360 likes | 575 Views
The Value of Trees. Arboriculture J.G. Mexal Spring 2001. Roots growing between concrete slabs. Arboriculture The Value of Trees/ Pirone 2000. Supply Oxygen Sequester Carbon Dioxide Reduce Noise Pollution Trap Particulates Alter Microclimate Improve Aesthetics
E N D
The Value of Trees Arboriculture J.G. Mexal Spring 2001
ArboricultureThe Value of Trees/Pirone 2000 • Supply Oxygen • Sequester Carbon Dioxide • Reduce Noise Pollution • Trap Particulates • Alter Microclimate • Improve Aesthetics • Enhance Outdoor Urban Spaces • Alter the Character of a Community • Provide products
How a Tree Grows Arboriculture J.G. Mexal Spring 2001
ArboricultureHow a Tree Grows-Terms • Trunk or bole • Crown • Terminal bud (scar) • Apical dominance- terminal bud • Apical control - crowns • excurrent- strong apical control • conifers, sweetgum, holly, • decurrent- weak apical control • most deciduous trees
ArboricultureHow a Tree Grows-Terms Excurrent Decurrent
Earlywood Latewood Sapwood Heartwood Tracheid-(conifers) Vessel- (hardwoods) Cambium Xylem Phloem Bark Periderm Cork cambium ArboricultureHow a Tree Grows-Terms
Cambium Bark Earlywood Heartwood Latewood Sapwood
Forestry & SocietyXylem production- earlywood vs latewood Phloem 1,2 = Developing xylem cells 3,4 = Latewood cells 5 = Earlywood cells L = Preceeding year
Forestry & SocietyHow a Tree Grows/Diffuse vs Ring Porus Silver Maple White Oak 50X
Leaves leaves fruit Fruit Annual rings Taproot Lateral root Forestry & SocietyHow a Tree Grows-Idealized
Maximum diameter growth occurs at the base of the live crown. As the tree grows, the crown tends to rise with increased shading. Basal pruning raises the crown and raises the point of maximum diameter growth. Year 3 Year 2 Year 1 Tree Growth
Maximum diameter growth occurs at the base of the live crown. As the tree grows, taper decreases, creating a more cylindrical bole. Often there may be some flare at the butt of the bole (not illustrated). Tree Growth Year 3 Year 2 Year 1
ArboricultureHow a Tree Grows-shoots Shoot elongation (cm) Whorl number Branch type Physiol. Of Woody Plants p428
Forestry & SocietyShoot Growth in Eastern White Pine Terminal growth = 44 cm Lateral branch = 26 cm 2o lateral = 12 cm Lateral branch = 19 cm Lateral branch = 14 cm 2o lateral = 10 cm 3o lateral = 6 cm 2o lateral = 10 cm
Radical Taproot Lateral root 1o 2o Mycorrhiza(s) [e] ectomycorrhiza endomycorrhiza Root hair Sinker root Mother root Actinorhiza Russian olive Alder Nitrogen fixer Legumes ArboricultureHow a Tree Grows-Terms
ArboricultureHow a Tree Grows-roots (7 wks) Robinia pseudoacacia Pinus taeda (cm2) (cm2) (cm) (cm2) (cm2) (cm) Physiol. Of Woody Plants p 27
ArboricultureHow a Tree Grows-roots Percent Pinus taeda Δ = Growing tips Physiol. Of Woody Plants p 28
Quercus rubra (red oak) wound 10 = Bark characteristics 9 = ‘Normal’ growth resumes 8 = Excessive growth to recover 7 = Tree harvested in spring 6 = Recovery takes 5 years 5 = “Walling-off” the injury 4 = Buckshot wound 3 = Declining growth (competition?) 2 = Rapid early growth 1 = Pith http://www.chesco.com/~treeman/SHIGO/AUTO.html
ArboricultureHow a Tree Grows • Dormancy-lack of visable growth • Ecodormancy- environmental stress induced • Endodormancy- requires chilling • Paradormancy- regulated by other buds • Cold-hardiness • Ability to survive freezing temperatures • Function of tissue, season, growth stage
Dormancy & Cold-hardinessDormancy Cycle/ Fujigama and Nee 1987 Degree Growth Stage Model Growth 0 90 180 270 360 Dormancy Cold Hardiness (oC) 0 -5 -10
Dormancy & Cold-hardinessDormancy Cycle/ Fuchigama and Nee 1987 Degree Growth Stage Model Eco- Eco- Endodormancy Growth 0 90 180 270 360 Dormancy Cold Hardiness (oC) 0 -5 -10
Dormancy & Cold-hardinessDormancy Cycle/Zones of Manipulation Degree Growth Stage Model Growth 0 90 180 270 360 Dormancy Cold Hardiness (oC) 0 -5 -10
Dormancy & Cold-hardiness Dormancy Cycle : intensity varies Photoperiod Photoperiod 36o N latitude 45o N latitude RelativeDormancy 30o N latitude 20o N latitude
Red = free water (ecodormant) Blue = bound water (endodormant) Yellow = intermediate Black = no water b = bud g = gap p = pith ph = phloem bs = bud scale Dormancy & Cold-hardinessDormancy Cycle: Role of Water-Grape/ Fennnel & Line 2001
Tolerant Pinus pinea Shoots = -40oC Roots = -10oC Intolerant Eucalyptus camaldulensis Shoots = -10oC Roots = -3oC Dormancy & Cold-hardinessFactors Affecting Acclimation-Tissue
Spring Buds = -3o Cambium = -4o Roots = -4o Seedling = -3o Germinant = -2o Winter Buds = -25o Cambium = -50o Roots = -10o Seedling = -30o Dormancy & Cold-hardinessFactors Affecting Acclimation-Size
Dormancy & Cold-hardinessWinter Injury Increases with Severe Water Stress- Leucaena leucocephala/ Mexal unpubl. Dieback (% of maximum) Distance from runoff water (m)
Dormancy & Cold-hardinessCold - Hardiness of Apple Blooms Growth Units Chilling Units 20 1.0 0.5 15 10 0 -0.5 5 -1.0 0 0 5 10 15 20 25 30 Temperature (oC)
Dormancy & Cold-hardinessCold - Hardiness of Apple Blooms LT50 (oC) Tight Cluster 12mm Green Full Bloom Full Pink Green Tip Dormant Photos by: Silver Tip Growing Degree Hours (oC)