Week 41
I see it whenever I am on my land yet spare it barely a thought. It is a vital, critical feature of what I possess and an essential zero-technology, organic item in an otherwise technology-dependent world. It is generally sturdy, but not always so, and without it trees would not exist. It can become shelter, warmth, and vessel. It is in the pages of a book, the hearth’s embrace, and the walls surrounding me as I write.
What is it? Wood, of course. It has become so much part of life that I have taken it for granted when I should not. I walk past it, I touch it, I even smell it. I adore the aroma of fresh wood. It is a most wonderful material.
There are three basic types of wood - softwood, hardwood, and engineered wood[i]. Softwood is not always soft, as what divides it from hardwood is the cellular arrangement of the wood itself. Most softwoods are strong and are used extensively in the building trade. Examples are the conifers, such as pine[ii], spruce[iii], and cedar[iv]. However, these woods will often be used for interior rather than exterior projects. Hardwoods are generally from deciduous trees and can have attractive wood grain patterns. Examples might be ash[v], oak[vi], and mahogany[vii]. The hardest wood in the world is sadly not English, a blow to my patriotic self, but can be found in Australia[viii]. It is the Australian Buloke tree (Allocasuarina luehmannii)[ix]. Engineered wood is not something for these pages, as it does not feature in the natural environment. It is often made from wood off-cuts that are bonded together with either plastic or resin. Think Medium-Density Fibreboard (MDF) that is widely used in construction.
Wood is a structural tissue that is found in the stems and roots of trees and other woody plants. It is an organic material that has been used for thousands of years for fuel, construction, tools, weapons, furniture, and paper. As a fuel[x], hardwood is preferred over softwood, as it burns for longer and produces less smoke.
Wood is - so far anyway - an abundant, carbon-neutral, renewable resource. Globally, mankind deforests approximately ten million hectares of forest each year[xi]. That is an area the size of Portugal (9,222,520 hectares) annually. About half of this deforestation is offset by regrowing forests, so overall mankind loses roughly five million hectares each year. This is an area larger than The Netherlands, or Belgium, or Switzerland, and nearly five times the size of Lebanon[xii].
Nearly all (95%) deforestation occurs in the tropics, although there are some around me in Lakeland, which is anything but tropical, who appear obsessed by felling trees. Shamefully perhaps, 14% of deforestation is driven by consumers in the world’s richest countries, as we import beef, vegetable oils, cocoa, coffee, and paper that has been produced on deforested land[xiii]. Many countries have considerably less forest today than they did in the past. For example, nearly half (47%) of France was forested 1000 years ago. Today, that is just under one-third (31.4%). The same is true of the United States. In 1630, 46% of the area of the modern USA was covered by forest. Today that has shrunk to 34%. Scotland, too, where 1000 years ago 20% of its land was covered by forest. By the mid-18th century, this had reduced to 4%.
In some locations, but it is only a beginning, this trend is reversing, as a move from deforestation to reforestation takes slow shape. For the last two centuries some forests have been growing and are nearly back to where they were 1000 years ago[xiv]. Take England as an example. In the late 11th century, 15% of the country was forested, and over the following centuries two-thirds of its trees were cut down, so by the 19th century the forest area was reduced to a third of what it once was. England then reached a transition point and, slowly but incrementally, its forests have since doubled in size[xv]. It still escapes me why anyone might wish to fell a tree, but even with these blinkered folk, it is not always depressing. With focussed effort, and clearly education, it should be possible to reverse current trends.
I frequently find myself studying the trunks of fallen trees that are scattered around my land. There are not many, as I generally use their fallen wood for other things, but there are still occasional stumps and logs to find. There are many ideas of what can be done with a fallen tree. Logs and stumps can be used for furniture, milled for future woodwork, turned into coasters, cutting boards and candle holders, converted into a wildlife habitat, and so much more besides[xvi].
The trunk of a fallen tree so often tells a story, thanks to its tree rings. Wood increases in diameter by the formation, between the existing wood and the inner bark, of new woody layers which envelop the entire stem, living branches, and roots. There is a seasonal difference, this process leading to the formation of tree rings (growth rings), which can usually be most easily seen on the end of a log but are also visible on other surfaces. If there are differences within a growth ring, then the part of a growth ring nearest the centre of the tree and formed early in the growing season when growth is rapid, is usually composed of wider elements. It is normally lighter in colour than that near the outer portion of the ring and is known as earlywood or springwood. The outer portion, which is formed later in the season, is then known as the latewood or summerwood[xvii].
