Posts Tagged ‘fire management’

‘The Environment of Early Man in the British Isles’

February 12, 2014

http://www.pendleburys.com/shop_image/product/166557.jpg

I recently learned a lot from reading this book, which was recommended by a commenter under one of George Monbiot’s rewilding articles. It was published back in 1975 so I’m not sure how much of it still holds true or whether there has been much development or debunking of the theories he presents from various scientific disciplines in the time that has elapsed since. But I can say that it made a lot of sense to this reader, who found it eye-opening, provocative and highly informative (if a little heavy-going at points) nearly forty years after it was written.

The main thing it got me thinking about was this polarisation of whether human cultures are ‘meant’ to exist in a largely open or closed environment – basically the choice between grasses and trees which we talked about before. Evans makes clear that this isn’t a simple delineation between forest-dwelling hunter-gatherers and field-based farmers. In fact there have been very large differences in the patterns of subsistence adopted by hunter-gatherers in this land even before the arrival of agriculture, around 6,000 years ago, heralded the more active management of the land with which we’re familiar today at its totalitarian extreme. The main cause for these differences was the background climate, to which prehistoric man adapted along with all the other creatures in the surrounding ecology. Evans separates them into two main types – the Upper Paleolithic (old stone-age) cultures, who hunted herds of large game feeding on the grasslands that prevailed during the glacial Devensian period between 70,000 and 10,000 years ago:

In the Mendips, pollen analysis of cave deposits indicates values of between 25 and 40 per cent trees and shrubs, mainly birch and willow. An environment of park tundra—scattered birches in a generally open landscape, but with denser woodland in the sheltered valleys and ravines—can be envisaged for much of Britain at low altitudes. A fauna similar to that prior to the Full Glacial was present with large herbivores predominant. Horse and reindeer appeared early in zone I [beginning 14,000 years ago]; elk was present by zone II [10,000 years ago], and in Ireland [...] the Allerød period [ie:  zone II] is characterized by the giant Irish deer. But the mammoth, wooly rhinocerous, hyena and lion were all absent, for some reason not having been able to return to Britain after the glacial maximum [...]

In Britain, faunal evidence suggests horse often as important or even more important than reindeer for food and raw materials [haha!]. Abundant herds of horse were probably available along the upland/lowland contact zone as indeed they would be today in the High Altai of Mongolia were it not for modern man [...] The tundra vegetation, on which low temperatures and a short growing season were limiting factors, was not directly exploitable for food on a large scale by man, although seeds and berries were doubtless eaten. But the reindeer and the horse were ideally suited to it and it was through these animals that man’s livelihood was largely gained. (pp.51-3)

and the Mesolithic (middle stone-age) cultures who lived in the forested environment favoured by the more temperate climate of the ‘post-glacial’ which began around 10,000 years ago and continues to the present day:

Man responded to these changes variously. He adopted his methods of hunting to the pursuit of individual animals rather than herds and began to make greater use of the bow and arrow. He widened his range in the quest for food and became less specialized, pursuing a grater variety of animals than in the Ice Age. It is inevitable too, although we have little evidence for this, that a more varied plant diet was exploited than was possible in the sub-arctic tundra.

The earliest forest-dwelling Mesolithic culture in Britain is the Maglemosian, named after the type sit of Maglemose (literally ‘big bog’) in Denmark. It is classically associated with forest, marsh and reed-swamp habitats, and, as far as we can tell, adapted readily to the changed environment of early Post-glacial times [...] The best-known Maglemosian site is Starr Carr where the main animals exploited were red deer (80 examples), roe deer (33), elk (11), ox (9) and pig (5), a fauna reflecting the prevailing forest vegetation. Other animals present were the pine marten, hedgehog, hare, badger, fox, beaver, and domestic dog. (pp.87-8)

