arboricultural report bs5837 03.19ml - lang toon times · tree survey details 1 scope of limitation...

DRAFT

TREE SURVEY

&

ARBORICULTURAL REPORT

FOR

Trees at Auchterarder to Muthill railway path upgrade Active travel route

Requested by: Perth and Kinross Countryside Trust Prepared by: Martin Langton Report reference: MGL 1 Date: March 2019

Auchterarder to Muthill railway path upgrade: Tree survey and arboricultural report 1 Langton Tree Specialists Ltd., March 2019

Summary This assessment has been carried out at the request of Perth and Kinross Countryside Trust, as part of a feasibility study to upgrade the old railway path between Tullibardine Road, Auchterarder, and Sallyardoch Wood, Muthill. The route runs between areas of farm land, private woodland, occasional private gardens, and may also deviate to roadside locations. I have been asked to assess the existing tree cover and to consider the general impact of the proposals on the trees in relation to any future application for planning consent. The route of the path will follow the old railway line where possible. There are occasional obstructions but there is at present a clear pathway for almost the entire route, with trees and scrub lining each side in places. Consequently the assessment provides only basic information for the smaller trees of <50cm or so, such as species, location and tree work required. More detailed information is provided for larger trees, generally with diameter >50cm. I have surveyed 272 such trees beside the proposed line of the new path. These trees have been assessed according to BS 5837:2012 ‘Trees in relation to design, demolition and construction – Recommendations’, which provides an objective method to identify the quality and value of the significant trees. All arboricultural information is presented at the Tree survey schedule, appendix 2. The above and below ground tree constraints (in the form of crown spreads and root protection areas) have been plotted on the Tree Survey and Constraints plan, which accompanies this report. Much of the route follows raised embankment where the hard base of the railway line remains and the requirement for drainage is minimal. Even at cuttings the hard base remains and there is often evidence of old drainage channels beside the path. These factors will serve to minimise the likely impact of the proposals on the adjacent trees. The tree cover is of varied species, age and condition. Much of the tree cover includes multi‐stemmed Sycamore, Ash, and Willow, which has been cut back periodically beside the old railway. Other species include Beech and Oak. There are small, distinct areas of substantial mature trees, notably at Oak Wood (Auchterarder), Caerlaverock, South of Station House, and at Sallyardoch Wood. These trees, in particular, will require careful protection. Careful path design and special construction measures may be required for small areas of the path where a hard sub‐base is not present. In general, depending on the finalised route, only minor tree removals are anticipated over and above those due to poor tree condition in the current context. Trees removed to facilitate construction should be replaced with new trees of good quality (on a 1 to 1 basis) to ensure sustained tree cover in keeping with the local landscape and character of the area. Further details can be provided.


Tree protection measures are outlined that will safeguard the long term well‐being of retained trees.

CONTENTS Page No. SUMMARY 1 TREE SURVEY DETAILS 3

1 Scope and limitations of survey 3 2 Survey method 4 3 The site 5 4 Existing tree resource 6 5 Arboricultural tree works 10 6 Tree constraints 12

PATH CONSTRUCTION 13

7 Proposals 13 8 Outline anticipated arboricultural impact 14 9 Tree protection measures 16

RECOMMENDATIONS 18

Site photographs

APPENDICES A Description of path route and tree cover with photographs

1 Tree protection measures 2 Tree survey schedule

2A: Summary of arboricultural work 3 Plan 1: Tree survey and constraints plan 4 Tree Quality Assessment Chart (BS 5837: 2012 Table 2)


ARBORICULTURAL REPORT Auchterarder to Muthill railway path upgrade: active travel route Brief: This Tree Survey report has been prepared as part of the feasibility study for the upgrade of the core path between Auchterarder and Muthill. I have been asked to provide an assessment of the tree cover and to consider the general effect on the tree cover of upgrading the old railway line and of new areas of path construction. The trees on site have been assessed in the current context in accordance with British Standard 5837:2012 ‘Trees in Relation to design, demolition and construction ‐ Recommendations’ and in the light of my own experience. This report provides general outline guidance for remedial tree pruning; and for larger trees, an assessment of anticipated tree losses and pruning needed. It is expanded to consider outline guidance on the protection of retained trees during construction works.

