Arboricultural Assessment and Report 2 Osborne Street, Flora Hill
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Arboricultural Assessment and Report 2 Osborne Street, Flora Hill 26 February 2019 Tree Logic Ref. 009789 Prepared for La Trobe University Pre pared by Timothy Burgess – Tree Logic Pty. Ltd. Contents 1 Objectives ................................................................................................................................................. 3 2 Method ...................................................................................................................................................... 3 3 Observations ............................................................................................................................................. 4 4 Photographs .............................................................................................................................................. 7 5 Tree Permit Requirements ........................................................................................................................ 8 6 Tree Protection Zones .............................................................................................................................. 9 7 Discussion ............................................................................................................................................... 10 8 Conclusion .............................................................................................................................................. 11 Appendix 1: Tree Assessment Data: 2 Osborne Street, Flora Hill .................................................................. 13 Appendix 2: Tree Location Plan: 2 Osborne Street, Flora Hill......................................................................... 14 Appendix 3: Arboricultural Descriptors (December 2017) ................................................................................ 15 Appendix 4: Tree Protection Zones ................................................................................................................. 22 Construction Guidelines................................................................................................................................... 26 Disclaimer ........................................................................................................................................................ 28 File No. Version Author Issue date Edits Issued by. 009789 1 Timothy Burgess 26/02/2019 Draft TB Treelogic Pty Ltd Unit 4, 21 Eugene Terrace Ringwood VIC 3134 Tree Report │ 2 Osborne Street, Flora Hill 1 Objectives 1.1 Tree Logic was engaged to undertake an arboricultural assessment and prepare a report to ascertain the current status, condition and arboricultural value of the trees located within the nominated study area at 2 Osborne Street, Flora Hill. The requirements of the arboricultural report include; • To provide information on the species, origin, dimensions, health and structure of the trees and their appropriateness for retention; • Determine the Tree Protection Zones (TPZ) for trees compliant with AS4970 ‘Protection of trees on development sites’; • Provide appropriate tree management recommendations with regard to potential development at the site. 2 Method 2.1 A site inspection was carried out on Thursday 21 February 2019. 2.2 The trees were inspected from the ground and observations were made of the growing environment and surrounding area. The trees were not climbed, and no samples of the tree or soil were taken. 2.3 Observations were made of the assessed trees to determine the species, age category, and condition with measurements taken to establish tree crown height (measured with a height meter) and crown width (paced) and trunk dimensions. Descriptors used in the assessment can be seen in Appendix 3. Where trees were on neighbouring properties, estimations were made on some measurements. 2.4 Assessment details of individual trees are listed in Appendix 1 and a copy of the tree location plan can be seen in Appendix 2. 2.5 Each of the assessed trees was attributed an ‘Arboricultural Rating’. The arboricultural rating correlates the combination of tree condition factors (health and structure) with tree amenity value. Definitions of arboricultural ratings can be seen in Appendix 3. 2.6 The assessed trees have been allocated tree protection zones (TPZ). The Australian Standard, AS 4970-2009, has been used as a guide in the allocation of TPZs for the assessed trees. This method provides a TPZ that addresses both the stability and growing requirements of a tree. TPZ distances are measured as a radius, from the centre of the trunk at (or near) ground level. All TPZ measurements for are provided in Appendix 1. Documents viewed; • Planning Property Report, 2 Osborne Street, Flora Hill – Department of Environment, Land, Water and Planning, dated 13/02/19 Treelogic Pty Ltd Unit 4, 21 Eugene Terrace Ringwood VIC 3134 Tree Report │ 2 Osborne Street, Flora Hill 3 3 Observations 3.1 The nominated tree study area was a large parcel of land covering approximately 7.2 hectares located on the western side of Osborne Street in Flora Hill. The site contained wide open spaces, an existing single storey brick building and the remnants of previous campus buildings which had since been demolished. Most trees were evenly spaced and scattered throughout the entire site. Refer to Figure 1 below for an indication of the study area. Figure 1: Aerial view showing the extents of the study area. Tree population 3.2 One hundred and seventy-one (171) individual trees were formally assessed within the nominated study area. This included forty-five (45) council managed street trees on the periphery of the site. • Individual tree details are provided in Appendix 1; • Refer to Appendix 2 for tree numbers and locations. 3.3 Tree group features were recorded where trees were found to be closely grown, of the same species, a similar size and condition which did not warrant detailed individual assessment. 3.4 Approximately sixty-six (66) trees were inspected and collected as four (4) tree group features with data including primary species, number of trees within the group, and average records of trunk and tree dimensions, health and structural condition and arboricultural value. Treelogic Pty Ltd Unit 4, 21 Eugene Terrace Ringwood VIC 3134 Tree Report │ 2 Osborne Street, Flora Hill 4 3.5 The tree population comprised a palette of forty-four (44) different species, including a wide variety of exotic species planted for garden and amenity purposes, introduced Australian and Victorian native specimens, and large naturally occurring trees which were indigenous to the local area. 3.6 The most prevalent species on site were River Red Gum (Eucalyptus camaldulensis) and Grey Box (Eucalyptus microcarpa), making up 29% of the population. See Table 1 below for a breakdown of the six (6) most commonly occurring species. Table 1: Breakdown of the most commonly occurring species. Species Origin Count Eucalyptus camaldulensis Victorian 26 (River Red Gum) native/indigenous Eucalyptus microcarpa Indigenous 24 (Grey Box) Cotoneaster sp. Exotic evergreen 8 (Cotoneaster) Fraxinus ‘Raywood’ Exotic deciduous 8 (Claret Ash) Eucalyptus melliodora Victorian native 7 (Yellow Box) Eucalyptus nicholii Australian native 7 (Narrow-leaved Peppermint) 3.7 Tree health was assessed based on foliage colour, size and density as well as shoot initiation and elongation. • The majority of assessed trees (125 trees) were displaying characteristics considered to be typical or better of the species growing in this environment under current conditions; • Twenty-one (21) trees were in Fair to poor health with symptoms including reduced foliage density and suppressed growing environment; • Twenty-five (25) trees were in a state of decline, with deficiencies including extensive crown dieback. 3.8 Tree structure was assessed for structural defects and deficiencies, likelihood of failures and risk to potential targets. • The majority of the assessed trees (93 trees) displayed Fair structure in terms of primary branching arrangement and architecture; • Sixty-four (64) trees displayed Fair to poor structure with defects such as previous failures and acute forks; • Twelve (12) trees displayed Poor structure; • Two (2) trees had Very Poor structure. Treelogic Pty Ltd Unit 4, 21 Eugene Terrace Ringwood VIC 3134 Tree Report │ 2 Osborne Street, Flora Hill 5 3.9 Arboricultural Rating The assessed trees were attributed with an arboricultural rating. This rating relates to the combination of tree condition factors, including health and structure (arboricultural merit), and also conveys an amenity value. Amenity relates to the trees biological, functional and aesthetic characteristics within an urban landscape context. It should be noted that the arboricultural rating is different to the conservation, ecological or heritage values placed on trees by other professions. Definitions of arboricultural ratings can be seen in Appendix 3. Arb. Rating 3% 4% High 9% Mod. A Mod. B 37% Mod. C 38% Low None 9% Figure 2: Breakdown of arboricultural ratings. Trees with a High rating were in excellent to good condition, were a prominent arboricultural/landscape feature and may have significant conservation or other cultural value. Retention of these trees is highly desirable. • Five (5) trees were attributed an arboricultural rating of High. Trees with a Moderate A rating were in good to fair condition and were a prominent arboricultural/landscape feature. Retention of these trees is highly desirable. • Fifteen