A wintry visit to Greenwich Park, London

Yesterday, as part of our monthly aim of visiting sites across the south east of England, a half-dozen strong group of arboriculturalists made the journey to London’s Greenwich Park – myself included. Indeed, as much of the park consists of deciduous specimens (principally, avenues of Castanea sativa and Aesculus hippocastanum), the park was rather bare in the foliage sense, though such barren canopies did allow us to appreciate the true magnitude of – most notably – some of the veteran sweet chestnuts. The frost-clad ground and crystalline sky provided a similar beauty, and thus we shall begin with one of the most iconic vistas from Greenwich Park – the city skyline.

As we stood adjacent to the observatory, we could admire – amongst the furor of tourists and scout groups – the sightly perverse beauty of a city. I say perverse, as such artificial and polluted landscapes don’t tend to suit those who don’t consider themselves urbanites, which includes myself.

Of course, we didn’t go there for the view, so let’s get into the main bulk of this account – trees and fungi. There’s no real order to how the below series of images rank, so don’t consider this post a chronological reflection of our trip!

Perhaps the best place in which to start the core section of this post are the huge sweet chestnuts, though we must begin on a rather sombre note. With a species of Phytophthora suspected on site and some of the older individuals exhibiting stunted and chlorotic leaf growth, there is a valid concern for the future of these veterans which is – without doubt – highly concerning. During the winter months, fully appreciating this contemporary issue is difficult, though we did spot some foliage on the floor that was certainly smaller in size than would be typically expected. Alas, this situation should not impact adversely on our admiration of these trees, and should in fact raise attention and draw intrigue to those within the industry and beyond, with an eye to ensuring we continue to care for the current and future populations of veterans. Therefore, promoting the Ancient Tree Forum and their most recent publication on ancient and veteran tree management is critical. And now, for some fine shots of various veterans!

This veteran sweet chestnut was the first one to greet us as we entered the park from the southern end. Not a bad induction!

As the city blocks paint the skyline to the right, we get a brilliant juxtaposition between the historic and the contemporary. In such a dynamic and ever-changing landscape such as London, this veteran sweet chestnut acts as a vestige of the old.

From another angle, the same sweet chestnut as above’s form can be more greatly appreciated. The helical patterns of the wood fibres and bark are as if they have been wound like rope.

This veteran has seen better days, though still stands proudly by the cafeteria. The ground beneath is woefully compacted, which must be having an impact upn the tree’s ability to function as a living being. Unlike the two shown above, it also doesn’t have a layer of mulch applied around its rooting environment.

Some of the veteran sweet chestnut we came across were also home to two annual common wood-decay fungi – Fistulina hepatica and Laetiporus sulphureus. Without doubt, the state of the fruiting bodies was not good, though when ravaged by time, wind, rain, frost and sun, to still even have a form is respectable! Certainly, a summer visit would have yielded a much greater haul of these two fungi on the sweet chestnuts, so a summer visit is probably on the cards.

One of Greenwich Park’s many veteran sweet chestnuts with an added extra – a small and rather weathered…

…you can see it…

…Fistulina hepatica! Picked off by parasitism before it reached a respectable stature, it still nonetheless produced a hymenium and thus likely produced spore.

A second sweet chestnut, this time slightly smaller, but again with Fistulina hepatica.

The state of it is, however, diabolical!

A smaller and thus younger sweet chestnut, in this instance.

It sports a fungal fruiting body, nonetheless!

A chicken of the woods, which is beaten and bruised.

Another smaller sweet chestnut, and another Laetiporus sulphureus.

Note how it emerges from behind a bark-covered area.

Again this sporophore is long beyond its best, though retains a little more dignity in the face of its impending crumble.

