The most natural succession of woodland


It seems like I have been bombarded for weeks now with propaganda about the special character of British landscapes. At the recent Wildland Research Institute seminar, it was refuted by someone from Natural England that landscape character assessment and National Character Areas (NCA) set landscapes in stone. There was a general disbelief at this claim, especially since only a couple of weeks before, Natural England had published a study that set out to find support for the NCA system in advance of its updating by Natural England (1). This avowedly qualitative study, based on a small selection of NCAs, sought only to interview people living in those character areas, and thus the people who had a vested interest in not seeing change. It was a veneration of cultural landscapes that took no account of the views of the 80% of people in England who do not live in but have to visit the “bucolic” countryside that these NCAs describe, and have to accept whatever legacy past millennia of agricultural land use has left in its wake.

The week after the seminar, and I was at the launch of Natural England’s Vital Uplands - a 2060 Vision for England’s uplands (2). It got a rocky reception from the National Farmers Union, Moorland Association and Tenant Farmers Association, even though it bends over backwards in the vision to say how important their activities are for the uplands - so much hyperbole, repeated on the day, that someone from Cranfield University said to me that there was a formula for measuring "hot air" so that it can be carbon offset. My worry about this exaggeration of the virtue of agriculture for the uplands is that all it does is entrench the narrow-mindedness of an increasingly beleaguered group of farmers (and I don’t expect to be at a meeting at this level where there is a tacit condoning of wildlife crime). In particular, there was a rejection of an aim in the vision to increase native woodland cover in the uplands to 25%, even though every survey shows that the public want it. I suspect this gloss about the contribution from farming to the uplands is the “brilliant light” you see just before an incandescent bulb burns out.

Landscape that thrills

I am no fan of much of the British landscape, but then I have explicit views about the landscapes that I do like. It has to have the sensual thrill that comes from the visual coherency of it “looking right”, coupled with a physical intimacy from my being enveloped by it’s structural complexity and the attention and commitment of effort that is needed to navigate that complexity. Flat, feature-less, open landscapes hold little curiosity for me on their own unless they are a component part of a much more varied landscape matrix. Even so, add water - in the way of rivers, lakes, and wetland - then that flat, open land is bustling with potential. The water provides movement, sound and visual stimuli as well as habitat; and the wetland and riversides, if left to wild nature, would develop vegetation as structural elements that move the landscape up into the third dimension.

That third dimension can also come from land form that gives texture, such as hills, mountains, and valleys. It is however the smaller scale texture that is especially appealing in this higher ground, from rocky crags and outcrops, and narrow valleys and ravines. Water in these landscapes, as lakes, plunging brooks and waterfalls, builds up that structural complexity and variety of stimuli, and the more physically intimate locations are often where water cuts down through those ravines and small valleys. The physical intimacy can also come from structural vegetation in upland locations - shrubbery and woodland - but these would be more widespread if wild nature was left to govern. If only this were the case in our upland landscapes.

A simple explanation would be to say that I favour landscapes that are the most natural. There will be those biophysical elements present that I have described, such as water, geology, land form and structural vegetation, but it is also what is not there that is just as important. Thus a natural landscape is one that appears to be unaffected by human activity – it has none of our cultural artefacts (buildings, roads and boundaries) and it is in the control of natural processes that are beyond our cultural influence. A semi-natural landscape, which is often used to describe the uplands in Britain, is one that has been modified by human activity but has some natural elements left intact. These are described as “wild lands” by those who have no other measure of what wildness means than by making a comparison with the entirely agricultural landscapes of improved grassland or bare soil (this travesty popped up again at the launch of the Vital Uplands vision – see earlier). But there is still agricultural use or land management activity in these “wild lands”, and so they should more honestly be described as semi-agricultural rather than semi-natural, since the modifying activity of agriculture has been, and still is the greater influence on the land than wild nature.

Less in question is that agricultural landscapes are those that have been totally arranged by human activity, with very few of the structural components of the natural vegetation, but often with non-native components that are brought in. What natural elements are still present in an agricultural landscape only persist if they contribute to or do not hinder extractive use. These are the landscapes that have the least degree of naturalness.

