The blog tends to write about trees in the context of woodlands and forests, but the trees to be found in hedgerows, parks, streets and gardens are important in many ways.  London is sometimes referred to as an urban forest, as it has some eight million trees within its boundaries.  Though their individual contributions of any given tree may be small, collectively the trees help with : Carbon storage  Carbon sequestration Air pollution removal Removal of pollutants (e.g nitrogen and sulphur oxides) Capture / removal  of particulates Reducing runoff, helping with flood mitigation  Noise réduction temperature regulation. The role of trees in temperature regulation has received some attention recently.   With climate change, many parts of the world have experienced periods of extreme hot weather / heatwaves.  Whilst it is true that extreme cold weather is associated with more deaths than hot, heat waves and the associated deaths are a significant problem.  Heatwaves, such as that experienced in 2015, have been associated with cardiorespiratory problems and premature deaths.   Cities, in particular, record higher temperatures than the surrounding countryside or the suburbs. the so-called urban heat island effect.  The lack of vegetation, the use of air conditioning systems, coupled with the dark asphalt of roads means that heat is retained / trapped; giving rise to the urban heat island effect.  On a summer’s day, some city centres may be some 10oC hotter than the surrounding countryside.  Europe saw its hottest summer last year, and its second warmest year.  Cities in southern and eastern Europe were particularly affected by recent heat waves. They tended to have significant urban heat island effects and low tree coverage.   In contrast, 27% of Gothenburg is covered by trees.  Studies / modelling by the Barcelona Institute for Global Health have indicated that increasing tree cover to 30% of the urban space could decrease the deaths associated with heatwaves / extremes of hot weather (perhaps by a third).  A number of cities, like Barcelona and Seattle have committed to increasing tree cover.  Indeed, Barcelona’s Trees for Life Master Plan is making progress towards its goal of covering 30% of the city with trees,  Barcelona is also encouraging green roofs.  Studies have also shown that ‘green spaces’ can have other benefits from reducing cardiovascular disease, poor mental health, and helping to improve cognitive functioning of children and the elderly.

Poplars belong to the same family as the willows. Like willows, they have a 'preference' for wet soil. There are a number of poplar species – white, grey and black poplar and the western balsam poplar,   A poplar that is common is the Lombardy Poplar, it is a variant of the Black Poplar and probably the most recognizable poplar,  as its branches grow almost parallel to the main stem.   It is a tall, thin tree. The leaves of black poplar (Populus nigra) are arranged along the stems in an alternate fashion. The leaf has a long, slender leaf stalk – which is slightly flattened. The leaf is sometimes described as ‘triangular’ or ‘diamond shaped’. When first formed, the leaves may have a bronze tinge and the young shoots, leaves and stalks have fine, tiny hairs.   The upper leaf surface is a dark green, whereas the lower surface is not such a deep green. In Autumn, the leaves may turn a vibrant 'banana' yellow. The bark of the Black Poplar is grey / brown and deeply fissured with age. The tree may grow to a height of 100 feet, but is usually smaller than this.  The species is dioecious, that is, there are separate male and female trees. In some parts of the country, like Cheshire, the number of Black Poplars is falling, due to changes in land management, a reduced need for particular timbers and an ageing population of trees.  The natural regeneration of black poplars is limited because : male and female trees need to be near each other the fertilised seeds are only viable for a short period  and the seeds need to fall on damp ground   Added to this, there is the risk of hybridisation with other forms of Poplar. So, The Canal and River Trust in conjunction with Chester Zoo have initiated a program to plant black poplar trees in Cheshire’s Weaver Valley.  They have taken cuttings from native Cheshire trees and raised over 1,000 new trees, which have been planted in sites across Cheshire since 1995. For example, male and female trees have been planted by the River Weaver (Hartford) to encourage future natural propagation. Such black poplars can help promote biodiversity, providing homes for moths, bees, birds and butterflies.   Should you have a portion of woodland that has damp soil, and are considering planting some black poplar, there is company that seems to specialise in Poplars : http://www.poplartree.co.uk/poplartree/.  It lists some of the uses / benefits of poplars.  

