This book is about the early medieval (sixth- to twelfth-century) hill country in the present Belgian-German borderland. A trip on Google Earth shows that it is now about one-third forest and one-tenth the peat-bogs of the Hohe Venn (Hautes Fagnes); the remainder is agricultural land in fields divided by hedges and walls; settlements are mostly grouped into villages. In the early Middle Ages the forests, fields, and maybe villages were already there, though not necessarily in the same proportions as now: the book says little about the bogs. The principal landowners, beside Carolingian kings, were four Benedictine monasteries. Even in this quiet and seemingly remote area, life could be precarious: there was enough portable wealth to attract raids from both Vikings and Magyars. The land was thoroughly Christian, although people still remembered (or thought they did) when they had bowed down to ‘Diana’.

This book seeks to ‘explore the ways that the natural environment shaped monastic experiences and imaginations’, on the basis of a dozen or so surviving writings by monks of two of the monasteries. What is ‘natural’? Ellen Arnold, as an American, starts from the idea of Wilderness, rightly pointing out that it does not readily transfer to Europe. She then asserts that there is no real dualism between the wild and the domesticated: that there is no real separation between a garden tree and a tree in a natural wood. Here I disagree: my apple-tree is there because I put it there and because my ancestors brought its ancestor from its homeland in Kazakhstan; the native wild crabapple-tree in Hayley Wood is there because God put it there by the agency of a passing field-mouse. The dualism between domesticates and wildlife has been real since Neolithic times, even if not absolute. There are plenty of intermediates, but all students of the natural world are used to handling intermediates.

Some medieval writings at a low literary level show familiarity with natural objects, like the Anglo-Saxon charter perambulations that mention things like badger setts and a red-leaved oak and a crabtree when defining the boundaries of estates. Many others mention nature or pseudo-nature in a vague and tendentious way, often when they have some allegorical axe to grind. The two Bestiary manuscripts in my college library mix up familiar animals like hedgehog and ox, real but unfamiliar animals like elephant and vulture, and fabulous beasts like caladrius and tyger – and show hardly any interest in which is which.

Most of the surviving Ardennes writings appear to be of the latter kind. Unfortunately the author quotes only snippets, so the reader cannot be sure what exactly they say and what the Latin words mean. (She claims that terms like silua, nemus, boscus and even foresta were interchangeable; but does this mean any more than that these particular writers did not know their exact meanings, much as journalists today confuse their modern equivalents?) There is, however, one big book, originating in the ninth century, recording monastic management of land and a few perambulations. Even in this supposedly Dark Age woodland was not just wildwood. Monks used woodland on a huge scale: not just timber and coppice-wood and acorns for feeding pigs, but vast quantities of bark – it would have to be pine bark – burnt as torches for lighting. The author calculates that 100,000 trees were harvested annually for this purpose, which implies surprisingly much pine and a surprisingly rapid turnover. (English monks, having no pine-trees, were reduced to the ‘dim religious light’ of candles made from animal fat or beeswax.)

The author passes quickly over this uniquely early body of definite material to writings of a more nebulous character: about fifteen of them, comprising a chronology, Lives, miracles and translations of saints, and the letters of the great (but absentee) abbot Wibald. Little if any of this is directly concerned with nature.

As in many hagiographies, historical verisimilitude – let alone accuracy – is a subordinate consideration. The sources are works of fiction, historical mini-novels. They seem not to be great literature by the standards of any age. They are tediously verbose, copy shamelessly tales lifted from earlier tellers, cite topos after topos (sometimes traceable back to the scholastic platitudes of St Isidore of Seville), with an occasional display of the author's classical learning. Landscape plays a walk-on part in these stories: a landscape in which some places are nice (though it often takes many words to say so) and a few are nasty, all forests are the same, all fields are fertile, weather is sometimes terrible, and Satan lurks in odd corners. There is a tale of how a precursor of Shakespeare's Birnam Wood (significantly not named) marched to attack a precursor of Dunsinane. Beasts and springs play a part in the acts of the saints – but the wolves in the stories more often have two legs than four.

This is pious fiction, in which storms and springs and the occasional wild pig have parts written and re-written for them. Producing it hardly amounted to much of an interaction with nature. Still less can it be claimed that the Ardennes monasteries derived a particular religious identity from the forests, whereas Ely and Glastonbury (for example) took a different religious identity from their fens.

People who really understood nature, or listened to nature's version of the story, were seldom prolific writers. Maybe someone else wrote of a recognisable Ardennes, with lots of minor place-names, where the bank is whereon the wild thyme blows, which tree the owl sat in and which the nightingale, where fairies danced round Herne's Oak, where the dark wood was in which the straight way was lost, and other specifics of familiar beloved (or even hated) places. If anyone did, the writing has not survived. The author is a persevering scholar, writes well, has copious and instructive endnotes, and has done wonders with a difficult research project. I hope she will go on to apply her insight and ingenuity to more tractable source material.