Looking past the cultural baggage

So how do we distinguish a natural landscape when it is not just a question of the absence of recognisable human artefacts like buildings or boundaries? Given that water and landform texture depend on location, it then comes from a sense that the landscape has had a break from all the modifying influences: that the eradication of structural components of the natural vegetation has or is being reversed, and that there is little presence of introduced, non-native components. The reversal inevitably requires that the continuous extractive use that maintained the modified landscape is removed since it will just hazard the return of that native structural vegetation. A semi-agricultural landscape will always only be a semi-natural landscape.

It takes the eye of a visitor to these lands, unencumbered by British cultural baggage, to expose the falsity that leads people to call our uplands wild. Thus I have written before of Guy Hand, who on seeing the emptiness of the Highlands of Scotland described them as the “saddest place on earth” (A walk in the forest of forgetting (3)). Hand grew up in Boise, Idaho, with the ecological richness of the Sawtooth Wilderness area on his doorstep, a natural landscape unshackled by agriculture. He took his Scottish wife to Sawtooth, in the thought that she too would enjoy the sense of closed-in sanctuary he always felt in the forests of that wilderness. Instead there was fear, a dread of wooded land. “Too many trees”, Mairi said, the tension only relieved on reaching the scree and boulder slopes above the tree-line, to a landscape she could understand from her Highland childhood: “open country, tree-less country, country filled with nothing more than grass, rock and sky”

Jon Merryman, also from America, gives us a more recent, but workaday reflection of his rambling in our uplands. Jon has a personal quest to visit all the National Parks in America, also unshackled by agriculture, and so far he’s enjoyed the rich ecology of 29 out of the 58 parks. On his business trips to England, he likes to have a look at our national parks as well, walking last year in the North Yorkshire Moors NP. While heading over to Goathland from Levisham, his first view of the moors was rather disconcerting (4):
“They seemed to go on forever, and although you could see a very long way since there were no trees on the moor, the town was still nowhere in sight. Halfway across the moor, following a muddy, narrow, rutted path through the heather, I stopped at a rockpile, which was a welcome sign on an otherwise homogenous landscape…….as I hiked, it seemed I could always see the top of the hill ahead of me, and when I got there, more uphill remained. It’s a very strange landscape, and I suppose having very few reference points lends itself to illusions and misjudging of distances”

Merryman’s round trip was completed by taking the steam train from Goathland back to Levisham. Along the route, he would have passed Fen Bogs, a mire that lies at the head of Newton Dale. This mire has yielded pollen records that chart a picture of the regional pattern of vegetation change, covering a period of 9000 years (5). At that earliest date, vegetation cover was well on its way of recovering after the last ice age. The landscape had a scattered (30%) returning native tree cover of mostly birch as the dominant tree, with pine, hazel, willow and bog myrtle, and some elm, oak and alder. Open space species predominated, including sedges, grasses, meadowsweet and heather. Woodland continued to advance over the next 5000 years, pushing out open spaces species, and going through phases where the dominant tree changed from birch to pine, to be followed in turn by oak and alder, trees that were favoured by the warming climate. The appearance of notable amounts of lime and elm also point to this warming, the increasing presence of ferns and dog's mercury showing a ground flora indicative of an expanding woodland habitat.

There follows a period between 3,400 and 2,280 years ago when ash and sporadic beech make an appearance, but the pollen data starts to indicate a series of small temporary openings of the woodland canopy, as shown by the varying amounts of grass and heather pollen, as well as other plants indicative of a pastoral use. Confirmation that these openings were likely to be from human activity comes from the next phase of 800 years where major clearances are indicated by the tree pollen dropping markedly, and a rise in a very wide range of herbaceous species, including early agricultural crops. The data continues to show that open character up to its latest date of 150 years ago. This major clearance phase is later than found in other regions, but what it demonstrates, as is often the case, is that our landscapes became progressively more wooded after the last ice age, only to be changed by the human influence of clearing the woodland to supplant it with agriculture. We lost those structural components of a natural landscape.

