RFI - Aboricultural Impact Assessment

A PPENDIX 1: D EFINITION OF T ERMS
 Age Class (AC): Is based on tree size and general visual characteristics of growth
 Y        Young:
          Early stage of growth, immature size and characteristics.
 EM       Early Mature:
          A fast-growing, well-established tree which has not yet reached its mature size.
          Strong upright growth habit with a dominant apical leader.
          Increased internode spaces between leaves and twigs.
          Slender lower trunk.
 M        Mature:
          The tree reached its mature size for the species and location.
          Exhibiting slowing growth rates with reduced internode spaces between leaves and twigs.
          Reduced apical dominancy with a more divisional growth habit.
          Minor naturally forming dead or dysfunctional wood.
          An increasing trunk girth to height ratio.
          Minor hollows.
 AA       Advanced Age:
          The tree has reached a mature size and is unlikely to increase noticeably in height or mass.
          The vigour/growth rate has reduced to the point that extension growth is very limited, if achieved.
          Canopy density is lessening and/or with some visible dieback/early retrenchment.
          Retrenchment of the upper crown, with increased vegetative vitality in the lower crown, creates a more compact
          form.
          The tree is displaying aged characteristics, including trunk swelling, enlarged buttress flare, trunk growth ridges,
          enlarged burrs, hollows, etc.
          Fungal activity and wood decay, and increased colonisation by flora and fauna.
 V:       Veteran:
          A tree with advanced retrenchment, reduced crown size and annual increment growth, extensive hollowing, crown
          collapse, low vigour, advanced heartwood decay, and advanced colonisation by fauna and flora.
          The former canopy is replaced with secondary adventitious growth.
          Sections of branches on the trunk are dead or dysfunctional – potential stag.
 Health (H): Is based on the tree’s general appearance and vigour, weighed against its genetic potential
 G        Good:
          Full canopy with foliage having good colour, size, and density of leaves.
          Strong vigour with a high canopy ratio, typically found in trees up to a mature age class.
          Minimal pathogen damage.
 F        Fair:
          The majority of the canopy has foliage with average colour, size, and density of leaves; discolouration may be
          present, typical for the species in the location.
          Slowed vigour and average canopy ratio; typically found in Mature and Advanced-Age classes or on younger trees
          under stress.
          Some minor twig or small-diameter deadwood, the canopy may be unbalanced.
          Minor pathogen damage.
          General health could be restored to Good with mitigation measures.
 P        Poor:
          A tree with a depleted canopy and limited to no vigour
          The canopy has notable dieback and a low canopy ratio.
          Detrimental pathogen damage.
          The tree may be in irreversible decline.
 D        Dead
          Dead and/or dysfunctional tree with minimal canopy ratio.
          Branches predominantly have no life.
 Structure (St): Is based on a visual assessment of the tree’s general form and visible defects
 G        Good:
          Structurally sound with no major visual defects.
          Trunk and buttress with no major wounds or decay.
          Canopy with sound stem and branch unions.
          The root system appears undamaged.
          No tree part failure is predicted
 F        Fair:
          A tree with minor defects or disorders which are notable in the canopy.
          Small areas of bark are missing, and small cavities are on stems and the main trunk.
          Canopy with asymmetrical growth resulting in an uneven canopy form.
          Tall phototropic growth habits.
          Minor damage due to root zone intrusion.
          Limited tree part failure is predicted.
 P        Poor:
          A tree with visual defects and disorders that are negatively affecting the tree's structural condition.
          Defects in the canopy, weak unions, actively decaying wounds and cavities, and problematically damaged roots.
          Increased tree part failure is predicted.
 H        Hazardous:
          A tree with a major defect and visual faults that may fail at any time
          Active tree part failure is occurring.




25_10_21_AIA_TPA_23BottlebrushAve                                                                              Page 18 of 19