Oak trees, moths and resilience.
Ecology is concerned with understanding the relationships between organisms, and their relationship with their environment. This can involve how climate and soil influence the growth and development of organisms. Ecological studies may focus on a particular organism (autecology) or specific areas. One area that has been intensely studied is Wytham Wood, which lies just outside Oxford. The area includes ancient semi-natural woodland, secondary woodland, grassland and ponds. It is a designated SSSI, where some 500+ plant species and 800+ lepidopteran (butterfly and moth) species have been recorded. Records of bird populations go back some sixty or more years (with the work of David Lack and others); other ecological studies with long-term data include those on badgers, and also work on climate change. Wytham Wood belongs to Oxford University. Historically speaking, it is possibly the most intensely studied woodland in the world. Read more...
Woodland web updates 6.
Pesticides problems. The effect of pesticides on bees and bumble bees is now well documented. However, the combined effect of different pesticides is less well known. If pesticide A is known to kill 10% of the bees in an area that has been treated, and pesticide B kills another 10% then it might be reasonable to assume that 20% of the bees would be killed - IF the effects are additive. However, evidence is beginning to indicate that the effects of the pesticides is more than the sum of the parts - the pesticides work together / synergistically. Pesticide formulations that are sold to farmers are often ready mixed ‘cocktails’ so exposure to more than one pesticide is often the norm, so it is important that these co-operative effects are understood and known. Honey bees have been affected by not only pesticides but also varroa. Varroa is a mite, which lives and feeds on honeybees and their larvae. Fortunately, bees have complex hygienic behaviours, for example, removing dead larvae or pupae. Research indicates that honey bees are modifying this behaviour to deal with varroa mites. Helping pollinators Researchers at the University of Freiburg have recently published work establishing the importance of semi-natural habitat regions next to orchards and other agricultural landscapes for pollinators. Such areas (ditches, banks, overgrown fences etc) help ensure that flowers (and therefore nectar and pollen) are available over a significant period of time. This is important for pollinators such as hover flies, solitary bees, bumblebees etc. as nectar / pollen provided by crops is only available for a short and limited period. Such areas are also important for overwintering, nesting sites, providing food for larval stages etc). Their work focused on orchards near Lake Constance in Southern Germany. Soil remediation with lupins. There are many sites around the world where the soil is contaminated with metals (such as arsenic) as a result of past mining / industrial activities. Such arsenic contaminated soil might be ‘revived’ by using the natural mechanisms that some plants have evolved to deal with certain contaminants. The white lupin (Lupinus alba) is an arsenic-tolerant plant that might be a candidate for phytoremediation of soil. The tolerance of the white lupin to arsenic is thought to be due to the release of chemicals by the roots into the soil. Staff at the University de Montréal placed nylon pouches close to the roots to capture the molecule released. The chemicals were then analysed to see which could bind to the arsenic (phytochelatins). Phytochelatins are known to be used within plants to deal with metals but here they seem to be used externally. Quite how they work is yet to be determined.
August Fungi Focus: Yellow Stagshorn (Calocera viscosa)
Quite remarkably, this is the 50th of my monthly Woodlands fungi blog posts since I began some four years ago with a short piece on Chicken of the Woods. They originally went out unto the heading of ‘Monthly Mushroom’, but this changed to ‘Fungi Focus’ a couple of years back, with my piece on Ash Dieback reflecting how my own interest in the mycological world had moved past the point where the first question I asked when finding a new species was whether it was edible or not. Instead, the posts were intended to reflect the wider questions I began to ask myself around such ideas as where certain species fit within the wider woodland ecology and what wider purpose they might serve – questions that the more I continue to dig deeper into the subject, the more I realise how much more we still need to learn about this cryptic world. I’ve also hoped to show that there’s a lot more to fungi than the familiar agaric cap, gill and stem types – a world of crusts, rusts, discs and jellies that also leads into other related areas such as slime moulds. In fact, as I look back over my posts so far from 2021, I realise that only one of the subjects, the Fairy Inkcap, is a conventionally umbrella-shaped one. [caption id="attachment_35959" align="aligncenter" width="650"] Yellow Stagshorn (Calocera viscosa).