Topic for discussion

Is the information from the text 3 new for you?

Who are dendochronologists?

 

Unit 3 Trees

3.1 Active vocabulary:

alder	ольха
ash	ясень
aspen	осина

 

baobab	баобаб
beech	бук
birch	берёза
chestnut	каштан
cedar	кедр
cypress	кипарис
Douglas fir	лжетсуга
eucalyptus	эвкалипт
elm	ильм, вяз
fir	пихта, ель
juniper	можжевельник
hemlock	тсуга
holly	остролист
larch	лиственница
lime	липа
maple	клён
oak	дуб
pine	сосна
poplar	тополь
rowan	рябина
spruce	ель
teak	тик
willow	ива
yew	тис

 

Read and translate the text 1 using the active vocabulary and a dictionary.

A. Cypress

Cypress trees (figure 3.1) are evergreen trees or largeshrubs, growing to 5-40 m tall. The leaves are scale-like, 2-6 mm long, arranged in opposite decussate pairs, and persist for 3-5 years. On young plants up to 1-2 years old, the leaves are needle-like, 5-15 mm long. The cones (figure 3.2) are
8-40 mm long, globose or ovoid with 4-14 scales arranged in opposite decussate pairs; they are mature in 18-24 months from pollination. The seeds are small, 4-7 mm long, with two narrow wings, one along each side of the seed.

The Cypress tree grows mainly along the southern coastlines and inland areas. The tree produces an oil called cypressine which acts as a

natural preservative within the wood. This inherent characteristic of the Southern Cypress makes it durable and extremely resistant to harsh weather conditions, insects and fungus. Since Cypress wood lacks sap and doesn’t bleed, it takes well to sealers, stains and paints. Its color varies in shades of light to dark honey. If left outdoors unfinished in its natural state, the appearance of the wood will become a light pewter color over time. The lumber is lightweight, scarce of knots textured, and dimensionally stable with a closed straight grain.

It is easy to cut, saw, nail, and resists splitting, warping, checking, splintering and cracking. Cypress wood compliments any interior or exterior architectural style from Rustic, Traditional to Modern. Cypress siding has been commonly used for years on coastal and resort homes. It was also used by colonial builders for their homes, barns, cotton gins, warehouses, boatbuilding and docks. Cypress wood has even been reused from 100 year old structures. Other beneficial uses today include: porches, bridges, shingles, shutters and greenhouse construction.

 

B. Sugar Maple

 

The Sugar Maple (figure 3.2) is a deciduous tree with a round crown. It is a prominent tree in the hardwood forests of eastern North America. Also Sugar Maple is grown in parks and gardens in Europe. It reaches heights of 15 metres (50 ft) to 24 metres (80ft) tall. Sugar Maple are distinguished by opposite leaf arrangement. Theleaves are deciduous, 8-15 cm long and equally wide with five palmate lobes. The basal lobes are relatively small, while the upper lobes are larger and deeply notched.

In contrast with the angular notching of the Silver Maple, however, the notches tend to be rounded at their interior. The fall color is often spectacular, ranging from bright yellow through orange to fluorescent red-orange. The leaf buds are pointy and brown colored. The recent years growth twigs are green, and turn dark brown.

The flowers are yellow-green. The fruit is a double samara or “maple keys” with two winged seeds. These seeds occur in distinctive pairs each containing one seed enclosed in a “nutlet’ attached to a flattened wing of fibrous, papery tissue. They are shaped to spin as they fall and to carry the seeds a considerable distance on the wind. Seed maturation is usually in a few weeks to six months of flowering, with seed dispersal shortly after maturity. Maples are important as source of syrup and wood. In North America the sap of this species is used to make Maple Syrup (figure 3.3). Some of the larger maple species have valuable timber, particularly Sugar Maple in North America. Sugar Maple wood is one of the hardest of the maples, and is prized for furniture and flooring. Bowling alleys and bowling pins are both commonly manufactured from sugar maple. Trees with wavy wood grain, called “birdseye maple”, are especially valued. Maple is also the wood used for basketball courts including the floorsused by the NBA, and it is a popular wood for baseball bats, along with white ash. The Sugar maple is a favourite street and garden tree, because it is easy to propagete and transport, is fairly fast-growing, and has beautiful fall color; however, its intolerance of pollution and compacted soils common to inner city conditions make it a frequent victim of maple decline.

Also, the increased use of salt over the last several decades on streets and roads has decimated the sugar maple’s role as a “street-front” tree. It also has some of the most dense shade to be found in shade trees. The shade and the shallow, fibrous roots may interfere with grass growing under the trees. Deep well-drained loam is the best rooting medium, although Sugar Maple can grow well on sandy soil which does not become excessively dry. Poorly drained areas are unsuitable and the species is especially short-lived on flood-prone clay flats. Its salt tolerance is low and it is very sensitive to boron.

C. Silver Fir

Silver Fir or European Silver Fir (figure 3.4) is a fir native to the mointains of Europe, from the Pyreness north to Normandy, east to the Alps and the Carpathians, and south to southern Italy and northern Serbia, where it intergrades with the closely related Bulgarian Fir. It is a large evergreeen coniferous tree growing to 40-50 m (exceptionally 60 m) tall and with a straight trunk diameter of up to 1.5 m. It has a smooth bark of a greyish-brown colour, which in aged specimens becomes rugged and fissured longitudinally, and of a silvery-grey colour.

The leaves are needle-like. They are dark, rich green above, about an inch long, and on the flattened underside there is a bluish – whitestripe on each side of the midrib, which gives a silvery appearance to the foliage when upturned, as is usual on the fertile branches. The tip of the leaf is usually slightly notched at the tip. The cones are cylindrical, 9-17 cm long and 3-4 cm broad, with about 150-200 scales, each scale with an exserted bract and two winged seeds; they disintegrate when mature to release the seeds.

Silver Fir is the species first used as a Cristmass tree, but has been largely replaced by Nordmann Fir (which has denser, more attractive foliage), Norway Spruce (which is much cheaper to grow), and other species. The wood is moderately soft and is used for general construction, interior work and paper manufacture.

D. English Oak

The English oak (figure 3.6) is native to Europe, east Russia, south west Asia and north Africa.

This is an extremely long-lived tree, possibly surviving for over 800 years, and can grow to over 30 m. The fruit (acorns) grow on long stalks, or peduncles, hence the tree’s alternative name of the pedunculate oak. The acorns fall in October.

The male flowers are yellow catkins and the female flowers are tiny green globules, and these appear in May. Leaves are alternate (figure 3.5) and leaf-base is heart-shaped with auricles. Bark is grey-green and somewhat shiny at first, becoming thick, grey-brown and ridged.

Oak trees are home to more species of animals than any other European tree, including 30 species of birds and over 250 species of insects (mostly moths). Oaks are prone to attack from tiny wasps, which cause different types of gall including currant, hop and spangle galls, and oak apples. Each part of the tree has its own associated wildlife.

English oaks have been exploited for timber, although they are still a common sight in the British countryside. It is planted for forestry, and produces a long-lasting and durable heartwood, much in demand for interior and furniture work. The wood is characterised by its distinct (often wide) dark and light brown growth rings.

 

E. Baobab

Baobab (figure 3.7) is the common name of a genus of eight species of trees, native to Madagascar (the centre of diversity, with six species), mainland Africa and Australia (one species in each). The mainland African species also occurs in Madagascar, but it is not a native of that country. Other common names include boab, bottle tree and monkey bread tree. Baobabs are distinctive trees, growing up to 25 m tall, and up to 7 m (exceptionally 11 m) in trunk diameter with an immense girth and a relatively small crown. The thick trunk serves to store water (with the capacity to store up to 120,000 litres of water)soaked upduring infrequent rainy spells.

They are deciduous and lack leaves for as much as nine months of the year. The leaves are also common as a leaf vegetable throughout the area of mainland African distribution, including Malawi, Zimbabwe and the Sahel. They are eaten both fresh and in the form of a dry powder. In Nigeria, the leaves are locally known as kuka, and are used to make kuka soup. The dry pulp of the fruit, after separation from the seeds and fibers, is eaten directly or mixed into porridge or milk. The seeds are mostly used as a thickener for soups, but may also be fermented into a seasoning, roasted for direct consumption, or pounded to extract vegetable oil.The tree also provides a source of fibre, dye and fuel.

The bare branches and thick trunk gave rise to the African legend that God uprooted the tree in a rage and planted it upside down, with the roots pointing to the sky. Baobabs are one of the longest-lived trees in the world, and some of the largest specimens are thought to be as much as 3,000 years old. The pendulous waxy white flowers have an unpleasant smell and open at night. They are pollinated by fruit bats and flies. The large fruit grows up to 24 cm long, and are sometimes known as monkey bread.