TREE SURVEY DETAILS

1 Scope of limitation of survey

1.1. This survey (and report) is concerned with the arboricultural aspects of the site only. The survey was carried out during February 2019.

1.2. It is restricted to trees within the site or those immediately out with that

may be affected by its re‐development only. No other trees have been inspected.

1.3. The survey of larger trees (>50cm) has been carried out following the

guidelines detailed in British Standard 5837 (2012) ‘Trees in relation to design, demolition and construction ‐ recommendations’.

1.4. With reference to Perth & Kinross Council web site, the trees are not

afforded statutory protection through Tree Preservation Orders and are not located within a Conservation Area. However, I recommend that Forestry Commission Scotland and the Local Authority Planning Department are consulted prior to undertaking any remedial tree work recommended in this report. Tree works are subject to owners consent.

1.5. Only trees of significant stature have been surveyed: trees with a stem diameter less than 75mm ‐ 150mm in woodland – and large shrubs have been excluded. Trees with diameter between 150mm and 500mm are indicated on the Tree survey and constraints plan (plan 1), where basic information is provided such as species, location and diameter.


1.6. Groups of trees are indicated collectively on plan where individual identification and separate treatment is considered unnecessary.

1.7. No plant tissue samples have been taken and no internal investigation of the tree has been carried out.

1.8. No soil samples have been taken and or soil analysis carried out.

1.9. I have no detailed knowledge of existing or proposed underground services.

1.10. This report should be read in conjunction with the Tree Survey and

Constraints Plan – Plan 1 that accompany it (see appendix 3).

2 Survey method

Small trees <500mm diameter 2.1 Walk by survey conducted, with trees and main groups indicated on plan 1.

Tree work to be carried out according to general prescription (see later). Trees of 500mm diameter and above

2.2 The survey has been conducted from ground level with the aid of binoculars.

2.3 It is based on an assessment from ground level and examination of external features only – described as the ‘Visual Tree Assessment’ method per Mattheck and Breloer – stage 1 ‐ (The Body Language of Trees, DoE booklet Research for Amenity Trees No. 4, 1994).

2.4 I have estimated the height of each tree visually having first measured a

sample of trees across the site using a hypsometer. 2.5 Trunk diameters of single stemmed trees have been measured at 1.5m above

ground level. Multi‐stemmed trees have been measured immediately above the root flare.

2.6 The crown radii have been estimated by pacing and are given for the main

compass points: north, south east and west. 2.7 Where access to trees was obstructed or obscured, measurements have been

estimated.

2.8 The details of all inspected trees are given in the Tree Survey Schedule, appendix 2.


3 The site

3.1 The proposed route of the path extends from Oak Walk, Tullibardine Road, Auchterarder to Sallyardoch Wood near Muthill, following the old railway line, where possible. It runs through a rural landscape including open agricultural fields and private Estate woodland (including at Strathallan and Drummond Estates), passing through small settlements at Caerlaverock and Drumness. It crosses small water courses in a number of locations. The route under consideration deviates significantly from an area of the old railway at Machany.

3.2 Much of the route follows the old railway, with long sections of raised embankment and generally smaller cutting sections. The hard base remains from the railway and old drainage channels can often be found at the edge of the path at the foot of banking.

3.3 The proposed route may deviate from the old railway line in several locations under consideration: At Oak Walk, Tullibardine Road; south of Caerlaverock, where the route runs on soft ground beside a private garden; at Caerlaverock Wood and the boundary of Fimm potatoes; and possibly at Sallyardoch Wood, beside the north boundary. Ground conditions vary in these locations but they all lack the hard base found along the old railway line.