Various Wildlife Trusts are experiencing financial problems as a result of Ash Dieback.  Dead and dying trees are to be found in woodlands up and down the country, (some of which are managed by local Wildlife Trusts).    The fungus has its origins in Asia and has spread across Europe for the last thirty years. It was seen in Denmark in 2002, and has spread across the country by 2005.  It  is now to be found in  Austria, Belgium, the Czech Republic, Denmark, Estonia, Finland, France, Germany, Hungary, Italy, Latvia, Lithuania, The Netherlands, Norway, Poland, Slovenia, Sweden and Switzerland. It probably arrived here on imported (and infected) plants, though its spores are easily spread on the wind.  Once infected, the fungus affects the movement of water, minerals and sugars as the vascular system (xylem and associated tissues) is impacted.  Once a tree has been infected with the fungus, it may then be colonised by another pathogen such as the honey fungus (Armillaria spp).  Symptoms of ash dieback may include Shoot tips become black and shrivel, side shoots on young trees may die. Dead and ‘black’ leaves can be seen, their veins and stalks of turned brown.  Leaves shed early. Branches begin to dieback Diamond-shaped dark lesions form on the trunk near to dead side shoots.  In late summer, small white fruiting bodies can be found on blackened leaf stalks (see Jasper’s detailed blog). [caption id="attachment_39049" align="aligncenter" width="600"] the fungus emerging from blackened dead ash petiole.[/caption]   The dead and decaying trees pose a threat (as they become weakened and brittle), and need to be removed.  Removal is an expensive process and takes money from the Wildlife Trusts that would otherwise be used for habitat restoration, new planting etc. Apart from affecting the beauty of our woodlands and hedgerows, the loss of these trees has ‘knock on’ effects for other species.  Brown eared bats and barbastelle bats are known to nest in ash trees, the trees also provide perches and nest sites for birds and act as a substrate for epiphytes such as lichens and mosses.  The loss of ash tree will also affect the plants beneath, plants that like damp shady conditions such as lady fern (Athyrium filix-femina) and dog’s mercury; these may be replaced by light loving species / grasses. Featured image : Ash in winter Detailed information of Ash Dieback : https://cdn.forestresearch.gov.uk/2017/06/fcrn029.pdf [note this link downloads a PDF].  

In recent times, peatlands and areas of blanket bog have been recognised as important parts of our landscape.  Blanket bog is mostly found in wetter and more northern regions - in parts of Ireland and Scotland; in England a lot is to be found in Yorkshire.  Peatlands and bogs play an important part in controlling the run off of water from hillsides, plus they also represent an enormous store of ‘sequestered carbon’. The remains of plants (and animals) have been buried in wetlands but have not decomposed fully (usually due to the acidic conditions). Sometimes large chunks of trees are found in peat bogs, and occasionally even human remains (for example Tollund man) have been found.  Some of the peat deposits are incredibly thick and the material stored in them may be many thousands of years old.  Moorland ‘management’ techniques have been implicated in the severe erosion of certain areas, and the peat (that has accumulated over thousands of years) is being washed away. [caption id="attachment_32147" align="aligncenter" width="650"] Water logged conditions are ideal for peat formation[/caption] The UK has lost many areas of wetland habitat in recent times. A research team lead by Dr Swindles (Leeds University) examined many peatlands and looked at the changes that have occurred over the last two millennia.  They found that the majority of peatlands have become drier.  This drying out changes the role of a peatland from carbon sink to carbon source; i.e. releasing carbon into the atmosphere - contributing to global warming and climate change.  The streams and rivers that permeate these areas often turn a deep, rich brown as this organic material is washed out. [caption id="attachment_34388" align="aligncenter" width="650"] Stream flowing through peat moorland[/caption] Various efforts are being made to help stabilise these valuable ecosystems and a number of techniques to have been tried. At Fleet Moss, a North Yorkshire moor between Wharfedale and Wensleydale, the Yorkshire Peat Partnership project has been working to restore areas of degraded peatland by creating dams and reintroducing wildlife.  