I’m a Londoner and I learned most of what I know about fungi and nature in London. Take that in physical and psychological terms, having spent most of my life there. One Tree Hill is a Local Nature Reserve in south-east London that has offered many happy wild hours (ecologically). I visit One Tree Hill as often as I can and did so to find some Christmas shrooms this year.
One Tree Hill has a weird history of being a remnant ancient woodland that had been cleared of trees and then has re-wooded itself in the past 60 years. It has old oak trees and new oak woodland spread across areas of old acid grasslands, which are rare but not in good condition anymore. It provides one of the best views of London you can find. You can read more about it here.
December is never a good month for the most exciting fungi species because it’s cold and they struggle to fruit without milder weather. But I found a few species that I look for at this time of year.
This photo was actually taken over Christmas 2018 at One Tree Hill but it’s one of the more photogenic things you can find at this time of year. They grow out of the fissures in bark, most of the time on oak. I’m not sure of the species.
I think this is the same species but growing from a horizontal position in the late summer.
In the more open, grassy areas atop One Tree Hill I found something I’ve not seen before. This is a deceiver (Laccaria laccata) with gills growing out of the top of the cap. I don’t know what the name for this ‘deformity’ is and an internet search definitely didn’t help.
Deceivers get their name because they come in many different shapes and sizes, looking like different species each time. This year I saw huge numbers of them in the Sussex Weald. Here’s one in better condition:
In December I did some recording with BBC Radio 4’s Open Country, presented by David Lindo and featuring The River Effra, the London National Park City and Queen’s Wood. It was great to be able to represent the Friends of One Tree Hill and London Wildlife Trust on the programme. Please listen here: http://www.bbc.co.uk/programmes/b088fx30
For the past five years I have been searching hedge lines, woods, parks and boundaries for the undulating mass of an old oak. This search has not taken place in the English countryside, instead the border of the London boroughs of Southwark and Lewisham. The southern towns of Southwark were once the parish of Camberwell and its boundary with Lewisham still supports centuries-old oak trees that were the previous markers between old Camberwell and Lewisham. Along with the Dulwich Woods and One Tree Hill, these trees are the strongest ties to the much diminished Great North Wood.
The Great North Wood
The Great North Wood was a landscape of woods and commons that stretched from Selhurst to Deptford. It was worked over centuries for its timber and underwood (sessile oak, hornbeam and hazel, mainly) for ship building, tannin extraction and charcoal burning. Its origins are in the wildwoods that spread after the end of the last glacial period 10-12,000 years ago at the start of the Holocene. The oaks remain where other species have disappeared as they are tough, long-living (sometimes 800 years in open land) and are of great use to our species. The Forestry Commission approximates that London’s trees are worth £43billion in their environmental and amenity value. Oaks are some of the most important. Their carbon storage capabilities should be remembered by those controlling planting regimes in cities today.
This old image (likely early 1900s) shows what One Tree Hill’s western slopes were like. The earlier map, dated 1799, shows that One Tree Hill was an isolated ancient woodland. It once connected with the Dulwich Woods which skirt the left hand side of that image, and spread even further before humans began managing the woods. That could have been thousands of years ago, however. The Dulwich Woods are very likely several thousand years old. There is no woodland at all but plenty of shrubs, likely including gorse and hawthorn. The landscape swelling into Lewisham shows much of south London’s old landscape was farmland. The boundaries of the farms were marked by old oaks.
One of the first mistakes made by those (myself included, of course) looking for old trees in the landscape is to head for woodland first. The oldest trees are usually living in isolation in what has longest been open land. The great Oliver Rackham told us that ‘ancient woods are not the place to look for ancient trees’. The best trick is really to get an old map, compare it with a current one and see if there are any clear boundaries where trees may have been planted or perhaps wild trees maintained as standards. Sometimes the old maps show trees dotted along the edges. The image above is a pollarded English oak (Quercus robur) at the entrance to One Tree Hill on Honor Oak Park. The tree is actually in the grounds of the Honor Oak Allotments and a line of similarly old oaks can be found running up alongside it.
This oak, one down from the previous, has clearly been pollarded (c.1900s) and is now swamped by other trees. Logic says that pollarding it again and removing some of the surrounding growth would allow the trees to re-balance and go on living indefinitely, but experimental pollarding taking place in Epping Forest suggests otherwise. Lapsed beech pollards are known to die when pollarded again. These oaks may be so unused to management that pollarding them will kill them off. We may have to accept that these landmarks of the Great North Wood have a limited time left.
The Oak(s) of Honor
One Tree Hill is a good case study for remnant Great North Wood sites as it was open land until the mid-20th century but was woodland on the north-western slopes up until the 1840s. Today it is returning to woodland having been largely managed through non-intervention, bar access works and hedge planting, by the Friends of One Tree Hill and Southwark Council.
One Tree Hill gets its name from the single English oak (pictured) which was replanted in 1905 when the hill was reopened to the public after a battle to save it from becoming a golf course. 15,000 people conducted a mass trespass on 10th October 1897 to challenge the Honor Oak & Forest Hill golf club’s attempts to fence and enclose the hill.