3.4 The tree cover varies, with frequent clumps and intermittent multi‐stemmed

Ash and Sycamore found in agricultural land. Willow is more frequent near woodland areas, along with early‐mature Oak and occasional Beech. There are substantial mature trees in certain locations such as at Oak Walk; Birks of Tullibardine; Caerlaverock Wood; and at Sallyardoch Wood: species include Oak, Ash, Beech and occasional Douglas Fir. The path runs alongside 2 areas of recently established broadleaved woodland areas in farmland on the outskirts of Auchterarder. In addition, there are some substantial individual and small groups of mature and late mature trees, often at the edge of farmland. A full description of the route including photographs of tree cover is provided at appendix A.

3.5 The topography varies; although much of the site is relatively level, either on

old railway embankments or cuttings. Soils appear to be mineral in composition and relatively free draining, although with damper areas at gully cuttings, particularly in woodland e.g. at the north end of the Birks of Tullibardine.


4 Existing tree resource

General

4.1 The tree cover is of varied species, age and condition. There is a high proportion of multi‐stemmed trees, particularly Ash, Sycamore and Willow, which have been cut back periodically beside the old railway. Other species include Beech and Oak. There are small, distinct areas of substantial mature trees, notably at Oak Wood (Auchterarder), South of Station House, at Caerlaverock, and at Sallyardoch Wood. A description of the tree cover is provided at appendix 1 starting at Oakwood, Auchterarder and following the proposed route to Sallyardoch Wood near Muthill.

4.2 The locations of the trees are shown on the Tree Survey and Constraints Plan

(plan 1), appendix 3. Notes and basic details are provided for the smaller trees, which make up the majority of the tree cover. More detailed information is provided for larger trees which may pose a greater constraint to construction works. Survey of larger trees (diameter >500mm

4.3 Two hundred and seventy two individual trees located on and immediately

adjacent to the proposed line of new path construction have been surveyed (with some tagged on site): tree numbers run from 1001 to 1274 (with 2 tags missing).

4.4 The locations of the trees are shown on the Tree Survey and Constraints Plan, plan 1, appendix 3; the condition categories are shown, colour coded as per BS 5837: 2012. The tree details are shown on the Tree Survey Schedule, at appendix 3.

4.5 The main areas of tree cover are as follows:‐ T1001 to 1012 (Oak Walk): This comprises mature Oak and Scots Pine

beside the existing path. An alternative route west of these trees would reduce losses to trees of high landscape value (plate 1)

T1013 to 1019 (East Hill to Middle Third Farms): Willow and Sycamore on farmland. (plates 4 to 8)

T1020 to 1042 (Middle Third Farm to stables): Multi‐stemmed and

single stemmed Sycamore with an increasing percentage of early mature Oak. A significant group of mature Oak near the stables on level ground. The route could follow low but damp ground beside the road, or existing embankment (plates 8 to 12)


T1043 to T1067 (Station House to Birks of Tullibardine): Mixed tree cover, with large specimen Oak and Douglas Fir set back from path. Semi‐Mature Atlas cedar at Station House (plates 13 to 16)

T1068 to T1084 (Birks of Tullibardine to pond): Mixed tree cover with

multi‐stemmed Willow, and with Ash, Oak and Birch (plates 17 to 18) T1085 to T1110 (pond to Rannoch Wood): Multi‐stemmed Willow and

Ash and with mature Oak at Rannoch Wood set back to west of path (plates 19 to 24)

T1111 to T1116 (Rannoch Wood to Farmton): Multi‐stemmed Willow

and Ash, with occasional early mature Oak (plates 25 to 27) T1117 to T1124 (Drumness Farm to burn): 4 mature roadside Oak at

Drumness; and group of Oak in open farm land. Mature Ash and self‐seeded Elm beside bridge (plates 28 to 32)

