THREE years ago, on a bright cold morning in May, I walked out into the Lewis moor for a day at the peats. I was meeting islanders who had dug each summer for years, had grown up with the annual toil, had grown to love it, and who were able to teach me some of the Gaelic peat-words which had come down from their distant forefathers. The slabs of peat, chocolatey when first cut, were fàds, and inside were rusty fibres, known as calcas, which could be smoked, in a fagless emergency, in lieu of tobacco. The fàds, stacked on the bank, are known as rùdhan. Later, I spoke to the artist Anne Campbell. She told me that, following the example of her late father, she always walks barefoot when going to dig peat, and she gave me a glossary of moorland terms which she had collected, among them the word ‘èit’ which has a beautifully precise meaning – the placing of quartz stones in moorland streams so that they sparkle in the moonlight and attract salmon.

 That word, and Anne Campbell herself, both feature in Robert Macfarlane’s Landmarks, a book concerned with landscape and language, and how the latter can illuminate the former and draw us to it, like that piece of quartz glowing moonlit, moorlit in a burn. Landmarks is, in Macfarlane’s phrases, a ‘word-hoard’ and a partial ‘Terra Britannica’. He has travelled Britain collecting local words for particular aspects of the landscape, in the manner of the blues field recordists of old, and presents them here, giving over around a third of his pages to a glossary which goes from ‘alpenglow’ (a mountaineering term for sunlight on summits) to ‘zwer’ (the whizzing sound made by a covey of partridges as they break cover) and contains around 2,000 other poetic and fascinating words, many of them in Scots and Gaelic. There are nine glossaries – Flatlands, Woodlands, Coastlands etc – and these sections in particular would benefit from an audiobook version, voiced by local speakers, so we can better appreciate the beauty of the words.

Their beauty is important. Macfarlane is not collecting for its own sake, but in the hope that greater familiarity with the language of nature will lead us to a greater intimacy with the natural world. He quotes a 2012 National Trust report that between 1970 and 2010, the area in which British children were allowed to play unsupervised had shrunk by 90 per cent. ‘Nine out of ten children can identify a Dalek,’ Macfarlane writes, ‘three out of ten a magpie.’ He notes, too, that the editors of the Oxford Junior Dictionary had deleted several words felt to be no longer relevant to the lives of children, among them bluebell, cygnet and mistletoe, their places taken by blog, chatroom and MP3 player. Macfarlane’s indignation at this is neither simple nostalgia nor horrified aestheticism. He regards the withering of our lexicon as both a counterpart and an exacerbating factor in environmental destruction: ‘Language deficit leads to attention deficit.’ If we do not have the words for things, we care about them a little less. If we do have the words, and if those words are themselves beautiful, even magical, then we may care a good deal more. It is Macfarlane’s mission to make us care, to equip us with the words to make us fall back in love with the land.

Is this fanciful? Perhaps not. He tells the story of the 2004 attempt by the British Energy and the engineering company AMEC to build a wind farm of 181 turbines on Lewis’s Barvas Moor, claiming that the scheme’s eventual rejection by the Scottish Government on environmental grounds was a victory for local campaigners, among them Anne Campbell, who had begun to compile the moorland glossary as a counter to those arguing that the peatlands were simply a dead wilderness. To make the moor seem valuable, it was first necessary to make it seem wonderful, and to do so by listing those words and stories which spoke of its long relationship with humankind.

What is true of the Barvas Moor is true of the rest of our landscape – and therefore while Landmarks is ‘a celebration and defence’ of language, it is also a shield and lance raised by a champion of the land. Its moral thrust is explicit in a way that had hitherto only been implied in Macfarlane’s previous books, but it is part of a strong tendency in his work. When he says, of the author Barry Lopez, ‘while writing about landscape often begins in the aesthetic, it must always tend to the ethical’, he could be discussing his own motivations. Macfarlane’s writing may, on rare occasion, have a touch of the questing vole passing feather-footed through the plashy fen, but only because he desires, through his elevated style, to ensure safe passage for the creature and richer future for all of us. If there is hope, he seems to say, it lies with the voles.

