We know that forests are important to all life on the planet.  They have often been referred to as the ‘lungs of the earth’, a reference to the fact that they produce vast quantities of oxygen - which is essential for respiration for so many forms of life.  They also take up carbon dioxide and ‘fix’ it into complex organic molecules - from starches, to cellulose and lignin.  Thus, the carbon is locked away for months, years or even millennia.  The equatorial forests of Brazil and Sumatra are species rich, incredibly diverse, but deforestation and the expansion of agriculture are threats to many biodiverse, forested areas across the world. As so many forests and woodlands have been felled, there is now a movement to plant millions and millions of trees (across the world) in an attempt to mitigate climate change and in the UK to increase our percentage tree cover from a pretty low base.  Sadly, twentieth century forestry in the U.K was largely based on monocultures (for timber production). The trees planted were large stands or plantations of conifers - using Scots Pine, Larch and Spruce. These plantations not only lacked biodiversity, but were / are susceptible to wide scale pest infestation and extreme weather events.   Woodlands and forests that have a diverse range of tree species are not only healthier but show greater growth and carbon fixation. They are more resilient.  The diversity of trees ensures the each species accesses slightly different resources from the environment  - from soil minerals, water and light.  Diversity means that trees of the same species are less likely to be clustered together so pest and pathogen outbreaks are less common or less severe.  One area that has undergone an extensive and diverse planting regime is Norbury Park Estate (near Stafford).  Since 2009, over 100 different tree species have been planted, and the woodlands can now produce 1500 tonnes of new wood each year, and harvest 5000 tonnes of carbon dioxide from the air.  Not only can diverse woodlands / forests fix carbon, supply harvestable timber but they also offer areas for rest and relaxation. Whilst it is not possible to plant an 'instant' forest or woodland, it is possible to plant a range of tree and shrub species that will in time grow and mature to form a diverse and species-rich area.  As Charles Darwin said many years ago “more living beings can be supported on the same area the more they diverge in structure, habits, and constitution” [On the Origin of Species by means of Natural Selection, 1859] Managing woodlands for wildlife - see here.   N.B.  Opens a PDF.    

‘The Fall’ in the eastern United States has been colourful and plentiful this year.  There have been bumper crops of acorns, maple seeds and pine cones.  It is a Mast Year.  The trees have produced enormous numbers of potential offspring. These seeds and fruits will have significant 'knock on effects' in the ecosystems for some years.   Beeches and oaks can release so many seeds that they significantly increase the organic content of the soil and its nutrient value.  This fuels fungal and microbial growth. Small mammals feast on the acorns / mast and their numbers increase.  They, in turn, are food for foxes, owls and other predators *.   Quite what drives a mast year has long been a cause of speculation.  Ideas have included  masting evolved to overwhelm seed predators (mice, squirrels etc.) and thus ensure that at least some seeds survive to germinate and grow on.  fluctuations in nutrient availability affect the trees and flower / fruit production environmental prediction - that masting occurs in those years when seeds are likely to have good weather for sprouting in the following Spring.   even sunspot activity has been invoked Recently, a database [MASTREE] was created of mast years (for Beech and Norway Spruce) that extends back centuries.  This has enabled scientists to explore the environmental prediction idea, that is, whether masting is correlated with climatic events and occurs when seeds are likely to have favourable weather for germination and growth in the Spring after their production. On comparing the data with climate records, they found masting events [in beeches] correlated with climate patterns associated with the NAO - North Atlantic Oscillation, i.e. changes in air pressure between Iceland (low) and the Azores (high).  A “positive” NAO phase favours both masting and subsequent seedling growth; that is warm wet winters promote seed production and dry springs favour seedling growth.  Quite how the trees turn such climatic events into ‘signals’ for masting is another matter. Not all are convinced however. Some argue that the resources used up in producing so many seeds / fruits mean that the trees are exhausted and it takes time for these resources to be replaced and for the tree to flower and fruit fully again.   Professor David Kelly has a somewhat different hypothesis related to weather .  He suggests greater warmth in the previous growing season(s) may be the trigger.  Quite how the trees ‘remember’ the warmth that they have experienced is not known; but one thought is that it is due to what is termed ‘epigenetic marking’.  It is possible that the DNA of the genes that affect flowering is changed by the warm temperatures.   The activation of particular genes can be altered by their DNA undergoing methylation - a process where methyl (-CH3) groups are added (or removed) from the DNA.  Further information on masting and climatic effects on trees - visit science.org * [Sadly, a Swiss study found good masting years were later associated with a rise in tick-borne disease.]  