T1125 to 1144 (Burn to Caerlaverock): Areas of scrub, multi‐stemmed

Willow and intermittent tree cover; T1138 to 1143 located in private garden (with other smaller trees) east of path, include mature Beech, Larch, groups of Gean and Poplar. The existing path may require special construction measures to protect tree roots (plates 33 to 39)

T1145 to T1158 (Caerlaverock Wood): Significant groups of mature

Oak and boundaries of significant landscape value with mixed, broadleaved trees and occasional specimen Douglas Fir (plates 40 to 43; 59 & 60)

T1159 to T1230 (Pirnhill Plantation to Sallyardoch Wood): Groups of

multi‐stemmed Willow and Ash, with increasing proportion of Oak (plates 46 to 51)

T1231 to T1269 (Sallyardoch Wood): Mixed woodland, with groups of

Willow and Ash giving way to mature Oak, with Birch, Beech and Sycamore. Closely spaced trees line top of gully feature at NE of wood (plates 52 to 58)

T1270 to T1274 (Roadside East of Machany): Large mature individual

roadside trees including Oak, Sycamore and Ash.


Species composition

4.6 The survey population incudes around 16 species. These are listed below in order of frequency (in the survey). The most commonly recorded are Oak and Birch, which together account for almost 70% of the trees assessed.

Species No. of trees Percentage Oak 95 35% Willow 68 25% Birch 27 10% Ash 27 10% Sycamore 22 8% Beech 14 5% Scots Pine 6 2% Alder 3 1% Douglas Fir 2 <1% Gean 2 <1% 266 98%

Birch is the next most frequently surveyed tree and probably includes Silver and Downy Birch. The remaining species, include the single Atlas Cedar, Holly, Larch, Cypress, Norway Spruce and Sitka Spruce. The smaller trees, not subject to detailed survey, include a much higher proportion of Ash and Sycamore.

Age structure

4.7 A mix of age classes exists across the site, as surveyed, although most semi‐

mature trees are likely to be under the 500mm diameter threshold. The population includes 138 early mature trees and 113 mature trees. The mature trees are located throughout the site, although proportionally they are found in greatest frequency at Oak Walk, Caerlaverock Wood, and Sallyardoch Wood. Further details are provided in the data sheets at Appendix 2A.

4.8 Table 1 below provides a break‐down of the trees by age group, as surveyed:‐

Age class

Location Young Semi‐mature

Early‐mature

Mature Late‐mature

All areas 0 19 135 113 6

Total 0 19 135 112 6

Percentage 0% 7% 50% 41% 2% Table 1: breakdown of tree survey population by age


Tree management to date

4.9 Following closure of the railway in the late 1960’s a path has been maintained for the majority of the route between Auchterarder and Muthill. Trees have been periodically cut back, forming multi‐stemmed coppice trees, particularly in areas of farm land. Maintenance has been less intensive where the route passes through Estate woodlands, but collapsing trees have generally been pruned back to the edge of the path and some crown lift pruning has been undertaken. There is further work which could be done, as has been recommended in the Tree survey schedule (appendix 2). Tree condition

4.10 Although the assessment of a tree’s condition is a subjective process,

British Standard 5837: 2012 gives clear guidance on the appropriate criteria for categorising trees and the factors that assist the arboriculturist in determining the suitability of a tree for retention.

4.11 Under BS 5837: 2012, trees can be categorised as follows (see

appendix 4):‐

Category U: Trees of poor condition, such that any existing value would be lost within ten years and which, in the current context, could be removed for reasons of sound arboricultural management.

Category A: Trees of high quality and value: in such a condition to make a substantial contribution to amenity (a minimum of forty years is suggested).

Category B: Trees of moderate quality and value: those in such a condition as to make a significant contribution (a minimum of 20 years is suggested.

Category C: Trees of low quality and value which might remain for a minimum of 10 years, or young trees with uncertain potential.

