Both a friend and I had the pleasure of trecking around parts of the New Forest with a well-respected mycologist at the weekend. As you can very well imagine, we came across a wide variety of fungi – notably corticioids and polypores. Unfortunately, the poor light levels rendered getting decent photos of corticioids quite tricky (many were on standing hosts), so beyond some rather frequent Amylostereum laevigatum, Byssomerulius corium, Cylindrobasidium evolvens, Schizopora paradoxa and Vuilleminia comedens (which themselves were tricky to get good photos of) there weren’t many other opportunities. Regretfully, I therefore share below some images of poroid fungi and some larger Ascomycetes, though I hope you can nonetheless appreciate the finds!
We’ll start with a really cool find and a find that is my first for the species – the candlesnuff fungus, though not the stereotypical one! In this case, we have the candlesnuff of beech husks, known as Xylaria carpophila. As is evident in the species epithet, it likes to munch away on seed husks. Unlike its companion, it’s also much more slender and harder to spot. Your best shot is to peer into the leaf layer on the forest floor and hunt for some white hairs emerging from between leaves and from exposed husks.
We now move on to some splendid examples of Kretzschmaria deusta, in both its anamorphic and teleomorphic state. The first set of shots is showing ‘kretz’ tucked neatly within a very tight compresion fork of a large beech, with cambial dieback stretching quite far up the insides of the stems. Certainly a site for future failure! The following images show anamorphic fruiting bodies upon / ajacent to Ganoderma australe (again on beech – note that we were also told that Ganoderma applanatum is genuinely rare in the New Forest, with most finds being Ganoderma australe) and then on the underside of a very decayed beech log and finally a failed end. As both my friend and I remarked, this trip changes our perspective on the fungus, and we now recognise it as an important species in the effective decomposition of decaying wood from – or upon – dead (parts of) the host tree.
Moving towards the Basidiomycetes, the first set of photos to share is of Ganoderma pfeifferi on – you guessed it – beech! Honestly, this tree species is superb for fungi and probably the best of all native trees as regards to diversity and abundance. Some of the brackets on this beech has at least 20 sets of ‘growths’, suggesting they could be up to 20 years old!
Rather similar to the Gano is this duo of Fomes fomentarius. On a large dysfunctional lateral of a beech (who would have guessed…!?) that has subsided to the ground, we can see the two sporophores hiding amongst brash.
To round off (as I’m running out of time to write this post after a busy day at work!) I also share some Phellinus ferreus (now known as Fuscoporia ferrea). I won’t even bother noting the host as you’ll know already, and in both cases the sporophores are upon dead parts fallen from the host. Do note that the fungus also occurs on attached but dysfunctional (i.e. dead) parts of living hosts of species other than beech, too!
Trees, and more specifically groups of trees, are of significant importance to avifauna. Their provisioning of food, either directly (fruits, nuts, blossom) or indirectly (attracting insects and other types of prey), in addition to their ability to act as a nesting site, roosting site, or otherwise, makes tree presence absolutely crucial to a successful and healthy bird population. Of course, different bird species will respond favourably to different tree species and stand structures, and this – amongst other aspects – is discussed below.
As alluded to above, the structure of a woodland stand will have a marked impact upon bird species present within a site. For example, active coppice woodlands will provide habitat to bird species not frequently (if at all) found in old-growth stands or even coppice of over 11-12 years since the last cycle (Fuller & Green, 1999), though wood pastures, forest glades, and even agricultural fields bordering woodland may provide niche habitat for particular birds, of which many may be associated with grasslands and the transitional zone (ecotone) between grassland and woodland (Costa et al., 2014; Hartel et al., 2014; Hinsley et al., 2015) – including the nightingale (Luscinia megarhynchos) and the chiffchaff (Phylloscopus collybita), in the UK.