The conservationists have been using grass seed to try and stabilise the peat, hoping that as it grows and extends its roots, it will stop the peat from being washed away while allowing bog plants and sphagnum to flourish.  Sphagnum moss can hold 26 times its weight in water.   Their work is already bearing fruit,.  Originally, the land was largely acres of heather, with little variety in terms of the animals and plants that had made a home there. But over time, owls, frogs, foxes and weasels have appeared.  With time, the grass should stabilise the peat and allow bog plants to establish themselves. However, it has not been an easy process. Whilst the scattering of grass seed has worked in some areas, this does not always work everywhere, particularly on exposed sites; seeds can be battered by rain and wind.   Even at the height of summer, the weather on some of England’s highest terrain can be fierce, and scattering grass seeds on areas that are battered by wind and rain has proved to be problematic. So now in some areas a hydroseeder is being used where grass colonisation has failed. This is where green sludge and the bioengineering company TerrAffix come in. TerrAffix uses a hydroseeder to spray the mix of brash (chopped heather), grass seeds, fertiliser and a special adhesive (or tackifier), to areas facing particular challenges.  This equipment has been used to reseed prairies in the States, and can also be used on the steep slopes of motorways,   It will be some time before it is known whether this technique is successful in boggy and peatland areas.  If it does show signs of success then plugs of plants such as bog asphodel and sphagnum will be added, in the hope of recreating a more natural and diverse flora for the areas.   Further information on the restoration of peatlands can be found on Dr. Emma Shuttleworth's web pages and in articles such as this. Featured image is a 'book' made from bog oak.  

The soil and the litter layer in a woodland is teeming with many different forms of animal life, particularly invertebrates that include many types of insects (beetles, springtails), arachnids, spiders and mites (arachnids), centipedes and millipedes (Myriapods), roundworms (Annelids) such as earthworms.  One group of animals that is often forgotten is the woodlice, they are terrestrial crustaceans belonging to the same group as crabs and lobsters.  Their ancestors were probably amongst the first animals to make the transition from sea to land  (millions of years ago). Indeed, they are still confined to a moist / damp environment as they breathe through ‘gill-like’ structures on their back legs (pleopods) and their body surfaces are susceptible to water loss. Consequently, they are usually found in damp, dark places, under rocks and in decaying logs / wood; they tend to be more active at night (which again reduces the risk of dehydration).  To protect their offspring, their fertilised eggs are placed inside a fluid filled pouch (carried between the female’s legs, and they are provided with water and nutrients).  The young go through a series of moults before reaching maturity. Woodlice are detritivores, feeding mostly on dead plant and animal matter in the soil and leaf litter.  Once, they have ingested and digested this material, what remains passes out of their bodies and micro-organisms will continue its breakdown (forming part of what is termed the detrital food chain).  They excrete ammonia through their exoskeleton, so they have a ‘distinctive smell’.  The ‘blood’ or haemolymph of crustaceans contains an oxygen carrying pigment that is blue when oxygenated.  It is based around a copper atom, our red haemoglobin is based around an iron atom. There are five woodlice species that are common in the U.K.   The "famous five species”,  they are Oniscus asellus (the common shiny woodlouse), Porcellio scaber (the common rough woodlouse),  Philoscia muscorum (the common striped woodlouse),  Trichoniscus pusillus (the common pygmy woodlouse) and  Armadillidium vulgare (the common pill bug).  Common names for woodlice vary throughout the country.   Several of the names refer to the fact that some species can roll up into a ball (armadillo bug, roly-poly, roll bug).  Apparently, the collective noun for woodlice is a quabble.  

