Acer pseudoplatanus is known as the sycamore in the U.K, or the sycamore maple in the United States. It was first described in botanical terms by the Swedish naturalist Carl von Linné in 1753.  It is thought that the sycamore is an introduced species, as its native range is central Europe and Western Asia.  It probably arrived in this country in the Tudor period (circa 1500 CE).  That it has no old native names is perhaps indicative of its absence before Tudor times, (Some say it has been here longer and have suggested that it persisted in Scotland).  It was recorded in the wild in Kent in 1632.  The sycamore is probably best regarded as a neophyte.  A neophyte is a plant that is not native to a particular area / region and has been introduced in recent history. Whatever its background, the sycamore is now to be found spread across the country. Its spread is due in no small part to the capacity of a single tree to produce many hundreds, indeed thousands of seeds.  The seeds are ‘winged’.  The wing of each seed develops from an extension of the ovary wall.  Two seeds are joined together to form a structure termed a double samara - a 'helicopter-like' device.  The wings catch the wind and the fruit rotates as it falls from the tree. This slows the descent and enables seed dispersal over a greater distance.  The sycamore has been deliberately introduced in a number of countries as it is tolerant of air pollution, salt spray and wind and it readily invades disturbed ground (abandoned farmland, brownfield sites, roadsides etc).  It is now regarded as an invasive species in, for example, New Zealand.  The leaves of the sycamore are simple but large. Each leaf has five distinct lobes and five veins radiate from the base of the leaf into the lobes. The edge of the leaf is somewhat ‘ragged’ with rounded 'teeth'. The lower surface may bear some hairs. The leaves are arranged in opposite pairs around the twigs / stem. In Autumn,  heavy leaf fall can mean that the ground under a sycamore tree can be smothered with a significant layer of the leaves, consequently the diversity of the ground flora underneath the tree may suffer. In spring and summer, the leaves can support large populations of aphids. Evidence of aphids on the leaves may be seen in the form of honeydew; this is the sugary waste of their feeding.   It may fall onto lower leaves (and cars); it provides food for flies and other insects.  The aphids themselves are a food source for ladybirds.  Sometimes the leaves are covered with small, red 'blobs' / projections - these are galls caused by a mite (a small spider-like creature).  The female mite lays eggs in these structures. Sycamores can be coppiced, that is, cut down to a stump which will rapidly produce new growth - for poles etc.  The timber of the sycamore is close grained, white to cream in colour that turns ‘golden’ with age.  It can be used in making musical instruments (violins), furniture, wood flooring There are many other species in the genus Acer, for example, Acer platanoides - the Norway Maple, Acer campestre - the Field Maple, Acer palmatum - Japanese Maple, and Acer saccharum - the Sugar Maple.  All of these have a (diploid) chromosome number of 26. Interestingly, the sycamore has a chromosome number of 52 - the number of chromosomes per cell has doubled.  The sycamore is a polyploid. A couple of interesting historical points about sycamore ;  The Tolpuddle Martyrs' Tree is a very old sycamore. The tree was used as a meeting point (in 1833) for six local agricultural labourers to discuss low wages and their poor living / working conditions.  They are associated with the birth of the trade unionist movement.  The 'Tolpuddle Martyrs' (as they came to be known) were sentenced to seven years of penal labour in Australia and were transported to Botany Bay. Dule trees were used as gallows for public hangings and also used as gibbets for the display of the corpse after such hangings.  One such dule tree lies within the grounds of Leith Hall, near Huntly, Aberdeenshire. This tree is a sycamore. The strong timber of sycamore made it a favoured tree for this purpose. [caption id="attachment_36329" align="aligncenter" width="645"] emerging leaves[/caption]  

More problems for bees. There is some evidence that power lines could be affecting honey bees as the lines emit an electro-magnetic field; these fields alter the bees ability to learn.  Lab experiments in which bees were exposed to electromagnetic fields similar to those under power lines showed that the bees were slower to learn to respond to a threat More likely to show aggressive behaviour Bee balls and hornets. The asian hornet is an invasive (non-native) species.  They arrived in Europe (France) in 2004.  DEFRA is trying to prevent them becoming established in the UK through the eradication of individuals and nests.  They are honeybee predators, capturing workers and feed them to their young. Back in the ‘home territory’ of the asian hornet, bees have a defence against attack.   Hundreds of worker bees quickly swarm into a balls around the hornet.   The bees then vibrate their wing muscles so quickly that they generate heat and the temperature inside the ball rises and roast the hornet alive with their body heat.  These “hot defensive bee balls” were  seen in Japanese honeybees (in 1995). The ball must form quickly before the hornet can send out pheromones to attract others of its kind. Sadly, this act of altruism by the workers comes at a cost.  Normally, workers live for several weeks but the bees that contribute to the ball die within 10 days. Unfortunately, our European honeybees do not possess such defensive strategies. Consequently, bee keepers are experimenting with various methods to deter the hornets, for example,  meshes, sticky patches and flashing lights on the hives. Warming soils ? Soils store vast amounts of carbon (in the form of humus / organic remains), more than the carbon locked up in trees.  Scientists from universities at Exeter and Stockholm have looked at data on some 9000 soil samples from around the world, and found that carbon storage declines with increasing temperature.  Coarse soils lose carbon faster than clay rich ones.

Firstly think trees Perhaps not the youngest tree around Someone crazy about bricks and mortar? There's two of these trees by the sound of it ? Would you find this tree close to the sea? There's nothing fancy about this tree If you're up one of these, you definitely stuck! Morecambe, San Francisco and Bengal have this tree in common Now think flowers and plants Who is the patron saint of gardeners, horticulture, florists, brides and brewers? What is pomology the study of? Vanilla flavouring is derived from which flower? Which fruit was cultivated from crossing a blackberry and a raspberry?  What colour is a Welsh poppy?  Which football team is nicknamed the Cherries, after their stadium was built on a cherry tree orchard? What is the biggest seed in the world? These emojis might signal a tree or two 🐒🧩 🍬♟🥜 🦀🍎 🐍🖋 🏴󠁧󠁢󠁳󠁣󠁴󠁿🅿️9️⃣   Answers  here  

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.