Trees & Me with Dr Vince Lea I’ve been involved in conservation work ever since I was at school, when one of the teachers asked if any of us wanted to help cut down some trees to help improve a woodland ride. It was great fun as a kid chopping down trees, and the teacher explained that by letting in light this part of the wood supported a lot more wildflowers in summer, and that as the trees grow back, they create a much denser patch of habitat than the widely spaced mature trees in the rest of the woodland, so it was going to be much better for small birds and some of the other wildlife. The teacher explained that he helped look after this wood to make it better for the pheasants which he like to shoot, an early lesson in the idea that sustainable land management can be beneficial to us and wildlife. At University I found a group of people who did conservation volunteering on the weekends and joined them. We spent a lot of our time cutting down trees either growing in the wrong place, or of species that shouldn’t be here. We did have one memorable wet week in Wales planting trees on a barren hillside, but most of the conservation work was about cutting them down, something a lot of people don’t understand. In fact, a lot of our most threatened wildlife lives in the bits between the trees, the temporary habitats that develop when trees are absent. To understand this, you need to know that complete tree cover is not a natural situation. In the past Britain would have had ‘megafauna’, mammoths, aurochs, elk, woolly rhinoceros and so on, all of which have a habit of knocking trees down to eat the leaves. Also of course, beavers would have been actively felling trees wherever they occurred near watercourses. Before we drained the landscape, there would have been periodic flooding events ‘drowning’ tree-filled valleys, and any drier areas would have accumulated enough dry matter for occasional wildfires to clear out big areas. Our trees have evolved to cope with being under attack from all angles, and wildlife has evolved to take advantage of the gaps between trees in the short period of time that becomes available when trees are not dominating a patch of land. These early- and mid-succession species are now highly threatened because woodland is in much smaller blocks, and most woods lack gaps between the trees. The worst examples are the dense, close-planted non-native evergreen plantations of sitka spruce, noble fir and other such timber trees where no light ever reaches the ground, but even these plantations can be good for wildlife in the few years after the timber has been harvested and new trees are getting established. The traditional use of woodland in lowland England was to coppice it, a regular harvest of small to medium stems of the trees would be taken from most woods, leaving just a few selected trees to grow bigger for special uses such as building material for houses, barns or ships. Most of the trees would be cut down every few years, providing a large quantity of small wood for fuel, tool handles, fencing and basket making. This method of harvesting could truly be described as sustainable, as it was continued for at least a thousand years in some woods with the same trees producing new shoots after each round of coppicing. The wildlife that we have in our woods adapted to this management and when it finally stopped being a routine part of our rural economy, the woods grew up, shaded out and much of the wildlife disappeared. This started to happen around the time of industrialisation, but modernisation after World War II really put an end to most coppicing. The late Professor Oliver Rackham was one of the main people to first become aware of this link between woodland management and wildlife, making the link in his undergraduate studies from Cambridge University, when he went on field trips to Hayley Wood in the 1960s. Hayley Wood became a Wildlife Trust reserve and was particularly important for a rare relative of the primrose, the oxlip. These spring-flowering plants survive long periods of shading which kills off a lot of other vegetation, but to flower and produce seeds, the oxlips need a few years of full sun. They are perfectly adapted to the coppice cycle, biding their time while the trees grow up then taking full advantage of the opportunity when the trees are cut down. Another important oxlip site is Hardwick Wood, and Oliver studied this wood in great detail as it is somewhat closer to Cambridge and was for a time owned by the Diocese of Ely who maintained detailed records which he was able to consult to get a picture of the past history of the woodland management during the Middle Ages. Oliver encouraged the reinstatement of coppice management in these woods and several other reserves, which soon showed that oxlips and other wildlife responded well to this management, and it has become standard practice in many sites as a result. However, it has also become apparent that coppicing isn’t always as effective as it should be due to the big increase in wild deer in the later half of the 20th and now 21st century; in the absence of natural predators and with few people hunting them, deer have become more abundant now than ever. They are particularly good at eating trees at ground level, for example the new shoots of coppiced stumps, or a young sapling trying to grow from seed. The requirement for tree guards whenever trees are planted is purely down to the excessive abundance of deer, particularly the non-native species such as muntjac and fallow. We would not need to plant trees if deer were at more normal levels in the countryside. My partner Louise Bacon and I took over as wardens of Hardwick Wood in 2004, and it was obvious to us that the coppicing wasn’t working properly, because the tree canopy was almost completed shading out the underwood. We spent the first couple of years tackling the medium-sized trees which had grown up over the last 30 years or so, which helped a bit, but it was obvious that the oak trees were too big for us to tackle, and too close together. A quick mapping exercise showed that we had about 50 oaks per hectare, while the ‘recommended’ ratio is about 12 per hectare. The current owner took some persuading that we needed to thin them, as his ancestors had planted these oaks. But as he was a farmer, we eventually persuaded him that this was the harvest that his ancestors had been planning for! In 2006 we finally got the go-ahead to start a tree thinning exercise, taking about 30 trees per year to bring the density down to 25 per hectare; because the trees had been planted fairly closely, they were quite slim and the shading was not too bad at this density, though they are now spreading out and we have to take a few more each year to achieve good growth on the coppice. The first year of tree felling was very exciting as we had the help of a local horse-logger to move the timber out of the wood. We told Oliver Rackham about the work, and he was very keen to come along to see it, and to collect samples from each tree so that he could work out the age from the tree rings. His research had indicated a major oak planting event in 1836, to restock the wood after the timber had been used to supply the shipbuilding needed for the Napoleonic Wars. He was able to confirm that most of the trees were indeed exactly this age and that what to most people look like a natural woodland full of oaks was in fact a plantation. Since the oaks have been thinned, the coppice has been growing back really well apart from where the muntjac have had their way with it. Fencing has had to be used to protect it in places. The wildlife has responded, with several species of birds such as willow warbler, garden warbler and spotted flycatcher returning to the wood and a big increase in oxlip and other wildflowers, followed by an abundance of butterflies and other insects. The sale of oak brought in a good one-off income to the Wildlife Trust, and the annual harvest of coppice poles are sold to gardeners for bean poles, pea sticks and many other uses, raising well over £1000 a year while also enhancing the habitat. And, despite being somewhat older than when I first did it, I still think it’s great fun cutting down trees!