Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.

Isa trees and construction mark


Published on

Published in: Education
  • Be the first to comment

Isa trees and construction mark

  1. 1. Trees and Construction Chapter 13 ISA Arborists’ Certification Study Guide – Domains: Urban Forestry & Protection and Preservation<br />Mark Grueber, Urban Forester<br />
  2. 2. Describe how trees can be injured or killed as the direct result of construction damage.<br />Discuss the importance of arborists’ participation in the planning stages of development if trees are to be a part of the landscape.<br />Explain the steps that can be taken to preserve trees on a construction site.<br />Discuss some techniques that can be used to preserve trees when the soil grade must be changed.<br />Explain the limitations for treatment of trees that have been damaged by construction.<br />Objectives:<br />
  3. 3. Key Terms<br />The Key Terms as listed in the Arborist’s Certification Study Guide will be defined and highlightedthroughout the presentation.<br />
  4. 4. “Trees never knew complete removal of trunks, machine compaction of soils, sudden changes in water drainage patterns due to roads, pollution, and disruption of niches for soil organisms…These actions have come suddenly. They are being repeated.” – Alex Shigo, A New Tree Biology<br />
  5. 5. Construction Damage to Trees<br />One of the most common causes of tree death and decline in urban areas<br />People want to “live in the trees” but most landowners, developers and builders don’t understand how to take advantage of the opportunity.<br />
  6. 6. The Missing Link: Trees are part of the community’s infrastructure<br />Trees are an important and vital part of a community’s infrastructure<br />What do trees require?<br />What do we provide in an urban/ suburban setting?<br />Planning for trees<br />
  7. 7. What’s missing?<br />
  8. 8. Elements that affect plant growth<br />What we can’t impact<br />Sunlight<br />Oxygen<br />Carbon Dioxide<br />Soil texture (sand, silt or clay)<br />Temperature<br />What we can impact<br />Available Water<br />Available Nutrients<br />Soil structure (how a soil hangs together)<br />Available space<br />
  9. 9. …and a professional arborist or forester to tell them that.<br />Trees CAN be protected and preserved on construction sites<br />A professional arborist or forester MUST be involved early – during the planning stage.<br />
  10. 10. How are Trees Damaged During Construction?<br />The most serious damage to trees caused by construction is underground.<br />Root damage and soil disturbance.<br />
  11. 11. Roots…a review.<br />Which is a more accurate representation of a trees root system?<br />Fine absorbing roots are concentrated in the upper few inches of the soil<br />
  12. 12. Roots…the real picture<br />Mark Grueber, Ecological Consulting Services<br />Mark Grueber, Ecological Consulting Services<br />Mark Grueber, Ecological Consulting Services<br />
  13. 13.
  14. 14. Root Damage from Construction<br />Root injury may show decline in a few months or several years<br />Remember the mortality spiral?<br />Common symptoms: yellowing or early fall color, watersprouts, dieback of small twigs and eventually major branches<br />
  15. 15. Construction Damage - Physical Injury to Trunk and Crown<br />Damage to vascular tissues<br />But trees heal…don’t they?<br />Mortality spiral…again!<br />Note the “tree protection fencing”<br />
  16. 16. Construction Damage - Cutting of Roots<br />Digging and trenching[digging to install utilities; of concern due to root damage] will likely sever roots<br />Usually due to misunderstanding of root growth habit (1-3x branch spread)<br />Amount of damage depends on proximity to trunk and area of root development<br />
  17. 17. Cutting of Roots - continued<br />Severing 1 root can remove 15 to 25% of root system<br />Root loss may increase potential for tree failure<br />
  18. 18. Construction Damage – Soil Compaction<br />[Compression of the soil resulting in a reduction of the total pore space, especially the macropores]<br />Ideal soil has 50% pore space – filled with H20 and air<br />O2 is reduced; CO2 and other gases increase<br />Root growth is diminished; absorption reduced<br />
  19. 19. Construction Damage – Added Soil<br />90% of fine roots that absorb water and minerals are in the upper few inches of soil…got it???<br />Additional soil – even a few inches – can dramatically alter the infiltration of water and oxygen; fine roots die within 30 minutes<br />Altering the drainage pattern may also cause significant issues<br />
  20. 20. Construction Damage – Exposure <br />Trees grow in communities with other trees and/or non-turf type plants<br />Types of injury: sunscald, improper taper, aforementioned root and soil issues<br />It all comes back to understanding the biology of trees and “forests”<br />
  21. 21. Are there alternatives?<br />Tree Protection Planning and Preservation<br />Planting site improvements<br />Soil<br />Rooting space<br />Conservation development – preserving a portion of trees (not on exam!)<br />
  22. 22. Planning and Preservation<br />Tree protection planning cannot wait until construction<br />Must involve a professional arborist or forester who can communicate with developers and builders<br />Arborist must be involved from beginning to end<br />
  23. 23. Considerations of Tree Protection Planning<br />Don’t try to save every tree!<br />Species, size, location and condition<br />Don’t save a hazard<br />Younger trees may survive the stress<br />
  24. 24. Tree Protection Planning<br />Arborist – evaluates, selects and maps trees<br />Landscape Architect – assists with plan preparation to consider other parts of infrastructure<br />Don’t just consider the trees – remember it’s an ecosystem!<br />
  25. 25. Tree Protection Planning<br />Consider design changes or construction procedure modifications to accommodate trees<br />Tunneling [alternative means to trenching for installation of underground utilities] instead of trenching is one of the most common<br />