If a tree grows all its life in the open and the conditions of soil and site are unchanged, it will make its most rapid growth in youth, and gradually decline. The annual growth rings are for many years quite wide, but later they become narrower. and the rings become thinner as the trunk widens. As a tree reaches maturity its crown becomes more open and its annual wood production decreases, thereby further reducing the width of the growth rings.
For forest and woodland trees, the situation can be different, as so much depends upon the competition of the trees in their struggle for light and nourishment. Consequently, periods of rapid and slow growth can alternate. This will affect the appearance of a growth ring. Some trees maintain the same width of ring for hundreds of years, while for others the size of growth ring varies. Overall, however, in a forest and woodland setting, as a tree becomes larger in diameter the width of its growth rings decreases.
Tree rings are valuable, as they offer a snapshot of Earth’s past climate[xviii]. For example, for the fallen Algerian Fir on my land, I have calculated from its tree rings that it was at least 40 years old before Storm Arwen toppled it, which will mean it first appeared around 1980. In the late 1990s it saw excellent growth, which matches with the UK’s higher temperatures during some of the years at about that time. In the early 2000s it did not grow so well, perhaps because of the lower than average temperatures in 2001, and again in 2010, when the tree rings are closely packed[xix]. These tree rings are a real gateway to the past and tell me much about my land. Of course, tree rings are only visible outside the tropics, in temperate latitudes such as Lakeland. In the tropics, trees grow throughout the year and will not have alternating rings[xx].
Plants developed a woody structure for the first time about 400 million years ago, a change that has been described as one of the most significant features in the history of the Earth[xxi],[xxii]. Trees can also become fossilised, as petrified wood demonstrates. This is the result of the tree being replaced by stone through a mineralisation process[xxiii]. Petrified wood forms when woody stems of plants are buried in wet sediments saturated with dissolved minerals. The lack of oxygen slows decay of the wood, allowing minerals to replace cell walls and to fill void spaces in the wood[xxiv]. I have yet to find any such wood on my land, although I will wager it is there, as there was once ancient woodland exactly where I live, and plenty of wet sediments. I will keep looking. I have certainly seen some on the fells that surround me.
Thanks to my land having plenty of wood scattered around, wood stacking is something I have tried to learn. There is a skill to it. Proper stacking protects the wood from moisture, mould, and pests. Moisture in stacked wood encourages animals to make it their home, as well as the growth of mould. Once mould sets in, the wood does not burn as well as it might do when dry. Wood can be stacked outdoors or indoors. When outdoors, if the stack is slightly angled against the prevailing wind, in my case from the south-west, the breeze will help keep the wood dry. Indoor stacking requires a space that has a good airflow and low humidity, which is difficult in Lakeland. However, there are some basic rules of wood stacking, as follows:
1. Safety first - wear gloves and boots when stacking.
2. Raise the stack off the ground - this prevents water from seeping in.
3. Allow for plenty of airflow - stack with the cut ends exposed as they absorb the most moisture. Ensuring good airflow reduces the chances of moisture accumulating.
4. Keep the area around the stack clean.
5. Ensure the stack is stable - avoid anything more than four feet high.
6. Give the stack proper cover - either indoors, a log store, or a tarpaulin.
There are various stacking methods - American, German, Amish, Norwegian, end-pillars, criss-cross, round stacking, cord stacking, close square, sculptural, and plenty more[xxv]. I must clearly do better with my own wood pile, which is turning out to be both an eyesore and a habitat for mice.
Although a wood stack, or wood pile, can be a work of art, indeed should be, its primary purpose is to ensure the wood dries, and remains as dry as possible. Wood is best when it is dried quickly. Quick drying also means that the wood may absorb less moisture. The ideal way to stack wood is thus as loosely as possible. Sufficient space, it is said, should be left between each log to allow a mouse to pass through should it wish. That does not mean a wood stack is being made for mice, far from it, but this gives an easy estimate of size. As wood changes from being unseasoned to bone dry, so it can shrink by 7-20%. This can even cause a stack to sag or collapse[xxvi]. A wood stack is thus seen by many as a thing of pride, while I confess that mine is a mess. If this was Eurovision, “Nul Points” would be my score. I must do better.
