When thinking of conifers, one might feel a bit ‘schizophrenic’.  Perhaps picturing a Leylandii encroaching on your garden, whilst also remembering your Christmas tree.  Maybe the typical image of conifers is that of a tree with dark green foliage all year round.  However, this would be something of a disservice to the Conifer family - the Pinophyta, which contains an amazing variety of trees, many of which are at risk of extinction.  This group includes cedars, firs, cypresses, junipers, larches, pines, hemlocks, redwoods, spruces, and yews. [caption id="attachment_32107" align="aligncenter" width="650"] Leaves on the branchlets of Dawn Redwood[/caption] Conifers are important because They dominate vast areas of land, particularly in the Northern Hemisphere,  forming the boreal forests or taiga. Softwood from conifers accounts for approximately 45% of global timber production. Pine, spruce and larch are often grown specifically for softwood production. The wood is also used in the paper production[.and, to a lesser extent, in making plastic from chemically treated wood pulp].  Some species produce edible seeds , such as pine nuts provide foods such as pine nuts for humans and wildlife and juniper berries, which are used to flavour gin.  The Monkey Puzzle tree, (also known as the Pehuen Pine, native to Chile and Argentina) produces seeds known as piñones; traditionally harvested by indigenous communities.  [caption id="attachment_27592" align="aligncenter" width="600"] Monkey puzzle tree[/caption] To see the diversity of the Conifer family one could visit the Bedgebury Pinetum.  This is home to one of the world’s most important conifer collections.  Bedgebury was established in 1925 by Kew Gardens and the Forestry Commission.  The curator at Kew had observed that the conifers there were ‘being choked by London Smogs’.  The site at Bedgebury, situated on the Southern Kentish weald, was ideal.  It offered an escape from the pollution of London and it had wet and free draining areas, plus varied soils so it a range of conifer could be grown. The land already had some conifers that had been planted by Viscount Beresford - an evergreen enthusiast.  In 1925, some 315 trees were planted.  This year, to celebrate reaching a century, some 89 of the original trees are marked with special yellow labels.  For  its first twenty years, the pinetum was managed by William Dallimore. His diaries record in some detail the trees he planted, and the challenges faced in establishing the pinetumIf you visit, then you might walk through through Dallimore Valley, and view his legacy. Bedgebury soon became a centre for the scientific interest in conifers, their conservation, and landscape planning.  The current curator is Dan Luscombe. Apart from seeing a range of conifers, the pinetum offers a variety of activities, e.g. family cycling, mountain biking and walking, There is also the play trail or you can explore the canopy on a Go Ape tree-top adventure or challenge.  It is rumoured that the Gruffalow lurks within the grounds of the  Pinetum. There is also a cafe, serving a range of drinks, plus  breakfast and lunch options. The pinetum is open from from 8 AM to 8 PM (March 2025 to 26 October 2025), and there are charges for car parking.  