[/caption] We are now moving into the peak season for the more eye-catching and recognisable fungi species, and I shall be returning to some more standard mushroom and toadstool examples over the coming months. Before this, however, I just wanted to dwell on a group of jellies belonging to the Calocera genus of ‘Stagshorns’ that have already started coming into their own, although they can be seen pretty much around the year. Geoffrey Kibby’s wonderful Mushrooms and Toadstools of Britain and Europe vol 1 (3rd edition published last year in 2020) lists five biological orders within the broad group of jelly fungi. The Auriculariales include Wood Ears and Tripe Fungus, as well as the two black species encompassed by the name Witches’ Butter, Exidia nigricans and Exidia glandulosa; while similar in form, the two yellow species known as Witches’ Butter belong to an entirely different order, Tremellales – the fundamental difference is that these types are not feeding on the dead wood itself (i.e. are saprotrophic) like the Auriculariales, but are parasitic on the mycelium of other fungi feeding within the dead wood. [caption id="attachment_35960" align="aligncenter" width="650"] Small Stagshorn (Calocera Cornea)[/caption] The Calocera species belong to a third order, the Dacrymycetales, which also includes the Common Jellyspot (Dacrymyces stillatus) that you might see proliferating all over fences, garden sheds and outdoor furniture in damp weather. (We’ll gloss over the other two orders Kibby lists that contain gelatinous fungi, Agaricomycotina and Sebacinales). Pat ‘O Reilly writes in First Nature that the name stems from the prefix ‘calo’’ meaning beautiful and that the ‘-cera’ part comes from the Ancient Greek for ‘like wax’, as indeed, these beautiful horn-like fungi do have a distinctive waxy texture to them. Within the Calocera genus itself there are 15 species, although just a few seem to be commonly found in the UK, and only two of these make it into most field guides. But they are all instantly recognisable, not to mention incredibly photogenic, despite their sizes making them surprisingly tricky to get a decent photograph of. [caption id="attachment_35961" align="aligncenter" width="650"] Yellow Stagshorn (Calocera viscosa)[/caption] Calocera viscosa, commonly known as the Yellow Stagshorn or Jelly Antler, is the type species for this genus – the species that typifies a particular group and which is considered the prime reference point for other species within it. Like the others, it is a bright yellow, with pale orange to red tints appearing in drier weather, although occasionally pale white versions can be found. The reason for the Stagshorn part of the name is fairly obvious. These grow in clumps of branching antler-shaped growths, like vivid yellow corals. They are not, however, related to other coral fungi, like the Ramaria species, which are a lot tougher in texture due to their flesh being the same solid mass of hyphal cells as the fruitbodies of normal mushrooms. The various Ramaria species seem to be a lot less common than the Yellow Stagshorn and in any matter, are not jelly fungi. The differences are easy to discern if you see them side by side than, though rather less easy to describe. If we ignore the superficial similarities, an obvious one is that if you try and take a sample of Yellow Stagshorn, it tends to squash between your fingers and it’s difficult to get home a piece home intact without it squishing or drying out. If you do manage to get to the stage of getting spores samples on a microscope slide, you’ll also notice that Calocera spores are white and more allantoid or sausage-shaped than the brownish more symmetrical ellipsoids of the spores of Ramaria species. [caption id="attachment_35962" align="aligncenter" width="650"] Yellow Stagshorn (Calocera viscosa)[/caption] Another feature that will points towards positive identifications of the Yellow Stagshorn is that they grow exclusively on conifer stumps and dead roots, I found one right at the base of the rare Antrodia carbonica crust fungi I found last summer on a Douglas Fir stump. They are typically not very large, seldom reaching 10cm in height, with several of my guidebooks listing a range between 2-8cm tall. This makes them relatively easy to spot but actually pretty tricky to photograph in terms of getting everything in focus. That said, they are considerably easier to snap than their relative, the Small Stagshorn (Calocera cornea), which appears in single pointed, non-branching protuberances, usually less than a centimetre in length and about a millimetre in width. You’ll see these spikes spreading almost like hairs across their hosts, the decaying wood of broadleaved trees, particularly beech. Again, quite striking and difficult to miss, but individually difficult to photograph without a macro-lens and, en masse, it is difficult to get everything in focus. [caption id="attachment_35963" align="aligncenter" width="650"] Small Stagshorn (Calocera Cornea)[/caption] Kibby and the authors of Fungi of Temperate Europe list a couple of other Calocera species. The Forked Stagshorn (Calocera furcata) is about the same size as the Small Stagshorn but has bifurcating tips like the larger Yellow Stagshorn, although appears dotted across its substrate rather than bunched at the base. Calocera glossoides grows in small single clubs, and while it doesn’t have a common name listed in the British Mycological Society’s list of English names, Kibby writes that ‘glossoides’ means shaped like a tongue. That leaves one more Stagshorn for our focus, the pallid looking and spatula-shaped Calocera pallidospathulata, or Pale Stagshorn. It is not dissimilar in form to C. glossoides, but it’s gelatinous flesh is pale and semi-translucent at the stem, yellowing at the top. This is a bit of an interesting one, this one, because while it appears