The low flying renaturer

Week 28

There is a problem with renaturing in Lakeland, and it is not all about those who fell trees, although they are a good proportion. The problem is LFA17.

A Eurofighter Typhoon flies low overhead (Photo by SaiKrishna Saketh Yellapragada)

The UK contains 20 Low Flying Areas (LFAs) and one of the most exciting is the Lake District National Park, LFA17. Barely a day goes by without jets flashing overhead at 250 feet[i], transport aircraft somewhat higher, or helicopters reaching ground level. The din is impossible to ignore. Part of me feels proud, as Lakeland is doing its bit for the country, but part of me feels sad. It is because however needed such training may be, low flying fighters can be damaging.

The serenity of my land may appear to be temporarily shattered, but what about the more lasting environmental effects? These thundering jets unfortunately contribute to environmental pollution. The primary pollutants released include nitrogen oxides (NOx), sulphur oxides (SOx), particulate matter (PM), and unburned hydrocarbons (HC). Each of these has different effects on the environment, but they all contribute to air pollution, which can affect plants, wildlife, and human health. The use of fossil fuel is vast. For example, an F-15 can burn through 23,000 gallons of fuel each hour, or 385 gallons/minute[ii].

Low flying fighters (F-16 here) produce plenty of emissions (Photo by Jon Robinson on Unsplash)

The most pronounced of these effects is perhaps the NOx emissions, which contribute to the formation of acid rain. Acid rain alters the pH level of the soil, which in Lakeland is already acidic, and can inhibit the ability of plants to absorb essential nutrients. For my renatured land, this can lead to a slow deterioration of the health of the existing plants and a diminished capacity to attract new species.

Meanwhile PM emissions contribute to a phenomenon called global dimming[iii], a term that describes a reduction in the amount of sunlight that reaches the Earth's surface. This decrease in sunlight can impact photosynthesis, stunt plant growth, and disrupt the complex interactions between plants and pollinators.

Those who are aware of PM emissions, but whose heads are in the sand about mankind’s environmental behaviour, will often blame volcanoes. After all, volcanoes do erupt in distant lands on occasion and spew large quantities of debris into the air. How about Iceland’s Eyjafjallajökull volcano[iv] in 2010, which erupted for 71 days and required a six-day airspace ban that accounted for 48% of total air traffic and disrupted the plans of 10 million passengers[v],[vi]? Volcanoes offer a perfect excuse. Furthermore, even Lakeland was once volcanic with plenty of eruptions of its own.

Some 460 million years ago there was a deep ocean, the Iapetus Ocean, south of the Equator. Three continents then fused and around the Iapetus Ocean appeared an arc of volcanoes as part of a huge mountain chain[vii]. This was early Lakeland, which slowly migrated northwards to where it is today, and brought its volcanoes with it. However, despite this history, the impact of volcanoes on atmospheric sulphur levels is short-lived. Man-made (anthropogenic) sulphur emissions since the Industrial Revolution[viii] dwarf anything a volcano can do. Consequently, for climate deniers, there is no escaping that mankind is at fault, and low flying jets do not help. Military aircraft are better than they were[ix], but are still a major problem.

Noise pollution from low level flights is another concern. The aircraft are loud, often exceeding 100 decibels, and comparable with the sound of a chainsaw or loud rock concert. For reference, the level at which employers are supposed to provide hearing protection is 85 decibels (adjusted)[x]. Meanwhile the permitted noise level for environmental noise is 34 decibels (adjusted)[xi]. Low flying aircraft in Lakeland are way over these levels but are exempt from these regulations. Such sudden noises can cause stress responses in wildlife, and lead to changes in behaviour, reproductive interference, and sometimes even death. Insects, birds, and small mammals on my land are especially vulnerable to these disturbances. Bird species, for example, demonstrate disruptive behaviour such as abandoning nests or even changes in singing patterns. In turn, such changes can influence reproductive success. Sound has been shown by many researchers to affect plants, sometimes promoting but also reducing a plant’s so-called index of biological integrity[xii], or biotic index. A biotic index is a scale for showing the quality of an environment by indicating the types and abundances of organisms present in a representative environmental sample[xiii].

