dendrology: tree parts and functions
DESCRIPTION
A Tree Is… A tree is a woody plant that has a well-defined stem and a formed crown usually at least 8 feet tall. The three main parts of a tree are: roots trunk (a.k.a. stem or bole) crown www.OneLessThing.netTRANSCRIPT
A Tree Is…
• A tree is a woody plant that has a well-defined stem and a formed crown usually at least 8 feet tall.
• The three main parts of a tree are:• roots• trunk (a.k.a. stem or bole)• crown
2www.OneLessThing.net
Roots
• The purpose of roots is to anchor the tree and absorb water and nutrients.
• Rootlets are the small branches that form off the main root.
• Root hairs are fine, hair-like roots that absorb water and nutrients from the soil.
• Pine trees lack root hairs so they have mycorrhizae fungi to serve that function.
3www.OneLessThing.net
Roots
• A tap root is a large main root that grows straight into the ground.
• Lateral roots are roots that grow horizontally from the tree.
• Trees with shallow root systems or that are in heavily cut-over areas are at risk for windfall.
4www.OneLessThing.net
The Trunk
• The purpose of the trunk is to conduct water and nutrients from the roots to the crown.
• Heartwood is the older dark-colored, center portion of the tree trunk.
• The wood at the core of the tree is dead so its purpose is only to provide strength to the tree.
5www.OneLessThing.net
The Trunk
• Sapwood is the light portion of a tree cross-section and it is living.
• The living portion carries nutrients and also serves as storage for food synthesized in the leaves.
6www.OneLessThing.net
Four Parts of the Trunk
• Heartwood – purpose is strength• Xylem – nutrient flow upward• Cambium – tree growth• Phleom – carries food downward
7www.OneLessThing.net
The Bark
• The outer bark is a dead, nonfunctioning layer that’s purpose is to protect the living tissue.
• It is formed by a thin layer of cells called the cork cambium.
8www.OneLessThing.net
The Crown
• The part of the crown that grows in height is the terminal bud.
• The purpose of the crown is to serve as the manufacturing part of the tree.
9www.OneLessThing.net
Photosynthesis
• is the process of converting carbon dioxide and water into food for the tree using the energy of the sun
• Most of the water carried to the crown enters the atmosphere as vapor through a process known as transpiration.
• Water exits the tree through leaf pores called stomata.
• Respiration is the process of a tree consuming oxygen.
10www.OneLessThing.net
Tree Growth
• The age of the tree can be determined by examining the trunk cross-section and counting the annual rings because each year produces one growth ring.
• Summerwood is the dark-colored area of a tree’s growth ring.
• Springwood is the light-colored area of the ring.
11www.OneLessThing.net
Tree Growth
• Trees that are closely-spaced or subjected to drought or stress will grow slower and produce rings that are narrow.
• Trees that are well-spaced and have abundant rainfall will grow faster and produce rings that are wider.
12www.OneLessThing.net
Thank you for learning withOne Less Thing!www.OneLessThing.net