1 of 23

Tree Physiology

2 of 23

Tree growth begins with photosynthesis to produce new wood when the growing season begins.

3 of 23

Infiltration

4 of 23

Crown/leaves – Carbohydrate production

Stem/bole – Support, nutrient/water

transport, waste storage

Roots – Stability and nutrient/water

uptake

5 of 23

Meristems: annual growth can also be seen in the branching patterns of many tree species (esp. conifers)

6 of 23

When we dissect the trunk, we can see this annual incremental growth, both upward and outward.

STEM ANALYSIS

7 of 23

Wood Anatomy and Tree Growth: ________

Tree ring diameter growth

Terminal height growth

8 of 23

Definitions:

Cambium: the growing (generative) layer between the xylem and phloem.

Xylem: principle strengthening and water conducting tissue of the stem, roots, and branches.

Phloem: inner bark, principal function to distribute manufactured foodstuffs.

Bark: dead, outer tissue that protects the cambium from the external

environment and exposure to pathogens and physical injury.

Vessel: the composite, tube-like structure found in hardwoods from the fusion of cells in a longitudinal column.

Fiber: an elongated cell with pointed ends and a thick or infrequently thin wall.

Rays: ribbon-shaped tissue extending in a radial direction across the grain of the wood.

9 of 23

Note the five major portions of the tree trunk.

10 of 23

Phloem (inner bark)

Xylem (wood)

Cambium

11 of 23

Role of heartwood is…?

Role of sapwood is…?

12 of 23

Viewing wood: tangential, radial, and transverse planes. We are only interested in which of these?

13 of 23

Locally Absent Rings

Rings may be locally absent along the length of the tree.

Wood Anatomy and Tree Growth: ________

14 of 23

False Ring

Cells leading into the false ring will gradually decrease in size and then gradually increase back to earlywood cells.

Wood Anatomy and Tree Growth: ________

15 of 23

General Ring Structure

Wood Anatomy and Tree Growth: ________

16 of 23

Tree Identification

Coniferous (Softwood) - Evergreen

Deciduous (Hardwood) - Broadleaf

-Leaves fall off at maturity

-Less conical

-Flat, typically larger leaves

-Vessels

-Aspen, Oaks, Maples, etc.

-Maintains leaves all year

-Strong apical dominance

-Needle-like leaves

-Tracheids

-Pines, Firs, Spruce, etc.

17 of 23

18 of 23

19 of 23

20 of 23

21 of 23

22 of 23

23 of 23

Limber Pine