Parts Of Trees

 Task Today-

1-Explain with a graphic the difference parts of a tree

-Leaves: A leaf is part of a plant/tree  that's usually green and attached to it by a stalk. When Autumn comes the leaves start to fall off and the green leaves become yellow and orange. A leaf is often flat, so it absorbs the most light, and thin, so that the sunlight can get to the cells. 

-Branch: A branch is a woody structural member connected to the trunk of the tree but  it is not part of it. There are big branches called Bough and the smaller branches are called twigs. The term twig often refers to a terminus, bough refers only to branches coming directly from the trunk. 

-Crown: The crown of a plant refers to the total of an individual plant's aboveground parts, these parts include stems, leaves, and structures.  The crown of a woody plant is the branches, leaves, and structures extending from the trunk or main stems. Shapes of crowns are highly variable. Crowns are also described by their width, depth and surface area. 

-Trunk: The trunk is the part of a tree that connects the leafy crown with its roots. The roots absorb water and nutrients from the soil, they are transported up the tree trunk in cells that are like pipes. This will allow the leaves to obtain water and nutrients.

Task 2- 

How do trees become timber? 

The full length of a tree might be too long to transport and work with, so the tree may be cut to a more manageable length. The tree trunks are transported to a sawmill, where the trees are cut to usable planks.

Task 3- 

Show and explain the different parts of the cross section of a trunk

Bark- the first layer is the bark,  the bark is the protective outermost layer of the trunk. Under it, it  is the inner bark which is made of the phloem. The phloem is how the tree transports nutrients from the roots.

Cambium-The cambium contains the growth meristem of the trunk. Directly to the inside of this is the sapwood, These cells transport the water through the tree.

Sapwood- Sapwood is usually lighter in color than heartwood. Sapwood are younger layers of new wood produced by the interior side of the vascular cambium within a tree trunk.

Heartwood-Most of the trunk in an old tree is dead wood called heartwood. The heartwood is old xylem that no longer transports water and minerals up the tree. ... The heartwood is often much darker in color than the sapwood. The heartwood gives the tree support,

Pith- Pith is a tissue in the stems of vascular plants, pith is generally present in young growth, but in the trunk and older branches the pith often gets replaced.

Task today-

Describe explain the different types of cut (eg quarter sawn)

Plain Sawn- Plain sawn in which the blade has teeth with no pitch. Plain sawn lumber is produced by making the first cut on a tangent to the circumference of the log. Each additional cut is then made parallel to the one before. 

Rift Sawn- Rift sawn wood is used for applications that require straight lined grain through and through. Tables, chairs and other furniture legs benefit greatly from having all exposed sides with the same linear appearance. Rift sawn lumber milling is more labor intensive than both plain and quarter sawn

Quarter Sawn-  Quarter sawn wood is more dimensionally stable than the plain sawn lumber. When cutting a big log into four quarters, then plain sawing each quarter, you end up with lumber that naturally resists cupping.  

Give an example of defects in timber 

Knot Knots are imperfections from branches that cause living wood grain to grow around them.

 

Give examples of timber used in NZ 

Rimu (red pine)  

Matai (black pine) 

Douglas Fir (Oregon) 

Redwood-A redwood tree can't grow to be the tallest tree on earth alone. Redwoods create the strength to withstand powerful winds and floods by extending their roots more than 50 feet from the trunk and living in groves where their roots can intertwine.

Kauri- Kauri is a tall timber tree of New Zealand found in large harbours