to be a lot more commonly found than the previous two I’ve just mentioned, this was not always the case. [caption id="attachment_35964" align="aligncenter" width="650"] Pale Stagshorn (Calocera pallidospathulata)[/caption] In fact, according to this brief article ‘An alien tale: the history of Calocera pallidospathulata’, the species was only discovered in Yorkshire and subsequently named as recently as 1969. This wasn’t just the first UK record; it was the first record of the species anywhere in the world. How and where it came from remains a mystery, although the article claims that the renowned mycologist and slime mould expert Professor Bruce Ing has conjectured its origins might lie as far afield as Mexico. Certainly I focussed on a similar case of a fungi taking to British woodlands like a duck to water earlier this year with a blog piece on Crimped Gills. The Pale Stagshorn also seems to have spread rapidly across the UK. In the first decade since its initial 1969 sighting, it had been recorded in a number of locations across the north of England, but made the leap to the south with its first record in the New Forest occurring in 1989. Fungi of Temperate Europe describes its range as “Common in the UK, where probably introduced from North America, but likely to be spreading to other parts of temperate Europe, e.g. the Netherlands; all year.” [caption id="attachment_35965" align="aligncenter" width="650"] Pale Stagshorn (Calocera pallidospathulata)[/caption] I have to say, that while I have yet to come across Calocera furcata or Calocera glossoides, I did find a patch of Pale Stagshorn in a woods near Canterbury a few years back, so I can vouch for the fact that this particular species has spread to East Kent. Not that we should have anything to fear by this seemingly rapid spread. The Stagshorn species all appear on dead wood, and are not harmful in any way to living trees. Still, it makes one wonder what the processes and mechanisms might be by which more harmful species such as the Ash Dieback fungus might spread across the country. Supplementary images. [caption id="attachment_35967" align="aligncenter" width="650"] Pale Stagshorn (Calocera pallidospathulata[/caption] [caption id="attachment_35968" align="aligncenter" width="650"] Yellow Stagshorn (Calocera viscosa)[/caption]
Deer, damage and the pandemic.
Across the UK, there are several types of deer to be found in woodlands and rural areas namely : Red deer Sika Deer Roe Deer Reeves Muntjac Deer Fallow Deer Chinese Water Deer In recent times, the number of deer has increased and it is thought that there might be as many as two million wild deer in the UK - the highest number for many hundreds of years. Unfortunately, deer can cause substantial damage to trees and woodlands. Their feeding can cause a range of problems, which can include [caption id="attachment_34910" align="aligncenter" width="650"] Deer damage - bark removal[/caption] Stripping shoots, flower buds and foliage from plants Damage to woody stems, where a deer has bitten part way through the stem and then the shoot is tugged off - leaving a ragged end Eating the bark from younger trees. This mainly happens in winter when other food sources are scarce In addition to the damage associated with their browsing / eating activities, there is also the damage done by male deer who rub their heads / antlers against the trunks of younger trees. This rubbing may be for scent marking or to remove the outer skin (velvet) present on a new set of antlers. The antler rubbing results in cuts in the bark. [caption id="attachment_34415" align="aligncenter" width="700"] Remnants of birch woodland near Loch Muick are subject to browsing by red deer (especially in the winter), so temporary fences have been out in place to allow for regeneration and tree guards in place[/caption] Deer numbers are reduced by culling in order to supply restaurants, farm shops, and the hospitality sector with venison. However, with the onset of the pandemic and subsequent lockdowns / restrictions the demand for venison dropped significantly (as has price) so very few deer were culled. Consequently, the number of deer is increasing. Deer have probably gone through one or two breeding cycles since the first national lockdown, and numbers are set to increase. The increase in deer numbers not only affects the trees in a woodland but also plants of the herb and scrub layer. The loss of plant species and aspects of the structure of the woodland means that particular microhabitats are lost so that species such as nightingales and warblers are at risk. Without careful management of deer numbers, woodlands could become much more ‘uniform’ as deer have no natural predators (in the UK). It is important that deer numbers are monitored as they will do significant (most) damage to woodland in Spring as there’s not much food elsewhere for them. Young trees are particularly at risk, unless they are protected.
Heat, bumblebees and foraging
Silwood Park is part of Imperial College, a postgraduate campus, located some 25 miles west of central London, near Ascot. It is a centre for research and teaching in ecology and allied disciplines. The campus includes areas of wet woodlands, acid grasslands, traditional orchards and parkland. The veteran and ancient trees support an significant number of rare species of insects, lichens and fungi that depend on decaying wood. Silwood is the heart of the wildlife corridors for the surrounding area. Read more...
