Leave the leaves alone

Updated: Apr 20, 2023

Week 5

I despair. What is it that goes through someone’s mind when they fell a tree? I understand a tree may be diseased, but there is a mentality that fells trees to make space for a building, or to improve a view. Frequently an excuse is created to justify the deed. A common one is the worry that a tree may fall, and property be damaged. To me the answer is simple. If treefall is a worry, live somewhere that has fewer trees. The annual risk of being killed by a falling tree is 1 in 10 million[i], and some would say this is an underestimate. For reference, it is 600 times more likely that one will die in a road traffic accident[ii].

After Storm Arwen in November 2021, I will forever remember the sound of chain saws echoing across Lakeland for several months. Some properties were structurally damaged by falling trees during the storm and there were also some human deaths. Each of these events is an extreme tragedy for many. Yet in proportion to the more than 16 million trees damaged in Scotland alone by Storm Arwen[iii] and the multiple thousands in Lakeland[iv] and across the United Kingdom, added to the power outages that lasted for several weeks in some cases, most trees hit the ground without damaging manmade infrastructure.

The phrase “tree management” in Lakeland appears to mean tree felling, just as the phrase “deer management” is often used to justify a hunter with a rifle. In Lakeland I see huntsfolk, too. A year ago, a local tree surgeon visited my land as I was seeking advice about planting, not felling. I intend to leave this world having put back more than I have taken away. The tree surgeon arrived with his company’s logo emblazoned on the side of his truck. Yet the moment passers-by saw the truck’s logo, they approached to ask which trees I would be felling. They could not understand when I replied, “None.” Meanwhile the tree surgeon freely admitted that, for him, planting was a rarity. Mostly he was chopping, lopping, and felling.

Trees, and my land has plenty, are one of this planet’s many assets. They provide food, protect the land, help us breathe, provide shade and shelter, encourage biodiversity, conserve water, and are fantastic for our mental health[v]. They shelter livestock from our increasingly unpredictable weather, improve soil health, prevent soil erosion, and help protect bodies of water and their wildlife from the pollution created by farm run-off.

How I hate the sound of chainsaws (Photo by Benjamin Jopen on Unsplash)

Trees do not just mitigate carbon by removing it from the atmosphere, they also sequester it, absorbing carbon dioxide during photosynthesis and then locking it up for centuries[vi].

One mature tree can provide the same amount of oxygen in a growing season as ten people will inhale in a year. One acre of trees will annually consume the same amount of carbon dioxide as will be produced by driving an average car for 26000 miles (41843 kilometres) and provide sufficient oxygen for 18 people to breathe during that year. Two mature trees can provide sufficient oxygen for a family of four[vii]. Different trees behave differently, with pines being near the bottom of the list in terms of oxygen release but Douglas fir, spruce, beech, and maple being near the top[viii]. Trees save energy as well. Planting a tree on the west side of a house can reduce energy bills by 3% in five years, simply by protecting the house from prevailing weather[ix]. Indeed, the evaporation from one tree can produce the same cooling effect as ten room-sized air conditioners running all day. Trees also provide shade and have a tremendous cooling effect. The air under a tree can be up to 25°F (13.9°C) cooler than the air at the tree’s tip.

Trees are also brilliant at absorbing water, so in a flood-prone area, trees are invaluable. A healthy 100-foot-tall tree has approximately 200,000 leaves and can absorb 11,000 gallons of water from the soil in a single growing season[x]. Different trees again behave differently but those with plenty of absorption are the red maple, river birch, weeping willow, bald cypress, and white cedar[xi].

Tree felling - try psychotherapy first (Photo by Benjamin Jopen on Unsplash)

And then there is biodiversity, for which a tree’s support is essential, especially in a world that is extinguishing 200 species daily as I write. This is the fastest rate of extinction since the dinosaurs, 65 million years ago[xii].

My conclusion is simple. Do not even think about felling a tree, whatever reason you might need. Leave that tree alone. If you feel the need to fell a tree is overwhelming, then see a psychotherapist first. Then, and only then, allow someone loose with a chainsaw but hang your head in shame when you do. Remember there is a recognised anxiety disorder associated with a fear of trees. It is called dendrophobia[xiii] and treatment is available.