Plantations are generally monocultures of economically important tree species, trees that are valued for their timber and rapid growth.  Compared to natural woodland, biodiversity is lower in monocultures. They are less resilient to extreme climatic events, attack by pests and/or disease and offer fewer ecosystems services.  Adding different trees into the mix of species can result in an increase in biomass (timber) production and resilience. Since the 1930’s, a ‘nursing mixture’ of Pines and Sitka Spruce has been used to establish Sitka forest in nutrient-poor soils (without the use of fertilisers or herbicides).  Quite how the pines benefited the growth of the Spruce was not known. One possible ‘mechanism’ is plant soil feedback [PSF], where plants change the nutrient make-up and/or the  bacterial and fungal community of the soil.  These changes then benefit the subsequent growth of seedlings / saplings.  Important in this respect are the fungi that can establish symbiotic / mycorrhizal associations with plant roots.  Ectomycorrhizae (ECM) exist mainly as an external coating on the roots, with some of the hyphae penetrating into the root tissue. Ectomycorrhizae are often associated with woody tree species, particularly conifers. There are a number of parts to a mycorrhizal association with trees: The Hartig net, this is the fungal hyphae that penetrate the roots of the tree, and make contact with the root cells, allowing for the exchange of carbon compounds, mineral nutrients, and water. The Mantle is the sheath of hyphae that covers the tree roots.  It is a more substantive structure than the Hartig net.  The fungal sheath probably offers some protection to the delicate root tips from pathogens and pests.   The Extra-radical hyphae. These grow out from the mantle into the soil. They may spread a significant distance from the actual roots, increasing the surface area for the absorption of water and minerals.  The Fruiting bodies.  These are the reproductive structures of the fungus and are visible above ground. Now some evidence is accumulating about how nursery mixtures / species have their effect.  Last year, researchers at Manchester University looked at the nursing effect of pine and silver birch on Sitka Spruce.   They collected soil from Cannock Chase, where these tree species co-existed.  The soil was sieved and some sand added and then placed in pots. Four groups of pots were created Pots with pine seedlings Pots with Spruce seedlings Pots with silver birch seedlings Pots with all three types of seedlings Pot Treatment Species grown in the conditioned soil Pine conditioned soil  Pine Spruce Birch Spruce conditioned soil  Pine Spruce Birch Birch conditioned soil  Pine  Spruce Birch Pine, Spruce & Birch conditioned soil  Pine Spruce Birch All the pots were placed in a greenhouse and the seedlings allowed to grow on for 34 weeks.  This allowed the growing seedlings to ‘condition’ the soil.  At the end of this time, the seedlings were removed and soil sieved and placed in fresh pots.   The four ‘types’ of ‘conditioned’ soil were then used to grow on newly germinated seeds of the three tree species.   One seedling was grown per pot, and the pots grown on for 24 weeks in the greenhouse again.   At the end of the 24 weeks, the seedlings from each pot were harvested and carefully examined.  For each, many features were recorded Root length Branching intensity Root tissue density Total root length dry weight /mass recorded Ectomycorrhizal colonisation (microscopic analysis) Specific leaf area VIII.Leaf dry matter Photosynthetic rate The soil was also subjected to detailed analysis (e.g : pH, nitrates, microbial enzymes etc). The results showed that  The Spruce seedlings grew best in the soil that had been previously ‘conditioned’ with Pine growing in it. The Spruce fared less well in the previously Spruce ‘conditioned’ soil The increased growth was associated with greater root colonisation by mycorrhizae. Longer term increased growth in the silver birch ‘conditioned’ soil might be associated with increased availability of soil nitrates It would seem that Pines facilitate the growth of the Spruce through the enhanced establishment of symbiotic, mycorrhizal connections.  These connections allow saplings to access vital mineral nutrients such as phosphate.  This study therefore goes some way to explaining the nursing effect of mixed species planting. Full details of this work may be accessed here :  https://besjournals.onlinelibrary.wiley.com/doi/10.1111/1365-2664.14848

We had been looking for a wood preferably with a open area for sometime.   We had a look at a few that were not right for us, thinking it was never going to happen.   One day I opened an email and there it was - in September 2022.  Golden Hill Wood, I immediately called Stuart, the area manager, and we arranged to view it.   Well,  it was just perfect and literally five minutes away from our home, so the ball started to roll. It was time for some research on equipment, we got some good advice locally, so a chainsaw, brushcutter, and other equipment was purchased.  Having a walk around with Stuart, taking on some good advice, we then started to work on our new heaven. Golden Hill Wood has some old broadleaf trees but mainly spruce, fur and a few Douglas Firs amongst others.  The wood not been cared for in many years, so I set to taking lower branches off to head height, a few had to be removed including a couple of tactical removals with trees broken half way up, removing the many brambles that had stored from the ground to the canopy in a web like manner.  I found myself pulling brambles from one tree only to see I'm pulling a tree further away as there was so much of it.   Patience is a virtue and I got there.   It is not the end, but everything is now manageable so I have a few hours work and then a chill out. I have a couple of tarpaulin areas which the granddaughters just love and embrace and lend their little hands.   When Roe or Red Deer are about, we have two sets of Buzzards along with Red Kite and. of course, Bunnies.  We spent New Years Eve 2022-23 there and I've made a wild camp under a basher. I'd recommend anyone taking a wood on.  It is so peaceful and calming.

