Tree of the year 2009

Sycamore Maple (Acer pseudoplatanus)

The tree of the year in Germany is annually chosen by the Kuratorium "Baum des Jahres" (site available in German only).

Family: Aceraceae
Type: Maple (genus Acer)
Species: Pseudoplatanus
English names: Sycamore maple, great maple, sycamore plane, harewood

Origin: Mountains of Europe and West Asia
Plant sexuality: Monoecious
Distribution: Anemochory (spread by wind [meteorochy: with wings])
Pollination: Cross-pollination, melitophily (= bee pollination)
Breeding: Coppice

Habitus

The sycamore maple is a deciduous tree which can grow up to thirty meters high and up to two meters thick. In old age it becomes high-scapey with a broad-round, overhanging crown. It can attain an age of 300 (but also here and there over 400) years. The sycamore maple is especially in its youth very fast-growing. The growth however ceases on average habitats already relatively early, so that it is consequently overran by the (more shadow-bearing) copper beech.

Bark of a young sycamore maple

Bark of a young sycamore maple

Diffuse-porous wood

The sycamore maple has diffuse-porous vascular tissues (small wood vessels). These transport the water in the youngest annual ring as well as also in some of the earlier annual rings. The vascular tissues are relatively thin. That is a big disadvantage in times of acute drought, as it prolongs the period for an irrigation success.

Bark

As a young tree, the sycamore maple has a sage to auburn bark (similar to the beech), which begins to exfoliate as drab flake-bark in old age. A using of maple bark in vast extent does not occur.

Leaves

The top is dark green and the underneath is sage. The leaves are big, taut, with five broad, blunt lobes and pointed bights, roughly serrated. They are long-stalked and arranged opposite. Their size is between 8 to 16 cm and they become golden yellow in autumn.

Buds

The sycamore maple has one (bigger) terminal bud and two (smaller) side buds a time. The bud colour is mostly rich green, the edge of the bud flakes often dark (brownish). Also the buds are opposite as they always grow in the old leaf axils.

Blossom

The sycamore maple blossoms annually in april/may, on high levels however only every two or three years. The blossoms are unisexual, partially even hermaphrodite. The male, female and hermaphrodite, stalked blossoms form 8 to 15 cm long, grape-like, dense blossoming yellow green to reddish, hanging panicles.

Fruit

The fruit is composed of two carpels, which secede when they are mature. The fruit is also called wingnut. In children, those wingnuts are very popular. The wing fruits are arranged approximately rectangular resp. obtuse-angled. These wing fruits can cover large distances due to their airfoil with the wind. The seedlings always form two willow leaf-shaped germ bud leaves before the first typical maple leaves appear.


Roots

The sycamore maple is rather a deep-rooted than a heart-rooted plant: It occupies heart- and sinker roots with low root energy. Heart-rooting plants are typical for the majority of deciduous wood. Many vertical main roots that form a compact root system are characteristic. The actinoid outgoing roots enable intensive macerating of the root space. For the sycamore maple, the quick litter depletion (meaning the fast decomposition of the yielded autumn foliage) is typical and it therefore spreads its roots very quickly in the whole ground surrounding.

Preferred Sites

The sycamore maple likes it sunny to half-shaded. It is fairly modest but prefers fresh to moist, profound, calcareous soils and is not waterlogging compatible. The sycamore maple is (in old age) extraordinarily frost-hardy, very wind resistant and rather salt compatible, but on the other hand very sensitive towards air pollution, sensitive to heat and in the youth late frost-threatened. It thrives best with plenty water supply, why it grows preferentially in the mountains with high precipitation.

Usage

The sycamore maple has a good protective effect for slopes as it is a heart rooted to sinker rooted tree. It sprouts again and again with by coppicing after sawing off, what makes it very important in protection forests Ð e.g. also after a rockfall or the like. The maple tree can be used in bioengineering measures as it is deemed to be a soil consolidator.

It is very popular in primary successions. It loves an alkaline, moist habitat which is accordingly nutritious. Also north positions with increased humidity aren't an obstacle for it. On high ground however it occurs predominantly at sunny slopes.

In horticulture, the maple is only used in bigger gardens or parks. In landscaping, the sycamore maple is mostly used on large grounds where its habitus has a great effect. It is also a good avenue tree (alley tree) which is salt resistant, whereby it is suitable in inner-city areas.

Ecological importance

The sycamore maple is a very good honey plant. Further it is well suitable for deer for grazing and also as backing when it does intense coppicing. For the soil development it is a moderately important tree, where erosions are prevented however. Especially in higher mountainous regions, the sycamore maple has a major importance for the fauna. The maple tree has honeydew, meaning with intense aphid infestation, much sticky honeydew drops to the ground. The sycamore maple can occur on a height up to 1700 m above sea level, whereby its percentile is about 900 m above sea level.

Hazard / Diseases

For young trees, there's danger of late frost. By tar spot, a reduction of assimilation can happen. This has adverse effects on the resistance towards other diseases or vermins. Because the sycamore maple is a very popular grazing wood, it suffers from browsing damage, partially also by mice. A disease which can be observed especially often in urban areas is the infestation with Rhytisma acerinum, the tar spot. This disease however doesn't kill the tree.

Description of the Wood

Heartwood colour: yellowish white to white
Sapwood colour: yellowish white to white
Vessel assembly: diffuse-porous

The wood of the sycamore maple is a light-coloured (nearly white), hard and easily processible wood. It is very close-grained, resilient, tough and tends to rip at too fast drying. Planed longitudinal sections are silk gloss and very popular when they are fiddleback maple. Out of that, the sidewalls of particularly valuable violins are manufactured. In the radial cut, the wood fibres are visible as little mirrors.

The wood of the sycamore maple is neither weatherproof nor particularly resistant to fungal- and insect infestation. Hence it is solely used in interior construction and cabinetmaking - and the maple tree was in former times the vintage supplier for tavern tables. The veneering is used, but also the wood generally for apparatus engineering and cabinetmaking, parquet floorings, musical instruments and in the woodturning range. The fiddleback maple is, besides for violins, appointed for particularly beautiful, bright furniture. Because of the high gross density, maple wood however is also a very valuable fuel, which doesn't 'squirt' in the stove in contrast to conifers containing resin and doesn't soot up the chimney appreciably in contrast to oak wood.