Hungry caterpillars. Many insects feed upon the leaves of the canopy in woodlands and forests.  They can vary from aphids, leaf miners, sawflies to butterfly and moth caterpillars.  Every few years there are significant ‘outbreaks’ of particular moth caterpillars, for example, gypsy moth caterpillars. These caterpillars feed on the leaves of many broadleaved trees but are 'partial' to oaks [and poplars (Populus species)] in woodland / forest situations.  When their numbers of high, they can cause significant defoliation.   A study undertaken by researchers at Cambridge has revealed that moth outbreaks can have significant effects on the surrounding ecosystem(s).  As the numbers of caterpillars are so high, they eat large amounts of leaf material.  This has a number of consequences  The amount biomass in leaf fall in the autumn is reduced The caterpillars convert the carbon-rich leaves into nitrogen-rich frass. The caterpillars are not very good at using the leaf nitrogen for their own ends.  Frass is the excrement / faecal material produced by the caterpillars.   This frass can pass into streams / waterways and end up in lakes and ponds. Once in the lakes etc, it changes the chemistry of the water and it favours the reproduction of bacteria that release carbon dioxide. This happens at the expense of the algae, which remove carbon dioxide from the atmosphere. The amount of carbon entering streams and lakes is reduced in caterpillar outbreak years. Caterpillar outbreaks significantly affect the carbon and nitrogen cycles in woodlands and associated freshwater systems. Details of the work (which focused on forest and lake systems in Canada) can be accessed here.   Air pollution and wood burning stoves. Tiny particles called PM2.5 (released from a variety of sources, such as road traffic) pollute the air.  They are harmful to our health as they can pass into the lungs and out into the blood stream.  They then circulate around the body and end up in various organs.  One source of these tiny particles is the burning of wood in wood burning stoves.  One recent study has suggested that wood burning may account for some 40000 early deaths in Europe each year!  The biggest single source of PM2.5 air pollution in the U.K is domestic wood burning, which is said to produce three times as much pollution as road traffic.  The situation is similar across Europe.  Only 8% of the population use wood burners New wood burning stoves are said to be more environmentally friendly but they still emit more tiny particle pollution than an HGV truck. The ecodesign standard developed by the EU allows wood stoves to emit 375 g of PM2.5 for every GigaJoule of energy produced.  By contrast, an HGV can only release 0.5 g per GJ.  HGV have filters and catalytic converters that capture / reduce pollution.  The burning of wood in stoves involves many factors, including air flow, fuel quality / dryness and the amount of fuel being burnt.  Full details of the European Environmental Bureau report “Where there's fire, there's smoke.  Emissions from domestic heating with wood” can be found here . Bees, weather and disease. It is well known that weather has a direct effect the foraging ability of honey bees, now it is known that weather / climate also affect the incidence of disease in hives.  A study undertaken by Newcastle University has revealed infection  / disease in hives is affected by climatic variables. For example, varroa mite infestation increased as climatic temperature increased,  but was reduced during heavy rainfall and wind.  Full details of this investigation can be accessed here.

Climate change is affecting all parts of the world, from the melting of the ice caps in Antarctica, to droughts in Australia and California.  On a more local level, we may see changes in our rainfall pattern.  Certainly for many parts of the UK, it has been a very dry start to the Spring, coupled with some very cold nights. Cold and dry weather affects plant growth in significant ways.  Warmth is needed for a plant’s enzymes (catalysts) to work, speeding up reactions and allowing growth.  Similarly, if water is in short supply, growth is stunted; plants do not realise their full ‘potential’. They are smaller overall as is the number and size of flowers that they produce.  Flowers attract visitors by colour, size and scent; or combinations thereof.   Smaller and fewer flowers, in turn, have ‘knock-on effects’ for their pollinators - bees, bumble bees, hoverflies etc. The effects of drought on pollination has been recently investigated by researchers at Ulm University in Germany.  They studied the effect of drought on field mustard (aka Charlock) : Sinapsis arvensis.  This is an annual plant that is to be found in fields, waysides and field margins across Europe.  It has bright yellow flowers, with four petals.  It is visited by many different pollinators (it cannot self-pollinate).   The researchers compared the number of visits by bumblebees (Bombus terrestris) to drought-stressed plants to well-watered ones.  The data showed that as the number and size of the flowers decreased so did the number of pollinator visits.  [caption id="attachment_21589" align="aligncenter" width="600"] Bumblebees also favour the teasels[/caption] The ‘attractiveness’ of the plants / flowers to pollinators was reduced, and it is possible that the smaller flowers were more difficult for relatively large pollinators (like the bumblebees) to ‘deal with’.  If pollen movement is reduced, then fewer fruits / seeds will be set and (insect pollinated) plant populations could decline.  The effects of reduced rainfall and water stress need to be considered alongside the declining number of pollinators.  The reduction in pollen movement has lead some to speculate that it might lead to a selective pressure for self-pollination / self-fertilisation, with plants dispensing with the need for visiting insects.  Other Woodlands blogs have reported on the falling numbers of insects / pollinators. Featured image : garlic mustard.

