Peering inside a failed beech bole

The New Forest has no shortage of failed beech, given the fact that most of the beech are mature or veteran in age. Typically, the species of Ganoderma can be found to be devouring the remaining stumps and stems, though sometimes further fungi pop up in the most unexpected of places. In this case, looking inside the significantly-hollowed bole yielded a sight of various sporophores of the fungus Phlebia tremellosa (known commonly as ‘jelly skin’).

Because this species is considered to be generally be saprotrophic, the extensive decay (which appears to be caused principally by a white rot) wasn’t created by this fungus and was likely generated instead by Ganoderma australe and / or Ganoderma resinaceum. However, upon windthrow of the bole, or perhaps even before that time, spores of this fungus germinated upon the wood substrate and have since produced fruiting bodies. Such structures are also kept snugly within a consistently warmer and more humid microclimate, which has probably ensured they have endured the frosts that covered the outside world in the prior weeks.

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Peering inside a failed beech bole

Roadside Pseudoinonotus dryadeus in abundance

This is only a short post to close-off the weekend, though ideally one that is appreciated – notably, because it showcases the fungus Pseudoinonotus dryadeus in its senescent state and the associated pronounced buttressing employed by the host oak (Quercus robur). I don’t know exactly where this was, though it somewhere along the A371 in one of the villages between the border of Dorset and Somerset through to Cheddar (as if that narrows it down!).

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A sublime crown reduction, no doubt!
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Perhaps this has something to do with it – what came first, the topping or the fruiting bodies? Given the lean on the oak, I admit I don’t actually know. Maybe the pruning wound low down on the right saw a large chunk of the crown removed, enabling for the entrance of fungal propagules and leaving the tree so one-sided?
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Conks of Pseudoinonotus dryadeus litter the central region between two very significant buttress roots, though we can see how the decay extends beyond the strict basal zone. The fibre buckling discernible in the above picture around the location of the fruiting bodies indicates reaction growth, in response to said buckling under the white rot conditions occurring within.
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Tearing off a small fragment of one of the old fruiting bodies, we can see how spiders have used the bracket as a nesting site (assuming the white mass is a spider’s abode for eggs, which I have seen similarly in spent conks of Ganoderma spp.).
Roadside Pseudoinonotus dryadeus in abundance

Trees in the ecosystem pt I: Trees & fish

The extent of attention as to exactly how critical trees are for fish populations is unfortunately not all that significant (in comparison to the study or trees and birds, for example), though this is not necessarily surprising – this is perhaps because fish spend their lives largely under water, and thus their presence is not necessarily recognised to the degree it would be if fish were land-based organisms. However, there is certainly a healthy array of research that has been undertaken into this relationship of trees and fish within the forest ecosystem, as is demonstrated below.

Many undisturbed pools (areas of slow-moving or still water within in rivers and streams) in forests are either created or enhanced by the presence of deadwood (as either driftwood or sunken wood). Such deadwood presence can also raise water levels locally and create a diverse range of aquatic habitats (Hodge & Peterken, 1998) by damming up rivers and streams, and reducing flow velocity (Barbour et al., 2001; Gippel et al., 1996). Large woody debris (including fallen stems and large branches) is particularly critical in this regard, and research has shown that nearly 30% of pools within a stream or river may be created by such woody debris (Mossop & Bradford, 2004).

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A gathering of many fallen branches significantly obstructs the flow of this stream through the New Forest, UK. Such obstruction creates niche habitats on both sides of the log jam. Source: Author (2016).

Other research has, whilst not focussing on large woody debris exclusively, identified that as much as 75% of all pools may be created from submerged woody debris (Robison & Beschta, 1990a). Through the creation of these habitats, fish populations can increase, as their range of viable habitat increases – notably for feeding and spawning (Harvey, 1998). However, because even the largest of woody debris will likely not persist for over 50 years, there is a need for a continuous replenishment if streams and rivers are to retain the presence of deadwood-induced pools (Hyatt & Naiman, 2001). When pools are instead created by wood jams, which are made of small (and sometimes also large) branches and stems clustered together, their average viable retention time may only be between 2-3 years (Lisle, 1986). Again, a need for a constant supply of such deadwood is necessary, and this should obviously mean management practices retain trees that can constantly provide for such woody material (Robison & Beschta, 1990b).