Of course, these differences depicted among modern humans (Homo Sapiens has been in Britain for around 40,000 years) probably apply to the different cultures among earlier subspecies, Neanderthalensis, Heidelbergensis and Antecessor, (among others?)  who would have lived through similar swings in climate and either changed their subsistence accordingly, migrated to more favourable climates or become locally extinct. For example the recent news of human footprints and artifacts discovered in Happisburgh on the Norfolk coast, and dated to between 800,000 and a million years ago, mentions a background climate where:

[...] the local vegetation consisted of a mosaic of open coniferous forest of pine (Pinus), spruce (Picea), with some birch (Betula). Alder (Alnus) was growing in wetter areas and there were patches of heath and grassland. This vegetation is characteristic of the cooler climate typically found at the beginning or end of an interglacial or during an interstadial period. (from the original paper)

In other words much closer to the kind of environment where we can expect subsistence on herds of large herbivores rather than smaller forest-dwelling individuals.

Evans wears his prejudices on his sleeve when it comes to describing what the resulting human cultures were like, and appears to see a narrative of progress linking the open-environment people of the Upper Paleolithic to the Neolithic farmers, with the woodland Mesolithic people presented as an unfortunate intermediate stage where nothing much happened, possibly because their environment wasn’t ‘challenging’ enough. Compare the concluding paragraphs to his chapters on the two periods:

The Later Upper Paleolithic peoples endured in western Europe for over 4000 years. With their cave art, their carvings, their tools and weapons of extreme beauty, their sophisticated annual migratory movements and their possible near domestication of the reindeer and the horse they drew from Western Europe and gave to it a fitness and a legacy which was not to be surpassed until the introduction of agriculture—and some would say never. The possible future of these communities had the Late-glacial environment been maintained is totally speculative. But there is little doubt that the Post-glacial amelioration of climate and the eventual spread of mixed deciduous forest drove the reindeer herds northwards and broke up one of the finest and most successful life styles ever known. (p.54)

[...]

This then is the environmental background to the early Post-glacial hunting communities of Britain—a warming climate, a rising sea with yet marshy extensions to the east and links with Europe, an increasing variety of game and plant food, and the spread of all pervasive forest—conditions quite different from those experienced by Upper Paleolithic man. These changes may have had a very great psychological impact on man, the equable conditions and diversity of habitats and food supply both obviating the need for specialization and also retarding development [...] it is a fact that not only in Britain but in Europe as a whole Mesolithic man has left little of artistic wealth. We have few clues to his beliefs, and burials, apart from a few examples such as the horrible nests of human skulls at Ofnet in Bavaria, are rare. There is nothing of the brilliance of the Upper Paleolithic hunters living as they were in the stimulating landscape of the Ice Age, nor anything of the vital urgency with which later farming communities were to settle and cultivate the lands of western Europe and the British Isles. (pp.89-90)

This may relate to his personal politics which he lays bare at the end of the final chapter, which left a bad taste in my mouth for several days. After describing the horrors of soil erosion, whereby, because of agriculture and the removal of field boundaries, hedges etc. ‘[w]e are, in effect, returning to an almost ‘Late-glacial’ landscape of steppe, pasture and bare ground, with processes of physical erosion—dust storms and ‘solifluxion’—rife’, the topsoil ‘lost, literally in a day’ through wind erosion, he then questions the value of environmental organisations and conservation efforts, asking:

Do we have the right to lay down the requirements and attempt to mould the environment of the future? And in doing so, are we not betraying earlier, and more important, future generations of man? [...]

