TREE SURVEY REPORT FOR BELFAST CASTLE & CAVEHILL COUNTRY PARK. Tree survey carried out by Viliam Krupa ISA certified Arborist

Transcription

1 TREE SURVEY REPORT FOR BELFAST CASTLE & CAVEHILL COUNTRY PARK Tree survey carried out by Viliam Krupa ISA certified Arborist Start date: 14 of February 2013 Completed: 14 of October P a g e

2 INTRODUCTION: Belfast City Council attaches great importance to the contribution that trees make to our environment. As part of the parks management plan the Woodland and Recreation Unit carried out a health and condition report of the trees growing within Belfast Castle and Cavehill Country Park. The survey carried out started on 14 February 2013 and was completed 14 th October All trees with a stem diameter (DBH) over 150mm at 1.5m height and areas of significant woodland vegetation or regeneration were recorded. The surveyed trees were identified with durable aluminium numbered tags fixed at a consistent orientation and height above ground level. Tree positions were accurately marked up and recorded on a tablet PC using City Trees Management system and MapInfo. The survey detailed the location of trees, tag numbers, species, accurate crown spreads, approximate age, notes on condition and recommended remedial actions. Other features such as planted woodland and areas of regenerating woodland were also noted. Physiological condition has been assessed by visual ground based inspection using the surveyors personal experience and recorded as dead, dying, very poor, poor, fair, good, any other specific defect within the trees have also been recorded i.e. cavities, weak unions, fungi, ivy, deadwood, stem failures, root failures, vandalised trees and fire damaged trees. Vigour has been assessed by as either normal or low. Semi mature trees with DBH cm at 1.5m high, light green colour. Mature trees with DBH cm at 1.5m high, green colour. Fully mature trees with DBH cm at 1.5m high, brown colour. Over mature trees with DBH 96 cm above at 1.5m high orange colour. Woodland zones have been created and recorded Mixed, Coniferous and Deciduous A total of 2683 individual trees were identified, surveyed and recorded. Each tree that requires remedial action has been categorised and given a priority 1 to 4. Priority 1 being of the highest urgency and priority 4 being the least urgency. 2 P a g e

3 Annual work programme one to five years Year one Management Remedial tree surgery P1 and P2 All year round BCC contractor Removing Ivy Winter BCC Selective woodland thinning Winter BCC Planting Winter and early spring BCC Monitoring Spring, Summer and Autumn BCC Year two Management Removing ivy Winter BCC Selective woodland thinning Winter BCC Planting Late autumn and early spring BCC Monitoring Spring, Summer and Autumn BCC Year three Management Removing ivy Winter BCC Selective woodland thinning Winter BCC Monitoring Spring, Summer and Autumn BCC 3 P a g e

4 Year four Management Removing ivy Winter BCC Selective woodland thinning Winter BCC Monitoring Spring, Summer and Autumn BCC Year five Management Removing ivy Winter BCC Selective woodland thinning Winter BCC. Recommendations Recommendations included in this report outline the most appropriate action to be taken to minimise any risk or damage to property and people. Work recommendation Prune: Removal of branch or limb to correct point in order to increase the chance of formation of internal chemical barriers and reaction wood to seal the wound over time. The size of any wound during the pruning should be kept to minimum and some species react better than the others. The final cut should not extend into the main stem and should be limited to the branch collar if present or branch bark ridge if not. Both these must be retained as they are part of the main stem. Removal of them will result in damage and increased decay in three main stem. Crown Reduction: Crown reduction, referred to as a measurement of branch or limbs requiring removing, is the volume of the crown to be removed. This involves reducing Crown Lift: Removal of the lowest branches or limbs. This is usually specified as a ratio of complete height and should never result in a crown being less than 2/3 the height of tree. 4 P a g e