Recently, while committing my guilty conscience to a day of fashioning a tidy wood stack, I saw something different. It was the last thing I was expecting to find yet is the right time of year. Barely inches from the ground, it was a huge mushroom and had already been nibbled by something with a large jaw. Likely a fox, I concluded, as the animal is known to eat mushrooms[xxvii]. There were large chunks missing from the edge of this common and edible autumn mushroom, the Brown Birch Bolete[xxviii].
The Brown Birch Bolete is remarkable, as it only grows in association with birch and is normally found underneath Silver Birch or Downy Birch[xxix]. On my land this was different. The mushroom was not under a tree but a few paces from multiple silver birch seedlings. The mushroom is also mycorrhizal. These are fungal associations between plant roots and beneficial fungi. The fungi effectively extend the root area of plants and are thus extremely important to most wild plants. They are less significant for garden plants where the use of fertilisers and cultivation disrupts and replaces these associations[xxx]. On my renatured land I was witnessing a true symbiotic relationship. The fungus takes sugars from the plant in exchange for moisture and nutrients gathered from the soil by the fungal strands. Neither fungi nor plants could survive in many uncultivated situations without this mutually beneficial arrangement.
Mycorrhizas[xxxi] also confer protection against root diseases. The Brown Birch-Bolete that had sprung up on my land, almost overnight, was a perfect example. When it comes to growing, there is little to beat a mushroom. They are so fast they can double in size in 24 hours. That is a growth rate of 4% an hour[xxxii], a truly remarkable pace. For the moment then, I must preserve the Brown Birch-Bolete, but I can see it will not last long. It is fading almost before my eyes, while I am sure the passing fox sees it as a tasty morcel. The mushroom will not last long, even if it is well camouflaged and not always simple to see.
Fungi offer an insight into a different world. There is more to follow about them, of that I feel certain.
***
Acknowledgement
Take it from me - none of this would be possible without the help of RSG Horticulture. Rufus, who runs it, has far more energy than me and is full of ideas and skills. Do contact him through https://www.rsghorticulture.com.
Hashtags
References [i] Types of wood you need to know about. 7 October 2020. See https://www.buildersmerchant.com/blog/types-of-wood-you-need-to-know-about/#:~:text=The%20types%20of%20wood%20can,and%20neither%20are%20Hardwoods%20hard. Accessed 27 September 2023. [ii] See week 39 entry. [iii] Britannica, The Editors of Encyclopaedia. "spruce". Encyclopedia Britannica, 29 Sep. 2023, https://www.britannica.com/plant/spruce. Accessed 30 September 2023. [iv] Cedar (Cedrus libani). Cedar is a majestic, evergreen conifer which can grow to 35m. The bark is blackish brown with closely spaced ridges and cracks, and twigs are brown and slightly hairy. It has a distinct shape, with several trunks and clear horizontal layers in its structure. See https://www.woodlandtrust.org.uk/trees-woods-and-wildlife/british-trees/a-z-of-british-trees/cedar/. Accessed 30 September 2023. [v] See week 39 entry. [vi] See weeks 1, 23, 31, 34, 37, 38, & 39 entries. [vii] Libéron. Mahogany. See https://www.liberon.co.uk/help-advice/types-of-wood/mahogany/. Accessed 1 October 2023. [viii] See https://www.hitchcockandking.co.uk/h-k-news/top-10-hardest-woods-world/#:~:text=1.,Janka%20hardness%20of%205%2C060%20lbf.. Accessed 27 September 2023. [ix] Wikipedia. Allocasuarina luehmannii. See https://en.wikipedia.org/wiki/Allocasuarina_luehmannii. Accessed 27 September 2023. [x] Sterrett FS. Alternative Fuels and the Environment. 