Forest Science
Scientific potential of the Federal Forest Service of Russia is presented now by 10 recent institutions situated in different regions.
In addition, forestry - oriented research is carried out in the institutes of the Russian higher schools.
The key directions of scientific research comprise scientific principled of multi-resource forest management; optimization of development, allocation and organization of multi-purpose forestry; development of ecologically safe methods of forest management; improvement of methods for prediction and control of forest fires, foci of pests and diseases; development of systems for scientific and information support of forests management.
:
- recent -
- forestry ,
- carryout -
- comprise -
- allocation -
- improve -
- fociofpests -
- support
:
1. :
- .
2. :
- What is this text about?
- Scientific research is carried out in the institutes of the Russian higher schools, isnt it?
- What are the key directions of scientific research?
3. :
1. development
) wood
2. improvement
b) increase
3. forest
c) locate
4. situate
d) investigate
5. research
e) progress
Botanical classification of wood
Trees, being plants, fall into the botanical classification system of taxonomic groups divisions, classes, orders, families, genera, and species. Hardwoods are included in the class called angiosperms, while softwoods fall in the class called gymnosperms.
The gymnosperms are divided into seven orders, one of which is conifers which includes all commercially useful softwoods. The angiosperms are further classified into two sub-classes of Monocotyledonous and Dicotyledonous.
Hardwoods of commercial importance belong to the Dicotyledonous sub-class.
Trees, as well as other plants, are referred to most precisely by scientific names, which are composed of their genus and species: black walnut, for example, is JUGLANS NIGRA L. However, the common name (black walnut) is sufficient for most practical purposes. The initial following the scientific name denotes the scientist who named the plant, in this case Linnaeus, a Swedish botanist.
:
- plant -
- fall (into) -
- taxonomy - ,
- division -
- order -
- genus (genera) -
- species -
- hardwoods -
9. softwoods -
10. conifers -
11. aswellas -
12. refer (to) -
13. precisely -
|
|
|
14. scientific -
15. compose - ,
16. blackwalnut -
17. common name -
18. sufficient -
19. initial -
20. denote
21. angiosperm
22. gymnosperm -
23. monocotyledonous
24. dicotyledonous -
:
1. :
1) What taxonomic groups of botanical classification do you know?
2) What Swedish botanist do you know?
3) Are the angiosperms classified into three sub-classes?
2. :
1) The gymnosperms are divided ____ seven orders.
2) Hardwoods are included ___ the class called angiosperms.
3) Trees are referred ___ most precisely ____ scientific names.
3. :
botany, classify, divide, commerce, taxonomy.
, .
1) plant
a)
2) denote
)
3) commercial
)
4) initial
)
5) genus
)
.
How a tree grows
Most trees can grow in height and width sending out shoots formed by new wood cells. They grow in height at the terminal bud of the main stem. The candles of the pines are known to be the evidence of a new growth. A tree also grows in thickness (or in girth) adding coats for new wood cells. Wood layers thus developed are called annual rings. Once formed, annual rings remain unchanged in size or place they are located in. The rings could be clearly seen on the cross-section of a tree trunk, pith is in its center. 
The wood section next to the bark which is often lighter than that in the center is called sapwood. It is a part of living wood through which the water taken up by the roots of a tree can pass on to the crown. Over a certain period of time sapwood is gradually substituted with heartwood due to infiltration of the chemical substance and some certain changes in the nature of cell walls. So wood becomes darker in colour and nearly lifeless. Heartwood serves to support the living parts of a tree. That is why hollow tress may still flourish and bear fruit.
The cells located between the bark and the last sapwood layer give a start to a cambium layer (true cambium). The inner side of the cambium layer can give a start to new wood growths. As for new bark it is develop from the outer side of the cambium. There is another kind of cambium which forms the outer corky bark. Like the true cambium layer, cork cambium may start a tree or form separate bark films in case older layers located nearer to the wood body are dying out.
Trees can bear flowers and are reproduced by means of seeds. When the tree enters its long winter rest, it has the next year buds already formed. The buds expand and grow until they finally open into flowers or leaves in spring.
Some trees, as the elm and the red maple, blossom and set fruit before the leaves open. Other trees wait until their leaves are party grown to produce blossoms, while some others, such as the chestnut, do not flower until early summer. Some trees mature their seeds rapidly to scatter them early in spring. Most trees provide great quantities of seeds and their winged seeds are easily scattered by the wind. Having fallen from the tree to the ground, only one seed out of the thousands can take a root to start a new tree.
|
|
|
:
1. grow in height (width) ()
2. shoot
3. wood cells
4. terminal bud
5. girth
6. annual ring
7. cross-section
8. tree trunk
9. pith
10. bark
11. sapwood
12. heartwood
13. hollow tree
14. flourish
15. bear fruit
16. cambium layer
17. elm
18. redmaple
19. blossom ,
20. chestnut
21. mature seeds
22. scatter (seeds) ()
:
