Findings For Alder Tree

Alnus glutinosa – Common Alder Family – Betulacea

Findings Description. The common Alder sometimes called the European black or tag Alder, in Ireland in the old days it was sometimes known as the Owler, this fine tree is a native of Ireland it can grow to a height of 20 to 25 m tall with girths of up to ~5m. Its leaves are dark glossy green and lighter underneath with both male and female catkins on the same tree, the female catkins look like small cones and some stay on the trees all through winter. It is said the Alder is mature at around 60 years and has a life span of ~150 years. I picked this tree because it was very common around my area where I grew up, all along the river banks and in little groves near a lake only 5 minutes away from my house my mother went and transplanted an Alder tree into my back garden and I remember looking at photos of me and my sister standing beside the tree which was only a little bigger than us at the time we were only four at that time, 30 years later we had moved away and I was working as a tree surgeon having been in the area I got a call from the new owners of the house who wanted the tree taken down as it was easily 60-70 feet high, I went to give them a quote and unfortunately had to take the tree down as it was starting to lean badly to one side. History The story of Irish forests begins at the end of the last ice age about 13,000 years ago and a combination of dramatic climate conditions and humans continuing to exploit the forests that lead to a decline in Ireland’s forests and woods. It is said that amongst our native trees in Ireland Alder arrived around 8.500 years ago the alder was at first not as widely distributed as the oak and elm and was mainly restricted to wet areas at first but became better established by 7000 years ago. All up through the years it is easy to see that man made good use of this tree and only in the last 100 years have we seen a decline in woodland arts like coppicing & pollarding and charcoal burning for which Alder was grown and managed quite a lot. Charcoal from the alder is high grade and is used often in gunpowder manufacture. Today, our native woodlands are owned by private owners and some state owned as well, Until very recently, there was a lack of concern for their welfare their long time sustainability and their over all importance to our communities, some efforts have been made to manage and sort out our existing native woodlands, but it has generally been very little. The history of our woodlands is not a happy one, by the turn of this century, less than 1% of Ireland’s native woodlands remained. A lot of our woods and forests were felled to make ships to support England’s reign of the last century. Habitat The Alder tree loves damp places, Marshes, riversides, lakesides and beside streams and damp woods and any where were the ground is damp, boggy, or even water logged on and off, in fact if you come across an Alder tree you are very likely to find water near by. Alder trees are often used in land reclamation schemes, and the trees roots are at home in damp soil their roots are great at holding river banks together. It is found in all parts of Ireland but probably more so in the higher rainfall areas of the west and southwest. It will grow on a range of soils though prefers damp nutrient rich

sites. It is known as a hardy tree, an accommodating species capable of growing on all but the most infertile of sites. It is a Pioneer, light demanding species which regenerates easily. Alnus glutinosa as with most of the Alnus Spp, has seeds that can float, so can easily float off to germinate on muddy banks of rivers and lakes. The seeds are reported to be viable even after 12 months floating in still water.

Ecology In old and mature Alders the bark is covered in fissures along with deep cracks and small little spaces for insects to hide one report says something on the lines of the Alder supports twice as many organisms as some of our other native hardwoods, beech for example. Many insects feed on the Alder Spp. But there are a number of moths which feed on nothing else but Alder Spp. Most of them over winter in the loose bark of the trees or near by. These 3 moth species are reported to feed exclusively on Alder Spp. The Coleophora alnifoliae, the May Highflyer, and the Bucculatrix locuples. Because the Alder trees roots are water resistant a lot of fish and other animals and invertebrates take shelter in the roots away from predators and floods, the leaves from the tree quickly decomposes in water and therefore add nutrients needed by life forms in the water. Most of the Alder Species have the ability to form nodules on their roots which help to release nitrogen to the surrounding soil it is done by a bacteria which grow on the trees roots and take nitrogen from the air and then make it available to the tree, the tree in turn give the bacteria carbon which they get from photosynthesis. As well as all this the Alder trees help to support a variety of moss and lichen species on its bark and branches. This is because it grows by rivers and streams, where there is often a higher humidity in the air due to spray. In winter, alder is sought out by flocks of Siskin’s and Redpoll. Both species feed on the seeds held within the miniature cones.