Stand structure will also impact upon the growth of young chicks, with some species growing better in older stands and others in younger stands (Hinsley et al., 2002). This is due to some bird species feeding up in the crown of a tree, whilst others forage near to ground level. For ground foraging birds, there will likely be a lack food sources available, where canopy closure has occurred; as will there be a lack of ground-cover for nesting (Fuller & Green, 1999). Similar conditions can however be created by grazing mammals, with deer being a notable example in the UK and North America (Gill & Fuller, 2007; McShea & Rappole, 2000). Furthermore, ground-nesting and ground-foraging birds are also more sensitive to disturbance, and therefore their presence may also be limited in high-traffic areas and locations where predators (and herbivores – including deer and other grazing animals) are found in abundance (Ford et al., 2001; Fuller, 2001; Martin & McIntyre, 2007; Schmidt & Whelan, 1999). Vehicular traffic may also be an issue, and notably when a woodland site runs adjacent to a busy road (Reijnen et al., 1995). Research has therefore suggested that established woodland sites, free of major disturbance and possessing greater structural diversity than succeeding woodlands or coppiced woodlands, will provide for a greater array of bird species (Gil-Tena et al., 2007; Hinsley et al., 2009), though even amongst structurally similar habitats the species composition of a site may have a marked impact upon bird species diversity (Arnold, 1988).
In fact, a greater mix of tree species may bolster bird diversity, as was demonstrated by Díaz (2006) when bird species in pinewoods and oakwoods were found to be lower than in a stand containing both species. By a similar token, species composition may impact upon bird species that forage amongst foliage for arthropods and other food sources. Investigations by Robinson & Holmes (1984), for instance, demonstrated that the distribution of foliage within the crown of a tree will impact upon the foraging ability of particular birds; as will, but only at times, the size (and other characteristics) of foliage. Similarly, as particular tree species will attract certain arthropods, the species composition of a stand will impact upon the constituent bird species and their abundance. Thus, a mosaic of habitats that is mainly – but not at all exclusively – mature and mixed woodland may be most preferable if seeking to attract many species of bird. Such woodland need not be extensive in canopy cover however, as wood pastures attract such an abundance of insects that insectivorous birds can be found in great abundance, assuming the land is not treated with pesticides (Ceia & Ramos, 2016).
Building upon the concept of stand structure, the presence of standing deadwood is also important for birds. Whilst cycles of management are beneficial for some species, those that rely on old-growth stands with minimal management intervention are heavily reliant upon standing deadwood as a source of habitat (Drapeau et al., 2009). Those species which nest within recently-dead snags (or dead portions of living trees), including the woodpecker (Smith, 2007) – though also many species of secondary (successional) cavity-nesting species – will far more readily be found in stands of significant age that contain tracts of large (over 30cm DBH) potential habitat (Bednarz et al., 2004; Remm et al., 2006). Granted, not all standing deadwood is equal. For example, in the forests of British Columbia, USA, woodpeckers will preferentially frequent trembling aspen (Populus tremuloides), to the point that 95% of all cavity nests are found within this species – even in spite of its limited abundance within forest stands (Martin et al., 2004). Similarly, forest edge standing deadwood may be more preferable for some cavity-nesting birds (Remm et al., 2006), and at times standing deadwood created through recent forest fires may be most suitable (Nappi & Drapeau, 2011; Saab et al., 2004). Therefore, post-fire salvage logging may be detrimental to cavity-nesting birds (Hutto & Gallo, 2006). It should however be noted that not all cavity-nesting birds will create their own cavities from sites of decaying wood, and may instead use natural cavities that have formed at the branch junctions of snags (Remm et al., 2006).
The benefits of standing deadwood extend beyond the mere provisioning of viable nesting sites, however. They also act as suitable feeding platforms for many bird species, again including the woodpecker. In particular, decaying snags with lower wood densities will provide the suitable conditions for foraging (Farris et al., 2004; Weikel & Hayes, 1999). This is because such decaying snags attract saproxylic insects, which are viable sources of food for birds (Drapeau et al., 2009). However, this does not necessarily mean that such snags should be extensively degraded, as research has also suggested that snags with only some deterioration (through fungal decay and fire damage) are optimal for foraging (Nappi et al., 2003; Nappi et al., 2010). Without question, larger snags will normally provide for greater foraging potential, and not only because of the greater diversity of foraging site types (small branches, large branches, and the stem), but also because of the greater surface area upon which birds (including woodpeckers) may forage (Smith, 2007). By a similar token, snags can also be used for perching and communicating (Lohr et al., 2002), which could be of advantage to predatory birds and breeding birds, respectively.
