Wytham Woods: Tales from the a long-studied woodland with Dr Keith Kirby

In this episode we talk to Dr Keith Kirby MBE about Wytham Woods, a Thames Valley hill of limestone, ancient woodland and one of the most intensively studied woodland sites in the world. Keith traces the site’s deep history (a coral reef 150 million years ago), the human influence on the landscape over centuries, and the key decisions that shaped the wood we see today: enclosure and planting by estate owners, the university bequest in the 1940s, and the later tussles between foresters and ecologists over management.

Keith shares highlights from decades of scientific monitoring: the bird-box programme started in 1947 (now over 1,000 boxes), permanent 10×10 m vegetation plots set up in the 1970s and remeasured repeatedly, badger and small-mammal studies, and how changing deer numbers and later ash dieback altered forest dynamics. He reflects on the practical lessons — how deer control enabled ground flora recovery, how some management mistakes left long legacies, and the rare moments of continuity (including recent tree plantings by the family of Charles Elton). Keith also points out the small, poignant human stories inside the woods: WWI practice trenches under a spring carpet of bluebells, and the rediscovery of rare plants.

The Wytham Woods Book is here:
https://global.oup.com/academic/product/wytham-woods-9780197610602?cc=gb&lang=en&

And you can find more information about visiting the wood here:
https://www.wythamwoods.ox.ac.uk/visit
and you can find the guidebook here:
https://www.wythamwoods.ox.ac.uk/shop

To here more from Keith you can watch his lecture here:
https://www.youtube.com/watch?v=ICD4B3d28b8

or read his popular blog here:
https://theoldmanofwytham.com/

The Leverhulme Centre for Nature Recovery is interested in promoting a wide variety of views and opinions on nature recovery from researchers and practitioners.

The views, opinions and positions expressed within this podcast are those of the speakers alone, they do not purport to reflect the opinions or views of the Leverhulme Centre for Nature Recovery, or its researchers.

The work of the Leverhulme Centre for Nature Recovery is made possible thanks to the support of the Leverhulme Trust.

Transcript

00:00:05 Stephen Thomas
Can you tidy up this transcript

Welcome to the Nature Recovery Podcast.

00:00:10 Stephen Thomas
We're going to take a closer look at some of the solutions to counter biodiversity decline, and we'll find out more about the people behind these ideas.

00:00:25 Stephen Thomas
So I'm delighted that our guest today is Dr. Keith Kirby, MBE.

00:00:31 Stephen Thomas
Welcome to the podcast, Keith.

00:00:32 Stephen Thomas
And maybe you can start by just introducing yourself and telling us a bit about your background and how you came to be where you are today.

00:00:40 Keith Kirby
Well, I was brought up in Essex and was interested in trees and wildlife, mainly through watching David Attenborough programmes.

00:00:50 Keith Kirby
At some stage, I decided I wanted to be a forester. I didn't really know what it involved, but I was lucky enough to get a place in Oxford to read agriculture and forestry science.

00:01:03 Keith Kirby
And then went on to do a DPhil working in Wytham Woods, which I think we'll be talking about later.

00:01:11 Keith Kirby
And thereafter, I joined the Nature Conservancy Council, which was the government conservation agency, which in various forms then I stayed with for 30-odd years. It's now Natural England, it's morphed into.

00:01:29 Keith Kirby
But I was there as a forest ecologist and involved with more or less anything at a national level from policy down to local advice to our reserve wardens as to why all their trees were dying or not dying — that sort of thing.

00:01:47 Keith Kirby
So I had quite a wide background, but I kept up some research in Wytham that my supervisor had set up. And when I retired, I retired to Oxford and then picked up working in Wytham again.

00:02:03 Stephen Thomas
Wow.

00:02:04 Stephen Thomas
And so a rich history of forestry and a woodland. And I guess seeing how forestry has changed so much over the years. I mean, I did a little bit of forestry and one of the things I used to love was — foresters in their early years, they can come up with management plans and they can say things. And basically, you can make a lot of mistakes and no one will ever find out because in 30 years' time, you will have left and moved on.

00:02:29 Stephen Thomas
But you've sort of stayed and had a connection with Wytham for a long time. So I guess you've seen a huge amount of transition during that time from not only the woodland itself, but actually, you know, woodland policy and sort of what we want from forests and how we manage them.

00:02:45 Keith Kirby
Yeah, that has changed immensely. I mean, in fact, the reason I did the DPhil, rather than going on the MSc on Forest Management, was that I had discovered during my undergraduate course that forestry at that time, which was the early 1970s, was about making money from growing Sitka spruce. It wasn't about walking through nice broadleaf woods looking at plants and insects. So I shifted from, if you like, the economic side to the ecology.

