Week 43
I suppose, for a renaturer, I should not be planting anything, but simply allowing Nature to steer me. Yet I admit to having cracked, as I do like to see flowers, although those that please me are not the same as might delight a Stripy Lawner. Autumn is a planting time of year and a season when I can prepare for next spring.
The way it appears to work with my land is that Rufus suggests, I agree, and then something happens. It is why I am now surrounded by a delivery of wild plants, each a so-called plug. I have taken the plunge and am now planting plugs from a long list of wild vegetation. These include devil’s bit scabious[i], chicory[ii], cowslip[iii], field scabious[iv],[v], fox and cubs[vi], lady’s bedstraw[vii], musk mallow[viii], oxslip[ix], salsify[x], teasel[xi],[xii], wild carrot[xiii], wild wallflower[xiv], great burnet[xv], meadowsweet[xvi], cotton thistle[xvii], ragged robin[xviii], marsh marigold[xix], and wild primrose[xx]. I can but hope for a brilliant floral display next year, but such things are always a gamble.
The process of planting vegetation is a vital component of all forms of land management, be they for the casual gardener, committed renaturer, farmer, indeed all those who deal with land. There are various methods of planting vegetation, each with its unique advantages, disadvantages, and applications.
Seeds are the most common way of planting vegetation. They are the reproductive units of flowering plants and are typically enclosed in a protective outer layer. When planted in soil, seeds undergo germination, a process that involves the absorption of water, leading to the swelling and softening of the seed coat, and ultimately, the emergence of a shoot and root system[xxi]. Seeds can be directly sown into the ground or started indoors in containers before being transplanted outside. Direct sowing is often used for vegetables and annual flowers, while indoor sowing is preferred for plants with longer growing seasons, such as tomatoes and peppers[xxii]. Remember it is unlikely that all seeds in a packet will be viable, some will be dead before sowing even begins.
Bulbs are another popular method of planting vegetation. These are specialised storage organs that contain a complete, miniature plant, including a shoot, root, and leaves, all enclosed in a protective covering. When planted in soil, the bulb grows into a full-sized plant. Bulbs are typically planted in the autumn, before the ground freezes, and they bloom in the spring[xxiii]. Examples of plants that can be grown from bulbs include tulips, daffodils, and lilies. Again, not all bulbs purchased will be viable.
Then there are plugs, as I have just planted. These are small, individual plants that have been started from seed or cuttings and grown in containers until they are ready to be transplanted. They are an efficient way to establish vegetation, as they are less prone to weed competition, easier to handle, and have a higher success rate than direct seeding[xxiv]. Plugs are often used for grasses, groundcovers, and perennials.
There is then the so-called in-the-green planting, which refers to the transplantation of vegetation while it is actively growing, as opposed to dormant. It is commonly used for spring-flowering bulbs, such as snowdrops and bluebells, which are lifted and divided while in leaf and then replanted immediately. In-the-green planting can also be used for other types of vegetation, such as grasses and perennials, if care is taken to minimise root disturbance and the plants are adequately watered after transplanting. The phrase “in-the-green” not only covers bulbs but also corms, rhizomes, and tubers. There are various reasons for this method of buying plants, the main one being that it guarantees a bulb is viable. Certain spring-flowering bulbs are more likely to establish and flower if acquired as living plants rather than bulbs. Historically, there has been a problem with some imported bulbs. They may have been sold in good faith but were incorrectly stored or treated before selling. The dried-out bulbs were not likely to ever grow leaves or flower[xxv].
Another method of planting vegetation is through cuttings. This involves taking a piece of a plant, such as a stem or leaf, and allowing it to root in soil or water before planting it in the ground. Cuttings are a convenient way to propagate plants, as they are often easier and faster than growing from seed[xxvi]. Many types of plant can be propagated through cuttings, including shrubs, trees, and herbaceous perennials.
There are also various specialised methods of planting vegetation, such as layering, grafting, and tissue culture. Layering involves bending a stem or branch of a plant to the ground and covering it with soil, allowing it to root before being separated from the parent plant. I have certainly layered a Eucryphia[xxvii] on my land and now, 12 months later, the layered branches are definitely viable. Shortly I will have to separate them from the main plant and watch as multiple, new Eucryphias grow. Mind you, if each layered branch survives, I am not sure what I will do with ten Eucryphias.