According to some interpretations of the bible, the Magi or ‘wise men’ travelled from afar bearing gifts of gold, frankincense and myrrh to present to the infant Jesus. The meaning and significance of these gifts has been debated over the years.  One things is clear - all were valuable materials as might have been presented to a king or deity.  Together with spices, frankincense and myrrh moved through ancient trade routes for thousands of years. Gold is a relatively rare element and as such is a precious metal that has been used for jewellery and coinage throughout recorded history.  It is a noble metal, that is it is relatively unreactive, resisting attack by most acids - with the exception of aqua regia, a mixture of nitric and hydrochloric acids. But what of frankincense and myrrh?   Their origins are not geological as both are plant products.  They come from a group of plants known as the Torchwood family or the Burseraceae.  These are trees or shrubs that have prominent resin ducts / canals.  The resin ducts are tubes, surrounded by cells which produce and secrete a resin into the canals / ducts.  The resin is viscous, ’antiseptic’ and aromatic (often smelling of almonds) and helps to prevents microbial attack (and may deter wood boring insects). Frankincense comes from trees of the genus Boswellia.  Nearly all species of this genus have a bark that produces an aromatic sap but it is B. sacra, (also known as the olibanum tree) that is the main source of frankincense (from its papery, peeling bark).  It is found in Somalia, Yemen and Oman, often growing in relatively inhospitable places.  To obtain the resin, the bark of the tree is cut and resin seeps out and is collected, rather like the tapping of a rubber tree.  The trees do not produce resin until they have reached a certain maturity and over-exploitation of the trees can lead to their death.  The seeds from heavily tapped trees are less likely to germinate than those from trees that have not been ‘drained’ of resin.  All Boswellia species are threatened by habitat loss, over-exploitation, and damage by long horn beetles. What is Frankincense used for?  The word derives from the Old French ‘franc encens’ meaning high quality incense.  Many tonnes of frankincense are traded each year and are used in religious ceremonies, and in the making of perfumes and natural medicines.  In ancient times, the Egyptians used it in the process of mummification, it was added to the body cavities together with natron (a mixture of sodium salts).  The resin has also been used in traditional Chinese medicine for its antibacterial properties and ‘blood moving’ properties. Like Frankincense, myrrh is a resin harvested by wounding the bark of a tree. The bark is a silvery grey, and the twigs are quite spiny (see image).  The resin that exudes is ‘waxy’ and quickly congeals becoming hard and glossy, darkening as it ages. The tree in question is Commiphora myrrha.  It is found in north east Africa - Somalia, Yemen, Eritrea and parts of Saudi Arabia.   The related Commiphora gileadensis, native to Israel, Palestine and Jordan, is also accepted as an alternate source of myrrh.  Myrrh has been used as an antiseptic in mouthwashes, and as a constituent in salve / ointment for skin abrasions, bruises and sprains.  It  has also been used in perfumes and  as a special flavouring for wine.  Like frankincense, it was used in making incense❋ and in the preparation of bodies for mummification / embalming.  In Exodus [30:22-24], God said to Moses to take the best spices and liquid myrrh to make a holy anointing oil.  Anointing oil is still used in certain ceremonies / rituals of both Eastern Orthodox and Western Churches.  In some cultures, it can be used to ‘fumigate’ or refresh a house, giving a warm, earthy and balsamic odour.  It is also said that myrrh is a powerful detoxifier, can lower cholesterol and stabilise blood sugar levels.  Both frankincense and myrrh were extensively traded in ancient and more recent historic times, along with various spices (such as cinnamon, ginger and nutmeg) across the Mediterranean and Arabian peninsula, through to India.  Interestingly, in Ancient Rome, myrrh was priced at five times the cost of frankincense. ❋ Incense can be made from various aromatic plant materials that produce a scent. The actual ingredients used vary by region / area. Apart from frankincense and myrrh, incense may contain cinnamon musk patchouli (from a plant of the mint family) sandalwood. Many thanks to Pixabay for images of frankincense and myrrh  (Leo_65, xbqs42  et al))   .