Driftwood may be particularly beneficial for fish populations, as not only will its presence control flow velocity, but also protect its banks from erosion, create waterfalls and pools, and thus provide protection for fish spawning as well as increasing habitat diversity (Gurnell et al., 2002). Additionally, driftwood can provide hiding places for species of fish, assisting either in their predatory pursuits or in evading predation (Crook & Robertson, 1999; Werneyer & Kramer, 2005).

Sunken (or partially submerged) deadwood, for those fish species which are insectivorous, can also be highly valuable (Barbour et al., 2001). The wood’s provision of habitat for invertebrates means there is a potential abundance of prey for such insectivorous fish (O’Connor, 1992). A study into the effects of deforestation on wood input levels into woodland stream environments there unsurprisingly showed how reduced amounts of sunken deadwood led to reduced fish diversity and abundance (Wright & Flecker, 2004). In such wood-void streams, wood-eating fish (such as certain species of catfish, whilst not ‘true’ xylivores) may also suffer (German & Bittong, 2009; Lujan et al., 2011), though the loss of diversity in a stream (or river) environment, both because of reduced wood presence and the faster flow associated with such a lack of wood, may also have wider implications for fish species overall (Lancaster et al., 2001; Shields & Smith, 2002; Tsui et al., 2000); particularly when it is understood that a lack of (large) sunken wood is indicative of a degraded stream (Shields et al., 2006). It is also suggested that sunken wood may aid with orientation for fish (Crook & Robertson, 1999).

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Some significantly-decayed deadwood from a fallen willow (Salix sp.) will offer aquatic organisms – including fish – the opportunity to forage and seek shelter. Source: Author (2016).

Deadwood that has fallen and become (partially) submerged is also beneficial, as previously ascertained, because it creates pools within a stream or river ecosystem. These pools are areas of a stream or river where the flow is potentially very slow, and in the redwood forests of California downed trunks and branches of trees are considered to be crucial for constituent salmon populations (Barbour et al., 2001). Notably, in areas of steeper ground, this fallen deadwood can create tiers of pools, which actually enable salmon (that travel upstream to breed) to ascend up the river with more ease, as the salmon can ‘leap’ from one pool to another, and swim against a current with reduced velocity (which is critical for the enabling of salmon to conserve vital energy). These pools also reduce bankside erosion and catch up to 85% of sediment (which may amass behind a large branch or stem, though perhaps even more significantly amongst larger wood jams comprised of deadwood of varying sizes), ensuring the rate of sedimentation of the stream or river is slow and sustainable (Berg et al., 1998; Smith et al., 1993; Thevenet et al., 1998). This is important for the salmon, as females nest within the clean gravel beds in the riverbed, and any marked rate of sedimentation would prohibit this (Madej & Ozaki, 2009). These nesting sites may also, in fact, be located within close proximity to large pieces of woody debris (Senter & Pasternack, 2011). The very same deadwood can also support plant life, particularly when a large stem has fallen across a river, and therefore the plants growing atop the log can shade the river and keep the water cooler – this is also critical for the salmon, which prefer cooler waters (Welsh et al., 2001).

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This willow has fallen but remains alive, offering a further and somewhat different aspect to the aquatic environment. Source: Author (2016).

Across the United States, in the Appalachian Mountains, research by Jones et al. (1999) has also revealed that the reduction in sedimentation created by fallen woody debris is critical for other species of fish (including the rainbow trout Oncorhynchus mykiss), that spawn in sediment-free riffles within the forest areas of the mountains. Furthermore, their research highlighted that deforestation along riparian zones as little as 1km in length can have massive adverse effects upon the quality of habitat for fish, due to the removal of the source of such critical deadwood. The associated re-growth after the felling, whilst still injecting debris into the water courses, cannot match the size of the debris from older-growth stands, and therefore rainbow trout occur less frequently and at lesser densities (Flebbe & Dolloff, 1995). Deforestation also increases the risk of severe flooding and high flow velocity within the Appalachian Mountains, which can both extensively decimate viable habitat for rainbow trout within the ecosystem. In part, this is because such factors eliminate the fauna that occupy the river bed, which the trout almost exclusively predate upon.

Beyond the realm of deadwood, the beneficial impacts of shading by large trees adjacent to such aquatic environments can also improve the suitability of the habitat for fish (Beschta, 1997; Larson & Larson, 1996). Using the redwood forests as an example once again, it has been recognised that large conifers that reside by a water course cast shade and thus reduce maximum temperatures and the risk of thermal pollution (Madej et al., 2006). Such cooler temperatures, much like how deadwood can support plants that shade and cool waters, protects critical nesting locations for female salmon, reduces the subsequent mortality of juvenile salmon, and improves their growth rate.