Grafting involves the joining of two different plants, with the root system of one plant (the rootstock) supporting the shoot system of another plant (the scion). Tissue culture is a technique that involves growing plants from small pieces of tissue, such as a leaf or stem, in a sterile environment, and is often used for the rapid propagation of rare or endangered plants[xxviii].
There are thus many ways to plant vegetation, each with its advantages, disadvantages, and applications. Seeds, bulbs, and plugs are the most common methods, while in-the-green planting, cuttings, layering, grafting, and tissue culture are also widely used. The choice of method depends on various factors, such as the type of plant, the growing conditions, and the desired outcome. On this occasion I have opted for plugs.
While planting, and presently I am doing plenty of that, I am also on the look-out for better screening and have held lengthy talks with several arborists. I am thinking towards the evergreen holm oak, Quercus ilex[xxix]. Although this is a native to the Mediterranean, it came to the UK in the 1500s and has become well established here. The holm oak is resistant to salt-spray from the sea and is often planted as a windbreak in coastal areas. Sadly, the tree cannot stand freezing conditions so during severe winters it is prone to dying or losing its leaves. For this reason, the holm oak is more common in the south of the UK[xxx]. However, possibly one of the benefits of global warming is that there is now a better chance a holm oak will survive in England’s north - that is where you will find me - than there might have been 20 years ago. I will most likely plant several and see.
There was a frost this week, although it did not last long, but is the first sign of winter approaching. Frost[xxxi],[xxxii] occurs when the temperature of the air in contact with the ground is below the freezing point of water. There are different types of frost - ground, air, and hoar.
A ground frost refers to the formation of ice on the ground, objects or trees, whose surface has a temperature below the freezing point of water. An air frost is when the air temperature is below the freezing point of water at a height of at least one metre above the ground. A hoar frost is formed by the same process as dew, but when the temperature of the surface is below freezing[xxxiii].
Frost can be damaging to land, although plants do what they can to protect themselves. Sometimes bark can act as insulation, and occasionally plants can accumulate materials such as sugars and amino acids that can behave like anti-freeze. More effective is the ability of some plants to allow their cell contents to superfreeze, where the cell contents remain liquid even though below freezing point. In very severe climates, such as within the Arctic Circle, native trees remove water from their cells, and place the water between the cells where it can freeze without causing damage[xxxiv].
Frost is also excellent for tracking animals, so I was out on my land first thing on this week’s frosty morning. Sadly, there was not much to see, although there were the pawprints of a neighbour’s cat who uses my land as a nightly thoroughfare. The number of mammal tracks on my land has declined dramatically in recent months, and I am trying to understand why. Perhaps it is because of the intensive building that is taking place nearby, added to the loss of green space when previous natural habitat has been turned into hardstanding. The built environment is a significant driver when it comes to biodiversity loss[xxxv]. The so-called Biodiversity Intactness Index (BII) that has been adopted by the United Nations Convention of Biological Diversity has found that the UK has retained only half of its biodiversity relative to pre-modern times. Compare this with 65% for France, 67% for Germany, and 89% for Canada. The UK’s performance is appalling, and it seems as if very few people care.
One exciting time of day on my land is not day at all, but night. I sit outside in the darkness commonly, as it is such an excellent time and place to think. The several storms we have recently seen have reduced things slightly but in autumn the nights are slowly becoming longer and are quite often clear.
This has allowed me to stargaze. What is it about the stars? They seem impossible for lesser mortals such as me to properly understand, and yet there is something attractive about them. Perhaps I am following the words of the late Stephen Hawking:
“Remember to look up at the stars and not down at your feet. Try to make sense of what you see and wonder about what makes the universe exist. Be curious. And however difficult life may seem, there is always something you can do and succeed at. It matters that you don't just give up.”[xxxvi]
Stars are one of the few things that allow mankind to indulge into the past, and to see the world through the same lens as his ancestors[xxxvii],[xxxviii]. The country’s dark sky sites[xxxix] have been truly helpful, although even they are beginning to struggle as adjacent development takes place at speed. A major role of stars, for many millennia, has been to help with navigation. Stars have also been associated with hope, destiny, Heaven, and freedom[xl], while easing minds, rejuvenating spirits, and making mankind more compassionate[xli]. When I stargaze, the stars remind me that I am part of a larger universe, and I am no more than a tiny speck in history. As with Nature, I cannot feel in charge of a star. It is manifestly in charge of me.
