Quiz: Describe the difference in wood structure between diffuse porous and ring porous trees.

 

 

Meristem- key to tree growth,

Undifferentiated cells, located on surface area of tree, apical and lateral

 

 

Growth of individual tree parts

 

1. Branches (aka Shoots) and Leaves:

 

 


Growth: primordia located in buds, leaves grow out first and then shoot elongation. Elongation stimulated by auxins.

 

 

Indeterminate vs. determinate (free vs. fixed)

IND- can grow throughout growing season, multiple flushes; maples, birches, cherries

Determinate- only one set of leaves and shoots per season- oaks and pines

 

Early Leaves vs. Late leaves

 

 

 

2. Roots:

 

 

 

 

Growth similar to shoot growth (cells)- at apical meristem.

Correlation of elongation to root diameter. Elong. Also affected by temperature, excess water (because of oxygen losses), compaction

 

 

3.      Bole

Growth:

Meristem divides into fusiform cells and ray cells ( both are in xylem),

 

Ring width and area:

Wood is produced along perimeter,

From base of crown downwards

 

 

 

Types of Wood:

Coniferous wood- tracheids, no differentiation in function (support or transport) of tracheids

Diffuse porous- small vessels spread throughout wood used for water transport

Ring porous- large vessels in early wood and smaller vessels in late wood

Diffuse vs. Ring Porous wood

 

Early vs. late wood

 

Diffuse vs. ring porous rings

 

 

Reaction Wood

 

Compression conifers, forms on underside

 

 

Tension- hardwoods, forms on the upperside

 

 

 

 

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