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The shade this single hornbeam (Carpinus betulus) provides the river beneath, whilst not necessarily significant, will be of measurable benefit. Source: Author (2016).

Beyond California, the cooler waters created through significant (50-80%) canopy shading are equally as important for fish, for similar reasons (Broadmeadow & Nisbet, 2004; Broadmeadow et al., 2011; Swift Jr & Messer, 1971). Such canopy shade may also enable for rivers and streams to support macrophytes (plants growing in or near water), which can act as a food source for some fish species both directly and indirectly. Similarly, they can provide refuge for fish seeking shelter from predators (Pusey & Arthington, 2003). Therefore, retaining riparian trees is mandatory, if viable habitats for fish are to be protected (Young, 2000).

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A line of willow and ash (Fraxinus excelsior) dresses the southern side of this river, meaning the water remains continually shaded throughout the day. Source: Author (2016).

References

Barbour, M., Lydon, S., Brochert, M., Popper, M., Whitworth, V., & Evarts, J. (2001) Coast Redwood: A Natural and Cultural History. USA: Cachuma Press.

Berg, N., Carlson, A., & Azuma, D. (1998) Function and dynamics of woody debris in stream reaches in the central Sierra Nevada, California. Canadian Journal of Fisheries and Aquatic Sciences. 55 (8). p1807-1820.

Beschta, R. (1997) Riparian shade and stream temperature: an alternative perspective. Rangelands. 19 (2). p25-28.

Broadmeadow, S., Jones, J., Langford, T., Shaw, P., & Nisbet, T. (2011) The influence of riparian shade on lowland stream water temperatures in southern England and their viability for brown trout. River Research and Applications. 27 (2). p226-237.

Broadmeadow, S. & Nisbet, T. (2004) The effects of riparian forest management on the freshwater environment: a literature review of best management practice. Hydrology and Earth System Sciences Discussions. 8 (3). p286-305.

Crook, D. & Robertson, A. (1999) Relationships between riverine fish and woody debris: implications for lowland rivers. Marine and Freshwater Research. 50 (8). p941-953.

Flebbe, P. & Dolloff, C. (1995) Trout use of woody debris and habitat in Appalachian wilderness streams of North Carolina. North American Journal of Fisheries Management. 15 (3). p579-590.

German, D. & Bittong, R. (2009) Digestive enzyme activities and gastrointestinal fermentation in wood-eating catfishes. Journal of Comparative Physiology B. 179 (8). p1025-1042.

Gippel, C., Finlayson, B., & O’Neill, I. (1996) Distribution and hydraulic significance of large woody debris in a lowland Australian river. Hydrobiologia. 318 (3). p179-194.

Gurnell, A., Piegay, H., Swanson, F., & Gregory, S. (2002) Large wood and fluvial processes. Freshwater Biology. 47 (4). p601-619.

Harvey, B. (1998) Influence of large woody debris on retention, immigration, and growth of coastal cutthroat trout (Oncorhynchus clarki clarki) in stream pools. Canadian Journal of Fisheries and Aquatic Sciences. 55 (8). p1902-1908.

Hodge, S. & Peterken, G. (1998) Deadwood in British forests: priorities and a strategy. Forestry. 71 (2). p99-112.

Hyatt, T. & Naiman, R. (2001) The residence time of large woody debris in the Queets River, Washington, USA. Ecological Applications. 11 (1). p191-202.

Jones, E., Helfman, G., Harper, J., & Bolstad, P. (1999) Effects of riparian forest removal on fish assemblages in southern Appalachian streams. Conservation Biology. 13 (6). p1454-1465.

Lancaster, S., Hayes, S., & Grant, G. (2001) Modeling sediment and wood storage and dynamics in small mountainous watersheds. Geomorphic Processes and Riverine Habitat. 4 (1). p85-102.

Larson, L. & Larson, S. (1996) Riparian shade and stream temperature: a perspective. Rangelands. 18 (4). p149-152.

Lisle, T. (1986) Effects of woody debris on anadromous salmonid habitat, Prince of Wales Island, southeast Alaska. North American Journal of Fisheries Management. 6 (4). p538-550.