A magnificent book about a woodland which dominates south London, even though only pockets of the woodland remain.  The author pulls off the trick of using the story of the Great North Wood to relate centuries of social history and much about woodland ecology.  It's gritty, too, and it soon becomes apparent that Christopher Schuler doesn't just volunteer in Dulwich Woods, a sizable remnant from the Great North Wood, but he also loves the woodland. The Great North Wood was really big - several thousand acres in extent - stretching seven miles from Croydon to Deptford and even the remaining segments run from Dulwich to Norwood (a shortened version of "North Wood").  It was also an important resource for many centuries mostly for firewood, building timbers and of oak trees for naval building.  But Schuler demonstrates the richness of its history and the contradictions in the way it has been managed - in the 18th century cash payments were made by the parishes to anyone bringing in badger heads or other "vermin", which we would now consider valuable wildlife. One tradition which Schuler explains went on for centuries, was the "beating of the bounds" where on a set day on April (25th, Rogation Day) every year the Parish boundaries were followed on foot by a formal group.  The members of this group would literally beat sticks against trees along the boundaries and mark some by carving crosses into them.  In order to make sure the boundaries were remembered they made sure that old men were included who remembered earlier "beating of the bounds" and teenage boys who would be expected to remember the boundaries for decades to come.  In order to help them remember more clearly their hands were sometimes pricked at key points so that they would be more likely to recall the spot. Often there was merriment and drinking on such occasions but there was also a seriousness as at certain notable points the priest would say prayers.  One of the more famous spots was the Vicars Oak at the end of the road which is now called Crystal Palace Parade.  This was a tree on the boundary of three different parishes and being at the top of a ridge was visible for miles around. [caption id="attachment_36450" align="aligncenter" width="650"] The North Wood[/caption] Many bodies influenced the course of the woodland - for a long period it was forbidden to cut any oaks for other than naval use in order to ensure the navy had enough timber which could be moved to a navigable waterway. The dominant owners over the centuries were various church organisations, although the freehold of most of Dulwich Woods now belongs to the Dulwich Estate and Southwark Council.  Both organisations tried to build housing on the woodlands in recent decades but this has been successfully resisted by conservationists, and the London Wildlife Trust (LWT) now manages most of the Dulwich Woods part of the Great North Wood.  Many people volunteer for the LWT and some have fought hard to stop oak trees being felled for bridge repairs or other expedient reasons. Christopher Schuler's "The Wood that Built London" will be the defining work on the Great North Wood for a long time to come. It was through the industry of London's labourers, as Schuler states,  that "the Great North Wood fuelled - quite literally - the growth of the great city that would ultimately consume it."