Coarse woody debris (fallen deadwood) upon the woodland floor can also be of use to bird species. Lohr et al. (2002) identify such downed woody debris as being important for foraging, perching, and communicating; albeit at a generally lesser rate than standing deadwood (snags), though not always (Spetich et al., 1999). Understorey bird species may also utilise downed stems for nesting. Where coarse woody debris is removed therefore, bird species diversity and population abundance will almost certainly suffer (Riffell et al., 2011).
Of course, it is not only standing (snags) and fallen deadwood (coarse woody debris) that are of benefit, but also the decaying wood of living trees. Typically, it will be trees with more extensive internal decay and thus thinner strips of functional sapwood that will be more preferable to cavity-nesting birds (Losin et al., 2006). However, it is the larger individuals within a stand that will again be more readily frequented, with research by Conner et al. (1994) finding that the red-cockaded woodpecker (Leuconotopicus borealis) requires decaying heartwood of 15cm in diameter (or greater) to form a viable nesting site. Such extensive and suitable heartwood can usually only be found in older trees (Hooper et al., 1991), which therefore outlines the importance of conserving old-growth stands and retaining mature individuals during harvesting operations. In fact, red-cockaded woodpeckers will seek-out older trees wherever possible, because of the greater heartwood extent found within such trees (Rudolph & Conner, 1991).
Furthermore, akin to standing deadwood, not all trees are equal in their provisioning of viable habitat for cavity-nesting birds. Certain bird species may favour particular trees that are being decayed by specific heart-rotting fungi. Using the red-cockaded woodpecker as an example again, it is understood that Pinus spp. being decayed by the heart rot fungus Porodaedalea pini (syn: Phellinus pini) are highly desirable sites for nesting for the species (Jackson & Jackson, 2004). Similarly, the great spotted woodpecker (Dendrocopos major) will commonly frequent large oaks complete with large tracts of decaying heartwood and fungal sporophores (Pasinelli, 2007).
Birds may also utilise the tree’s flower (florivore), fruit (frugivore), and seed crops (granivore), as a source of food. In fact, birds are considered the most significant dispersal agent of a tree’s fruit and seed crops, which is testament to the important relationship birds and trees have in this regard (Howe & Primack, 1975; Sedgley & Griffin, 1989). Certain birds are even associated largely with specific tree species, such as how the Eurasian jay’s (Garrulus glandarius) main food source is the acorn of the oak (Quercus spp.) (Vera, 2000). Open-grown mature trees may typically harbour the greatest crops (Green, 2007), and parklands, pastures (Galindo-González et al., 2000), savannas (Dean et al., 1999), and even gardens and orchards (Genghini et al., 2006; Herzog et al., 2005) may be home to many such trees.
Unfortunately, pressure on these environments, be it in the form of grazing, chemical applications (particularly in orchards), or simply human activities, has led to declines in constituent bird populations, in some instances (Bishop et al., 2000; Elliott et al., 1994; Thiollay, 2006), though historically orchards amongst extensively-grazed wood pasture were highly valuable for bird species, which would feed upon the abundance of insects (Barnes & Williamson, 2011; Oppermann, 2014). Beyond the open-grown tree however, copses, woodlands, and great vast forests all have the ability to harbour birds, courtesy of their crops. Secondary and regenerating stands may perhaps provide for the greatest abundance and diversity of food for birds, given that the greater light levels provide suitable conditions for a wider range of plant and tree species that flower and subsequently produce fruits (Martin, 1985).