Lujan, N., German, D., & Winemiller, K. (2011) Do wood‐grazing fishes partition their niche?: morphological and isotopic evidence for trophic segregation in Neotropical Loricariidae. Functional Ecology. 25 (6). p1327-1338.

Madej, M., Currens, C., Ozaki, V., Yee, J., & Anderson, D. (2006) Assessing possible thermal rearing restrictions for juvenile coho salmon (Oncorhynchus kisutch) through thermal infrared imaging and in-stream monitoring, Redwood Creek, California. Canadian Journal of Fisheries and Aquatic Sciences. 63 (6). p1384-1396.

Madej, M. & Ozaki, V. (2009) Persistence of effects of high sediment loading in a salmon-bearing river, northern California. Geological Society of America Special Papers. 451 (1). p43-55.

Mossop, B. & Bradford, M. (2004) Importance of large woody debris for juvenile chinook salmon habitat in small boreal forest streams in the upper Yukon River basin, Canada. Canadian Journal of Forest Research. 34 (9). p1955-1966.

O’Connor, N. (1992) Quantification of submerged wood in a lowland Australian stream system. Freshwater Biology. 27 (3). p387-395.

Pusey, B. & Arthington, A. (2003) Importance of the riparian zone to the conservation and management of freshwater fish: a review. Marine and Freshwater Research. 54 (1). p1-16.

Robison, E. & Beschta, R. (1990a) Coarse woody debris and channel morphology interactions for undisturbed streams in southeast Alaska, USA. Earth Surface Processes and Landforms. 15 (2). p149-156.

Robison, E. & Beschta, R. (1990b) Identifying trees in riparian areas that can provide coarse woody debris to streams. Forest Science. 36 (3). p790-801.

Senter, A. & Pasternack, G. (2011) Large wood aids spawning Chinook salmon (Oncorhynchus tshawytscha) in marginal habitat on a regulated river in California. River Research and Applications. 27 (5). p550-565.

Shields, F., Knight, S., & Stofleth, J. (2006) Large Wood Addition for Aquatic Habitat Rehabilitation in An Incised, Sand-Bed Stream, Little Topashaw Creek, Mississippi. River Research and Applications. 22 (7). p803-817.

Shields, F. & Smith, R. (1992) Effects of large woody debris removal on physical characteristics of a sand‐bed river. Aquatic Conservation: Marine and Freshwater Ecosystems. 2 (2). p145-163.

Smith, R., Sidle, R., Porter, P., & Noel, J. (1993) Effects of experimental removal of woody debris on the channel morphology of a forest, gravel-bed stream. Journal of Hydrology. 152 (1). p153-178.

Swift Jr, L. & Messer, J. (1971) Forest cuttings raise temperatures of small streams in the southern Appalachians. Journal of Soil and Water Conservation. 26 (3). p111-116.

Thevenet, A., Citterio, A., & Piegay, H. (1998) A new methodology for the assessment of large woody debris accumulations on highly modified rivers (example of two French piedmont rivers). Regulated Rivers: Research & Management. 14 (6). p467-483.

Tsui, K., Hyde, K., & Hodgkiss, I. (2000) Biodiversity of fungi on submerged wood in Hong Kong. Aquatic Microbial Ecology. 21 (3). p289-298.

Welsh H., Hodgson, G., Harvey, B., & Roche, M. (2001) Distribution of juvenile coho salmon in relation to water temperatures in tributaries of the Mattole River, California. North American Journal of Fisheries Management. 21 (3). p464-470.

Werneyer, M. & Kramer, B. (2005) Electric signalling and reproductive behaviour in a mormyrid fish, the bulldog Marcusenius macrolepidotus (South African form). Journal of Ethology. 23 (2). p113-125.

Wright, J. & Flecker, A. (2004) Deforesting the riverscape: the effects of wood on fish diversity in a Venezuelan piedmont stream. Biological Conservation. 120 (3). p439-447.

Young, K. (2000) Riparian zone management in the Pacific Northwest: who’s cutting what?. Environmental Management. 26 (2). p131-144.

Trees in the ecosystem pt I: Trees & fish

Horse damage to mature and veteran beech

Grazing rights on commons must be safeguarded, for these rights are an historical relic of an otherwise aggressively-advancing culture. Indeed, there are a wide range of benefits from grazing, including the ecological, socio-economic and cultural, though the New Forest – and probably many (or all!) other sites where grazing occurs under tree canopies – is also subject to the damage associated with unrestricted grazing.