00:03:21 Keith Kirby
And then, I mean, during the 1980s, we were loggerheads with the Forestry Commission because they were planting up sites which we now would call ancient woodland with conifers. They were planting up moorlands and forestry was definitely a bad word in conservation circles. And the trouble is actually that those mistakes that were made in the 70s are still with us in the landscape and still, I'm afraid, often taint discussions between conservationists and foresters because it's still — they secretly really want to plant Sitka spruce everywhere, and they don't. But there's still that nagging feeling that perhaps they might. But yeah, it's a much more positive relationship now with the production side as well.

00:04:17 Stephen Thomas
Yeah, and I remember learning about that. There was a whole drive for woodland and a lot of sites with peaty soils, you know, Sitka was planted and they do pretty well there. And again, you know, the thing that I've learned is it's not just the tree, the whole kind of UK timber industry is pretty much set up for one of a few species of tree, but predominantly Sitka because it's the right kind of size, it works well. So even sometimes if you want to grow with the trees, actually the sawmills can't take them. And then the engineering of our houses and so the demand is still there.

00:04:53 Stephen Thomas
But yeah, it's interesting now that I got into the world of nature recovery through trees. And of course, my naive view, which again, I still kind of think is we all need to plant trees everywhere. Now, I would argue that's true, but I think individuals need to plant trees and learn about them and watch them. And there's more rather than large scale planting. But now, of course, you know, with this work, you learn about peat restoration and all these kinds of things and the value of mixed forestry.

00:05:20 Stephen Thomas
So yeah, it's been fascinating to hear that story for you. And I guess I want to bring us back to the sort of central hub. And there's a new book out, which you've been a major author of, which is about Wytham Woods, a fascinating story accessible. And so I want to start, I guess, right at the start, which is, you know, before it was a woodland, kind of what was Wytham. And then maybe we can go through that up until the point where you first encountered it and then we can talk about the changes you've seen.

00:05:54 Stephen Thomas
So yeah, before this spot, which is the most — I think it's the most studied woodland in the UK and you can make a case it's the most studied woodland in the world. Now I don't know.

00:06:02 Keith Kirby
I would put a probably in there, like the old lager adverts, but yes, it's one of the most studied, certainly.

00:06:15 Stephen Thomas
Yeah.

00:06:17 Keith Kirby
But it's peculiar because we're in the Thames Valley and suddenly there is this hill and the Thames does a big loop around it. And it's great because, in fact, the top of the hill, which is, I think it's about 150 million years ago, was a tropical reef. And so, and it was laid down as limestone. And in the bits of limestone on the top there, you can still see the structure of the coral. And there are one or two places where you can find little scallop shells sort of embedded in the rock. And you're 160 metres above the...

00:06:54 Stephen Thomas
Yeah.

00:06:55 Keith Kirby
Up there. But that gives it a really nice sort of solid limestone cap to the hill with very shallow soils. And then underneath them there is a layer of calcareous sands and grits, which the badgers love because that's nice, easy tunnelling for them. And then below that, there is a layer of clay. And that's where the ancient woodland is, the bits of woodland that were left when early people were clearing the landscape, at least they may have been. Yeah, there may be a direct connection. We can't actually prove it. But because the clay soils were just the worst sort of thing to try and cultivate before you had mechanical ploughs. So you tend to leave the woodland there and the shallower limestone soil or the floodplain, which was great for meadows and hay crops, those you cleared of the trees first.

00:08:04 Speaker 3
Okay.

00:08:05 Stephen Thomas
So it's amazing just that you get a deep sense of, and I know we're in this period of climate change and polycrisis and coral reefs aren't faring well, but to recognise that there's an ancient woodland on top of an even ancient coral reef really sort of puts our human time frame in perspective when we look in sort of geological terms.

00:08:26 Keith Kirby
And the thing that I always emphasise when we go around Wytham is that what we're looking at is a cultural landscape that's been influenced by humans for at least 2,000 years and probably a lot longer than that. And that you can't just look at it and say, well, we can use ecology and environment to explain what we're looking at without also taking into account the way that people, and in some cases, just one individual can make a difference if they have the necessary influence.

00:09:03 Stephen Thomas
Yeah. And I guess getting, so then getting into the more — it seems wrong to call it modern, but we, ancient woodland is sort of 1600 or previous. And obviously, I mean, it sounds like it would have been known, perhaps used far before that, but you get into sort of unwritten records and fossil records and conjecture. Normally it's around, when I've seen other forests, it's around the time of the Domesday Book or kind of, you know, that you suddenly get written records. Is there anything about where it was first called Wytham Woods or where it first came up?