Additionally, the better light conditions mean such fruiting species are likely to be healthier and produce bigger and more plentiful fruits, which is of importance to foraging birds that seek out proteins, fats and carbohydrates from tree crops (Sedgley & Griffin, 1989) and insects attracted to flowers. One example of this would be how the plentiful silver birch (Betula pendula) stands, in Belfairs Wood (Essex, UK) during the 1970s, over-masted quite significantly and consequently attracted very large numbers of redpoll and finch (Carduelis spp.), which all foraged eagerly for the seed. By-and-large, as birds will seek-out fruits and seeds that are larger than average and in healthy supply upon a tree (Foster, 1990; Wheelwright, 1993), it is perhaps not surprising that such regenerating stands are highly desirable. Granted, closed-canopy and late-successional stands also harbour tree crops (including the acorns of Quercus spp. and keys of Fraxinus spp.) that are of huge value to birds (Greig-Smith & Wilson, 1985; Koenig & Heck, 1988). However, the poor soils (nutritionally and hydrologically) of many mature woodlands adjacent to agricultural landscapes had led to – at least in Australia – declines in fruit and seed crops and, as a result, bird population density (Watson, 2011).
Moving away from the woodland and forest stands, though not entirely returning to open-grown trees, we can observe how trees within field hedgerows can be of huge benefit to birds, as can trees within agricultural windbreaks. Benefit may come in the form of landscape connectivity, where hedgerows and windbreaks act as corridors connecting woodland patches to one-another (Davies & Pullin, 2007; Harvey, 2000; Leon & Harvey, 2006; Morelli, 2013), though they may also be used – albeit perhaps less frequently now, courtesy of increased hedgerow management (at least, in the UK) – as nesting sites and foraging sites (Benton et al., 2003; Netwon, 2004). Grass buffers either side of the hedgerow may aid with suitability for birds, as may the presence of a greater number of large trees within a hedgerow (Hinsley & Bellamy, 2000; Herzog et al., 2005).
Within urban environments, the presence of trees and hedgerows adjacent to busy roads can however have a negative impact upon birds, by increasing mortality rates (usually associated with birds flying out into oncoming traffic). Research by Orłowski (2008) concludes as such. Of course, the presence of trees is also of benefit, much like within farmland hedgerows. Urban street trees, and also those within gardens, can improve landscape connectivity, allowing for bird species to travel between more significant areas of tree cover found in parklands and urban woodlands (Sanesi et al., 2009). In particular, connectivity to older parks with remnant woodland fragments will support a greater diversity of bird species (Fernández‐Juricic, 2000). The advent of large coniferous tree (and hedge) planting in many urban areas, courtesy of the planting of the cypress and other conifers (including Chamaecyparia lawsoniana, Cupressus macrocarpa, and x Cupressocyparis leylandii), has also led to an increase in resident bird populations and primarily because of the over-winter shelter such coniferous tree species provide (Jokimäki & Suhonen, 1998; Melles et al., 2003; Rutz, 2008; Savard et al., 2000). Furthermore, sheltered trees within the urban landscape that have abundant fruit and seed crops can be of huge benefit to birds, by providing essential food sources in an otherwise somewhat undesirable landscape. For such reasons, urban parks and woodlands may potentially provide the best conditions for certain feeding birds, though large gardens complete with dense vegetation may also be of great importance. Tree-lined streets may also be critical, and notably so if trees are large, have dense crowns, and have an edible fruit or seed crop.
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Here’s a nice one! As I was out surveying, there sat this large roadside beech (Fagus sylvatica) that sported a trio of sporophores of the lacquered bracket (Ganoderma resinaceum). Curiously, this association between host tree and parasitic fungus is a not-so-common one in the present day, in comparison to this fungus upon oak (Quercus robur) – in spite of the lacquered bracket historically being more common on beech than any other tree.
Evidently, judging by the past prunung cuts, an arboriculturist made the decision to manage this beech. Whether or not it was due to the presence of this fungus is something open to speculation, though there’s certainly reason to prune this beech once more for good arboricultural reasons associated with hazard management – notably because of the busy road directly adjacent to the beech. A PiCUS test might be the best investigative route of action here, though that decision remains with the landowner.
I’m sure that you’ll be able to appreciate the issue to do with hazard management, from the pictures below!