Away from the sweet chestnut, there was a variety of other large trees. Below, I share the ones that were home to fungi, through the identification of fruiting bodies. Absolutely, all trees on site are host to many species of fungi, though fruiting is not necessary in many instances, and it certainly costs the fungus energy to create and sustain. To begin, we’ll take a look at the ever-accomodating mature Robinia pseudoacacia in the park, which didn’t disappoint. In all, the population supported three species of wood-decay polypore, as we will see in the below images.

A very mature false acacia, with a very mature Laetiporus sulphureus fan on the main stem.

Well, sort of a fan – the remains of!

I imagine someone yanked this off, as it looks like a rather clean break.

Very close by, a second false acacia cradles another Laetiporus sulphureus.

Here, we can see how it’s at the base of the main stem, in place of higher up the structure.

This second one is far worse for wear!

A double-stemmed Robinia pseudoacacia, which was once at least triple-stemmed.

At the base, a senescent Perenniporia fraxinea and a cluster of broken active sporophores can be seen.

For good measure,here’s a better look at the entire bunch.

It’s a little disappointing that the fruiting bodies have been damaged, though that doesn’t stop them being Perenniporia fraxinea!

And a second example of Perenniporia fraxinea on this false acacia, too.

Right at the base, to the left.

This one appears slightly different to how it’d usually look (it’s not photogenic!).

Regardless, a showing of the trama reveals it as Perenniporia fraxinea.

It looks like the park managers are aware of the decay on this Robinia, as it has already been pruned!

If you look between the buttresses and into the basal cavity, you can spot a single Ganoderma australe. More were on the other side of the tree, though were old and worn.

With the sun behind the camera, this southern bracket looks rather pretty.

Steering attention away from false acacias, I now turn towards a focus on the brown-rotting polypore Rigidoporus ulmarius. With both horse chestnut (Aesculus hippocastanum) and beech (Fagus sylvatica) on the site, the chances are that there would have been a few examples of this fungus. Indeed, there were, as we will observe.

This first example, on horse chestnut, is an interesting one.

It’s the return of the cavity-dwelling Rigidoporus!

Away from the wrath of the elements, this sporophore doesn’t have the algal green stain atop and bathes in its own substrate.

A cutting identifies this specimen as Rigidoporus ulmarius, with the cinnamon tube layer and brilliantly white flesh.

The second horse chestnut sits in line for the toilets, patiently waiting for soneone to give it the 20p needed to get beyond the toll gate.

If you want, you can even sit down to inspect this tree!

This might well be this sporophore’s first season. I wonder how many more years it will see before it gets knocked-off or is aborted.

Half way up this steep hill, a beech stands seemingly without significant issue.

Oh, wait – here’s the issue!

Is that a shade of green?

From this shot, it looks most probably like Rigidoporus ulmarius. If so, we have two examples in one site of its cavity-dwelling abilities!

Greenwich Park also has a good number of large plane trees (Platanus x hispanica). The most abundant fungus on these trees was massaria (Splanchnonema platani), and there probably wasn’t a plane in the park that didn’t show at least some signs of its presence. However, it was the large plane with Inonotus hispidus that gained much of my eager attention, given I am not often around mature planes with extensive fungal decay.

A rather lofty plane tree.

As the crown breaks, we can spot a single Inonotus hispidus sporophore.

Whether there is an old wound at or around this site is hard to say, though for this fungus to be able to colonise one would expect so.

Perhaps an old branch stub above the fruiting body?

To round this post off, which has admittedly taken a long time to write, I’ll share some lovely images of a not-so-lovely bird – the parakeet (Psittacula krameri). Plaguing many of London’s parks and beyond, these things produce an utter cacophony and are certainly invasive, though one must admit that they are incredibly photogenic. Below, I share a few examples of where the parakeets were using cavities for shelter.

A horse chestnut monolith, seemingly vacant.

Wrong! Enter the parakeet(s).

This one stands proudly atop a pruning cut.

Along a plane tree branch, this parakeet appears to be guarding its abode.

“Oi m8, w0t u lookin’ @???”

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