Uses The Alder tree can be planted to enrich poor ground and to prevent erosion along river banks. The wood is tough and water resistant, and is used in foundation poles for houses, bridges, jetties and to make sluices. Also for wooden shoes and clogs, broomheads and handles, cotton reels, etc. It is a good turnery wood. It is yellow when seasoned and used to be known as Scottish Mahogany. The bark leaves and fruit all yield dyes. The leaves have been used in tanning leather. They are clammy, and if spread in a room are said to catch fleas on their glutinous surface. Alder-wood is not very good firewood, but it makes a first-class charcoal. This used to be used in the production of gunpowder and is now sometimes employed in the manufacturing of fireworks. Medicinally the tree has had many uses, for example: In fevers and all illnesses caused by chilling, rheumatism, wound-healing, skin diseases and inflammations and mastitis, also used mostly in years gone by as a Tonic and astringent. A decoction of the bark is useful to bathe swellings and inflammations, especially of the throat, and has been known to cure ague. One of the main reasons why the Alder was not grown much in Ireland in years gone by, there are signs of this changing, is the wood is not very strong when dry,

when constantly wet like the pier poles in Venice the wood is like concrete but take it out of the water and let it dry, its no good, it is a poor wood for burning too. The tree is well known to be a good wind breaker and because of its ability to enrich soils it is used in land reclamation and similar situations, so add them two reasons why Alder is good and not to mention its ability to prevent soil erosion in riverbanks mainly because of it roots at home in wet conditions and their adventitious root activity I see plenty of reasons why a commercial grower should consider them. Folklore There are many folklore stories and myths about the Alder tree and to cite them all here would run into several pages so I will focus on a few. Alder is known as “The King of the Fairies”, The Celtic meaning of the Alder deals with giving and nurturing among the sacred Ogham for many reasons. Namely, its root system provides rich nutrients to the soil, more so than other trees. The alder can successfully restore poor soil conditions back to healthy Ph levels. Some folklore stories say the Alder is a powerful tree, associated with fairy energies and the ability to harmonize the elements of water and fire. The sapwood can turn orange-reddish when it is first cut and this 'bleeding' was seen as a powerful sign of its life-force. Its spirit was associated with ancient divine energies like Saturn, and the Black Raven. It has also been associated with the art of the Black smith. An Irish folk story mentions that the first man was made from the Alder trunk. Peasants on the Alps are reported to be frequently cured of rheumatism by being covered with bags full of the heated leaves. The Alder (Fearn or fair-n) is also mentioned in the old Ogham language it is the fourth tree in Ogham, and so falls in the fourth month of the Celtic tree calendar from March 18 to April 14. It is also the fourth consonant of the Ogham alphabet (Fearn). This is its symbol

Management As fuel the Alder is not as good in heating power to the Beech or Ash, but for this reason is useful for purposes where a slow heat is wanted. By far the chief use of the tree at the present day is for gunpowder-charcoal, for which it is grown to a considerable extent, It is treated as coppice, and cut down every five or six years. In recent years there has been an increase in the use of the common Alder as a forest tree in Ireland, it is used in other countries too to help fix soil problems in certain sites, and foresters sometimes grow red and common Alder on sites for a few years before they grow spruce and other hard woods. In Ireland the Alder being a native species is scheduled under the forest service afforestation grant-aid scheme. When growing the trees for harvesting at a later time like most hardwoods it is best to delay thinning until a branch free bole of 6 to 7 metres is achieved. Heavy thinning is then carried out when the 6 to 7 meters is achieved to release potential final crop trees from competition to enhance their crown and also their dia growth. Planting stock of common Alder used in Ireland is usually two years old and is usually in the height of 50 to 80 cm. The seed source should be of best Irish origin.

Pest & Disease Apart from the Phytophthora disease European alders are generally free from major disease problems, there is one phytophthora species that is known as the Alder Phytophthora this is a serious disease and is spreading widely around Europe in most of the Alder species even in Ireland there has been reports of the disease, people in the industry think alders from nurseries are helping to spread the disease to new areas. One of the key symptoms to look out for in the alder pathogen is a necrotic lesion in the inner bark of the stem, usually noticed externally by the production of a tarry or rusty liquid substance leaking out from the bark. In severely affected trees the leaves turn yellowish get smaller and become sparse on the branches, reports of heavy fruiting then occur. Such trees then appear to die very quickly but there are reports of some recovering. Over 140 phytophagous (plant eating) insects have been recorded on alder. These include the striped alder sawfly. In comparison to birches, there are only a few moths which feed exclusively on alder, but the May highflyer (Hydriomena impluviata) is specific to alder, and its larva lives in a shelter which is formed by two leaves that have been sewn together by silk. Another moth whose larva is a specialist feeder on alder is the dingy shell (Euchoeca nebulata), while 4 species of micromoths in the genus Phyllonorycter make blister mines on Alder leaves. Alder is browsed upon by red deer, and this prevents the natural regeneration of the tree in many areas, while domestic sheep have a similar effect throughout the country. However, other potentially more serious threats to the survival of Alder have recently been noted in the UK and Ireland. One is a fungus (Phytophthora sp.) as noted above, which grows upwards from the bottom of the tree, killing the roots and bark. This has become a widespread problem in England and Wales, where over 10% of riparian Alders are either dead or infected with the fungus, Crown dieback has also been said to threaten some Alder Spp. The reason for this disease has not yet been found. www.treesforlife.org.uk/forest/species/alder.html Note: If planting alders from seed make sure to use seed taken from known safe seed origins to avoid the introduction of phytophthora...! Imported material should not be used.