Because of the finite speed of light, when I gaze into the night sky I am looking into the past. For example, the bright star Sirius is 8.6 light years away. That means the light hitting my eye when I look at Sirius has been traveling for 8.6 years. I see the star as it was 8.6 years ago, not as it is now. The effect becomes bigger when objects are more distant. The stars of the Plough, also called the Big Dipper by many, are from 60 to 123 light years away. When I look at Dubhe, the front star in the “bowl” of the Plough, and 123 light years distant, I am seeing light from before I was born[xlii],[xliii]. The light was generated in the same year as the Siege of Mafeking, the Second Boer War, the Boxer Rebellion, or the last year of Queen Victoria’s reign. Want to feel minuscule and insignificant? Just look at the stars.
On a clear night, the naked human eye can see approximately 2500 stars, although it takes around 40 minutes for my night vision to acclimatise[xliv]. Once I have adjusted to the darkness, and I am dressed warmly, I can remain motionless for several hours. Stargazing has been shown to be wonderful for mental health and excellent for vision, while costing nothing.
Perhaps the commonest collection of stars, or asterism[xlv], and one recognised by so many people in the Northern hemisphere, is indeed the Plough, which can be seen in the northern sky. Seven stars form the Plough, which is part of the constellation of Ursa Major, the third largest constellation in the sky. The constellation contains 135 stars and is one of 88 different constellations[xlvi], so the Plough is only a small part of this.
The mythology that surrounds the Plough dates to prehistory[xlvii], and has given rise to many stories, especially if children are nearby. My favourite is that told by the Greeks, and goes like this:
Zeus, the King of the Gods, had an affair with a mortal huntress, Callisto. Hera, Zeus’s wife, disapproved, so turned Callisto into a bear. For a moment that was it, but shortly thereafter Callisto’s son, Arcas, was out hunting and saw a bear. He had no idea it was his mother. He was about to shoot an arrow into the beast, when Zeus spied the impending tragedy and quickly turned Arcas into a bear, too. He then turned mother and son into stars for their protection. Meanwhile, Hera was still distressed, so placed mother (Ursa Major) and son (Ursa Minor) into the very north of the sky, so they would be forever cold and committed to rotating around the North Star (Polaris) in perpetuity. That is where they are now. I love that story and have told it to many people, as well as muttering it to myself in the darkness.
The Plough is also one way to find the North Star (Polaris), which is one degree off true north[xlviii]. The two stars at the very end of the Plough are called Merak and Dubhe. If a line is drawn between the two and extended, it runs straight into Polaris, a star that sounds as if it should be bright but is quite faint. Polaris forms the very tip of the handle of the Little Dipper, or Ursa Minor.
Different nationalities have different stories about the Plough and see the asterism differently. The Greeks have one myth, the Romans have another, while certain Indian tribes in Canada believe that the Plough symbolises a bear being pursued by seven hunters. The Arabs believe the Plough is a coffin, the Finns see a salmon net, and the Dutch imagine a saucepan[xlix]. In India, the Plough is known as Saptarshi, with each star representing one of Seven Sages. In China, it is Beidou and signifies death, while the Little Dipper signifies life. In Korea, the Plough is called the Seven Stars of the North, each star representing a stepping stone placed by each of seven sons so their mother might cross a river[l]. The Plough comes with a very long list of different names and multiple stories, and remains the asterism recognised by most in the northern hemisphere. It is easy to see from my land.
Mankind has been navigating by the stars for many millennia and to our forefathers this was second nature. Certain animals can navigate by the stars, too. Some recognise the movement of star patterns, while others obtain their bearings from particularly bright, individual stars. A few even plot their course via our galaxy, the Milky Way[li]. Animal navigation has been extensively researched[lii],[liii] and there is no question that the night sky is an asset to many. Night-migrating birds certainly use the stars[liv]. For example, sparrows, warblers, thrushes, and ducks each migrate at night and use the stars and moon for navigation. Night migration also makes it easier to avoid predators, while the migrating birds are less likely to overheat, and the air is generally calmer[lv]. As I look overhead, be it by night or day, I can see that migration has begun. At the moment, the geese are largely flying south by day, but so many other birds are migrating overhead by night, and I see many from my land.