00:09:37 Keith Kirby
Well, unfortunately, we don't have a direct reference to Wytham in the Domesday Book. The Wytham village is referred to, so we know that there was a village there, some villages. In fact, there were two villages because there's one on Seacourt as well, just a Seacourt stream, but that was abandoned in the Black Death. But there is a reference to woodland in the Cumnor Parish, which probably encompasses what we now call Wytham Woods, because part of that is in Cumnor Parish. And it was attached to the Abbey at Abingdon. And so they actually sort of almost farmed out management of the land around Wytham to, well, before the conquest, it would be a sort of Saxon saying, and afterwards to a Norman knight, because knights were, it was easier for the knight to provide them armed men that were part of the feudal system to support the king. So they were effectively the local managers of the land. The first real reference we get that we can pin down to the woods actually in Wytham, I think are in about 1540, because with the dissolution of the monasteries, there were debates. Some of the land went to one person, some to another, and there were arguments as to who had got what, which went to a court. And the main arguments were between Sir John Williams and George Owen, who was the king's physician. But they describe an area of woodland thin-set with oak over hazel. And it's almost certainly from the name Beanwood, which still exists today and still has oak over hazel. And then there's a reference to Sir John Williams trenching out his wood. And that would mean probably he was digging out the ditch that marked the boundary. You can still see a boundary bank and ditch, which almost certainly is Sir John Williams' one because as you go on, in 1760 you get the first really detailed map that we've got and it shows quite clearly the great wood, following the route of this ditch, and Marley Wood as separate. So that gives us, those are the bits that we would call ancient, definitely ancient woodland, but then a few other little bits around the edges.

00:12:35 Stephen Thomas
I mean, I love that you've got this, not only this geological history in a woodland, but you've got this cultural history. These ones I've read don't often talk about woodlands as a place for fuel gathering or rights permissions, but to actually name the species of oak and hazel — so there's been oak over hazel there continuously. I don't think there are any woodlands in the UK that haven't been managed or influenced by humans. So that then lends the next interesting question, which is, okay, so there's a battle over the woodland from the king's position and they divide it up. But those days we're talking about Oxford University is pretty old. So at some point that's existing. And I'm guessing when did — are we jumping forward quite a few hundred years or how does it become?

00:13:40 Keith Kirby
If we go back to Sir John Williams, it looks like he or his successors gradually acquire what we now know as the Wytham Estate because one of his descendants becomes the Earl of Abingdon and they own the whole of the Wytham Estate and various other places around. And they essentially own that, carry through that ownership to about 1920. But the critical one is the fifth Earl who lives around 1800. And this is where it's that one individual that influences things because he moves his family seat from Rycote to Wytham and starts to live in the big house in the village. Because what the woods are now on his doorstep, he institutes various landscaping. So he plants up various areas, starts to connect up what had been the separate woods of the great wood on the north side of the hill and Marley Wood start to become connected. He also, in various ways, he passes the Enclosure Act, so common grazing on the intervening land is also stopped, closes down the public right of way. Which also, I mean, when he closes it because there's a new road goes round the west side of the hill, the B-road now between Oxford and Abingdon. So he's gradually privatising his estate. A lot of the big trees on Wytham Hill now, we can date back to the planting that he organises. We even have a painting of one of his plantations done by the artist Millet in 1850. The historian of Millet said, well, I know exactly where he was staying and where he's likely to have worked. So now can you tell me exactly where is there a piece of woodland there? Nigel Fisher said, okay, well, it must have been Marley Wood Plantation, about there. So we could within probably a few hundred meters say this is the landscape. I mean, he's got a couple of young children who are part of a fairy tale in the foreground. In the background, you've got a woodland worker, but it's obviously a young oak plantation.

00:16:09 Stephen Thomas
That's amazing to trace it back. And also touching on those very live issues now in nature recovery, which is public access and the commons of the land. While I love publicly accessible woodlands, there's also something interesting by enclosing it, you're changing the ecology of it and potentially allowing these trees to grow to a great age, which now we can benefit from. But there's a complex human history there as well of ownership and access that goes with it.