It is unlikely that high canopy woodland ever entirely covered the whole of the North Yorkshire moors, given the consistency of heather pollen at varying amounts over the pollen record. Some of the higher parts of the moor may have supported isolated heath communities, but even they would have had scattered trees and groups of trees within the heath, unlike the tree-less landscape that Merryman commented on. Thus before a significant human influence was felt, woodland coverage would have been extensive (the matrix would have been at least 60% woodland) and presented a very different picture than the one seen today.

Seeking naturalness in the ancient woodlands of today

Woodland cover today in the North Yorkshire Moors is now 21% (6). This is high by national standards (less than 9% overall in England) but that is explained by two thirds being made up from the conifer forest plantations of Dalby, Cropton and Boltby. Broadleaf woodlands make up less than 5% of the landscape of the North York Moors, and it is in those woodlands, especially the ancient woodlands, where there is the potential to glimpse vestiges of the natural landscape of the past.

One such wood is at Hayburn Wyke, an ancient wood on the coast about 11 miles E of Fen Bogs. Owned by the National Trust, this woodland follows Hayburn Beck as it cuts down through sandstone rock in a narrow valley, the beck emptying onto the beach in a waterfall, with the woodland turning into willow scrub as it continues onto a cliff shelf. The geological and fossil interest of Hayburn Wyke is as rich as the ground flora of this shady wood, full of beckside ferns, mosses and golden saxifrage, with clumps of wood sorrel, woodrush, wood millet, bugle, sanicle and woodruff (7). These plants indicate that the ground-layer of the wood has been undisturbed for some time, an important and distinguishing aspect of this of ancient wood.

I like the enveloping feeling of this valley wood, the path following alongside the beck as it flows over the cross-bedded pavement of sandstone and the scatter of washed down boulders. The high canopy of oak at the lower end of the wood has some ash, with an understorey of hazel, willow and wych elm. However, the beckside also has many young sycamores seeded in from the larger trees in the canopy. Couple the sycamores with the conifers present in the mixed woodland of the top half of the wood, plus the dotting of rhododendron through the cliff shelf scrub at the bottom, and then the overall impression of the wood becomes a bit less enthralling. While it has all those wonderful elements of water, rock, structural vegetation, land form and physical intimacy, the non-native trees in the woodland, and the non-native rhododendron in the scrub, make it lose that visual (and ecological) coherency of “looking right”.

Away from the coast, but 6 miles E of Fen Bogs, are the two ancient woodlands of Scar and Castlebeck, owned by the Woodland Trust. The woods occupy the W and E sides of the ravines and narrow valleys through which flow Jugger Howe Beck, Helwath Beck and Bloody Beck. These becks drain off the open moorland above, the latter two joining Jugger Howe at the top end of Scar Wood, and with Castle Beck and its ravine woodland joining from the E as an arm lower down. The woodland lies on sandstone and shales worn down by the becks, and leaving small step-drops as well as some higher sandstone sides to Jugger Howe. The path follows the beck as it progresses under high canopy woodland of predominantly oak, with ash and birch: there is an understorey of wych elm, hazel, holly, and some guelder rose; and with alder growing where it should, along the banks of Jugger Howe. My visit was late in the summer, and so the ground layer showed ferns (extensive hard fern) dog’s mercury and mosses, and with wood sorrel at its most emerald green, but there are more wildflowers known for this woodland (see 9).

The canopy of Scar Wood occasionally opens out into small areas of grassland and scrub. The visual and physical transition between these two is interesting, and perhaps bears on the prejudice that attaches to scrub: in the stretches of high canopy woodland, even with an understorey, there are relatively long views through the woodland, as well as little impediment to taking different routes off from the path. However, out in the open, scrubby, areas, the leaf covering of the small trees and shrubs block a longer view, and their close proximity to each other means that they also block passage. Given time, though, these open areas will develop past scrub and into canopy woodland. It is perhaps the paradox of upland agriculture that its control of inaccessible scrubland – an inaccessibility based only on human passage and not that of wildlife - is claimed as a virtue when wild nature has its own solution to that inaccessibility. Not all scrubland, however, is destined to become high canopy woodland. It depends on its location and the climatic forces acting on it. Thus the scrub on the coastal cliff shelf of Hayburn Wyke is likely to remain so because of the extremes of exposure to wind and sun, as will the extensive scrub woodland on a wider sloping shelf further N at Runswick Bay. This excellent scrub woodland extends inland up short valleys, but is isolated from other woodland by bleak, treeless farmland (6).