Willow bark and the covid virus. The Covid pandemic created great strains on health and business services, and the virus continues to impact society in many ways.  It is not surprising that there is an ongoing search for anti-viral agents. Finnish scientists have found that willow bark may have a role to play. Willow bark has been used as a natural medicinal product over the centuries as an effective agent to treat pain and inflammation.  The anti-inflammatory properties of the bark are generally ascribed to salicin, which was to lead to the development of acetylsalicylic acid, that is aspirin.  The Finnish scientists ground up the willow bark in hot water and then sieved it to create an ‘extract’.   This solution was then added to a number of cell cultures that were exposed to different viruses (enteroviruses, a seasonal coronavirus and SARS CoV2).  They then monitored the viral activity, cell infection and viral replication  The extract had an effect on all of the viruses.  In some cases, the extract affected the envelope of the virus (a structure surrounding the viral genetic material) so the viruses essentially broke down, whereas others were prevented from releasing their genetic material and reproducing.  Specifically, though the Covid-19 virus could enter cells when treated with the extract, it could not reproduce once inside. The research team analysed the extract’s chemical composition and tested some known constituents of bark but concluded the success of the extract probably resulted from the interactions of different biologically active compounds.  Compounds in the extract included many complex chemicals (for example, hydroxycinnamic acids, salicylates, flavonoids, flavan-3-ols, and proanthocyanidins (polyphenols).  Further work will focus on the role / interactions of these various compounds. The Hazel Dormouse in peril. The numbers of the hazel dormouse have fallen dramatically since the turn of the century.  The dormouse has disappeared from Staffordshire, Northumberland and Herefordshire in the last few years.  This loss is attributed to The destruction / fragmentation of their habitats Poor management of woodlands and hedgerows, leading to a loss of diversity / niches Rising deer numbers, feeding on saplings and shrubs Extreme weather patterns may also play a part Captive-bred dormice have been re-introduced to some 25 sites in 13 counties across the country, sadly nine of these reintroductions were not successful.  Dormouse bridges have been created to enable the animals to move between areas dissected by major roads (such as the M1), others are planned.   The dormouse (Muscardinus avellanarius) is a nocturnal animal and lives mainly in deciduous woodland,  it feeds among the branches of trees and shrubs. the dormouse rarely descends to the ground.  It feeds on a wide variety of 'foods' ;  flowers (nectar and pollen), fruits (berries and nuts), certain buds and leaves and some insects, such as aphids and caterpillars. The hazel dormouse is regarded as a ‘flagship species’, that is to say, if the dormice are thriving then it is likely that other species are too from butterflies to birds such as the nightingale.  Dormice are currently assessed as ‘Vulnerable’ to extinction in Britain under IUCN Red List criteria, but recent studies suggest a classification of ‘Endangered’ might be more appropriate.  Certainly, their future is uncertain. Detailed information on the hazel dormouse is available at PTES (note this link opens a PDF).  Their report details the state of hazel dormice in 2023. zsaqwa https://youtu.be/4u-yMkXOuTY Changes in the Boreal Forests. Boreal forests encircle the northern reaches of the Earth, lying just below the treeless under of the Arctic.  These forest cover large areas of Alaska, Canada, Scandinavia and Siberia.  These forests contain billions of trees, most are conifers but birch, poplar and aspen may also be found.  The trees (and soils) contribute significantly to the cycling of carbon in nature, absorbing carbon dioxide in photosynthesis. They are also home to many species of migratory birds, plus predator species such as lynx and brown bears, and wandering herds of moose. Due to the remoteness of these forests, they have remained (until relatively recently) unaffected by human impact.  Now these forests are warming at a rate above the global average.  This has a number of effects:  In the southern parts of the boreal forest. Conditions are becoming too warm for cold adapted trees; their growth is slowed and they may die. With the warming comes increased dryness, which leads to water stress and increased risk of insect attack /  infestation. The dryness also means that forest fires are more likely and occur with increased ferocity.  This year, the fires in Canada have been particularly extensive and damaging.  Some 18.5M hectares went up in flames.   The plumes of smoke spread far and wide. [caption id="attachment_40597" align="aligncenter" width="675"] Canadian forest fire[/caption] Scientists are now using satellites to track changes in the extent of the boreal forests.  If trees are being lost on the southern edge of these forest, then it might be expected that the northern limit for tree growth might change.  Indeed, there is some evidence for this in Alaska where young Spruce are now growing some 25 miles beyond the previous tree line, moving into the ‘treeless tundra’.  It may be the loss on the southern edge is compensated by extension of the most northern parts of the boreal forest, but it is not clear whether tree can ‘move’ at the rate of climate change.  