There is one very significant problem when I am scanning the night sky. It is light pollution, an emerging problem of great importance and urgency[lvi], largely neglected[lvii], and one of the most rapidly increasing alterations to the natural environment. Light pollution has a huge impact on biodiversity, including human health[lviii]. There is a long list of effects of light pollution on mankind, including a higher chance of developing breast cancer[lix], other cancers, sleep disorders, Alzheimer’s disease, and so much more[lx]. Light pollution near my land is already making it hard to see stars low in the sky. If mankind continues to build and construct in its unfettered way, the time will come even in Lakeland, when seeing the night sky and all it contains, added to the fantastic stories and adventures, will no longer be possible.
Dear me, what a future, and almost no one is listening.
***
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] See weeks 1 and 35 entries. [ii] Wikipedia. Chicory. Common chicory (Cichorium intybus) is a somewhat woody, perennial herbaceous plant of the family Asteraceae, usually with bright blue flowers, rarely white or pink. Native to the Old World, it has been introduced to the Americas and Australia. Many varieties are cultivated for salad leaves, chicons (blanched buds), or roots (var. sativum), which are baked, ground, and used as a coffee substitute and food additive. In the 21st century, inulin, an extract from chicory root, has been used in food manufacturing as a sweetener and source of dietary fibre. See https://en.wikipedia.org/wiki/Chicory. Accessed 20 October 2023. [iii] See weeks 18 and 24 entries. [iv] Landlife Wildflowers. Field scabious (Knautia arvensis). A tall native perennial wildflower plant with hairy stems found in grasslands across Britain. An individual Field Scabious wildflower plant can have as many as 50 purplish-blue wildflowers on it at a time. It is very attractive to wildflower butterflies. See https://www.wildflower.co.uk/index.php/products/wildflower-plugs-and-plants/field-scabious-wildflower-plants-knautia-arvensis.html#:~:text=A%20tall%20native%20perennial%20wildflower,found%20in%20grasslands%20across%20Britain. Accessed 20 October 2023. [v] Invasive Species Council of BC. Field scabious. See https://bcinvasives.ca/invasives/field-scabious/#:~:text=About%20This%20Species&text=A%20single%20plant%20can%20produce,Provincial%20Priority%20Invasive%20Species%20List. Accessed 20 October 2023. [vi] Pilosella aurantiaca. See https://www.gardenersworld.com/plants/pilosella-aurantiaca/. Accessed 20 October 2023. [vii] Lady’s bedstraw (Galium verum). Historically, lady's bedstraw was used to curdle milk in the process of cheese-making - a convenient vegetarian replacement for rennet, which is made from the stomach lining of cows. See https://www.wildlifetrusts.org/wildlife-explorer/wildflowers/ladys-bedstraw. Accessed 20 October 2023. [viii] Wikipedia. Malva moschata. The musk mallow or musk-mallow is a species of flowering plant in the family Malvaceae, native to Europe and southwestern Asia, from Spain north to the British Isles and Poland, and east to southern Russia and Turkey. Growing to 60 cm (24 in) tall, it is a herbaceous perennial with hairy stems and foliage, and pink saucer-shaped flowers in summer. The flowers are usually pollinated by bees. See https://en.wikipedia.org/wiki/Malva_moschata. Accessed 20 October 2023. [ix] Woodland Trust. Oxlip (Primula elatior). Easily confused with cowslip. See https://www.woodlandtrust.org.uk/trees-woods-and-wildlife/plants/wild-flowers/oxlip/. Accessed 20 October 2023. [x] Wade P. Salsify: The little-known Victorian root vegetable that's making a comeback. 