I felt exhilarated walking through Scar and Castlebeck Woods. It had all the components of water, land form and structural vegetation, and was enveloping. It also “looked right” because of it having almost exclusively native species, growing in the right place, and little evidence of recent coppice management or other disturbance. I saw only three small sycamores as I walked and no conifers or even beech, and realized how fortunate it was that this wood had escaped the unwanted intrusions that are found in Hayburn Wyke and so many of our ancient woodlands.

I was then glad to find that the Woodland Trust had come to a similar conclusion, their management plan for the woodland describing it as having “a very natural appearance and very few non-native species” and that it “should remain as undisturbed as possible” (10). They make the point that the woodland is a rare remnant of the once widespread mixed oak forest that once occupied the moors above. It has survived due to the inaccessible terrain it occupies – “its remote setting and natural feel being unparalleled in this area”. The management plan also explains that prior to the Woodland Trust taking ownership, the woodland had been degraded through heavy grazing - both sheep and cattle having had access from the surrounding farmland. The exclusion of livestock since taking ownership has led to some of the heavily grazed areas regenerating with birch, while others were planted up by the Trust in 1995/6 with a mixture of oak and birch. As I explained earlier, the exclusion of extractive use, as represented by the grazing of sheep and cattle, is a vital element of restoration that has contributed to Scar and Castlebeck Woods now having that natural feel.

It is obviously an imperative that the management approach of the Woodland Trust does not put this virtue at threat. Fortunately, and counter to much of the current orthodoxy of woodland conservation, the Trust have committed to minimum intervention. Thus the on-going windthrow and senescence within the woodland provides ample opportunity for regeneration, which will create and maintain a diversity of age structure. The open grassland/scrub woodland of the lower slopes will be left to develop into a high forest of oak and ash, as a continuation of the wooded upper slopes, allowing “the most natural succession of woodland possible within the site”. The naturalness will also be safeguarded by control of sycamore, but also beech, through monitoring every 10 years and removal of these non-native or out-of-region tree species that may invade from nearby plantation woodlands. My inclination would perhaps have been for a shorter monitoring cycle – I was itching to remove the offending sycamore as soon as I saw it - but 10 years is a short period in the life of a wood, and it may also be about limiting disturbance.

Scar and Castlebeck Woods have a significance that is far wider than their immediate location. Thus in a survey of residents in the North York Moors NP, people specifically associated the woodlands of the North York Moors as being valuable for wildlife, as opposed to its moorland landscapes (11). There have also been proposals for restoring and expanding native woodland habitat in the North York Moors NP using the Forest Habitat Network approach (6). The value of Scar and Castlebeck Woods is that they offer an excellent opportunity to see what that extending woodland of the future could turn out to be. As the Woodland Trust rightly concludes:
This large area of ancient woodland with very few non native species is a great opportunity to allow natural processes to take charge through minimum intervention, allowing the woodland to develop as naturally as possible”

Mark Fisher 24 November 2009

(1) Experiencing Landscapes: capturing the cultural services and experiential qualities of landscape, Natural England Commissioned Report NECR024, 9 October 2009

(2) Vital Uplands - a 2060 Vision for England’s uplands, natural England NE210, 12 November 2009.

(3) A walk in the forest of forgetting, Self-willed land (2004)

(4) North York Moors National Park: The Moor the Merrier, Jon Merryman, Homeschool rangers: National Parks for homeschoolers, 31 October 2008

(5) Late Quaternary vegetational history of the North York Moors. III. Fen Bogs. Atherden, MA Journal of Biogeography (1976), 3, 115-124

(6) Native Woodland Development in the North York Moors and Howardian Hills, George Peterken, 2002;id=5092

(7) Hayburn Wyke SSSI, Natural England

(8) Scar & Castlebeck Woods, Woodland Trust

(9) Castlebeck and Scar Woods SSSI, Natural England

(10) Scar & Castlebeck Woods Management Plan 2005-2010, Woodland Trust

(11) North York Moors National Park – Residents’ Survey, North York Moors National Park Authority (2005 and 2008) - quoted in (1)