By attempting to maintain the environmental status quo are we not denying ourselves and our progeny the opportunity and the ability to exploit challenging new environments both created by our own industrial and agricultural needs and by natural climatic shifts? Evolution depends on environmental stimulus, and the most successful groups of man have arisen in response to specialized simplified environments. If man had declaimed in the past at the felling of the forest he might still be at the Mesolithic stage of development. If there had been one of the specialized periglacial habitats, the brilliant Upper Paleolithic may never have emerged. And had there been none of the rigours of a cooling Pleistocene climate, there may well have been no man. (pp.186-7)

I don’t think this can be forgiven just because it was written the 70s. There’s some seriously insane thinking going on here, alongside the falsity of viewing evolution in terms of linear progress. Maybe he’d appreciate the ‘challenging new environment’ of the oil-soaked Gulf of Mexico, or defoliated, dioxin-laced Vietnam, or a tar sands trailing pond, or an ocean stripped of phytoplankton because of the greater acidity caused by excess CO2 in the atmosphere?

Canadian oil sands sitefancy a ‘challenge’? – source

He doesn’t appear to understand that civilised man has already done more than anyone to ‘mould the environment of the future’ – a largely desertified, if not entirely dead planet, but, unbelievably, his ire is directed at environmentalists who are trying to check this destructive ‘simplifying’ process. What gives them the right to try and preserve the rich, generous biodiversity that the natural world has tried so hard to bestow us with?

Anyhow, back on the subject of open vs. closed environments, there may yet be some truth to Simon Fairlie’s comment about ‘the health of the human psyche’ depending on ‘keeping land open to wind and sunlight’ which I criticised at the above link. Remembering the story the photographer Guy Hand tells in ‘The Forest of Forgetting‘ (pdf) about trying to introduce his Scottish wife to the pine forests of his native Idaho, I assumed that this was an attitude born from an abused landscape:

The instant we climbed out of Idaho sagebrush and into a dense stand of pine, in the Sawtooth Wilderness Area, I knew something was wrong. Mairi fell silent. Her pace slowed. I glanced over my shoulder to find the distance between us filled with shadow and half-light. She had hunched her shoulders and dropped her head. She moved with the wary posture of stalked prey. As she passed through a saber of light I could clearly see the fear in her eyes. I waited for her, but she walked past, pointed to a clearing, and by way of explanation, whispered, “too many trees.” Neither of us had known, until that moment, that Mairi held a secret dread of wooded land.

I felt as if I’d failed her, unable to convey the closed-in sense of sanctuary I’d always felt in that forest, the way, even as a child, the thick mat of pine needles and jigsaw bits of bark felt luxurious under my feet; the way the trees provided shelter against wind and mid-day glare; the way sounds were both softened and clarified; the way air held the sweet scent of pitch and the flutter of wings.

On the scree and boulder slopes above tree line, the tension drained from her face. She looked off into a landscape she could again understand: open country, treeless country, country filled with nothing more than grass, rock, and sky. It was only later, after peering more deeply into her Highland past, that we learned forests were part of her history, too, a forest lost to centuries of forgetting.

But the evidence shows that even woodland people also value open landscapes, whether we’re talking about the Native American practice of using fire to maintain the so-called ‘Oak Savannah’ habitats*, rainforest people clearing temporary patches to grow manioc and other vegetables, or the density of prehistoric artifacts found around ancient floodplains or other areas such as lakes or coastlines kept open through ‘natural’ causes:

spey

Over the past 200 years, rivers like the Thames have been embanked to prevent flooding, and the flow of water controlled by locks and weirs. Formerly their course were braided, i.e. split up into several channels which meandered over a broad flood plain [...] For agricultural peoples such a system of braided channels is wasteful of land, and artificial control has been imposed at various times in the past on river systems in the most heavily farmed areas of the country. But from the point of view of Lower Paleolithic man such conditions were ideal. They provided tracts of open ground in an otherwise forested country with the obvious advantages of defence against predators such as the lion, and of concentrating herds of game such as deer, oxen, horse and elephant attracted to the river valley for water. The variety of habitats—open water, reed swamp, woodland, and, as we shall see, at one stage, grassland—together with the variety of game animals both large and small obviated the need for specialization in hunting and food-gathering techniques, and presented man with what was probably a relatively congenial existence. (pp.3-4)

Perhaps climate change-induced flooding of the kind which low-lying areas in Britain have been recently experiencing will force a return to this kind of habitat?