At this time of year, certain flavourings come to the fore.  Cloves, nutmeg and cinnamon are a bit more prominent than at other times of year.  Though widely used in many cultures and cuisines, they are perhaps more associated with the winter months and Christmas.  Nutmeg comes from a dark leaved, evergreen tree Myristica fragrans.   The tree is indigenous to the Maluku Islands of Indonesia (specifically the Banda Islands), but is now widely grown in Indonesia, Malaysia, Grenada in the Caribbean and Kerala in India. The tree is dioecious, that is to say, there are male and female trees.  Male trees are unproductive in terms of nutmeg harvest, so grafting of cuttings from female trees is often used to produce new plants.  The trees take some twenty years to reach ‘peak production’. The fruit of the tree yields the Nutmeg, and the covering of the seed (the aril) is the source of Mace.  The fruits are gathered up and dried in the sun (for some 6 to 8 weeks).  As the structure dries,  the husk (seed coat) and seed separate.  The seed coat or shell is then broken and the seed picked out; it is separated from the reddish aril, which is the source of mace.  The grinding of the seed yields nutmeg.  Nutmeg has a distinctive, somewhat pungent fragrance and contributes a warm, slightly sweet taste to food.  It is used to flavour mulled wine, punches and cider, added to pumpkin pie and can be used to ‘spice up’ baking, from gingerbread to muffins or chocolate and fruit cakes. Nutmeg oil, which can be produced by a process of steam distillation, is rich in terpenes (like pinene and limonene).  It, too, can be used as a food flavouring or in products like toothpaste !  Mace, from the covering of the seed, has a more delicate flavour (than nutmeg) and may give a saffron-like colour to dishes - which may range from meat recipes to Christmas pudding. Cinnamon is used extensively in many cuisines and even in scented candles.  It is one of the most commonly used spices in Sweden.  Indeed, such is the ‘importance’ of their cinnamon buns - kanelbullar - that the Swedes now have an official Cinnamon Bun Day - on October 4th!  [caption id="attachment_39202" align="aligncenter" width="650"] Cinnamon 'buns'[/caption] Together with other spices such as turmeric, saffron, sumac, and cardamom, cinnamon is widely used in Portuguese, Turkish and Persian Cooking.  The properties of cinnamon come from the chemicals - cinnamaldehyde and eugenol. The cinnamaldehyde is largely responsible for the flavour and aroma of cinnamon,   whilst the eugenol has a pleasant, spicy, clove-like scent.  Cinnamon comes from the inner bark of trees of the genus Cinnamomum,  the trees belong the Laurel family.  They are four main species associated with cinnamon production “ Cinnamomum verum  Cinnamomum burmannii Cinnamomum cassia  Cinnamomum loureiroi C. verum has its origins in Sri Lanka and is sometimes referred to as ‘true cinnamon’, with the material derived from other sources sometimes referred to as “cassia’.  The material derived from the different Cinnamomum species has different physical properties.  Ceylon cinnamon gives a thin inner bark of a light brown colour, with a crumbly texture.  It has a subtle and aromatic flavour. , whereas, Cassia has a stronger, spicy flavour (and is much used in baking).   Most of the world’s production of cinnamon cassia now comes from Indonesia and China.  Cinnamon and cassia are often used interchangeably.  The trees are evergreen, with oval shaped leaves and a thick bark.  When a tree is two years old, it is coppiced.  That is, it is cut back to ground level so that in the following year a number of shoots are produced, which are allowed to grow on for future harvesting.  When cut, the stems have the outer bark is scraped off so that the inner bark can be removed.  It is this material that is rich in the spice.  As it dries, it curls up into rolls or ‘quills’.  Like many spices and metals, cinnamon was extensively traded across the ancient world.  It was utilized as a perfume in rubbing oils and was also used as a fragrance in the mummification / preservation of dead bodies in ancient Egypt.  Nero was said to have burned enormous quantities of the spice / incense at the funeral of his wife (Poppaea).  In recent times, cinnamon rich materials have been investigated for medical uses, specially in relation to type 2 diabetes and blood sugar control. Thanks to Pixabay for images (Emmie_Norfolk and aga2rk)