During a drought, the trees in a woodland or forest become 'stressed' and may die.  The  reason for their death is not immediately obvious (beyond lack of water), and  it is not possible to ‘transplant’ a mature tree and its complete root system to a lab for detailed investigations.  However, recently, researchers at the University of Innsbruck have taken ‘the lab’ to a set of mature pine and pine trees. The trees were fitted with rugged and waterproof ultra-sound detectors.  Some of the trees had their canopies covered by a ‘roof’ so that the summer rain was denied to the trees, and they essentially experienced a ‘drought’.   Drought stressed trees produce ultrasound ‘clicks’ (faint acoustic waves that bounce off of air bubbles) that can be picked up by the detectors.  Air bubbles or emboli form in the vascular system of the trees when they are struggling for water.  Water is drawn up the xylem vessels by the evaporation of water (via the stomata) from the leaves, there is a continuous column of water.  When the column of water breaks, bubbles form with the xylem vessels and the transport of water to the leaves is reduced.  If the flow of water is substantially reduced the tree will die. The sound detectors found that the spruces produced more clicks than the beeches when water stressed, suggesting more emboli were formed within their xylem tissues.  It may be that the beeches were able to access the deeper reserves of water in the soil, whereas the spruces had a shallower root system. Trees can, of course, reduce water loss from their leaves by closing down their stomates.  But when their stomates are closed, they cannot take in carbon dioxide for photosynthesis and make the sugars / starch that they need for their metabolism.  At the end of the experiment, the trees that experienced ‘drought’ were drenched with water and most recovered well, and their rates of photosynthesis caught up with the ‘control’ groups of trees (those with summer rain).  However, the spruces’ water reserves were somewhat depleted; this was determined by measuring the resistance the tissues offered to an electrical current. The ability to withstand / recover from drought could over time affect the make up of woodlands and forests,  particularly if the trend for hotter and drier summers continues. Interestingly, some work in the United States (at University of Wisconsin–Madison) suggests that young tree saplings that have experienced drought or heat are more likely to survive when transplanted into more challenging areas.  It seems that the soil microbes that young saplings experience can help young trees establish themselves.  Saplings grown in soil (and microbes) that have experienced drought / cold / heat are more likely to survive when later transplanted and faced with similar conditions.  Trees with ‘cold-adapted’ microbes survived better when experiencing Wisconsin’s winter temperatures. The work was conducted with different species of tree in a variety of locations in Wisconsin and Illinois. The transplant locations varied in temperature and rainfall.  It may be that fungi that inhabit the roots of the saplings are involved in these ‘responses’, though the microbial population of the soil is diverse. For more details of this work, follow the link here.