Protecting woodlands from pests and pathogens.
The fact that UK is an island has kept many potential pathogens and pests ‘at bay’. However, in recent times the growth volume of international trade has become a cause for concern. Pests and pathogens can ‘hide’ in important plants and plant products (for example, timber that has not been debarked or suitably treated). The Great Spruce Bark Beetle is likely to have arrived here in wood that had not had its bark fully removed. The beetle breeds under the bark of trees, creating tunnels resulting in the destruction of the cambium. The cambium is a highly active tissue, producing new cells that will go on to form xylem and phloem tissue. These tissues distribute nutrients and water around the tree. With a damaged cambium, a tree is weakened and more susceptible to other pests or pathogens. In the case of the Great Spruce Bark Beetle, a bio-control measure was allowed; a natural predator of the bark beetle has been introduced (Rhizophagus grandis). Consequently, the numbers of bark beetles have fallen. Wherever the bark beetle goes, its predator sooner or later follows. It is thought that its predator ‘finds’ the bark beetles due to the volatile chemicals released from the bark as a result of the beetles' burrowing activities. The U.K.’s control measures generally proceed by four steps : Try to prevents pests and pathogens arriving in the country eg. Inspection of plants etc at ports of entry If a foreign organism arrives then the authorities try to eradicate the pest / infected plants / trees, hopefully the organism does not become established If a pest or pathogen has become established then a containment policy is put in place If all of the above fail then the Forestry Commission and other bodies operate in a way that mitigates the effects of the pest or pathogen. Phytophora ramorum is a disease of many plants that probably arrived here through the plant import trade. It has persisted at a relatively low level for many years but from 2009 onwards it affected commercial stands of larch in South West England. Felling of infected trees helps restrict the spread of this fungus-like pathogen; and a map is available to show where outbreaks of this disease have occurred. Clearly, these introduced species of pest / pathogen could significantly affect the make-up of our woodlands over the coming years, if diseases like acute oak decline / ash dieback are not controlled or contained. Fortunately, the spread of disease-causing organisms and pests is monitored by both national and international organisations such as these : EU Plant Health Directive this requires nations to report new outbreaks or new pathogens, t the European Mediterranean Plant Protection Organisation is an intergovernmental organization responsible for cooperation in plant health within the Euro-Mediterranean region and the International Plant Protection Convention, a plant health treaty signed by over 180 countries.
August Fungi Focus: Oak Mazegill (Daedalea quercina) and Blushing Bracket (Daedaleopsis confragosa)
It is good to have points of orientation in the woods. No matter how familiar with a particular spot you might be, these environments can change so dramatically throughout the seasons – paths and clearings become overwhelmed with brambles, branches that weren’t an obstacle in the winter become suddenly more so when covered in leaves, and woodlands are ironically much gloomier in the summer months with a thick canopy overhead than when the trees are bare – that it’s surprisingly easy to lose ones bearings. One of the marker points in my favourite stomping ground, a chestnut coppice just outside of Canterbury, was a bracket fungus that I found growing from the top of a stump several years ago. It was a relatively easy identification for me from this sometimes daunting group – the labyrinthine arrangement of branching, elongated grooves quickly pointed me towards an Oak Mazegill, despite the fact it was growing on chestnut. Oak Mazegill For several years, this particular specimen by the side of the path also signalled the point where I knew I’d entered into a sector of more ancient woodland, and one of those hotspot areas where there were usually lots of exciting finds nearby. Then one day it was gone – the clean cut at the base where it grew from the wood indicating that is had been consciously removed with a knife. Even now, about a year later, I can still see traces of the patch where it had endured on the top of the stump for so many seasons. The Oak Mazegill, or Daedalea quercina – the first part of its latin binomial referring to the figure of Daedalus who in Greek mythology constructed the labyrinth at Knossos housing the legendary minotaur – is a particularly prevalent fungi in my local woodlands; much more so because, as a perennial, the fruiting bodies last for years rather than rot back or drop off at the end of the season. It shares this aspect with the tough woody brackets like the Artists Conk (Ganoderma applanatum), covered in passing in a previous post on brackets, which has been known to last for decades. Oak Mazegills aren’t quite as durable, although I’ve no real idea how long a fruit body might last. Their flesh is tough, but still possible to make a clean cut through it with a sharp knife with relative ease, as if it were a piece of rubber. Oak Mazegill This species highlights the importance however of always looking at the underside when trying to identify brackets. The top is rather nondescript, a sort of buff, pale yellowish