5 Major and Minor Deadwood: It is difficult to define major and minor deadwood. The location of the tree and target under the tree will define this. In the theory major deadwood would be that parts that could result in damage of person or property. In a practice deadwood up to 25mm is classed as minor and over 25mm diameter as major. Monitor tree: future inspection may be inconclusive from the ground based survey and it will be necessary to access tree canopy to visually inspect it. This may involve climbing with aid of rope and harness or mobile elevated work platform. Where internal decay is suspected, although is not visible the use of PICUS TOMOGRAPH may be required to assess for internal decay. This is specialised electronic instrument which can look internally into branch or tree trunk and display a computer generated image of its condition. It achieves this by measuring the speed that sound travels through the wood in a number of different positions and directions. Sound travels fastest through solid wood. Decayed wood will slow its path. By measuring the speed that sound takes to pass through a tree, an idea of its condition can be obtained. Natural fracture and habitat creation Monolithing and coronet cutting: Monoliting is a technique used to reduce the risk a hazardous tree poses due to structural weakness, such as dead or seriously decayed main stem. It involves the reduction of the tree to a specified height, leaving only main stem, which reduces vulnerability to wind and removes any long lever arms causing excessive stress. The remaining wood can then decay safely maintaining and enhancing biodiversity. Biodiversity and habitat opportunities can be further enhanced by incorporating natural fracture pruning techniques into tree work. Correct cuts at reducing cut points, such as the top of the monoliths, and as an alternative to pruning provide opportunities for aerial decay, increasing invertebrates. Increased surface area of cambium exposed by the cuts has been known to promote growth around the coronet cut and lower down the tree from dormant buts. In addition slots can be put into the tree using a chainsaw, providing roosting opportunities for bats and nesting opportunities for birds. Fungal Fruiting Bodies Commonly observed fungal fruiting bodies within Belfast Castle and Cavehill Country Park were: Armillaria mallea, Ganoderma aplanatum, Heterobasidion annonosum, Kretzschmaria deusta, Letiporus sulphurous, Polyporus squamosus, Pitopurus betulinus 5 P a g e

6 Location Belfast Castle & Cavehill Country Park is located in North Belfast off A6 Antrim road, and is set on the slopes of Cavehill Country Park in a prominent position 400 feet (120 m) above sea level. Its location provides unobstructed views of the city of Belfast and Belfast Lough. History The original Belfast Castle, built in the late 12th century by the Normans was located in the town itself.this was the home of Sir Arthur Chichester, baron of Belfast, but was burned down in Chichesters decided to build a new residence in the city's suburbs, today's Belfast Castle emerging as a result. The building that stands today was built from Castle was presented to the City of Belfast in In 1978, Belfast City Council began a major refurbishment over a period of ten years. The building officially reopened to the public on 11 November P a g e

7 Observations Majority of the trees are situated in 21 woodland zones that have been created within Belfast Castle & Cavehill Country Park. The age structure of the trees range from one year old self seeded saplings to older over mature trees. Most of them are located around Belfast Castle itself. Only small numbers of the trees are located in grass areas. Picture No. 1 showing natural regeneration of Beech in woodland zone 1 Tree species diversity includes: Alder, Ash, Beech, Birch, Cedar, Cherry, Chestnut, Cotoneaster, Cypress, Elm, Eucalyptus, Fir, Hawthorn, Holly, Hornbeam, Larch, Lime, Maple, Oak, Pear, Pine, Poplar, redwood, Rowan, Spruce, Walnut, Willow, Yew and recently planted Ginkgo. 7 P a g e

8 Many of the mature trees within the 21 zones have been fire damaged or vandalized and many others were identified as suffering from fungal pathogens Honey fungus (Armillaria mallea), Artist bracket (Ganoderma applanatum), Dryads saddle (Polyporus squamosus), Root rot (Heterobasidion annonosum), Chicken of the wood (Laetiporus sulphureus), Kretzschmaria deusta. 8 P a g e

9 9 P a g e Picture No.2 showing ryzozomorphs and fruiting bodies of Honey fungus (Armillaria mallea)

10 Trees within grass areas have been vandalized or damaged by lawn mower. Picture No.3 showing Turkish Oak (Quercus cerris) tree has been damaged by lawn mover There are also areas within the Park there are continuously vandalized. 10 P a g e

11 Picture No.4 showing vandalized tree tag num.159 in woodland zone 1 Picture No.5 showing ongoing vandalism in woodland zone 1 11 P a g e

12 Picture No.6 and 7 showing ongoing vandalism in woodland zone 1 Picture No.8 and 9 showing vandalized Maple trees, tree tag 351 that will be removed and tree tag1433 that have been removed at the lower car park. Trees are located in well used public area. 12 P a g e