Certainly, the number of horses within the New Forest, the unrestricted nature of their movement and the lack of safeguarding measures (and probably food) around veteran trees has resulted in some quite substantial (yet currently rather isolated and sporadic) damage to the beech trees. I would expect much of the damage comes during winter, when the horses are searching for food that is not in such great abundance, and luckily (or not!?) I managed to watch a few horses de-barking a fallen limb and the butt of one particular beech tree (whilst another horse was grazing upon the lower branches of holly), in addition to some recent examples of damage on other beech.

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On the left, a horse is feastung upon some low-hanging Ilex aquifolium, whilst on the right a plucky horse tries its luck at beech bark.
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Here, we can also spy another horse stripping a fallen limb of bark, too.
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Notice more historic grazing wounds beneath the much fresher wound currently being created.
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Nearby, this particular beech yields far more significant damage. This damage might have even occurred earlier in the morning.
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The lack of any callus / woundwood growth proves how fresh the damage is.
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One can also appreciate the style of damage, causing by the teeth of the horses as they strip the bark.
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Some flies are themselves grazing upon the sugars of the phloem that is now exposed so extensively.
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In Bolderwood, this beech is accompanied by a sign, which educates members of the public about grazing damage – sort of.
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“Keep the ponies out!”, they ask. Whether tourists bother reading this I do not know, though perhaps it’s a new addition to the tree, which is actually in an area (Jubilee Wood) fenced-off from horses.
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Said with such a long face…
Horse damage to mature and veteran beech

Fungi everywhere on a single declining beech pollard, New Forest (UK)

I was forunate to be able to spend some time in the New Forest yesterday, having driven back from Somerset after picking up a microscope (more on that, in due time). When last down there, which was during mid-summer, I spent a few hours sojourning around the Bolderwood / Knightwood Oak ornamental drive, with specific focus upon the myriad of mature and veteran beech pollards that dressed the roadside. One beech, even then, alluded to fungal parasitism, given its dire vigour and evident crown retrenchment (perhaps associated with ground compaction, given its close proximity to a car park and the Knightwood Oak). Therefore, I paid a visit to this beech, with the hope of finding some fungi – and I wasn’t disappointed!

I’ll actually be honest and say this beech is testament to the ability for the species to provide for many wood-decay fungal species. I really don’t think I have ever seen a tree more covered in fruiting bodies of many species than this one, and we’ll run through the suspected species below. First, we’ll look at the tree as a whole, however, and from the first image I don’t think there’s any debate over its poor condition. Granted, with the impending demise of a tree, weak fungal parasites and saprotrophs can enter, and this alludes to the cyclical aspect of energy transfer. In time, this beech will be the food for other plants and trees, though for now it’s fungal food.

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I wonder how many more years this beech has before its snatched from the throes of life! Probably not many.
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The arrows relate to the various fungal species found. Working clockwise from the tip of the centre, I spotted what I suspect are Hohenbuehelia atrocoerulia, Chondrostereum purpureum, Mensularia nodulosa (confirmed), Exidia plana and Bjerkandera adusta.
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Here, behind a limb adorned brilliantly with one of the ex-Inonotus species, sit some fresh oysters (Hohenbuehelia atrocoerulea). Evidently, they are free from frost damage, suggesting they are probably only a few days old.
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There’s also a younger set emerging just behind this cluster in the foreground!
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Looking down the main stem, here we can observe how Chondrostereum purpureum and Mensularia nodulosa are inter-mingling. On the whole, it appears the Chondrostereum is more limited in its amassed substrate, if the presence of fruiting bodies are anything to go by – the ex-Inonotus species is abundant on the trunk and further up into some of the limbs.
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In this image we can identify how the two species really do run right up to their respective thresholds.
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For good measure, these are older sporophores of Chondrostereum purpureum. In their juvenile days, they’d have been far more attractive.
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Further round the trunk, we enter the sole territory of the Mensularia nodulosa.
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Angling upwards, the slotted nature of the tube layers becomes very evident.
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Down on one of the buttresses, this witches’ butter (Exidia plana) gets comfy amongst mosses. Note that it’s more likely to be this species of Exidia, as Exidia glandulosa is more often found on oak. To discern between the two however, you’d need to inspect some spores under the microscope.
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Looking more closely one can appreciate (I guess…?) why it’s called witches’ butter.
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And up on another limb, we have what is probably Bjerkandera adusta.
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It seems to be ejoying the decay column from the pruning wound and general dysfunction.
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There’s also some gilled sporophores in this one, which could potentially be Panellus stipticus, though they were too sparse and too small to see properly.
Fungi everywhere on a single declining beech pollard, New Forest (UK)

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.