The previous Oak of Honor was thought to be much older and was a boundary tree for the old vice-counties of Kent and Surrey. It was also the edge of the Honour of Gloucester’s land. The idea is that in 1602 Queen Elizabeth sat under the tree and was thus honoured thereafter. Today the Oak of Honor is the most obvious tree to seek but by no means the oldest. I love that it has so influenced local place names. An old black and white photograph of the former oak (the church building can just be seen in the top right) gives the sense that the oak was not so old, perhaps only a few hundred years before it perished. This tree was destroyed by lightning in 1888.
To the right is the oak of Honor when it was only a decade old. The open landscape of early 20th century Honor Oak/Forest Hill is filling up with housing. The tree cover on the hill was largely hawthorn scrub, as can be seen behind the caged oak.
It’s worth remembering that though we are fixated by neat and tidy trees in urban areas, often for safety reasons, that oaks provide habitat for a great number of species. The Oak of Honor in September 2015 held many knopper galls, the protective case for a gall wasp (Andrus quercuscalicis), and oak apple galls.
The top of One Tree Hill is an excellent spot to find butterflies in spring and summer because it is open and sunny. This speckled wood (Parage aegaria), one of the contemporary Great North Wood’s most common butterflies, was enjoying some September sunshine on the great tree’s leaves.
The winter months provide ample opportunity to find nuthatch (Sitta europaea) which is often tied to oaks because of the invertebrates it forages from the bark and the old woodpecker holes it nests in. It makes a neat mud ring around woodpecker holes to make the entrance smaller and more protective for its young.
The purple hairstreak was the first ecological record at One Tree Hill when it was mentioned for the first time in the 1766 publication The Aurelian by Moses Harris. This overlooked butterfly was ‘commonly taken in plenty in Oak-of-Honour Wood, near Peckham, Surry.’ It’s one of the insects promoted by conservation groups in the Great North Wood, a good indicator of long-term woodland cover, especially at nearby Sydenham Hill and Dulwich Woods. The purple hairstreak is only usually seen by those straining to look up at the canopy or those lucky enough to stumble across one when it’s down and dazed on the path.
The oldest of One Tree Hill’s oaks is likely to be this lapsed pollard (whereby a tree is cut higher up – coppice is cut at the base – to prevent grazing animals eating regrowth) growing on the path that runs adjacent to Brenchley Gardens. I’ve seen a photograph somewhere of the tree isolated in open land, with Peckham’s farms rolling down to what is now Peckham Common.
The tree, seen here on the right of the photograph (its lean exaggerated by the distortion of my 10-24mm wide angle lens) is competing with the seedlings that have likely fallen or been stashed by grey squirrels (Sciurus carolinensis) and members of the corvid family, especially jays (Garrulous glandarius). You could suggest that the new woods of One Tree Hill are products of its old boundary oaks, where the dominant species is oak. Recent research has uncovered how important crows are in establishing new oak woods across the northern hemisphere.
One of the lower limbs is rotting nicely and providing habitat for slime moulds and small mushrooms, whether this is a bonnet (Mycena) or a parachute (Marasmius), I couldn’t tell you. The life that old oaks can support adds to the tree’s immense amenity and ecological value. Oaks typify the anthropomorphic but no less accurate notion of trees being ‘accommodating’ to many species.
Next door to One Tree Hill and its allotments is Camberwell New Cemetery, a more authentic remnant of Honor Oak’s open landscape of the past 200 years. One boundary, otherwise planted with Lombardy poplar (Populus nigra ‘Italica’), has two old English oaks. One has been hollowed out, possibly after being struck by lightning or affected by human damage. It’s an example of trees as habitat, something which people are generally uncomfortable with at first, especially with fungi as they think the tree is dying. In August 2015 the hollowed oak had the fruiting body of what I think was chicken-of-the-woods (Laetiporus sulphurous). Oak supports many insects and also fungus. The oldest oaks you are likely to find will be dependent to some degree on mycorrhizal relationships with fungi. Fungi can also help the oaks by removing bits of deadwood that may otherwise add extra weight to the tree as it ages. Some species are necrophratic and will eventually kill a tree because they ‘take more than they give’.
On first thought I was suspicious that the two oaks seen here might be the same two on the allotment-cemetery boundary. This is a photo from the 1920s that shows Camberwell New Cemetery and the Honor Oak Recreation Ground as open land being grazed by a flock of sheep. Evidently the sheep were used to keep the grass short for golf, or maybe also as a way to support a local farmer. The golf club house can be seen in the distance. The building on the hill in the distance is St. Augustine’s Church (1872-3). These two trees are too far away to be the same as those above, they are probably instead some of the black lines that can be seen in the distance. Note also the absence of any tree cover on One Tree Hill beneath and to the right of the church. Between the mid-1800s and this point, there ancient woodland had been well and truly grubbed out, possibly even some old boundary trees going as well. Today, this would be unacceptable.
Instead, I think this image of the old golf club house exhibits the line of oaks. These oaks look to be dying back, possibly because of the impact of building the club house where the trees’ roots were. The distance between St. Augustine’s and the line of trees is one parcel closer than the previous image (Steve Grindlay).