Tree Growth Dendrology - study of trees Dendrochronology - study of tree rings Tree Cross Section Outer Bark: Protection, insulation Inner Bark: phloem, carries food short lived - becomes bark/cork Cambium Layer : cell division, annual ring added Sapwood: new wood, carries water (xylem) Heartwood: strength, support Spring Cells Summer Cells This tree is 50 years old! Diameter Tape Measured at DBH - 4.5) Increment Borer Core sample Twig Diagram primary growth - growth upward secondary growth - outward growth Terms To Know BarkPrimary GrowthGravitropism Heartwood Secondary GrowthAuxins Sapwood Bundle Scar/Leaf ScarCytokinins Cambium Increment Borer Annual Ring Pith Diameter Tape XylemDBH PhloemDendrology Terminal BudDendrochronology Lateral BudPruning LenticelGrafting Bud Scale ScarPhototropism