Not all mushrooms have gills. Some, like the boletes, have pores on the underside of their cap. Others have arrays of downward-facing spikes that look like teeth. This third category are described as hydnoid, and include such aptly named species as the Wood Hedgehog (Hydnum repandum) and this month’s fungi focus, the Earpick Fungus (Auriscalpium vulgare), also known as the Pinecone Mushroom or Conetooth. These teeth, like gills and pores, constitute the ‘hymenium’, the fertile surface in basidiomycetes fungi on which spores develop and from which they are released. Look under a microscope at a mushroom gill or the inside of a pore or the edge of one of these teeth, and you will see it coated with thousands upon thousands of tiny spore-bearing structures known as basidia (as opposed to the other group of fungi, the ascomycetes, where the spores develop and are fired out from tubelike structures known as asci). These gills, pores and teeth are nature’s ingenious way of maximising the spore releasing area that contain the basidia.  Two toothed fungi species - The Ochre Spreading Tooth and the Fused Tooth It should be pointed out that not all of the toothed fungi are of the mushroom-shaped cap-and-stem variety. There are also bracket and resupinate hydnoid types, like the Ochre Spreading Tooth (Steccherinum ochraceum) or the leaf litter-dwelling Fused Tooth (Phellodon confluens). However, all these examples point to the important rule I always emphasise when trying to identify fungi or taking a photo for someone else to do the job for you – always look underneath! To be honest, you’d find it pretty hard to mix up the Earpick Fungus with anything else at first glance anyway. Not only does its felty brown kidney-shaped cap, perched atop a slender but bristly stem, with row upon row of downward-pointing teeth on its underside, make it look like some weird alien monster you’d expect to see in a film like Little Shop of Horrors or in a Pokémon game. Its identity is also defined by its specific substrate of pinecones or other conifer-related litter. Earpick Fungus That is if you notice them in the first place. Earpick Fungi don’t tend to get much larger than 5cm in height and their caps reach around 3cm across at their widest point – as mentioned, the caps are kidney-shaped rather than circular, with the stem on one side of it rather than the centre. Their dun colouration makes them blend in with their conifer cone hosts, so you’ll probably only find them if you’re actively looking. But get down to ground level and look closely and you’ll see nothing else like these stunning little things. Just how unusual are they then? There seem to be a number of other species in the Auriscalpium genus (the Latin name literally translates as ‘ear pick’), according to its Wikipedia entry, but Auriscalpium vulgare is the only one found in the UK thus far. Indeed, it is considered the type species for Auriscalpium - the first of its kind discovered (in 1821 by the British mycologist Samuel Frederick Gray) to which all others in the genus are compared. Earpick Fungus The First Nature entry describes them as “infrequent and apparently localised”, which could mean that they are under-recorded because they are so inconspicuous and that the few people who do know where to look and what to look for are the same ones recording their discoveries on general websites like iRecord or more fungi specific ones like The Fungus Conservation Trust database. Fungi recording being the piecemeal process that it is, they may be a lot more widespread than we might assume, and indeed, photos turn up on various specialist fungi social media groups fairly regularly. This is not to say I would personally pick them, even to take home for closer analysis or to look at spore samples. I know there are plenty of foragers out there who are beholden to the mantra that a mushroom is only the fruiting body of the larger fungi organism and therefore picking them does no harm. As they argue, the rest of the mushroom is in the form of an expansive network of mycelium that is hidden underground, so it is essentially the same as picking an apple from a tree. Clearly the logic is flawed for both the Earpick Fungi and many other species, even if it did make a for a particularly choice edible (which by all accounts it doesn’t). Clearly the mycelium of this particular specimen is limited by the edges of its pinecone substrate, and therefore the ratio of its fruitbody size to the entire organism can only be very low.  Earpick Fungus In other words, the effort that the Auriscalpium mycelium in the pinecone channels into putting up a single fruitbody must be considerably more than that of, say, an ectomycorrhizal species like a Russula or Agariuc, where the mycelium forms an expansive network stretching around and beyond the roots of its host tree. Therefore picking it removes a substantial part of the organism, if we assume the fruitbody to be an inseparable part of the organism. If you do come across one, it is probably best to leave it there intact to continue releasing its spores rather than picking it from the cone and risking killing it off entirely.