13 November 2018. See https://www.independent.co.uk/life-style/food-and-drink/salsify-root-vegetable-taste-recipe-what-is-it-waitrose-albert-bartlett-a8631251.html. Accessed 20 October 2023. [xi] Teasels. See https://www.woodlands.co.uk/blog/woodland-flowers/pinkpurple-flowers/teasels/. Accessed 20 October 2023. [xii] Plant Wild. Teasel. Teasel is a statuesque flower and is a biennial, so it flowers in the second year. In the first year, the leaves form a bright green rosette. Teasels do self-seed readily however, so when planted in a group there should be some flowers produced each year. See https://plantwild.co.uk/product/teasel/. Accessed 20 October 2023. [xiii] Royal Botanic Gardens Kew. Wild carrot (Daucus carota). One of the common names of the wild carrot, Queen Anne’s Lace, is in honour of Anne, Queen of Great Britain (1665 — 1714). The wild carrot cultivar Daucus carota subsp. sativus is a major root vegetable for human and livestock consumption, with over 40 million tonnes farmed each year. Wild carrot root is edible but is smaller and more woody than commercial cultivars. They are eaten when young, or are roasted, dried, and ground to a powder to be used for making coffee. The seeds are used as a flavouring in stews, and the flower heads are lightly battered and deep-fried. Wild carrot is also occasionally used as a companion plant for crops to help attract more pollinators. See https://www.kew.org/plants/wild-carrot. Accessed 20 October 2023. [xiv] Naturescape. Wild wallflower (Cheiranthus cheiri). Excellent on dry stone walls in open and anywhere else where full sun and good drainage are available. See https://www.naturescape.co.uk/product/wild-wallflower/. Accessed 20 October 2023. [xv] The Wildlife Trusts. Great burnet (Sanguisorba officinalis). The crimson heads of great burnet were once used to make wine in Cumbria, and herbalists used them to stop bleeding. See https://www.wildlifetrusts.org/wildlife-explorer/wildflowers/great-burnet. Accessed 20 October 2023. [xvi] Woodland Trust. Meadowsweet (Filipendula ulmaria). Meadowsweet is the food plant for the larvae of several moth species including the emperor moth, grey pug, Hebrew character, lime-speck pug, mottled beauty, and the satellite. Many species of insects are attracted to the flowers. See https://www.woodlandtrust.org.uk/trees-woods-and-wildlife/plants/wild-flowers/meadowsweet/. Accessed 20 October 2023. [xvii] NatureSpot. Cotton thistle (Onopordum acanthium). Biennial, producing a large rosette of spiny leaves the first year which exists throughout the first year, forming a stout, fleshy taproot that may extend down 30 cm or more for a food reserve. In the second year, the plant grows to its full height which may be 2.5 metres. Widespread throughout much of Britain, though never common, and scarcer in the north and west. [xviii] Wetland Plants. Ragged robin (Lychnis floscuculi). This is a pretty, native plant. Produces its pink, star shaped flowers in late spring/early summer. This is a moisture loving plant that grows in marshes and damp woodlands. Its name is inspired by the frilled edges on its pink flowers. It is a perfect wildlife plant attractive to butterflies, bees, dragonflies, and other pollinators. It will be happy around the edges of a pond, in a moist bog garden, or in damp wildflower pastures or marshy grounds. See https://wetland-plants.co.uk/shop/moisture-loving-and-bog-plants/lychnis-flos-cuculi-ragged-robin-native-moisture-loving/. Accessed 20 October 2023. [xix] See week 16 entry. [xx] Naturescape. Wild primrose (Primula vulgaris). The common name is primrose, or occasionally common primrose or English primrose. In appropriate conditions, the wild primrose can cover the ground in open woods and shaded hedgerows. It is found mainly by streams, under bushes, in orchards and clear, moist deciduous forests. Occasionally it also appears in meadows. Both flowers and leaves are edible, the flavour ranging between mild lettuce and more bitter salad greens. The leaves can be cooked in soup but preferably with other plants because they are sometimes a little strong. The leaves can also be used for tea, and the young flowers can be made into primrose wine. See https://www.naturescape.co.uk/product/wild-primrose/. Accessed 21 October 2023. [xxi] Bewley JD. Seed germination and dormancy. The plant cell. 1997 Jul;9(7):1055. [xxii] Heuser CW, Dirr MA. The reference manual of woody plant propagation: from seed to tissue culture,second edition. 