00:16:59 Keith Kirby
Okay, so that was a big change. He lived till about 1850. Then the 6th and 7th Earls in the latter part of the 19th century don't seem to have left much of a mark, as far as we can tell. Then the 7th Earl who lived through into the early 20th century — it's the typical story of, I think, at least one heir and possibly two heirs lost in the First World War. Big estates generally were losing money. And at this point, the next key individual steps in who we know as Raymond Fennell, who bought the estate. He'd made his money in South Africa in the gold fields. He has an interesting family history because his father had come over from Germany in the late 19th century. The family name was actually Schumacher, which is probably not a good name to have in 1915. They actually had to petition the king to allow them to change their name to take their mother's name, which was Fennell. He was also in the local regiment, so he was definitely on the British side. He fell in love with the Oxford area. He, his wife and daughter Hazel bought the estate. Initially they lived in some big marquees on the top of the hill because the big house still had a sitting tenant that had a couple of years to run. This is about 1922–23. He was involved with managing the woodlands, didn't do a lot, but there are some changes that he instituted. He was also a philanthropist. Although pictures show this typical shooting squire with a shotgun under his arm, big tweed jacket, he was also interested in children's outdoor education. For example, he brought children from the East End of London, poor kids, they were bused out to Wytham. It was an early form of field study centre, giving them fresh air and good food, which with TB was right. Similarly, people from schools in poor bits of Oxford also would go out there. That was Hill End Camp, which is still there and still takes local children.

00:20:00 Keith Kirby
The obvious thing would have been for his daughter to take on the estate, but unfortunately she died in the early to mid-30s, about 1939. There wasn't — there was a brother, but his brother had an estate in Hampshire, so for one reason or another, Raymond Fennell decided that he would leave the woods to the university and also sell the farmland around the woods to the university at a somewhat reduced rate. That happened in the back end of 1942–43.

00:21:52 Stephen Thomas
Okay, so the university connection is a lot more recent than I thought. But there is this long history of it being known. And I guess then, you may not be able to answer this, where does the science or the recording or the forestry management plans or where, because when we say it's the most studied woodland, that's quite a hard time scale to pinpoint, because obviously these estate owners were studying it and managing it and doing work, but would they keep records?

00:22:23 Keith Kirby
It's really from the 1940s, and the longest continuous study project is the bird work. The first 100 bird boxes were put up in, I think, 1947. That gradually expanded and expanded and I think there's over 1,000 now, and they've been recorded ever since — coming up for 80 years. Small mammal work also started early on, but there was a break and that's continued. Badger work really started in earnest in about 1972. The vegetation work, the long-term plots that I got involved with were initially set up by my supervisor in 1974. Initially, when the university was given the estate in the middle of wartime, they said, well, we've got some woodland, we've got a forestry department, forestry department you now manage the woods. We've got an agriculture department, agriculture department, you develop the farmland as the university farm for teaching. The village stayed with the estates department. The forestry department taught modern forestry as it was. The emphasis was on timber from our own resources. Many woods had been heavily felled during the war for the war effort, so planting up open areas was the practice. The long-term aim was mixed broadleaf woodland, but in the meantime they planted mixed species so they could show different stands to students — a bit half arboretum, half forestry teaching. Meanwhile, about 80 hectares were set aside as biological reserves, a lot of that old ancient oak over hazel coppice. The Bureau of Animal Population under Charles Elton started work. During the 50s, ecologists were getting worried with what the foresters were doing, particularly when foresters started felling big, misshapen trees with no timber value. There was a big bust-up; I suspect a lot of it was because the forestry professor and Elton didn't get on. The foresters wanted about 300 hectares, ecologists thought less, and it went up to the Nature Conservancy Council to decide what the woods were for. The bequest included a clause that the university should manage the woods to maintain their natural beauty. A group of academics judged which proposal best met the terms of the bequest and sided with the ecologists. The forestry department more or less withdrew from management. The plantations they had created were abandoned for about 20 years — overstocked, heavily shaded. I think there was a wasted two decades where we could have had interesting research on the impact of modern forestry operations. Gradually from the 1990s–2000s a thinning cycle was reintroduced and plantations became more interesting.

00:28:46 Keith Kirby
My real work with it started in 1973–74 when I started my DPhil studying the growth of brambles as part of the International Biological Programme. Bramble covered about a third of the wood at that stage. My supervisor, Collin Dawkins, set up a series of permanent vegetation plots. He and colleagues hacked their way through the bramble at 100-metre intervals, putting in posts at the intersections of the OS grid. At every other intersection they put in a 10×10 m vegetation plot marked at two corners with underground metal markers so you can go back more or less to within a metre or two of the same square. They recorded details of trees present, size, ground flora, and did some soil sampling. He wrote that up and said in about 10 years it would be worth doing these again. By that stage he'd retired and nobody else picked up the project immediately. I was working for the Nature Conservancy Council and we were interested in how to monitor long-term forest dynamics. I asked for three weeks off one summer to see if I could find these plots. We did a trial re-recording in the 80s of about a quarter of the plots to show it worked. Then in 1991 we got funding to re-record them all, and since then every 5–10 years I've been going back and redoing them.