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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!

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

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One of Greenwich Park’s many veteran sweet chestnuts with an added extra – a small and rather weathered…
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…you can see it…
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…Fistulina hepatica! Picked off by parasitism before it reached a respectable stature, it still nonetheless produced a hymenium and thus likely produced spore.
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A second sweet chestnut, this time slightly smaller, but again with Fistulina hepatica.
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The state of it is, however, diabolical!
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A smaller and thus younger sweet chestnut, in this instance.
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It sports a fungal fruiting body, nonetheless!
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A chicken of the woods, which is beaten and bruised.
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Another smaller sweet chestnut, and another Laetiporus sulphureus.
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Note how it emerges from behind a bark-covered area.
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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.

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A very mature false acacia, with a very mature Laetiporus sulphureus fan on the main stem.
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Well, sort of a fan – the remains of!
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I imagine someone yanked this off, as it looks like a rather clean break.
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Very close by, a second false acacia cradles another Laetiporus sulphureus.
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Here, we can see how it’s at the base of the main stem, in place of higher up the structure.
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This second one is far worse for wear!
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A double-stemmed Robinia pseudoacacia, which was once at least triple-stemmed.
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At the base, a senescent Perenniporia fraxinea and a cluster of broken active sporophores can be seen.
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For good measure,here’s a better look at the entire bunch.
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It’s a little disappointing that the fruiting bodies have been damaged, though that doesn’t stop them being Perenniporia fraxinea!
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And a second example of Perenniporia fraxinea on this false acacia, too.
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Right at the base, to the left.
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This one appears slightly different to how it’d usually look (it’s not photogenic!).
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Regardless, a showing of the trama reveals it as Perenniporia fraxinea.
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It looks like the park managers are aware of the decay on this Robinia, as it has already been pruned!
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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.
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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.

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This first example, on horse chestnut, is an interesting one.
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It’s the return of the cavity-dwelling Rigidoporus!
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Away from the wrath of the elements, this sporophore doesn’t have the algal green stain atop and bathes in its own substrate.
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A cutting identifies this specimen as Rigidoporus ulmarius, with the cinnamon tube layer and brilliantly white flesh.
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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.
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If you want, you can even sit down to inspect this tree!
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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.
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Half way up this steep hill, a beech stands seemingly without significant issue.
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Oh, wait – here’s the issue!
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Is that a shade of green?
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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.

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A rather lofty plane tree.
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As the crown breaks, we can spot a single Inonotus hispidus sporophore.
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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.
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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.

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A horse chestnut monolith, seemingly vacant.
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Wrong! Enter the parakeet(s).
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This one stands proudly atop a pruning cut.
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Along a plane tree branch, this parakeet appears to be guarding its abode.
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“Oi m8, w0t u lookin’ @???”
A wintry visit to Greenwich Park, London

Bridging walls for tree roots – when it actually happens, it’s beautiful

The tree is damaging my brick wall!“, they exclaim. “Fell the tree!“, they demand. Frankly, the word “no” would be sufficient, in at least a good portion of cases. After all, there’s an easy engineering solution that not only balances the need for a crack-free wall and the presence of a tree, but also signals ingenuity and a reasoned approach to situation management – the bridging of said wall around the butt of the tree and its immediatly-adjacent root plate. The issue is addressed in various publications, including Tree Roots in the Built Environment, and it is a message that needs to be communicated to homeowners and tree owners alike. More of the below, please!

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A fairly large sycamore (Acer pseudoplatanus) within touching distance of a low brick wall and a pathway. A recipe for disaster, surely? No! The tree can easily be retained via a simple feat of engineering, as we can see even from afar.
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Not only does the remaining wall have a much lower chance of being directly damaged by the secondary thickening of the sycamore roots, but it also saves on bricks!
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We can see how the roots sit snugly beneath the brick wall, and the tree is making itself even more cosy by girdling itself………… (?).
Bridging walls for tree roots – when it actually happens, it’s beautiful