Along with my wife Marie, we purchased a 3 ½ acre semi ancient woodland in South Wales from woodlands.co.uk in April 2020.   The site has a gentle slope from a country lane down to the river Rhymney, we have 2 springs, a stream, a wide variety of broadleaf trees, shrubs and a small amount of pine.   Much of the site had been neglected for many years and so with help and advice from others and a great deal of hard graft by Marie and I we are bringing the site back to a sustainable future. It is a delightful place to be, family and friends all enjoy spending time there and I don’t think I have ever been to the woodland without seeing or discovering something new.   We made a decision early on that an open area next to the river would be a good place to grow willow but we also wanted to utilise some willow for basketry. We had experience of neither.   The river can breach its banks and wash over the area occasionally although this is generally very short lived.  Although the rest of the woodland will be maintained with native species, the willow area is an experiment and we decided to plant a variety of species for basketry, some of these are non-native. We read a great deal about varieties, planting and harvesting and decided on the varieties we wanted to grow.   A very useful book titled Willow by Jenny Crisp gave us a lot of helpful information and ideas.  We based our choices around colour, they range from golden brown to yellow, red, green and black. Each variety will grow to different lengths in the same year once established, some as much as 17 feet. We searched on the internet for suppliers of cuttings for planting and were very fortunate to find a supplier, https://hattonwillow.co.uk/ based only a few miles away in Caerphilly.   Hatton Willow is run by a Sarah Hatton*, she has a plantation with 1000’s of willows and supplies cuttings for planting and basketry, runs basketry classes and makes various commissions as well as the odd appearance on 'The Repair Shop' and 'Country File'. The plants are supplied as rootless cuttings, about 12 inches long in the winter and need to be planted between November and March.  You are advised to lay weed suppressant material and to push the cuttings through this into the ground. If like us you are growing for harvesting, each row is planted 60cm apart and the cuttings 30cm to 60cm apart depending on the variety. This close planting ensures that the sticks grow straight and long and can be easily harvested the following year. We ordered 100 cuttings, 10 of each variety so the area taken up is relatively small. 100 plants won’t give us enough willow to go into production but supplemented with some bought sticks will give enough eventually to make some items for our own use. Once the leaves have dropped, we will cut this years growth back, some of which will become cuttings for new plants and over the years as the plants produce more sticks, we will have more to work with. The above image shows the growth on a few of this year’s saplings. Not as vigorous as we had hoped but next year they may establish better.  With our willows in the ground, we booked a course at Hatton Willow and used some of the £300 funding provided by woodlands.co.uk as part of our purchase to fund the course.  The  session taught us how to make a trug, the courses just span a day, all materials and tools are supplied and at the end of the day you come away having learnt enough of a new skill to repeat the work,  an understanding of the material and  expanded your knowledge  and created your own hand-made basket. What Next for us?  The options are endless, willow hurdles for our allotment, Christmas wreaths, nesters for birds, green willow sculpture, who knows, we’ll keep you posted. Marie and Marcus Beard. * Sarah runs her courses at the Nantgarw China Works, a venue worth a visit in it’s own right. Osier : Willows, also called sallows and osiers, from the genus Salix,  found primarily on moist soils in cold and temperate regions of the Northern Hemisphere.

The changing colours of the leaves in autumn is a phenomenon that affects the vast majority of deciduous trees (and some conifers, eg. Larch).   The leaves change from green to various shades of yellow, brown, orange, red and even purple.  The nature of these changes has been the topic of a previous blog. What is interesting is that this colour change is particularly marked in the trees of the North Eastern region of the United States. Indeed, bulletins are published listing the best places to see the myriad of colours that the trees display.  This difference in the colours of American and European trees was commented upon by Thomas Meehan,  back in the nineteenth century.  Meehan first worked as a gardener at Kew but later moved to Philadelphia (where he is credited with saving Bartram’s Garden). His botanical studies led to him being the editor of The Gardener’s Monthly, writing articles for various newspapers and authoring 'The Native Flowers and Ferns of the United States'.  In 1881, Meehan noted in a paper presented to the Proceedings of the Academy of Natural Sciences of Philadelphia, (Vol 33)  that the intensity and variety of autumnal colours was much greater in the States than in Europe.  He suggested that the difference might be due to the “American light” and that European trees might (after many generations) adapt to this light and then show similar colours.  Recently,  Renner and Zohner* have investigated this difference.  Their paper(s) offer a number of observations / findings: American trees start to break down their chlorophyll earlier in autumn than European trees, so the period in which the leaves operate as photosynthetic 'factories' is shorter. The earlier onset of senescence means they are at greater risk of light mediated damage in the bright days of early autumn (particularly if coupled with cold nights). Trees growing at a particular latitude in Eastern North America receive significantly more light than trees growing at the same latitude in Europe. North American trees react differently to the shorter days of autumn that European trees - when grown in the same area / garden. A greater percentage of North American trees produce anthocyanins - which give the red and purple colours. Anthocyanins absorb light over a wide range of wavelengths.  They act as a sunscreen, protecting the leaves at a time when they are undergoing rapid and complex changes that allow them to export valuable nutrients / resources to other regions. It would seem that Meehan’s comments about the ‘American light’ were remarkably prescient some 140 years ago. Renner and Zohner’s detailed papers are available here :  https://nph.onlinelibrary.wiley.com/doi/epdf/10.1111/nph.15900 https://www.research-collection.ethz.ch/bitstream/handle/20.500.11850/416178/nph.16594.pdf?sequence=3&isAllowed=y [caption id="attachment_36385" align="aligncenter" width="650"] Thanks to Oliver for this photo of autumn colour at Westonbirt[/caption]