Whilst the presence of herbivorous slugs and snails within forest ecosystems has been far from extensively researched in the past – usually because of their low density within forests (Emberton et al., 1996), though high density hotspots may exist in ideal habitat conditions provided by trees that are practicably inaccessible (Cameron & Pokryszko, 2005) – there has been an increased focus on surveying for their presence because of their sometimes unexplained high mortality rates (Hadfield & Miller, 1989), because of deforestation and woodland degradation (Kappes et al., 2009; Schilthuizen et al., 2005), and because molluscs may act as an indicator of ancient woodland (Alexander, 2011). Such research has demonstrated how individual (and groups of) trees are critical for the survival of molluscs, with large expanses of woodland cover (at times, over 1,000ha) being necessary to sustain diverse and healthy populations. This may be because molluscs cannot travel with any degree of pace by themselves, and thus the standard concept of fragmentation and its associated isolation effects will not apply to such species so steadfastly (Kappes et al., 2009). However, more open wooded landscapes, such as wood pastures, can also support molluscs, and notably when such wood pastures have a higher canopy cover; either due to abandonment or a reduction in grazing intensity.
The stumps of trees, or other habitats containing deadwood (including veteran trees and coarse woody debris), may be of great value for molluscs – even, at least in the short-term, where their provision is due to thinning or felling of stands. For example, stumps generated through management regimes can act as an attractive resting and hibernation spot for molluscs (Fondo & Martens, 1998), though where deadwood may exist within floodplain areas, land molluscs may take a preference to standing deadwood in order to avoid flood waters (Kappes et al., 2014). However, the openness created by felling operations, as well as its associated disturbances, will detract from the quality of the landscape (principally through the reduction in humidity), and therefore sheltered and undisturbed deadwood sites are of particular importance to many terrestrial molluscs (Rancka et al., 2015; Remm & Lõhmus, 2016). Thus, the presence of deadwood (such as coarse woody debris, though also standing deadwood) within a damp woodland setting may be highly beneficial for molluscs with regards to resting (Kappes, 2005) – particularly during advanced stages of decay (Stokland et al., 2012). Deadwood may also be beneficial for predaceous snails, where the remains of other organisms can be digested, or living organisms can be predated upon (Kappes et al., 2006).
However, it is not always the trees themselves that provide molluscs with the ability to travel between isolated patches, or even within the same woodland patch, but other species the woodlands attract – deer and wild boar are but two examples. Molluscs may ‘use’ these mammals to travel vast distances – intentionally or not – thereby enabling for effective dispersal of offspring (Bruinderink et al., 2003). This is particularly critical in terms of genetic diversity, as populations of mollusc may be very similar on a genetic level even across wide distances (Hillis et al., 1991). In addition, slugs may feed upon the sporophores of macrofungi and slime moulds, which are themselves harboured upon a wood substrate or supported by the presence of trees (Keller & Snell, 2002; Rathcke, 1985).
Curiously, it is not just terrestrial land molluscs that benefit from deadwood (Lorion et al., 2009). Deep sea bivalve molluscs may, for instance, bore holes into and lay their eggs within deadwood that has been washed down from rivers and into the ocean, where it has then sunk to a depth of up to 500m (Tyler et al., 2007), or perhaps been provided by a sunken vessel. In addition to this, riverine molluscs may also be drawn to deadwood and be found in particular abundance where a river runs through woodland (Thorp & Belong, 1998). Furthermore, driftwood may transport molluscs across many kilometres of ocean and to new shores, where the molluscs on board can then begin to colonise the new landscape. Not only this, but sunken driftwood harbouring estuarine molluscs has also been linked to such estuarine molluscs becoming fully adapted to marine environments, to depths of 135m (Kano et al., 2013). Interestingly, this research suggests that the versatility of molluscs is not fully understood.
Marine bivalve molluscs may also utilise wood, harvested by humans and then used to construct naval vessels (ships), for transport across vast tracts of ocean. The shipworm (Teredo navalis) is a fantastic example of a marine mollusc that disperses itself via this process, and its destructive presence for such ships it colonised by boring into led to, particularly in the centuries gone by, the hulls of ships being dressed in copper (Grave, 1928). This – and other – shipworms (known as teredo worms), would also colonise upon sunken deadwood (from ships), and other man-made aquatic wooden structures, such as bridges, piers and groynes, causing sometimes irreparable damage (Britton, 1875; Nordstrom et al., 2007; Thompson, 1830).