13 Recommendations Priority P1 Trees: There are number of trees which are infected by different fungal pathogens and are located in areas frequently used by members of public these trees have been prioritised as P1 trees and needs urgent tree surgery. This work will be conducted by Belfast City Council contractor specialized on the tree surgery and need to be completed within 90 days Priority P2 Trees: These trees are located near areas well used by members of the public and most of these have been recommended for pruning or crown reductions. This work will be conducted by Belfast City Council contractor specialized in tree surgery and need to be completed within 180 days Priority P3 Trees: These trees have been recommended for monitor. P3 trees need to be monitored on annually basis early spring checking the vigour of the trees or late autumn checking for fruiting bodies of fungal pathogens. This work need to be done by Woodland Officer. Priority P4 Trees: haven t been prioritised. Belfast City Council winter work: The tree survey showed a great presence of ivy choking and over weighting trees in all 21 woodland zones. The ivy extends upward to the crown. Remedial action should be taken to strip the ivy from the base of tree to 2 metres high on each covered tree. To minimize volume of tree crown and reduce extra weight from tree. Woodland zones numbers 5, 7, 8, 9, 10, 11, 12, 13, 15, 17, mainly consist of semi mature trees which are years old. The trees in these woodland zones are dense and thinning would be required. The poorer, weaker and suppressed trees should be removed to favour trees with greater potential. Picture No.8 showing woodland zone 5 this zone requires selective woodland thinning Replanting of removed trees 13 P a g e

14 As a result of tree survey one over mature Cypress (Cuperusus macrocarpa) has been removed from the grass area at the castle due to health conditions. This tree should be replaced with similar evergreen species. The planting pit should be twice the diameter and depth of the roots. Care should be taken to ensure the tree is planted at an appropriate depth so that the root collar is just below ground level and an appropriate slow release fertiliser will be mixed in to the backfill soil. Grass area at the Front entrance to Belfast Castle Estate consists of poor structured trees Sycamore, Birch and Rowan. These trees should be removed and replaced with trees suitable to area and soil condition, plants that thrive / flourish in wet condition should be chosen. Picture No.9 showing grass area at the front entrance 14 P a g e

15 Rhododendrons along main road are over grown by bramble and self seeded trees. Picture No.10 showing rhododendrons along the main road to castle The removal of dense vegetation and woodland thinning in the lower parts of Belfast Castle Estate should be completed as a part of the winter BCC winter work to avoid future vandalism and antisocial behaviour within the estate. 15 P a g e

16 Picture No.11 and12 showing the fire damage on trees in lover parts at Belfast Castle. To avoid any future damage to newly planted trees in grass areas mulch should be spread around the base of trees this will increase the survival rates of newly planted trees. Mulch also helps protect the tree roots from soil borne pathogens Phytophora and Armillaria Honey fungus. Picture No.13 showing newly planted Ginkgo (Ginkgo biloba) tree damaged by lawn mover Some tree trunks from the trees recommended for felling will be used as natural furniture for the general public to use. 16 P a g e

17 Picture No.14 showing remaining timber carved by a member of staff Picture No. 15 showing remaining timber from Beech tree tag number 33 this timber will be used as public furniture Monitor for ash die back 17 P a g e

18 All ash trees within Belfast Castle and Cavehill Country Park should be inspected and monitored on regular bases during early spring and late autumn. The purpose of the inspection is to identify any sign of Ash Dieback (Chalara fraxinea). Landscape Considerations Management proposals include a degree of felling, thinning and some localised coppicing. Internally, the effects of coppicing and to some extent, thinning will alter the immediate landscape. Whilst changes may be dramatic at first, regrowth from cut stumps and the development of the shrub layer will soften the changes over time. Externally, very little landscape change will be evident. As only small areas will be thinned, adverse landscape change will be kept to a minimum. Trees and public safety All trees close to roads, paths and definitive routes, within the Park and formal access points will be inspected by the Parks staff for signs of damage following high winds and storm conditions, findings will be reported to the Woodland and Recreation unit for remedial action(s). Trees located away from these areas will be inspected during routine visits and five yearly intervals to tie in with the Parks Management Report. Action will be taken as required. Further information Map Index See attached documents Light green coloured trees on the maps shoving trees cm DBH at 1.5 metre Green coloured trees on the maps shoving trees cm DBH at 1.5 metre Brown coloured trees on the maps shoving trees 71 95cm DBH at 1.5 metre Orange coloured trees on the maps shoving trees 96 cm DBH and above at 1.5 metre Red coloured trees on maps shoving trees that have been removed Tree Index See attached documents Priority reports See attached documents 18 P a g e