4.12 The break‐down of surveyed trees according to condition categories is

as shown in table 2, below:‐

Tree Quality Assessment Category

A B C U

All areas 66 142 52 12

Total 66 142 52 12

Percentage 24% 53% 19% 4%

Table 2: Tree Quality Assessment by location

4.13 The proportion of A and B category trees surveyed is in excess of 70%. These trees are of generally good quality and medium to long term potential. Of the 95 Oak surveyed, 90 are assessed as A and B category, of which 50 are


A category. The proportion of ‘A’ category trees at Oak Walk and Caerlaverock Wood is also not surprisingly high. Four of the six Scots Pine and the 2 Douglas Fir surveyed are also ‘A’ category trees.

4.14 Over 50% of the trees surveyed are recorded category B and are considered to be of moderate quality and potential. In addition to Oak, they include Ash, Birch, Sycamore and Willow. These trees are generally of reasonable form and condition, without serious defects.

4.15 The C category trees are of low quality and potential and include a high proportion of multi‐stemmed Willow – 32 of 52 trees surveyed.

4.16 I have recorded 12 U category trees, 8 of which are located between Pirnhill Plantation and Sallyardoch Wood.

5 Arboricultural recommendations Arboricultural recommendations in the current context

5.1 The tree survey schedule at appendix 2 includes recommendations for

remedial tree work in the current context, which will be required to facilitate path construction proposals. These include the suggested removal of 13 trees, which, with the exception of 1 Ash and 1 Sycamore are all multi‐stemmed Willow. These trees are as follows:‐ U category removals:‐ T1074; T1171; T1175; T1179; T1185; T1200; T1210 C category removals:‐ T1026; T1102; T1186; T1217; T1246; T1247 The removal of these trees represents sound arboricultural management. Other remedial tree work is summarised at appendix 2A and includes: removal of unstable or leaning stems; removal of dead branches or stems; removal of damaged or hanging branches; crown lift pruning of low branches to provide clearance over the path. The following remedial tree work is recommended in the Tree survey schedule.

5.2 Remove stem or branch: 12 trees with dead, leaning and unstable stems and

branches: T1039; T1059; T1072; T1076; T1083; T1092; T1116; T1119; T1129; T1170; T1173; T1235.


5.3 Crown clean: involving removal of dead, damaged and weakly attached branches: 18 trees including: T1007; T1012; T1024; T1034; T1041; T1042; T1054; T1060; T1062; T1071; T1118; T1136; T1145; T1146; T1234; T1235; T1265.

5.4 Crown lift: 55 trees of varying species and locations distributed along route of proposed path.

5.5 Conservation dead wooding: removing unstable decaying dead wood from Scots Pine T1004 & 1006; Oak T1265

5.6 Complete dead woodland: Roadside Ash T1270; and Oak T1274

5.7 Remove dead wood over path: 12 trees of mixed species; T1051; T1067; T1090; T1095; T1214; T1228; T1241; T1244; T1245; T1257; T1266; T1277. Generic specification for remedial tree work: smaller trees (<500mm diam.)

5.8 A safe, clear route is required and remedial work will generally be confined to 5m each side of the path.

5.9 Tree removals: felling of dead, diseased and unstable trees which would present a potential hazard for path users.

5.10 Stem removals: fell dead, and decaying stems and stems which lean over the path line. Coppice back to ground level

5.11 Crown lift pruning: to provide clearance of 4.5m height over the width of the proposed path line.

5.12 Dead wood removal: remove unstable dead wood >50mm diameter over path or with the potential to impact path.

5.13 It is recommended that, where possible, the above work is marked on site with paint in order to instruct contractors.

5.14 Disposal of arisings: Farmland and gardens: ‐ Firewood to be stacked for Farm/owner Lop and top to be chipped Woodland areas:‐ Firewood to be stacked for land owner Lop and top to be chipped or cut up in woodland (depending on site)


6 Tree constraints

6.1 The information listed in appendix 2, the Tree survey schedule, has been used to provide constraints guidance based on the location of the tree, the crown spread and available rooting.