In 2018, the blog reported on the extensive fires in Sweden, a country noted for its forests and woodlands, which cover approximately half of the country. Once the trees were mainly broad leaved species, but then oaks and alders began to decline.  By the middle of the  twentieth century,  Spruces and Pines were dominant.  This was mainly due to forestry management, to produce wood for fuel, charcoal [used in iron smelting], potash, tar and timber (for building). Fires burnt from the extreme north down to Malmo in the south. These fires affected some 20,000 hectares and destroyed woodlands valued at [circa] £50 million.  Now work by scientists at Uppsala University, the Swedish University of Agricultural Sciences (SLU), and the Swedish Meteorological and Hydrological Institute (SMHI) have examined the effects of the fires (of 2014) in the Vastmänland province, where the fires were ferocious, burning down into the soils. They have found that the 'forested areas' continued to lose carbon for several years after the fire, and that nitrate and phosphate input to streams and rivers increased after the fires. This spring and summer have again witnessed intense and widespread fires across the Mediterranean region, Canada and the United States. Fires are a problem not only because of their immediate destructive potential, but because they result in the release of carbon dioxide - which further contributes to global warming and climate change.  The United Nations Secretary-General said recently “The era of global warming has ended; the era of global boiling has arrived.” Data on these fires is not available as yet, but studies of the boreal fires in 2021 suggest those fires released some 1.76 billion tonnes of carbon dioxide into the atmosphere.  The fires contributed nearly one quarter of world wide carbon dioxide emissions from fires in that year.  [caption id="attachment_35352" align="aligncenter" width="650"] Woodland recovering from a fire[/caption] Boreal forests store roughly twice as much carbon in their trees and soil as tropical forests.  These forests (often referred to as the Taiga) surround the Arctic Circle and research suggests the Taiga is warming faster than the global average, so areas like Northern Canada and Siberia now experience more heat and drought than in the past, and consequently are more likely to suffer from fires. Clearly, when there is a fire, carbon dioxide (and many other carbon compounds eg soot / small particles) are released by the burning of the trees but there is also the effect of fire on the soil and its organic content - the humus.   Research indicates that during the fires in the boreal area some 150 tonnes of carbon dioxide may be released into the atmosphere per hectare.  Furthermore, even after the fire, carbon continues to be lost from the soil.  It may take some three years for carbon uptake by the soil to be recorded.   Fires also lead to the rapid loss (leaching) of nutrients (e.g. phosphate) to local lakes and rivers - as there is little or no vegetation to absorb the nutrients.   Rainfall is not intercepted by vegetation and so the flow of streams increases ( sometimes by 50%).    A research paper produced by the Desert Research Institute (in Nevada) has indicated that smoke from the burning of pines has the effect of making soil particles more water-repellent.  This repellency of smoke-affected soil particles could help explain the increased flooding, erosion, and surface runoff in fire damaged areas.  

At the end of the last Ice Age, the British Isles were recolonised; plant and animal species from the continent moved across the 'land bridge’ (doggerland) that connected us to Europe.  Trees, shrubs and plants began to move into the areas ‘released’ from the ice sheets, forests formed in many places.  At first, the forests were largely coniferous and they extended across the north of the UK to swathes of Europe and Asia: they formed an enormous area of boreal coniferous forest.  This vast array of trees provided shelter and food for a variety of animals -  wolves, lynx, elk and many other species.  Since the Ice Age,  forests and woodlands have been cut down for farming; trees felled for timber, sheep and deer ate young shoots and stopped native trees (like the Scots pine) from re-growing. Read more...

Forests and woodlands are important in the global ecosystem; they have taken up some 20 to 30% of the carbon dioxide released from fossil fuels in recent times. It had been assumed that the dense and biodiverse tropical forest ecosystems (close to the equator) were particularly effective in ‘soaking up this carbon dioxide’.   However, there is doubt that this will continue to be the case as forests shrink in size.  Plus, recent work at the University of Birmingham (Dr Tom Pugh) has shown that where forests were re-growing,  they took up large amounts of carbon partly because more carbon dioxide was available,  but also as a result of the younger age of the trees. This ‘youthful’ carbon uptake was not associated with tropical areas, but with regenerating forests of more temperate regions. Read more...