These trees have many uses. The fruit pulp is made into a drink and is used as a remedy for many diseases; and the leaves are eaten as a vegetable. The outer bark is used as a fabric after being softened and pounded, and the inner bark is twisted into rope.

F. Norway spruce

Norway spruce (figure 3.8) is native to mountains from Scandinavia to north west Russia and central Europe, and is grown throughout northern and central Europe and in eastern US. It is a cool climate species and grows at elevations of 1000-2200 m.

This conifer with a pointed, conical crown grows to about 30-50 m and has dark-green needles. Bark is grey or red-brown, flaky. The tree needs a good supply of soil moisture as it is shallow-rooted and prefers moist, deep, loose, loamy soils. Norway spruce produces the largest cones of any spruce, and these are 10-20 cm long. The cones ripen in autumn.

The timber is known as white wood or deal, and has many uses including paper pulp and roofing. Turpentine is extracted from the stem and the bark is used for tanning. Norway Spruce is one of the most widely planted spruces, both in and outside of its native range, used in forestry for timber and paper production, and as an ornamental tree in parks and gardens. It is also widely planted for use as a Cristmas tree. It is naturalised in some parts of North America, though not so extensively as to be considered an invasive weed tree. Several varieties are adaptedfor garden use.

G. Teak

Teaks a tall deciduous tree (figure 3.9) and a member of the laminaceae or labiatae family – the mint family. It is native to India, Myanmar and Thailand. It is also known locally as ‘tek’ or ‘teca’. Teak is a fast-growing species, and can reach heights of 40-45 m. The trunk can reach 1-1.5 m in diameter. Due to exploitation for timber, teak is considered to be endangered.

Teakwood is a very attractive golden to red-brown wood. Its natural oils make it very durable and resistant to moisture, and protect it from the drying effects of the weather. Its long life reliability and weather resistance have meant that it has become a very valuable wood and has been used for the decks of boats, furniture, flooring, carving and turnery.

Teak furniture dates back prior to the 19th Century, when it was used by the Chinese for export into Europe. Pieces of furniture over 200 years old have been discovered still in good condition.

The seeds and stem are used in alternative remedies to alleviate abdominal pain and diarrhea. The small flowers are white and are produced in June and July. Teak produces fruit in August and September. The timber is used in the manufacture of outdoor furniture, boat decks, and other articles where weather resistance is desired. It is also used for indoor flooring and as a veneer for indoor furnishings. Teak furniture is popular because it is usually high-ticket and is a status symbol. It is not uncommon to see teak patio furniture last 70 years out in the weather with proper care, and it’s common to see such heirlooms passed from generation to generation. Teak is used as a food plant by the larvae of moths.

Teak is easily worked and has natural oils that make it suitable for use in exposed locations, where it is durable even when not treated with oil or varnish. Teak cut from old trees grown slowly in natural forests is more durable and harder; teak from young trees grown in plantations is more prone to splitting and water damage.

H. Lodgepole pine

Lodgepole Pine (figure3.8), like all pines, is evergreen. Lodgepole pine is native to the Rocky Mountains from Alaska to Colorado. The tree is a tall, slender evergreen with a straight trunk. It averages a height of 12-25 m and a width of 6 m. It can live from 50-100 years and grows about 30-90 cm a year. The needles are in pairs and are stiff with a sharp point.

The 3-7 cm cones often need exposure to high temperatures (such as from forest fires) in order to open and release their seeds. The cones have prickles on the scales. The cones are short and cylindrical, and remain on the branches for many years. The scales protecting the seeds are armed with a sharp prickle. These trees tend to form dense forests, where little can grow underneath the thick canopy. The 3-7 cm cones often need exposure to high temperatures (such as from forest fires) in order to open and release their seeds. The cones have prickles on the scales. The cones are short and cylindrical, and remain on the branches for many years. The scales protecting the seeds are armed with a sharp prickle. These trees tend to form dense forests, where little can grow underneath the thick canopy. They are the most common conifer of the northern Rocky Mountains and grows on a variety of soil types and elevations. Lodgepole pines benefit from fire. Some of the cones on the branches will only open and release the seeds after being exposed to high temperatures. The seeds can then germinate in an environment where most other competitors have been destroyed by the flames. But not all the cones on the lodgepole have this mechanism, so that they can still release seeds without fire. The hard and straight trunk of lodgepole has meant that it has been used by Native Americans for lodge and teepee supports, and the timber today is used for the construction of housing and fences.