Looking out of the window as I type this month’s fungi focus, it is difficult to believe that but a few months ago we were at the tail end of a prolonged and intense heatwave and drought. Now as we plunge towards the depths of midwinter, the traditional mushroom hunting season is already well past its peak. Like heat and dryness, most fungi seem to have little tolerance for frost, snow and ice. But there’s no need to be too pessimistic that it’s all over for another year. There’s still plenty of stuff out in the woods and after several years of writing in these blogs about what can be found in any given month, as far as I’m concerned the season is never really over. “Seek and you shall find” is my chosen mantra when I head out with my camera. In fact, I perversely prefer the winter months to the brief but intense height of the season during September to November, a period that yields so many discoveries that photographing and identifying them all can be onerous and overwhelming, and when the forest floor is so dynamic it is difficult to know what species to make the subject of these monthly focusses. Winter is a great time to concentrate on the less showy side of the fungi kingdom; the crusts and the jellies and the other little things you might not notice until you actively start looking. This is the time to persevere with getting that ever-elusive perfect photo of such commonplace species as Candlesnuff Fungi (Xylaria hypoxylon), for example. It is most likely that in the process, while crouched amongst the crisp leaf litter, your eyes will wander and you’ll end up discovering something else you’d might otherwise never have noticed. Candlesnuff With this end-of-year windup for the winter, I decided to focus on a species that has just emerged over the past month that might be lingering a little longer while we wait for Spring. I’ve written before how jellies such as the Yellow Brain fungus and the various other types some refer to as Witches’ Butter manage to resist regular freezing and defrosting and can be found many months after they first emerge. To the list we might also add Jelly Ears and Tripe Fungi, but also another one I’ve not yet covered, which is the Purple Jellydisc (Ascocoryne sarcoides). These can take a variety of forms, from walnut-sized and brain-like to the more discoid example one might expect from its common name. They start emerging mid to late November, when the temperatures first start dropping, growing in clusters on dead deciduous trunks and branches – often beech but certainly not always – as if oozing from the wood. One might assume from the shape and texture that these are closely related to Yellow Brains and Crystal Brains, but whereas these other jellies are basidiomycetes (producing their spores on external structures), Purple Jellydiscs are ascomycetes (with their spores developing internally in sac-like structures called asci) - again, I’ve regularly covered this crucial taxonomic distinction, such as for example in some detail here. I would label the Purple Jellydisc a very common fungi, in that I’ve found it in every woodland I’ve ever spent much time in, although it is not as conspicuous as the other jellies. Yellow Brains, for example, seem to be appear quickly and fully formed, while Purple Jellydiscs seem to emerge small and grow slowly.  Black Witch I’m not entirely sure they are as durable as these other “true” jellies either; I’ve monitored a single growth of Exidia glandulosa, the Black Witches Butter, for a period of almost half a year, watching it dry, inflate, freeze and defrost through the seasons, but I am not entirely sure if I’ve really ever registered Purple Jellydiscs past January. These are also rather drab in the winter light too, more reddy brown than purple, and more opaque than glistening. They are consequently rather difficult to get a decent photo of, although with artificial lighting one gets a better sense of its blanched beetroot hues and jelly baby-like texture. This should all be enough for the casual nature lover to be able to look at a specimen fitting this basic description and to ascribe a name to it. As usually seems to be the case in mycology however, with the two near identical Yellow Brain species proving the point wonderfully, there are a handful of other species in the Ascocoryne genus that look pretty much exactly the same and share similar environmental niches. To prove this rather maddening point, just a few weeks back, I found a group of purplish discs growing in clusters on a fallen beech trunk that looked nothing like any other Purple Jellydiscs I’d ever found before, but they did fit descriptions of Ascocoryne cylichnium, which has the common name of the Budding Jellydisc. First Nature describes this species as “similar but its fruit bodies remain cup shaped rather than merging into a brain-like form.” So far so good, I thought, and if I didn’t have a microscope in my possession, I would have left it at that. But as First Nature also wrote, that “it can only be identified with certainty by microscopic study of the spores, which are much larger than those of Ascocoryne sarcoides”, I decided to dive in for a better look. At this point, I was also informed of the existence of a couple of further species that looked pretty much the same: Ascocoryne solitaria and Ascocoryne inflata. They could only be distinguished from one another and identified with any conviction through close microscopic scrutiny of specific structural details. Needless to say, they don’t have English common names. Anyway, to cut a long and potentially very tedious story short, I did look at my sample under the microscope and it turned out after all to be your bog standard Purple Jellydisc, Ascocoryne sarcoides, after all. I don’t think there’s much more to add at this point beyond a Merry Christmas and Happy New Year to all who have read this far!