2006. Timber Press. 978-1604690040. [xxiii] Hessayon DG. The Bulb Expert. Expert series, 1995. 978-0903505420. [xxiv] Dunnett N., Hitchmough J. The Dynamic Landscape: Design, Ecology and Management of Naturalistic Urban Planting. Taylor & Francis 2008, 978-0415438100. [xxv] What are bulbs in the green? See https://plewsgardendesign.co.uk/what-are-bulbs-in-the-green/. Accessed 19 October 2023. [xxvi] Hartmann HT, Kester DE, Davies FT, Geneve RL. Plant Propagation: Principles and Practices. 7th Edition, 2002, Prentice-Hall, Englewood Cliffs. [xxvii] See week 36 entry. [xxviii] Bhojwani SS, Razdan MK. Plant tissue culture: theory and practice. Elsevier; 1986 Jul 1. [xxix] Wikipedia. Quercus ilex. Holm oak is listed as an invasive species in the United Kingdom. Normally the tree is unable to withstand severe frost, which would prevent it from spreading north, but with climate change, it has successfully penetrated and established itself in areas north of its native range. The largest population of holm oak in Northern Europe is present on and around St. Boniface Down on the Isle of Wight and into the neighbouring town of Ventnor, a town known for its naturally warmer microclimate, and has shown to tolerate the high winds on the downs. It is thought that this population's propagation (which was established in the late 1800s after having been planted by Victorian residents) has been bolstered by native Eurasian jays (Garrulus glandarius), which harvest acorns from oak trees and store them by burying them in the ground where they may then germinate. Feral goats were brought to Ventnor to control the spread of the holm oak. See https://en.wikipedia.org/wiki/Quercus_ilex. Accessed 19 October 2023. [xxx] See https://www.woodlandtrust.org.uk/trees-woods-and-wildlife/british-trees/a-z-of-british-trees/holm-oak/#:~:text=Alamy%20Stock%20Photo-,The%20holm%20oak%20can%20grow%20to%2020m%20in,develop%20a%20large%2C%20round%20crown.&text=Leaves%20are%20oval%20and%20dark%20green%20in%20colour.,-Credit%3A%20Nature%20Photographers. Accessed 19 October 2023. [xxxi] Old English forst, frost "frost, a freezing, frozen precipitation, extreme cold," from Proto-Germanic *frustaz "frost" (source also of Old Saxon, Old Frisian, Old High German frost, Middle Dutch, and Dutch vorst), from the verb *freusanan "to freeze" (source of Old English freosan "to freeze"). See https://www.etymonline.com/word/frost#:~:text=Old%20English%20forst%2C%20frost%20%22frost,from%20suffixed%20form%20of%20PIE. Accessed 20 October 2023. [xxxii] See week 3 entry. [xxxiii] What is frost? See https://www.metoffice.gov.uk/weather/learn-about/weather/types-of-weather/frost-and-ice/frost#:~:text=Frost%20occurs%20when%20the%20temperature,air%20frost%27%2C%20respectively). Accessed 20 October 2023. [xxxiv] RHS. Frost damage. See https://www.rhs.org.uk/prevention-protection/frost-damage. Accessed 20 October 2023. [xxxv] Minett A. Construction’s biodiversity threat and how to mitigate it. See https://constructionmanagement.co.uk/constructions-biodiversity-threat-and-how-to-mitigate-it/#:~:text=Product%20supply%20chains%20also%20play,noise%2C%20air%20and%20water%20pollution. Accessed 20 October 2023. [xxxvi] See https://www.goodreads.com/quotes/490245-remember-to-look-up-at-the-stars-and-not-down. Accessed 15 October 2023. [xxxvii] McArthur D. Why the stars are so important. See https://devonmcarthur46.medium.com/why-the-stars-are-so-important-ee6ec70f5891#:~:text=They%20are%20the%20only%20things,help%20for%20the%20great%20future. Accessed 