Britton, T. (1875) A Treatise on the Origin, Progress, Prevention, and Cure of Dry Rot in Timber: With Remarks on the Means of Preserving Wood from Destruction by Sea Worms, Beetles, Ants, Etc. UK: E. & F. N. Spon.
Bruinderink, G, van der Sluis, T., Lammertsma, D., Opdam, P., & Pouwels, R. (2003) Designing a coherent ecological network for large mammals in northwestern Europe. Conservation Biology. 17 (2). p549-557.
Cameron, R. & Pokryszko, B. (2005) Estimating the species richness and composition of land mollusc communities: problems, consequences and practical advice. Journal of Conchology. 38 (5). p529-548.
Emberton, K., Pearce, T., & Randalana, R. (1996) Quantitatively sampling land-snail species richness in Madagascan rainforests. Malacologia. 38 (1-2). p203-212.
Fondo, E. & Martens, E. (1998) Effects of mangrove deforestation on macrofaunal densities, Gazi Bay, Kenya. Mangroves and Salt Marshes. 2 (2). p75-83.
Grave, B. (1928) Natural history of shipworm, Teredo navalis, at Woods Hole, Massachusetts. Biological Bulletin. 55 (4). p260-282.
Hadfield, M. & Miller, S. (1989) Demographic studies on Hawaii’s endangered tree snails: Partulina proxima. Pacific Science. 43 (1). p1-16.
Hillis, D., Dixon, M., & Jones, A. (1991) Minimal genetic variation in a morphologically diverse species (Florida tree snail, Liguus fasciatus). Journal of Heredity. 82 (4). p282-286.
Kano, Y., Fukumori, H., Brenzinger, B., & Warén, A. (2013) Driftwood as a vector for the oceanic dispersal of estuarine gastropods (Neritidae) and an evolutionary pathway to the sunken-wood community. Journal of Molluscan Studies. 79 (4). p378-382.
Kappes, H. (2005) Influence of coarse woody debris on the gastropod community of a managed calcareous beech forest in western Europe. Journal of Molluscan Studies. 71 (2). p85-91.
Kappes, H., Jordaens, K., Hendrickx, F., Maelfait, J.P., Lens, L., & Backeljau, T. (2009) Response of snails and slugs to fragmentation of lowland forests in NW Germany. Landscape Ecology. 24 (5). p685-697.
Kappes, H., Kopec D., & Sulikowska-Drozd, A. (2014) Influence of habitat structure and conditions in floodplain forests on mollusc assemblages. Polish Journal of Ecology. 62 (1). p739-750.
Kappes, H., Topp, W., Zach, P., & Kulfan, J. (2006) Coarse woody debris, soil properties and snails (Mollusca: Gastropoda) in European primeval forests of different environmental conditions. European Journal of Soil Biology. 42 (3). p139-146.
Keller, H. & Snell, K. (2002) Feeding activities of slugs on Myxomycetes and macrofungi. Mycologia. 94 (5). p757-760.
Lorion, J., Duperron, S., Gros, O., Cruaud, C., & Samadi, S. (2009) Several deep-sea mussels and their associated symbionts are able to live both on wood and on whale falls. Proceedings of the Royal Society of London B: Biological Sciences. 276 (1654). p177-185.
Nordstrom, K., Lampe, R., & Jackson, N. (2007) Increasing the dynamism of coastal landforms by modifying shore protection methods: examples from the eastern German Baltic Sea Coast. Environmental Conservation. 34 (3). p205-214.
Rancka, B., von Proschwitz, T., Hylander, K. a, & Götmark, F. (2015) Conservation Thinning in Secondary Forest: Negative but Mild Effect on Land Molluscs in Closed-Canopy Mixed Oak Forest in Sweden. PLoS One. 10 (3). p1-17.