Noise pollution (Photo by Elyas Pasban on Unsplash)

Many wildlife species on my land possess acute senses of hearing, and sudden noises can cause significant distress and panic. The roar of a low flying jet can lead to temporary or even permanent hearing loss in some animals. Beyond the auditory impact, noise can also cause animals to flee, potentially into dangerous situations, and interrupt feeding, breeding, and resting activities. Over time, this leads to changes in distribution and population declines. Manmade noise can certainly reduce the richness of bird species, as well as diversity in an urban environment, so I have no doubt the same is possible on my land[xiv].

The sound and vibration from jet engines can also lead to a phenomenon called "acoustic fatigue," causing structural damage to plant tissues, and potentially impacting plant growth and overall vitality. Surprisingly plants can hear, not something that was widely accepted at first, although plants cannot hear in the same way as humankind[xv]. Plants do have vibration-sensing receptors, so in this way low level jets run the risk of disrupting the renaturer. Plants can also make noises - indeed, I am serious - creating sounds that can be heard in specially designed acoustic chambers, and are species-specific[xvi].

As for sonic booms[xvii] - fortunately such things are uncommon but not unknown[xviii] - they can be particularly damaging[xix]. Not only can a sonic boom cause physical damage to property and structures, but the shock waves can also impact plant health. Repeated exposure to sonic booms can cause leaf drop, reduced growth, and, in extreme cases, plant death.

Wind erosion can shift a huge amount of soil (Photo by Khamkéo Vilaysing on Unsplash)

Then there is wind turbulence. Wind erosion has been shown to move 2.2 tons of soil per acre each year. Frequent low flying aircraft can increase this. Wind erosion truly picks up when the wind speed increases to 25 km/hr (15 mph), although any wind can shift soil, with such movement increasing by the cube of the wind velocity. The amount of soil transported increases rapidly with wind speed[xx]. The windier part of the Lakeland year lasts for 5.5 months, from 12 October to 27 March, with average wind speeds of more than 21.5 km/hr. The windiest month is January, with an average hourly wind speed of 25.4 km/hr. The calmer time of year lasts for 6.5 months, from 27 March to 12 October. The calmest month of the year is July, with an average hourly wind speed of 17.4 km/hr[xxi]. Wind gusts can be more than double the average speed[xxii].

In addition to all else they might do, low flying jets can also impact pollinators such as bees, butterflies, and even bats. These are vital actors in any renatured location, so however proud I may feel when a jet flies by, it is hard to ignore that my renatured land is suffering. Global conflict is in one hand while my land is in the other and I cannot decide which deserves priority. Ask a renaturer and I will get one answer, ask a soldier and I will get another. Ask a politician? I doubt I will get an answer at all. However, what seems true is that the global loss of pollinators is already causing about 500,000 early human deaths each year, simply by reducing the supply of healthy foods[xxiii]. Three-quarters of crops require pollination, the rest are spread by wind, even water, but the populations of many insects are declining.

I am struggling with insects at the moment, as my loyalties are being tested. On the one hand I have an entomological survey underway, have avoided the use of fossil fuels, and have certainly avoided weedkiller, moss killer and fertilisers. Indeed, anything that might do an insect harm. On the other hand, I have just discovered a wasps’ nest in my house and am wondering what to do. Many of my Lakeland friends have discovered wasps’ nests in their properties over the last few days. If I remain loyal to my cause, then I must be happy for wasps to buzz around my bedroom, kitchen, indeed anywhere indoors. I must take comfort in the knowledge that wasps are seasonal insects. Towards the end of March and the beginning of April, a queen wasp - basically, look for a large wasp - will emerge from hibernation to seek new locations, which are generally not where she chose for the previous year. A queen wasp can live for over a year, while a worker wasp is lucky to make it to 22 days[xxiv]. By the end of September wasps are much less of a problem. The first night the temperature reaches 0° Celsius, the worker bees die off, while the queens stay in hibernation[xxv]. By rights I should take it on the chin, let the wasps buzz freely and wait until September when I can breathe a sigh of relief.

Yet if I crack, and summon pest control, it is likely they will use the chemical bendiocarb[xxvi]. This is an acutely toxic insecticide, that has been taken off the market in the USA, and which is effective against a wide range of insects. It is also highly toxic to birds and fish. Humans are not immune from troubles, as high exposure can lead to pin-point pupils, tearing, excessive salivation, nasal discharge, vomiting, diarrhoea, muscle twitching, and problems with coordination. Severe poisonings can result in convulsions, coma, and death[xxvii].

Dear me, what must I do?

***

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.

The low flying renaturer

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