15 October 2023. [xxxviii] Why looking at the stars is a look back in time. 7 February 2018. See https://www.forbes.com/sites/quora/2018/02/07/why-looking-at-the-stars-is-a-look-back-in-time/?sh=4e50c64414ec. Accessed 15 October 2023. [xxxix] Dark sky sites in the UK. See https://gostargazing.co.uk/dark-sky-sites-across-uk/. Accessed 17 October 2023. [xl] The importance of stars for humans. See https://ec.europa.eu/programmes/erasmus-plus/project-result-content/2b975140-fa95-457f-b53b-b65395c64743/THE%20IMPORTANCE%20OF%20STARS%20FOR%20HUMANS.pdf. Accessed 15 October 2023. [xli] Miller MMF. Stargazing: a magical way to escape. 3 August 2020. See https://www.shondaland.com/live/body/a33419686/stargazing-a-magical-way-to-cenchanting-respite/#. Accessed 15 October 2023. [xlii] Powell CS. Scientists claim that if an alien 65 million light years away sees earth through a powerful telescope, they can see "dinosaurs". How can that be possible? See https://www.quora.com/Scientists-claim-that-if-an-alien-65-million-light-years-away-sees-earth-through-a-powerful-telescope-they-can-see-dinosaurs-How-can-that-be-possible. Accessed 15 October 2023. [xliii] Green S. See https://www.quora.com/How-far-is-the-Big-Dipper-from-Earth#:~:text=All%20told%2C%20The%20Big%20Dipper,Its%20roughly%205x10%5E14%20miles. Accessed 16 October 2023. [xliv] Look up at the sky - the benefits of stargazing. See https://opticalleyecare.co.uk/the-benefits-of-stargazing/. Accessed 15 October 2023. [xlv] Britannica, The Editors of Encyclopaedia. "asterism". Encyclopedia Britannica, 2 Jan. 2023, https://www.britannica.com/science/asterism-astronomy. Accessed 16 October 2023. [xlvi] Wikipedia. Ursa Major. See https://en.wikipedia.org/wiki/Ursa_Major. Accessed 16 October 2023. [xlviii] Cloudy Nights. See https://www.cloudynights.com/topic/395861-magnetic-north-true-north/#:~:text=From%20the%20UK%20it%20is,geographic%20location%20is%20a%20factor. Accessed 21 October 2023. [xlix] Howell E. The Big Dipper: a useful pointer in the sky. 12 May 2017. See https://www.space.com/27758-big-dipper.html#. Accessed 21 October 2023. [l] Ursa Major. See http://judy-volker.com/StarLore/Myths/UrsaMajor3.html. Accessed 16 October 2023. [li] McMillan F. From dung beetles to seals, these animals navigate by the stars. 4 November 2019. https://www.nationalgeographic.com/animals/article/stars-milky-way-navigation-dung-beetles#Dung%20Beetles. Accessed 17 October 2023. [lii] Åkesson S, Boström J, Liedvogel M, Muheim R. Animal navigation. Animal movement across scales. 2014 Aug 21;21:151-78. [liii] Gould JL. Animal navigation. Current Biology. 2004 Mar 23;14(6):R221-4. [liv] Wiltschko W, Wiltschko R. The interaction of stars and magnetic field in the orientation system of night migrating birds. I. Autumn experiments with European Warblers (gen. Sylvia). Z Tierpsychol. 1975 Jun;37(4):337-55. doi: 10.1111/j.1439-0310.1975.tb00885.x. [lv] World Migratory Bird Day. Night migration. See https://www.migratorybirdday.org/night-migration/#:~:text=The%20majority%20of%20migratory%20birds,of%20birds%20in%20many%20ways. Accessed 17 October 2023. [lvi] Hölker F, Wolter C, Perkin EK, Tockner K. Light pollution as a biodiversity threat. Trends in ecology & evolution. 2010 Dec 1;25(12):681-2. [lvii] Gallaway T, Olsen RN, Mitchell DM. The economics of global light pollution. Ecological economics. 2010 Jan 15;69(3):658-65. [lviii] Rajkhowa R. Light pollution and impact of light pollution. international Journal of Science and Research (IJSR). 2014 Oct;3(10):861-7. [lix] Chepesiuk R. Missing the dark: health effects of light pollution, 2009. [lx] Cao M, Xu T, Yin D. Understanding light pollution: Recent advances on its health threats and regulations. Journal of Environmental Sciences. 2023 May 1;127:589-602.
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