Somerset flooding

There is also some evidence for the use of fire in the opening up or maintenance of favourable hunting grounds. Apparently the man to check out is Ian Simmons, who wrote a 1996 book called The environmental impact of later Mesolithic cultures. Earlier writings of his having to do with the relationship between fire and the ‘vegetation changes associated with Mesolithic man in Britain’ and ‘Environment and early man on Dartmoor’ (both published in 1969) are summarised by Evans thusly:

simmons

Forest glades around springs and streambanks are seen as initial nuclei of open ground, created by animals coming to drink. The dual attraction to Mesolithic man of both water and game in these areas was probably exploited, and their enlargement by burning a logical follow up which in turn would have attracted more game animals. Game avoidance of the area or overkill by man may then have led to desertion of the clearing and subsequent regeneration of woodland. (p.97)

Where this happened on poorer soils it is seen as evidence that Mesolithic people were capable of permanently degrading the land in certain areas to the point where the trees wouldn’t regenerate and only heath- or moor-type plant communities could survive.

Fire is also mentioned whenever the discussion turns towards Hazel – higher representations of which in the pollen records are said to represent either spontaneous or human-encouraged conflagrations because ‘Hazel is a fire-resistant tree, springing up readily from burnt stumps’ (p.81).

[A.G. Smith, 1970] argues that the prevalence of hazel during the Boreal period [increasing warmth 9500-7500 years ago]  may too have been engendered by the continued use of fire. It is perhaps significant that the hazel maximum in the Post-glacial falls at a much earlier stage in relation to the climatic succession as a whole than in previous interglacials.

The purely climatic origin of the vegetational changes in the Boreal/Atlantic transition ['climatic optimum' starting around 7500 years ago] has also been questioned, largely on the grounds that they are so often exactly synchronous with layers of wood charcoal and Mesolithic flint artefacts [...] A secondary hazel maximum occurring around the Boreal/Atlantic transition, and occasionally coinciding with an increase of herbaceous pollen, is perhaps further evidence for widespread human interference with the vegetation at this time. (pp.100-1)

Herbaceous pollen, eh? This has echoes of the Indian practices we mentioned before*, in which fire is used to favour the growth of ‘bulbs and greens’ under a relatively open tree canopy – Hazel coppice, both in their neglected and actively managed states, around where I live have a lot of ground flora, probably due to the greater amount of light filtering through (although I understand he may not be saying the tree & herb pollen came from the same sites). Unfortunately Evans doesn’t consider that Mesolithic people might have been deliberately managing stands of Hazel for a nut crop, as more recent research has begun to explore†.

I felt a weird, nagging sensation while studying the many charts comparing the pollen representation of various plant species in the archaeological record. Here’s a simple one detailing the transition to Neolithic cereal farming at Barfield Tarn, ‘a kettle hole on the south-western edge of the Lake District’ (p.111):

pollen

Evans talks about the decline of Elm, which most researchers accept as diagnostic of the rise of farming, whether through introduced diseases, use as fodder for livestock until exhausted or deliberate clearance (as it often occupied the soils most suitable for cultivation). In this diagram the trees, with the exceptions of Oak and Elm, don’t appear to suffer that much from the ‘two episodes of land use’ although we are assured that ‘[r]egeneration of woodland did not occur’ (perhaps after the depicted period?) Anyway, what struck me as a forager looking at these diagrams is that, while I make extensive harvests from trees themselves, most of the plants that I would consider useful in a culinary sense – Plantain, Dandelion, Sorrel, Fat Hen, Nettle and mustard species – only become prevalent along with the grasses and cereal crops favoured by the Neolithic farmer/herders. I too have adapted to an open landscape! In reality, unless we accept the active fire management scenario described above (or the more passive attraction to ‘naturally’ open spaces), it seems likely that these ‘weed’ species were, if not entirely absent from Mesolithic diets, then much less abundant in their environment than they are today. Chris Thomas of York University’s biology department has made similar points (pdf) drawing on his knowledge of butterflies, summarised here by Mark Fisher:

[Thomas] sought to ask why so many animal and plant species in Britain, and in some other parts of northern Europe, are restricted to open habitats when the majority of the landscape would naturally be forested? He observed that most open-country species would have survived the mostly wooded state of the mid Holocene in the open areas of inland and sea cliffs, dunes, coast and lake shores, and possibly river-valley grasslands, fen, bog and mire, as well as above the tree-line, without the need to invoke major modification of the vegetation by large herbivores. They would have colonised twice: in the early Holocene after the ice receded but failing to persist once tree cover asserted, and then again after the trees were cleared for agriculture. Thus what ever the date of arrival, current distributions largely reflect recent conditions. In addition, the rates at which we see modern distributions adjust to new environmental conditions are sufficient to allow most animal species to assume new distributions within Britain in a few hundred years if conditions change. Current distributions thus reflect recent anthropogenic habitats far more strongly than they reflect the longer-term history of natural populations. (‘What is rewilding?‘)

Evans has plenty to say about the effects of agriculture once it arrived in Britain, and he charts the various technological developments that ensued as well as the negative environmental impacts it had, especially on the soil. He follows these effects right through to the historical period and the modern day, often showing how patterns of land use laid down in earlier times often strongly influenced the organisation of human settlements which we recognise today. Perhaps I’ll come back to explore this properly another time, but for now suffice it to say that nothing in this book has fundamentally altered my understanding of agriculture as ‘a regressive rather than a progressive evolutionary event’ (to use the words of Oak enthusiast David Bainbridge).

[Above images print-screened from the google preview of the book]

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* – ‘There was considerably less chaparral and underbrush [in aboriginal times], due to the Maidu practice of burning off the areas near where they lived each fall and winter. They preferred an open, grassy, oak savannah habitat for several reasons. Open country is much easier to travel in than country with thick underbrush; it is easier to find game and harder for enemies to sneak up on the camp. More bulbs and greens grow in such an environment, and it is easier to gather acorns on bare ground.’ – anthropologist John Duncan, quoted in Kat Anderson’s Tending The Wild, p.288

† – for example: ‘The Late Mesolithic phase is defined by the repetitive application of fire to the woodland to encourage a mosaic of productive vegetation regeneration patches, consistent with the promotion of Corylus [Hazel] and to aid hunting. In this phase, weed species including Plantago lanceolata [Ribwort Plantain], Rumex [Dock/Sorrel] and Chenopodiaceae [Fat Hen/Good King Henry] are frequent, taxa which are normally associated with the first farmers.’ (from the abstract to ‘Late Mesolithic and early Neolithic forest disturbance‘ – anyone with access to the full paper please get in touch!)

Fertility – Less or More?

June 22, 2012

A few of us have been discussing, among other things, soil fertility, pastoralism, deforestation, reforestation, agriculture (of course) and permaculture-type solutions for restoring the ecologies impoverished by this culture over on this Leaving Babylon thread. Here’s my most recent contribution on the topic of soil fertility vs. conservation:

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I’ve been thinking lots lately about this issue of soil fertility. On the one hand we’re living through a period of extraordinary fertility thanks to the nitrates and phosphates in petroleum-based fertilisers – ‘more atmospheric nitrogen is fixed by man (as fertilizer) than by all natural sources combined’ (Ken Thompson, No Nettles Required, p.160) – and all gardening and farming is geared towards maintaining or increasing this. And on the other hand we have a legacy of plant and animal species uniquely adapted to the impoverished soils resulting from hundreds/thousands of years of intensive, organic farming, grazing and forestry; a biodiversity that dies out when the soils get too fertile or specific management practices are discontinued. Here’s Michael Allaby writing in the Woodland Trust’s Book of British Woodlands:

The trees that are coppiced regenerate and go on regenerating for a very long time: far from injuring them, coppicing seems to extend their lifespans, so they become an almost perpetual source of wood. Chemically, the wood is composed of substances obtained from the air and soil, like any part of any plant, and cropping removes those substances. Livestock grazing among the trees returned some plant nutrient, but they, too, were removing vegetation by their grazing. The overall effect is a slow but steady export of plant nutrient and a decline in the fertility of the soil. This makes it sound as though the coppicing system is harmful, but harmful to what, or whom? Some plants are better than others at exploiting rich supplies of nutrient. Feed them well and they grow vigorously and, in relation to the plants around them, aggressively. On a fertile soil, therefore, the natural succession by which plants colonise an area will proceed fairly quickly to a situation in which a small number of aggressive species dominate the vegetation.

On a less fertile soil this cannot happen, because the aggressive species are denied the nutrients they need for more vigorous growth. This allows the less vigorous species, with more modest requirements, to thrive. The final result is a great diversity of plant species. The ecological rule-of-thumb is that the greater the fertility of the soil, the fewer plant species will establish themselves on it; and if you prefer a great diversity of species you need a poor soil. Over the years coppicing produces poor soils, and so coppiced woodlands tend to have a rich diversity of plant species. The greater the diversity of plant species, the greater will be the diversity of animals feeding on them, and since the arrival of herbivorous animals is followed by the arrival of predators and parasites of those animals, the entire ecosystem is enriched. (p.106)

So what direction do we pull in? Obviously the petro-fertiliser era is a blip which is going to end in short order, yet I’m less-than-convinced about the longterm viability of the systems that preceded it. Intentionally working to impoverish the soil? Surely sooner or later that will starve the ecosystem to death (although I’m not aware of any coppice rotations that have been stressed to breaking point in this way, even when supplying charcoal for industrial purposes). I think I agree that we have a responsibility to do right by the species we’ve in effect provided the selection pressure for over all these centuries of domesticating the landscape, whether that’s helping them adjust to the changing circumstances or, if that’s not possible, allowing them to die out with dignity. But I think the conservationists are wrong about greater fertility equating to lesser diversity. Maybe this would be the case in the short term, but after a while I expect it will simply be a different kind of selection pressure leading to an explosion of diversity in the more nutrient-hungry plants. How many different hybrid forms of Bramble, Nettle & Dandelion are there already in existence?

Fire-setting is another case in point. From what I’ve read it sounds like N American Indians burned grasses and forest understory purposefully to release the nutrients locked up in the standing dead plants, changing them into a form that was bio-available to the herbs, shrubs and annuals that would be growing on that spot by the next season. This was also an active selection for plants that provided edible, medicinal and other uses for the Indians (and, I assume, for the wildlife they shared the habitat with). It would be interesting to know the mix of woodland plants in Paleo/Mesolithic NW Europe – whether fire management caused this to differ in a similar way. A local conservationist has told me to look for Nettles and Brambles growing in places where our group had previously set fires in old coppice woodland, due to the nutrients released in the wood ash.

Over all it seems to be the case that humans are associated with enriched fertility in soils. That’s one line of archeological evidence for habitation by prehistoric man – at least in Europe you find seeds or pollen grains of Nettle, Plantain, Goosefoot and other associated ‘weeds’. We pitch camp somewhere for the season, eat, shit, do some burning and maybe a bit of gardening before moving on. My best nettle crops have come from places disturbed by people (the very best being where those people fenced off special areas in parkland for their dogs to come and do their business in the times before the ubiquitous small black plastic bags – mmm, dog poo nettles…) Anyway, the main problem with coppicing and other woodland management seems to be the same old civilisational problem of exporting resources far away from their point of origin. If people lived in the woods, building homes, cutting fuel, crafting necessary artifacts from the trees around them, and letting it all rot down on site, I think that could lead to a thriving & enriched ecosystem, supportive of a wide variety of plants and animals.


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