12 October 1994. CRC Press. ISBN 978-0-87371-978-0. [xi] Food and Agriculture Organization of the United Nations. Global Forest Resources Assessment 2020. See https://fra-data.fao.org/assessments/fra/2020. Accessed 27 September 2023. [xii] The World Factbook. 25 November 2020. See https://statisticstimes.com/geography/countries-by-area.php. Accessed 1 October 2023. [xiii] Forest transitions: why do we lose then regain forests? See https://ourworldindata.org/deforestation#:~:text=Globally%20we%20deforest%20around%20ten,deforestation%20occurs%20in%20the%20tropics. Accessed 27 September 2023. [xiv] Mather AS. Forest transition theory and the reforesting of Scotland, Scottish Geographical Journal 2004 120:1-2, 83-98, DOI: 10.1080/00369220418737194 [xv] Forest Research. National inventory of woodland and trees – England. See https://www.forestresearch.gov.uk/tools-and-resources/national-forest-inventory/national-inventory-of-woodland-and-trees/national-inventory-of-woodland-and-trees-england/. Accessed 27 September 2023. [xvi] Riverbend. Ways to repurpose or recycle a fallen or removed tree. See https://riverbendva.com/repurpose-recycle-fallen-tree/. Accessed 1 October 2023. [xvii] Farm Forest Line. Wood growth and structure. See http://www.farmforestline.com.au/pages/2.1.2.1_wood.html. Accessed 27 September 2023. [xviii] Stoller-Conrad J. Tree rings provide snapshots of Earth's past climate. 25 January 2017. See https://climate.nasa.gov/news/2540/tree-rings-provide-snapshots-of-earths-past-climate/. Accessed 27 September 2023. [xix] Mean annual temperature in the United Kingdom (UK) from 1990 to 2022. See https://www.statista.com/statistics/610124/annual-mean-temperature-in-uk/. Accessed 1 October 2023. [xx] Center for Science Education. Tree rings and climate. See https://scied.ucar.edu/learning-zone/how-climate-works/tree-rings-and-climate. Accessed 27 September 2023. [xxi] N.B. fossils show origins of wood. See https://www.cbc.ca/news/canada/new-brunswick/n-b-fossils-show-origins-of-wood-1.1052870. Accessed 27 September 2023. [xxii] Gerrienne P, Gensel PG, Strullu-Derrien C, Lardeux H, Steemans P, Prestianni C. A simple type of wood in two Early Devonian plants. Science. 2011 Aug 12;333(6044):837. doi: 10.1126/science.1208882. PMID: 21836008. [xxiii] Mustoe GE. Wood Petrifaction: A New View of Permineralization and Replacement. Geosciences. 2017; 7(4):119. https://doi.org/10.3390/geosciences7040119 [xxiv] Wikipedia. Petrified wood. See https://en.wikipedia.org/wiki/Petrified_wood. Accessed 1 October 2023. [xxv] Lumberjax. How to stack firewood to keep it dry and clean. https://lumberjax.com/how-to-stack-kiln-dried-firewood/#:~:text=It%27s%20best%20to%20stack%20your,of%20treated%202x4s%20or%20pallets. Accessed 27 September 2023. [xxvi] Mytting L. Norwegian Wood. Publ. MacLehouse Press 2015. 978-0857052551
[xxvii] Chris. 11 animals that eat mushrooms. 22 May 2022. See https://faunafacts.com/animals/what-eats-mushroom/. Accessed 1 October 2023. [xxviii] WildFoodUK. See https://www.wildfooduk.com/mushroom-guide/brown-birch-bolete/. Accessed 1 October 2023. [xxix] The Foraging Course Company. Brown birch bolete – Leccinum scabrum. See https://www.foragingcoursecompany.co.uk/foraging-guide-brown-birch-bolete. Accessed 1 October 2023. [xxx] RHS. Mycorrhizal fungi. See https://www.rhs.org.uk/biodiversity/mycorrhizal-fungi. Accessed 1 October 2023. [xxxi] Wikipedia. Mycorrhiza. See https://en.wikipedia.org/wiki/Mycorrhiza. Accessed 4 October 2023. [xxxii] Canadian Food Focus. How mushrooms are grown. See https://canadianfoodfocus.org/on-the-farm/how-mushrooms-are-grown/#:~:text=Mushrooms%20have%20a%20fast%20growth,grow%20into%20the%20larger%20portabellas. Accessed 1 October 2023.
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