other micro-organisms) to break it down for them. It has been estimated that there are no fewer than 1700 different species of invertebrates in Britain which depend on decayed wood for at least some of their life cycle (Alexander 1999, 109). The dependence of such saproxylic species can be direct (in that they feed on the fungi which decomposes the wood) or indirect (in that they predate on the former). Invertebrates also depend on such things as the loose bark and water-filled pockets which are characteristic of ancient trees. Large numbers of saproxylic species have been recorded from veteran trees in Norfolk, among which are twenty-two species of beetle, including extremely rare varieties such as Agathidium confusum (Collier 2001).

Veteran trees are also host to a range of lichens, many of which are, once again, largely restricted to this habitat and in particular to old trees growing in wood-pastures and parkland, where open glades provide the mixture of light and shelter which they need to thrive. The decayed structure of ancient trees, featuring numerous cavities, irregularities, areas of peeling bark and broken boughs, as well as the ‘bark fluxes’ caused by fungal or bacterial action, also provide an ideal range of niches for these often demanding organisms (Kirby and Drake 1993; Coleman 2002). Among the rare or unusual lichens found on veteran trees in Norfolk are Lecanactis lyncea and L. premnea. Some true plants – mosses such as Zygodon forsteri, liverworts and ferns – also grow on ancient trees, exploiting the fact that the irregularities in the bark surface provide shelter and permanently damp areas, while the often open canopy, punctuated by decayed branches, allows light to reach them. Snails and slugs such as the tree snail Balera perversa, feeding on both fungi and various mosses and ferns, also flourish, as do larger fauna, especially bats: of the fourteen species of bat found in Britain, twelve rely on trees, especially old trees, for shelter and/or food. Birds, especially owls such as the barn owl, nest in the numerous holes created as old trees decay. Mammals such as the stoat, weasel and dormouse also find shelter in ancient trees, while reptiles such as the great crested newt (Triturus cristatus) make their homes in cavities beneath loose bark and feed off the insects living there.

In short, veteran trees are host to a wide variety of plants and animals, reflecting both the extraordinary range of niches and habitats which they provide and the fact that, as has already been noted, much of our indigenous wildlife is adapted to an environment in which – as was presumably the case in the British ‘wildwood’ before the clearances, management and general ti...

Table of contents

• Cover
• Title
• Copyright
• Contents
• Abbreviations
• Acknowledgements
• List of Figures
• Chapter 1
• Chapter 2
• Chapter 3
• Chapter 4
• Chapter 5
• Chapter 6
• Chapter 7
• Bibliography