6.2 The crown spreads represent the above ground constraints to construction and development.

6.3 The Root Protection Areas (RPA’s): (the area where ground disturbance must be carefully controlled) have been established according to the recommendations set out in table 2 and section 5 of BS 5837: 2012. These have been assessed based on the trunk diameter of the tree. However, root morphology is influenced by factors such as past management, drainage and proximity to other trees. Therefore the RPAs as shown are likely to over emphasise the rooting areas particularly in areas of closely spaced trees.

6.4 The above and below ground constraints, as discussed above, are given in the Tree Survey Schedule and shown on the Tree Survey and Constraints Plan (see plan 1, appendix 3).

6.5 The ‘A’ and ‘B’ category trees represent the main constraint to the proposed works, particularly the substantial mature trees, due to their prominence and importance on site.

6.6 In my opinion, the C category trees are of limited significance and represent a minor constraint only, particularly where these can be replaced with better quality trees.

6.7 Where trees are located beside the existing hard base of the old railway line, tree rooting is not likely to be a material consideration to path upgrade and construction, particularly on areas of raised embankment. There is evidence of old drainage channels on cutting areas, which will also reduce the effect of the proposals on tree rooting.


PATH CONSTRUCTION

7 Proposals

7.1 The path is to be for shared use and requires an even gradient for disabled access. The route of the path follows the line of the old railway line where possible. This is generally clear of trees and has the advantage of a hard base.

7.2 The path design involves shallow excavation and a drainage channel/swale to be formed/reformed upslope in areas of cutting. The surface is to be tarmac.

7.3 The tree cover is found beside the path and only minor tree loss is anticipated. Path design near trees where hard base is not present

7.4 I recommend that, where practical, path design, for sections of path lacking a hard base and near mature A and B category trees adopts a ‘no‐dig’ design, incorporating a cellular confinement system ‐ such as ‘cellweb’ www.geosyn.com ‐ to prevent root severance and alleviate soil compaction. This system will facilitate water movement and gaseous exchange. Further details can be provided.

7.5 The design is likely to be considered in the following locations:‐ Near stables (South of Station House): on level ground South of Caerlaverock: beside private garden

7.6 The final design will be made by the project engineer.


8 Outline anticipated arboricultural impact

8.1 The route and low impact design of the path upgrade and areas of new path construction will minimise the loss of trees, which are an important asset on this site. There is a clear open path for much of the route, as previously indicated. Areas of substantial mature trees as identified in the report provide the main constraint and loss of such trees should be avoided where possible. Suggestions to avoid loss of mature trees

8.2 The route of the path should, if possible, avoid the following locations:‐ The existing path at Oak Walk, lined by mature Oak and Scots Pine Caerlaverock Wood, with groups of mature Oak at the west of the

woodland and significant broadleaved tree cover along the southern and north boundaries

2 mature roadside Oak trees at entrance to path: Drumness Farm

8.3 Special construction measures should be adopted where required, such as identified at section 7.4, and drainage works should be carried out with due care, particularly near mature trees (see later). Anticipated losses to facilitate path construction

8.4 Only minor tree losses are anticipated as previously mentioned, given section

8.2 above. The following locations are of note:‐ Middle Third Farm to Stables Loss of early mature trees (Oak, Sycamore and Ash): due, either to reforming steep embankment for disabled access, or due to tree cover between road and banking if route avoids embankment.

Caerlaverock (South) by private gardens Anticipated loss of group of semi‐mature Poplar and semi‐mature Gean beside path Sallyardoch Wood Potential loss of extended Beech hedge at edge of gully at NE of woodland if route deviates from existing hard track (see plates 55 and 56).

Further information can be provided as required.


