Timber Structure

Question 1

What is the pith or medulla in a tree?

Answer 1

Innermost central portion of the tree that nourishes the plant in its young age

The pith consists of entire cellular tissue.

Question 2

What happens to the pith as a plant becomes old?

Answer 2

The pith dies up and sap is transmitted by woody fibre around the pith

This indicates a change in the tree’s structure as it ages.

Question 3

What is heartwood?

Answer 3

Inner annular rings surrounding the pith that are dark in color and do not take an active part in growth

Heartwood imparts rigidity to the tree and provides strong and durable timber.

Question 4

What is the role of heartwood in a tree?

Answer 4

Imparts rigidity to the tree and provides strong and durable timber

Heartwood does not contribute to the active growth of the tree.

Question 5

What is sapwood or alburnum?

Answer 5

Outer annular rings between heartwood and cambium layer that are light in color and weight

Sapwood indicates recent growth and contains sap-rings less sharply defined than those of heartwood.

Question 6

What is the function of sapwood in a tree?

Answer 6

Takes an active part in the growth of the tree

Sapwood is essential for transporting nutrients and water.

Question 7

True or False: Heartwood is involved in the active growth of the tree.

Answer 7

False

Heartwood does not take an active part in the growth of the tree.

Question 8

Fill in the blank: The _______ is the core of the tree that nourishes it in its young age.

Answer 8

pith

The pith consists of entire cellular tissue.

Question 9

Fill in the blank: The _______ indicates recent growth in a tree.

Answer 9

sapwood

Sapwood contains sap-rings that are less sharply defined than those of heartwood.

Question 10

What is the cambium layer?

Answer 10

Thin layer of sap between sapwood and inner bark

Indicates sap that has not yet converted into sapwood

Question 11

What happens if the cambium layer is exposed?

Answer 11

Result in death of the tree

This occurs if bark is removed for any reason

Question 12

What is the function of the inner bark?

Answer 12

Protection to the cambium layer

It serves as the inner skin or layer covering the cambium layer

Question 13

What does the outer bark or cortex represent?

Answer 13

Outermost protective layer of the tree

Sometimes contains cracks and fissures

Question 14

What are medullary rays?

Answer 14

Thin radial fibres extending from pith to cambium layer

Their function is to hold together the annular ring of heart wood and sapwood