Rathcke, B. (1985) Slugs as generalist herbivores: tests of three hypotheses on plant choices. Ecology. 66 (3). p828-836.
Remm, L. & Lõhmus, A. (2016) Semi-naturally managed forests support diverse land snail assemblages in Estonia. Forest Ecology and Management. 363 (1). p159-168.
Schilthuizen, M., Liew, T., Elahan, B., & Lackman‐Ancrenaz, I. (2005) Effects of karst forest degradation on pulmonate and prosobranch land snail communities in Sabah, Malaysian Borneo. Conservation Biology. 19 (3). p949-954.
Stokland, J., Siitonen, J., & Jonsson, B. (2012) Biodiversity in Dead Wood. UK: Cambridge University Press.
Thompson, W. (1830) Observations on the Teredo navalis and Limnoria terebrans, as at Present Existing in Certain Localities of the British Islands. Abstracts of the Papers Printed in the Philosophical Transactions of the Royal Society of London. 3 (1830-1837). p291-292.
Thorp, J. & Delong, M. (1998) In situ experiments on predatory regulation of a bivalve mollusc (Dreissena polymorpha) in the Mississippi and Ohio Rivers. Freshwater Biology. 39 (4). p649-661.
Tyler, P., Young, C., & Dove, F. (2007) Settlement, growth and reproduction in the deep-sea wood-boring bivalve mollusc Xylophaga depalmai. Marine Ecology Progress Series. 343 (1). p151-159.
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.
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!).
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.
It’s somewhat overcast at the moment and it’s rather cold outside, though that doesn’t mean the world grinds to a halt. Indeed, fingers might move a little more slowly and words might be slurred as the wind howls and the frost lingers, but one can retain enough sensibility to grab a camera and get out to look at trees and fungi. Perhaps this is when the urban heat island effect is appreciated a little, in fact – urban parks aren’t as cold as the open countryside! There’s probably a joke in there somewhere…
Poor jokes aside, my morning sojourn around an urban park and the adjacent streets was rather fruitful, in terms of fungi that could be found. Admittedly, as winter builds its temporary bulwark everything runs for shelter – fungi are often no different in this regard, with mycelium remaining cosily within its sheltered substrate. Sometimes, and notably for polypores, the weathered remains of old fruiting bodies signals the presence of colonisation, and thus many of the below finds detail this. Of course, one must still be able to identify the remains of fruiting bodies where they exist with some dignity, and therefore a mid-winter exploration can in fact yield very constructive results. For me, the diversity of finds in this state was quite pleasing, considering I spent perhaps two and a half hours essentially walking in circles. Granted, some fungi are true hivernophiles, so look out for fresh fruiting bodies, too!
My morning walk first took me to an oak I actually drove past two days prior, though unfortunately at the time I couldn’t stop. Thus, I detoured via this park first of all, and snapped a few (heh, a dozen…or two) photos of a senescent Laetiporus sulphureus with a great view of passing traffic.
Detour over, I made my way to the main site for my morning’s walk. The first tree (or monolith) I came across, which was a horse chestnut (Aesculus hippocastanum), shown earlier in the year in this blog post, I inspected once again. With much of the dryad saddle (Cerioporus squamosus syn. Polyporus squamosus – it had its name changed recently) now senescent and dressing the floor beneath, my focus was turned to the now much larger southern brackets (Ganoderma australe) and the myriad of silverleaf (Chondrostereum purpureum) sporophores that adorned the trunk. The latter were of interest to other park users, who were taken aback by the wonderful colourations of this species. In one of the below images, you’ll even be able to see its cerebral-like morphology.
From here, I turned my attention to a few nearby trees. One hacked-at purple plum (Prunus cerasifera ‘Pissardii’) was littered with Ganoderma australe and cushion bracket (Phellinus pomaceus) sporophores, though I admit I was more interested in the high-up Laetiporus sulphureus on a lofty black locust (Robinia pseudoacacia). This is an association that is rather frequent, and given the higher parenchyma cell content of black locust, is perhaps less immediately serious when compared to the fungus’ colonisation of willow (Salix alba, notably).
Not too distant from this false acacia stood this ash monolith (this park is full of them, which is great), complete with four sporophores of Perenniporia fraxinea at and slightly distant from the butt. As you’ll recall from my recent post on the hosts of Perenniporia fraxinea, it actually has quite a broad host range (add hornbeam to this mix, too), though ash is arguably its most frequent host. The examples here aren’t too brilliant, though the one on a main anchorage root provides us with a curious example of why we should not just look at the stem base of the tree for this species.
Not wanting to now litter this blog post with countless examples of Inonotus hispidus on ash, I’ll instead take you to a close relative of this species: Inonotus cuticularis. Most often found on beech (Fagus sylvatica), though sometimes also oak, it operates in a similar fashion to its relative on ash and is therefore found most routinely on or around branch and stem wounds. Here the beech was directly roadside (and just outside the park), and the wound the sporophores were seen on probably arose from a branch removed during road construction / management.
Funnily enough, this beech stood almost opposite a silver maple (Acer saccharinum) – again roadside – that sported a few sporophores of Ganoderma australe. The future of this silver maple is potentially questionable, at least in its current un-pruned state, given the aggressive pathogenicity of this fungus.
Getting back into the park, there are a few fingal finds that are interesting enough to be shared. The first we have already seen on this virtual fungal tour, though this time it was colonising a poplar (Populus sp.) and was still attached to the tree. Yes, I’m harping on about Cerioporus squamosus! Up high on an old pruning wound sat a small duo of sporophores, senescent and probably sun-, frost- and wind-scorched!
To round off, there was also another monolith (!!), and once more provided courtesy of a horse chestnut, acting as a host to two species of fungus: Ganoderma australe and the giant polypore (Meripilus giganteus). The southern brackets, by virtue of their perennial nature, endure winter quite effectively. The giant polypore, on the other hand, does not. Nor, probably, does it appreciate dogs tearing it apart and urinating upon it! Regardless, the sight of a wrangled and devastated Meripilus giganteus is a rather common one at this time of year, and for all you fungal sadists out there this is for you!
Winter is getting on but fungi are still doing their thing, and below are two of the better ones I found this last week. The chances are that those of you reading this have seen these two fungi before, though what is curious about the below tree-fungi relationships is either the spectacular arrangement of the fungi on the host or the unusual host species.
Abortiporus biennis (blushing rosette) on Sorbus intermedia (Swedish whitebeam)
This association is posted as it’s just a really great example of what this fungus can achieve – with regards to sporophore (notably as a teleomorph, where a hymenium is present and there is sexual reproduction) production – with the right conditions. The poor Swedish whitebeam certainly has seen better days, and has evidently died either nearly or entirely. Thus, the mycelium of the blushing rosette is having a field day, and is devouring the principal roots, as we can clearly see from the below images.
Ganoderma resinaceum on Crataegus persimilis ‘Prunifolia’
The lacquered bracket is supposedly rare, in the UK – nationwide, perhaps. However, in the south east of England, it’s actually rather frequent, and is usually found on oak and less so beech. However, there do spring up a few more obscure hosts, and beyond seeing it on willow and poplar, I have now also seen it on the broadleaved cockspur thorn. A search of records indicates no prior record of this association between fungus and tree, and therefore perhaps this is the first time it has been observed. Honestly, I doubt it, as people see things everyday and don’t inform the correct fungal authorities (namely Kew Gardens, for the Fungal Records Database), though it is nonetheless a really awesome find and it did make my afternoon!
Granted, an elder isn’t always a true ‘tree’, though it can and indeed will become one if allowed to. Unfortunately, as their presence is oft seen as a sign of a lack of management of a site (such as in unused brownfield sites), they are prone to being cleared when sites are re-designed. Of course, they can also be found developing in scrub (perhaps on old plotlands and within corners of allotment gardens), woodland edges and within established hedge lines – such old hedges may indeed be the last vestige of the elder in more urbanised and intensely-managed agricultural landscapes. Specimens within these hedges can therefore – by virtue of their age and size – sport some surprising fungal finds, as we can see below!