00:34:09 Stephen Thomas
I won't ask you to give me all the research, but what are the highlights? I tend to think of woodlands as moving very slow, but when a tree falls, understories can be very fast. Brambles are relevant now with ash dieback because more light means brambles come back and that brings more birds.

00:34:35 Keith Kirby
At the start bramble was really high up. Then during that period deer numbers increased tremendously. Bramble is a fantastic winter food for them, so they actually took the bramble right down and much of the wood turned to grass-dominated ground flora in the mid-90s. Then the university instituted a proper deer cull around 2000 and it started to have an impact — the bramble has been creeping back. We've watched the cycle of plot changes, the impact of increased deer pressure, and the impact of control. That's been useful to the wider conservation world because deer are now a major problem across Britain. For a long while, people were saying they don't have an impact; we can show at Wytham that they do and that if you can get them under control you can get recovery. Just as we were thinking that's great, along comes ash dieback — the next big disturbance to hit the woods. There are also things that don't happen: Wytham is on an exposed hill; it was on the path of the 1987 storm and in the middle of the path of the January 1990 storm and very little blew over. Probably because it's so exposed it gets moderate winds quite often, so trees adapt. So it's the disturbances that do and those that don't which shape the woods.

00:37:03 Stephen Thomas
Fascinating. I could honestly listen to you for another two hours. There's so much more. I encourage people to get the book and to visit. It's a lovely place to wander around.

00:37:20 Keith Kirby
But you do need to have a permit.

00:37:22 Stephen Thomas
Do you need to have a permit?

00:37:22 Keith Kirby
Yes — you can get it from the university website; it only takes 24–48 hours. Don't bring your bikes, don't bring your dogs. It's beautiful but it's still curated and atypical, and special.

00:37:57 Stephen Thomas
Scientists aren't allowed to have emotions, but there's poetry in woodlands — writers in residence and all kinds of things. Do you have a favourite area of the woods?

00:38:04 Keith Kirby
Different bits at different times of year. One of the nicest areas is not that accessible; on the far side there's a beechland with First World War practice trenches. You can stand in these trenches; in the 1950s it was planted with beech and it's now a sea of bluebells in the spring. You stand on one trench line and can see the other trench line up there — that's what these guys who dug this would have faced in France. It's poignant to stand there.

00:39:23 Stephen Thomas
I tend to go to woodlands for solace, but you've brought home how woodlands are a product of human–nature relationships and different beats. Within Wytham there are many stories of changing ownership, management, and ecology.

00:39:54 Keith Kirby
I'll give you a positive thing to end on: the bust-up between foresters and ecologists about taking down big trees — the ecologists won, so the big trees were still there. They were saved from the foresters' axe, although not from the wind; occasionally they lose big branches. A few years ago we got Charles Elton's son and daughter and their children; they planted replacements for those trees. While they were doing it one of the kids ran off and I went to bring him back; I suddenly grabbed him and said look down there — it was yellow bird's-nest, one of the rarities in Wytham. We had thought it extinct for 14 years and then found a second place — Elton's grandson nearly trod on it. It was a lovely day.

00:41:16 Stephen Thomas
Beautiful story. I've never seen anywhere with as many bats coming out of the chalet — I was astounded. Thank you for your time. I'll leave you with one final question for you to muse on: if I said the phrase "nature recovery", what does that mean to you?

00:41:44 Keith Kirby
I think it means that we don't need conservation agencies and we don't worry about people picking flowers because we've managed to solve the conservation problems as part of our normal land use and there are so many wildflowers about that we don't worry about children picking them.

00:42:11 Stephen Thomas
Beautiful. Thank you, Keith Kirby. Thank you for your work and for joining us on this podcast. It was an absolute pleasure to talk to you.

00:42:18 Stephen Thomas
Thank you.

00:42:28 Stephen Thomas
You've been listening to the Nature Recovery Podcast with me, Stephen Thomas. Please don't forget to subscribe wherever you get your podcasts. And if you can, please consider leaving us a review, as it will really help other people to find us. Also, why not consider sharing this episode with someone you know? You never know, you might get them interested in the wonderful field of nature recovery.