Tree losses and mitigation planting

8.5 The loss of trees due to the path construction proposals can be mitigated by new planting of good quality trees in keeping with the character and local landscape. My recommendation is to replace losses of mature trees on a 2 for 1 basis in general. Any loss of Oak should be replaced on a like for like basis. Other species should also be replaced by suitable native species in farmland or woodland; such planting can enhance species diversity and suggested species could include Hazel, Rowan and Small leaved Lime, as well as Oak. Further details can be provided if required. Pruning to facilitate path construction

8.6 The pruning work identified in the Tree survey schedule (appendix 2) and summarised at appendix 2A will be essential in preventing damage to trees during path construction and for safe future use. For smaller trees, the main requirement will be to crown lift trees adjacent to the path and to clear unstable, collapsing stems and trees in order to provide clearance for pedestrians and horses. A minimum clearance of 4.5m is required, which will also facilitate construction.

Trees and construction: overview

8.7 Tree rooting is widely misunderstood and it is a surprising fact that typically, 80% of roots will be found in the upper half metre of soil and often extend well beyond the canopy spread. Threat to trees from development comes from:‐

Root severance and fracture Compaction of the soil, preventing gaseous exchange and moisture

percolation Possible changes to moisture gradients due to surface water run‐off

or interception Physical damage to low branches, trunk and root crown

8.8 The consequences for the tree of such damage are:‐

Instability, if severe enough Entry points for pathogenic fungi at wounds and fractures Loss of vitality and predisposition to pathogens

All of these can lead to root death which can cause a general decline or possible death of the tree.

8.9 As well as the physical footprint of any new installation, allowance needs to be made for the essential space requirements for construction activity. This includes machinery access, material storage and parking.


9 Tree protection measures Root Protection Areas (RPAs) and Construction Exclusion Zones (CEZ)

9.1 In order for retained trees to be protected during construction and to flourish

post‐development, it will be essential to restrict root severance or compaction of soils within the Root Protection Areas.

9.2 The RPA dimensions are provided on the tree survey schedule and are

calculated for each tree using the trees diameter: with measurements taken at 1.5metres for trees with a single stem, and above the root flare for twin and multi‐stemmed trees, although these will tend to overemphasise the effective RPA as previously mentioned.

9.3 Robust protective barrier fencing should be erected in stages as work progresses, at the limit of the RPA, where appropriate (or in a position to be agreed once further detailed proposals are available) in order to form Construction Exclusion Zones around retained trees. This must be done before any construction activity takes place or machinery is brought to site. For most of the site, protective fencing will be installed at the edge of the existing hard base of the railway line.

9.4 The design of fencing suitable for purpose and compliant with BS 5837 is given at appendix 1. The fencing shall be at least 2.0m high and comprise of standard ‘Heras’ welded mesh mounted on a scaffold framework. All fencing should be fixed in to the ground to withstand accidental impact from machinery and to ensure that the protective area is maintained. The design of light weight protective fencing is at appendix 1. Where the use of heras fencing is considered to be impractical due to topography, this should be discussed with the Local Authority and a practical solution found.

9.5 Ground protection can be used in conjunction with tree protective fencing as allowed for in BS5837. The design of ground protection is given at appendix 1A. Minor excavation near trees

9.6 Where excavation is required within the RPA of trees in new areas of path construction or in cutting areas of the old railway line, work should be carried out to conform to clause 7 of BS 5837: 2012. Excavation within the RPA should be undertaken carefully by hand or with the use of an air spade to limit the potential for root damage and ensure that root severance is kept to a minimum.

9.7 Any roots which are encountered during excavation should be cut back cleanly with secateurs. The excavation areas should be backfilled with inert


granular material mixed with topsoil. Finer roots should be retained in bundles. Further details can be provided as required. General protection measures

9.8 Within the CEZs the following prohibitions must apply:‐

No vehicular or plant access No mechanical digging or scraping No storage of plant, equipment, materials or soil No hand digging No lighting of fires

No handling discharge or spillage of any chemical substance, including cement washings

9.9 Further details of alleviating specific conflict between trees and construction on this site can be provided if required.