So far, I have planted more than 100 trees on my land, if you count the 81 Portuguese laurels[xiv] that were used to recreate a portion of hedge. They were two-and-a-half metres high, which did not make them cheap, but as a hedge there seems little to beat them. Deer[xv] do not take to them, likely thanks to the cyanide in a Portuguese laurel’s leaves. Discouraging deer is widespread in Lakeland, as there are dozens of the animals around and plenty have been seen on my land. Deer are capable of feeding on a variety of plants - camellia, rhododendron, holly, ivy, viburnum, yew, with new plantings being particularly at risk[xvi] - so my land is deer Heaven and I need to think of friendly ways to discourage them. This is difficult when the deer population is climbing, as they have no known local predators[xvii].

I have also planted three Callery pears[xviii], a species of pear tree that is native to China and Vietnam. By doing this I have sinned because they are not native. Native trees are those that colonised the land when the glaciers melted after the last Ice Age and before the United Kingdom was disconnected from mainland Europe[xix], so the native tree goes back a very long way. There are other trees and shrubs that are naturalised but not native and have been introduced into the wild, where they now flourish[xx]. Naturalised species include the sycamore[xxi], horse chestnut[xxii], European larch[xxiii], and rhododendron[xxiv], each of which is on my land. Native trees and shrubs might include silver birch[xxv], beech[xxvi], holly[xxvii], and yew[xxviii], again each of which is on my land.

Making leaf mulch beside the compost heap

Dead leaves are also proving troublesome, politically not practically, as some Stripy Lawners have suggested I should sweep mine up. I have not done so, because dead leaves are a gift to renaturing as they can do so much good. To a Stripy Lawner dead leaves smother grass and have led to the perception that dead leaves are bad. The removal of leaves are said to help eliminate lawn thatch, reduce any diseases carried by the leaves, give plenty of exercise and fresh air, and make a property look prim and proper[xxix], should that be what one seeks.

Yet in contrast, these leaves protect plants in winter and are a brilliant fertiliser, as nutrients are returned to the soil[xxx]. Leaves are also a good ingredient for compost and can convert to humus rapidly. Humus is the substance that is left over after plants and animals have undergone a long process of decomposition, done by earthworms, bacteria, fungi, and other microorganisms. It is found in the top few inches of soil[xxxi]. Humus and compost are different. When organic matter has almost completely decomposed, it becomes a stable material called humus, which in Latin means “soil”. Waste materials that are actively decomposing are called compost[xxxii].

Separate from my compost heap, I have constructed two wire-enclosed cylinders, where leaves are piled. Rapidly they are sinking down as the leaves turn into humus, ready to be spread at the base of my bushes and trees in springtime[xxxiii]. Leaf litter is also good as a wildlife habitat[xxxiv]. I have taken trail camera footage of the leaf piles at night, and the place has gone crazy. Field mice think the area has been made for them, as do the blackbirds, robins, pheasants, rats, and even the next-door neighbour’s cat. As humans we like playing in dead leaves. Wildlife is no different.

With dead leaves come the leaf blowers. Like chainsaws, leaf blowers give me bad nights as most are still powered by fossil fuels. They spew out carbon monoxide, smog-forming nitrous oxides, and carcinogenic hydrocarbons[xxxv]. The electric leaf blowers are not so bad. More than a decade ago a study was performed that showed a fossil-fuel-powered leaf blower emitted seven times more nitrous oxide than a pick-up truck and 13.5 times more carbon monoxide. The hydrocarbon emissions from a 30-minute leaf-blowing session in a garden are about the same as a 4000-mile drive in a pick-up[xxxvi]. The German government has advised its citizens that leaf blowers are contributing to an insect Armageddon and should not be used[xxxvii]. Leaf blowers are also noisy, and many towns and cities forbid their use. The World Health Organization has suggested that a healthy indoor noise level is around 55 decibels (dB). A leaf blower can operate anywhere between 70 and 90dB. The decibel scale is a logarithmic one, so every 10dB rise means a doubling of the sound. A leaf blower operating at 70dB will thus sound twice as loud as a leaf blower operating at 60dB[xxxviii].

The answer? Simple. Leave the leaves alone.

***

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.

Leave the leaves alone

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