1. Strengthening our Community Tree Canopy Through Education
Module #1:
Tree Growth and Biology in an Urban Environment
Laura Sanagorski, Environmental Horticulture Extension Faculty

2. Strengthening Our Community Tree Canopy
2012 Urban Forestry Series
This series is a part of a project titled “Strengthening Our Community Tree Canopy Through Education”.
This project is made possible by  a grant through the 2011 National Urban and Community Forestry Grant Program and the Florida Department of Agriculture and Consumer Services, and the Florida Forest Service.

3. Biology of Trees Why do we care? Helps us to:
Understand that trees grow differently in a
natural vs. urban setting
Understand how trees react to pruning cuts
Understand how a planting environment
can affect structural integrity and thus
anticipate pruning needs
Understand how to explain to customers
why pruning is necessary & what to expect

4. Tree Growth in Nature
Co dominate stems high
Photo: Laura Sanagorski

5. URBAN TREE GROWTH
NATURAL GROWTH
URBAN GROWTH

6. Tree Growth in Urban Landscape
Co dominate stems low
Photo: Stephen Davis

7. Trees with codominant trunks (also referred to as codominant stems / leaders)
Codominant trunk – two or more main trunks that are about the same diameter & emerge from approximately the same location on the trunk.
Photos: UF Laura Sanagorski

8. Included Bark
Little or no connective wood.

9. NATURAL GROWTH URBAN GROWTH
TEND TOWARDS CENTRAL LEADER / TRUNK
TEND TOWARDS MULTIPLE LEADERS / TRUNK - CODOMINANT
CODOMINANTS HIGH IN CANOPY
CODOMINANTS LOW IN CANOPY
FEWER TARGETS IN CASE OF TREE FAILURE
MORE TARGETS IN CASE OF
TREE FAILURE

10. BARK PHLOEM CAMBIUM XYLEM
International Society of Arboriculture, International Society of Arboriculture, Bugwood.org

11. CAMBIUM PHLOEM XYLEM BARK
International Society of Arboriculture, International Society of Arboriculture, Bugwood.org

12. ZONE OF STEM ELONGATION
APICAL MERISTEM
ZONE OF STEM ELONGATION
TERMINAL BUD SCALE SCARS
LATERAL BUD
LATERAL SHOOT
International Society of Arboriculture, International Society of Arboriculture, Bugwood.org

13. Branch Collar
Photo: Stephen Davis

14. Branch Union Branch Attachment: functions as screw
Ridges made up
Branch Attachment:
functions as screw
Photo: Laura Sanagorski

15. Strengthening our Community Tree Canopy Through Education
Module #1:
Tree Growth and Biology in an Urban Environment
Laura Sanagorski, Environmental Horticulture Extension Faculty