10 ARBORICULTURAL RECOMMENDATIONS

10.1 Tree works: and removals recommended in this report should be carried out by suitably experienced tree surgeons. Tree felling and pruning should comply with BS 3998: 2010 ‘Tree Work’.

10.2 Statutory wildlife obligations: The Wildlife and Countryside Act 1981 as amended by the Nature Conservation (Scotland) Act 2004 provide statutory protection to birds, bats and other species that inhabit trees. All tree work operations are covered by these provisions. Prior to undertaking any tree work, the trees should be inspected by a suitably qualified ecologist for the presence of Bat roosts and bird nests. If Bats and/or roosts or Bird nests are identified, Scottish Natural Heritage (SNH) should be contacted and an agreement made with regard to measures to be undertaken to protect Bats before undertaking any work which might constitute an offence.

10.3 Tree protection measures: should be used to protect the retained trees as indicated in this report. The implementation of these measures near mature trees, and subsequent adherence should be supervised by an arboricultural consultant.

10.4 An Arboricultural Method Statement (AMS): may be required where construction within the RPAs is unavoidable and tree retention is desired. The AMS will detail special mitigation construction measures and procedures that will minimise damage to tree roots and the surrounding soil. It should be supported with a Tree Protection Plan, detailing the alignment of tree protective fencing.

10.5 Appropriate replacement tree planting should be carried out post‐

construction to ensure sustained, effective long term tree cover on site as indicated in this report.

Martin Langton Bsc (Hons), For, MICFor, CEnv


Appendix A: Description of path route and tree cover (with photographs)


Appendix 1: Tree protection measures Tree Protection Fencing Specifications (BS 5837 default specifically outlined by outline box)

Heras Fencing Heras fencing describes the 2.4m galvanised steel mesh panelled fencing normally supplied with pre‐cast concrete bases. Bases are to be replaced with a fixed wooden frame to which panels are clamped/firmly fixed. For extra stability, scaffold poles/4 x 4 wooden posts are to be firmed in to the ground as supporting posts and supporting struts are to be attached at a 45 degree angle on the ‘tree side’ of the fencing and fixed in to the ground, as required.

1.5m (min) Chestnut Paling Fence on Scaffold Chestnut Paling to be affixed to a scaffold framework comprising two horizontal braces (top and bottom) supported by vertical scaffold posts driven firmly into the ground at 4.0m or less. Angled supporting struts are to be affixed ‘tree‐side’ as appropriate. 1.5m (min) Chestnut Paling on wooden supporting frame Stakes – 1.8m half round 100mm diameter untreated posts @ 1.8m centres (or as directed).

2 x 38 x 87mm rails (motorway)

1.2m Chestnut Paling will be industrially stapled to the rails Extra wooden supports to be affixed at an angle on the tree side of the fence. 2.4m Hoarding 3.0m 100 x 100mm square wooden posts 3 x 38 x 87mm wooden rails affixed to posts 2.4m x 1200mm outside grade ply panels (12mm) affixed to rails. 50 x 100mm angled supporting struts affixed internally (quantity as required). (Supporting posts fixed into position using concrete. All posts holes to be hand excavated. Post holes to be no larger than 300 x 300mm.)


Appendix 1 continued Figure 3 Specification for light weight protective barrier


Appendix 1A

Ground protection within the Root Protection Area if required

Figure 4: ground protection within Root protection area


Appendix 2 Tree survey schedule 2A: summary of remedial tree work


Appendix 3 Tree survey and constraints plan (plan 1)


Appendix 4: Cascade chart for tree quality assessment: BS 5837: 2012

arboricultural report bs5837 03.19ml - lang toon times · tree survey details 1 scope of limitation...

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