Since his 2003 book Mountains Of The Mind, Macfarlane has been a leading exponent of what an issue of Granta dubbed the ‘New Nature Writing’. His approach combines travelogue, memoir, science, history and literary criticism, all of it stewed together in lovely moreish prose. His writing is addictive but also functions as a gateway drug to other writers. His 2007 book, The Wild Places, for instance, included the story of WH Murray, the Scottish mountaineer, who in 1942 was taken prisoner by Rommel’s Panzer Division and spent years of starved captivity writing about Scotland’s mountains on scavenged sheets of toilet paper. Macfarlane’s next book, The Old Ways, a meditation on walking, was haunted by the restless spirit of Edward Thomas, the poet and essayist who was killed on Easter Monday 1917, aged 39, at the Battle of Arras.

Landmarks is an intensification of Macfarlane’s desire to pay tribute to the influence of others. It is, he writes, ‘a field guide to literature’ – an exploration of the lives and works of those writers whose writing taught him not only how to write about the natural world, but also how to see it properly in the first place. Certain books, he argues, are landmarks in our lives; they help us find our bearings in the world, our path through it, in much the same way as a particular summit or constellation might orient us on a moor.

The guiding stars of Landmarks include Nan Shepherd, the novelist and Cairngorms hill-walker who died in 1981; that particular chapter is a reworking and expansion of Macfarlane’s introduction to Shepherd’s The Living Mountain, reissued by Canongate in 2011. The book, Macfarlane notes, is full of imagery of weaving and interconnection – pine roots twisted like snakes, the ‘interlaced’ antlers of rutting stags – and he himself appears to have a deep desire to intertwine his work with that of earlier writers.

Macfarlane seems drawn, in particular, to those who seem to have struggled with depressive tendencies and for whom immersion in nature is a consolation. Edward Thomas, walking the South Downs in an attempt to escape the ‘crushing attacks of gloom and wretchedness’ that dogged him. Richard Skelton, the musician and writer with whom, in Landmarks, Macfarlane explores an unsettling tunnel in an abandoned quarry; Skelton, a ‘haunted man … drawn to haunted places’, began to walk and explore the West Pennine Moors in the aftermath of his wife’s death. JA Baker, author of The Peregrine (1967), whose obsessive personal identification with that bird, Macfarlane believes, grew out of his suffering from the painful chronic disease ankylosing spondylitis, a form of arthritis, grew out of a desire to leave his renegade body and fly free.

There is an answering sadness deep in Macfarlane’s writing. Every sentence carries a sigh. It’s that same sadness one feels at times in Glencoe or in the vastness of Sutherland, some mix of human absence and the presence of too much tragic history, and one wonders whether Macfarlane is drawn to these places by feelings of emotional kinship or whether the mood has simply got inside him over the years. Either way, he seems to understand it all too well and writes about it brilliantly. Melancholy, he says, ‘differs from grief in its chronic nature: it is an ache not a wound, it lies deeper down, is longer lasting, is lived with rather than died of. We might perhaps imagine melancholy hydrologically, as a kind of groundwater – seeping darkly onwards, occasionally surfacing as depression or anguish’.

An elegiac quality, a keening note, is characteristic of Macfarlane’s work. He can at times seem like an obituarist disguised as a naturalist. In The Wild Places he noted that between 1930 and 1990, over half of England’s ancient woodland had been cleared, or replaced by conifer plantation. In Landmarks he tells us that in half a century, Britain has lost more than 44 million breeding birds, fifty sparrows an hour for fifty years. Yet this is not an unhopeful book. Macfarlane says of the Victorian essayist and novelist Richard Jefferies that his writing functioned ‘as what might now be called a consciousness-raising exercise – an attempt to bring urbanites and suburbanites to a fresh awareness of natural beauty’. The same could be said of Macfarlane. He does not regard himself as being in the business of writing elegies; rather he is a poet-warrior of sorts, writing against humankind’s relentless land-taming advance, beating ploughshares into swords.

A father of two, Macfarlane concludes the main part of Landmarks with a chapter on what he calls ‘Childish’ – the language spoken by children, in which we were all fluent once upon a time. Children, he feels, perceive nature as we ought to see it – a place of possibilities, an imaginative and wondrous realm full of dens and doorways and stories, where a bluebell, whether in the dictionary or not, will always be more enchanting than a blog. He hears a child make up the word ‘honeyfurs’ for the soft seed-heads of wild grass and is moved. That is why the tenth and final glossary in this book has been left blank: it is for the words yet to come, coined by people yet to come, and the emptiness of those pages is an act of faith by a man whose feeling of profound emotional and intellectual companionship with those who came before him will, no doubt, be matched by writers and readers and walkers of the future who look back on Macfarlane’s tenderly attentive work and are inspired to set out on new paths of their own.