brown colour ranging to orangish brown and reaches up to 20cm across. They often grow in semicircular tiers, with the full width of the body firmly attached to the wood making them very difficult to dislodge, and sometimes have an upside-down pyramidal shape, so that if viewed in profile, the maze-like underside is very easy to see. The growth isn’t always so uniform, however, drawing attention to the fact that there can often be a fine line between the brackets and certain poroid resupinate or crust fungi, with the form they assume heavily influenced by the orientation of their substrate. Oak Mazegills don’t always immediately form brackets when first emerging, with the specimen depicted here assuming a more resupinate form. For example, I found myself once very confused by a newly emerged Oak Bracket growing from the top of a stump that had yet to form a cap, so that all that could be seen was a think bulbous growth covered in brain-like grooves that could look like a number of other thick poroid resupinate fungi, such as the Common Mazegill (Datronia mollis) – and it should be mentioned that the Common Mazegill, while often found in its flat resupinate form, can form caps if growing on a vertical substrate, albeit with thinner caps of a far darker colour. The not dissimilar resupinate fungus the Common Mazegill has a less pronouncedly maze-like pattern of pores Mature Oak Mazegills, I do find pretty distinctive, but the reason I’m covering them for this month is that it is during the summer months that the new fruitbodies start emerging, so if you have any problems identifying them, I’d suggest going back and monitoring their progress over the coming months, for there are a couple of species that you could confuse them with before they are fully grown. The first of these is the Birch Mazegill (Trametes betulina), but these form much more delicate annual fruitbodies which are thinner fleshed and more easily broken, with grooves on the underside that are sharper edged and look more like conventional mushroom gills (although as I described in the post linked above, these aren’t true gills) and a felty upper surface. They also grow on birch, rather than oak or chestnut, so there shouldn’t so much room for confusion here. The Blushing Bracket is less ‘chunky’ than the Oak Mazegill, despite certain similarities when viewed from above. Rather more easily confused for the Oak Mazegill, however, especially in their early stages of growth, is Daedaleopsis confragosa, the Blushing Bracket. Again, these feel a lot slighter, thinner and flatter than the chunky, coarse gilled bodies of the Oak Mazegill, although the flesh is similarly tough. However the base is much narrower where it grows out of the wood, making it look more fan-shaped. Looking underneath, the pores are much less maze-like, and more like straight lines, which become more elongated as the cap grows radially outwards. The underside of the Blushing Bracket reveals very different patterns than that of the Oak Mazegill The cap surface starts out a pale beige, but as it grows, it darkens through pinks, browns, russets and vinaceous purples to near black, hence the name. They also are more pronouncedly ‘zonate’, with subtle differences in texture and colour appearing from the centre and outwards. The Blushing Bracket might be confused with a number of other long-pored brackets in their early stages, but if you follow their development across the months leading into winter, it soon becomes clear what they are. Again, they favour deciduous woods, but are less likely to be found on oak and chestnut than on birch, alder and willow. Some of the literature suggests that Blushing Brackets are perennials, like the Oak Mazegills, but my experience suggests that while the new fruit bodies from any given summer may be found well into the winter, very few make it past a year. Blushing Bracket : The upper side of the Blushing Bracket darkens and reddens across the winter months Blushing Bracket : Sometimes reddening to a dramatic deep red These are but a couple of the more common hardwearing brackets with elongated pores that are found in the UK that might seem a little drab when just glimpsed in passing, but actually are quite interesting when you know what you are looking at. Like so many fungi, the exact differences are difficult to describe precisely in words, but once you get a feel for them, they can be recognised at a glimpse. If you are a regular woodland wanderer, it’s worth paying at least passing attention to them because, as mentioned before, the new fruitbodies will have already begun appearing by now, and given that they’ll be with us for some months yet to come, it’s rather fascinating looking at how both species develop in form and colour. Additional images. Blushing Bracket Oak Mazegill Oak Mazegill Blushing Bracket
Birds from Woodcock Wood : Part 2 Our Nest and Nest Box Record
Checking nest boxes is deeply satisfying, and a fitting reward for all the time spent during “lockdown” making and installing a dozen or more new boxes. We now have 27 in the wood - some are specialised such as those designed for Treecreepers, some for large birds like our two Tawny Owl boxes, but most are standard boxes designed for the tit family. Checking the Boxes: There’s a strong feeling of anticipation when you lift the lid of the Blue and Great Tit boxes. Sometimes the adult is there and stays steadfastly put, or sometimes off she goes, revealing what? - a beautiful clutch of eggs, a huddle of chicks (featured image). Read more...