  26. 26. Specifications<br />[detailed plans and statements of particular procedures and standards]<br />All tree protection MUST be written into construction specifications<br />All contractors (and subs!) must be made aware of these specs<br />Consider fines (or incentives) using tree and landscape valuation methodology<br />
  27. 27. Construction Damage Avoidance<br />Barriers [fences or other means to establish a protection zone around trees on construction sites]<br />Place as far away from tree as possible…or a minimum of 1’/1” dbh<br />No traffic or storage of building materials, waste or excess soil<br />NO DISTURBANCE!<br />
  28. 28. Avoidance - Limit Access<br />Limit access to one route [means of entering and leaving a property during a construction operation] on and off property – but be realistic! Remember parking.<br />Specify areas for storage of equipment, soil, building materials; as well as areas for burning, washout, etc.<br />
  29. 29. Avoidance – Compaction Reduction<br />Build a “mulch road” - six to twelve inches of wood chips.<br />Must be CAREFULLY removed or reused<br />Plywood sheets<br />
  30. 30. Avoidance – Grade Changes<br />Terracing[method used to lower the soil grade in stages]<br />Maintain original grade as far from tree as possible<br />Must be accompanied by root pruning and care where roots are exposed<br />
  31. 31. Avoidance – Grade Changes continued<br />Tree Island[soil or landscape surrounding a tree, such as within a paved area]<br />Similar to terracing<br />Excellent for retaining small groves<br />
  32. 32. Avoidance – Grade Changes continued<br />Aeration systems[the set of holes or trenches created in a tree’s root area to improve oxygen availability to the roots]<br />Tree wells[wall constructed around a tree when the soil grade is raised to maintain the original soil level and provide oxygen to the root zone]<br />Lack of supporting research<br />Gravel or stone below fill does NOT improve water or oxygen flow<br />Consider tree size, species, drainage patterns, soil conditions, fill depth, irrigation and future maintenance<br />
  33. 33. Avoidance – Good Communication<br />The arborist must be involved during all phases of building<br />Take good notes and photos<br />This is where projects usually go wrong<br />
  34. 34. “We only took the fencing down for a moment.”<br />A tree protection plan without monitoring by an arborist is a waste of resources<br />Very few projects result in good tree protection<br />Plan for post-construction tree maintenance<br />
  35. 35. Treatment of Construction Damaged Trees<br />Periodic inspection and monitoring (post-construction) is a must<br />A little turf can hide a hazard<br />Safety first..but beware of unscrupulous contractors<br />
  36. 36. Construction Damage Treatments - Pruning<br />Remove only broken, damaged, or diseased limbs<br />During construction limbs may have to be pruned for equipment clearance<br />DO NOT thin the canopy to “compensate” for root loss – why?<br />
  37. 37. Construction Damage Treatments – Cabling & Bracing<br />Some trees can be preserved with remedial treatments<br />Cables must be inspect periodically<br />Inherent liability for the arborist<br />
  38. 38. Construction Damage Treatments – Wound Repair<br />Wounding is common on construction sites<br />No wound dressings and STOP telling people it will “heal!”<br />Bark tracing[cutting away torn or injured bark to leave a smooth edge<br />
  39. 39. Construction Damage Treatment – Irrigation and Drainage<br />Maintain adequate but not excessive moisture<br />Monitor for changes in drainage patterns<br />Most irrigation systems are inadequate and cause more harm than benefit<br />
  40. 40. Construction Damage Treatments – Mulching <br />Inexpensive and very beneficial when applied properly<br />Use chipped bark, wood, or pine needles if possible – why?<br />Mulch as much of the root width as practical for the landscape<br />No volcanoes!<br />
  41. 41. Construction Damage Treatments – Aeration (Vertical Mulching)<br />[filling vertical drilled holes in the soil with materials such as gravel, perlite, peat or sand]<br />Drill holes 2-4” in diameter; 1-3’ on center<br />Drill holes to a 12” depth unless fill has been placed over the root system<br />
  42. 42. Construction Damage Treatments – Aeration (radial trenching)<br />[means of aerating the soil in the root zone of a tree by removing and replacing soil in a spoke-like pattern]<br />Air excavator [device that blows air at high force; used to remove soil from the root zone of trees]<br />Mechanical trenchers should not operate within 4-8’ of trunk<br />Trench at least to dripline; 1’ depth<br />
  43. 43. Construction Damage Treatments – Fertilizer? or “Let’s Feed that Sucker!”<br />AGH!!! (pet peeve – this is where I go off for a while, sorry)<br />Why is this not a good idea?<br />If used ISA recommends a slow release to minimize risk of root injury<br />
  44. 44. One More Time!<br />Monitor, monitor, monitor.<br />Use your knowledge of tree biology and the site conditions to guide you<br />Obviously, this should be done by a professional…not this guy<br />
  45. 45. It’s Quiz Time!<br />Name 5 ways that trees can be adversely affected by construction:<br />Root injury<br />Soil compaction<br />Injury to trunk or branches<br />Grade change<br />Excavation/severing root system<br />
  46. 46. When soil is compacted, the ______ _______ between soil particles is reduced.<br />pore space<br />
  47. 47. Two detrimental effects of soil compaction are:<br />Suffocation<br />Restriction of growth<br />
  48. 48. A technique used to reduce soil compaction around trees on a construction site is to spread a temporary, thick layer of _______.<br />Mulch<br />
  49. 49. The overriding objective of an arborist involved in a development project is to save every tree on the site (true/false).<br />False…but aren’t they cute?<br />
  50. 50. It is better to tunnel directly under a tree than to cut directly across the root system of a tree when excavating for utility lines (true/false).<br />Duh.<br />
  51. 51. An important action that should be taken at the start of a construction project is to erect _______ around all of the trees that are to remain.<br />Protective fencing or barriers<br />
  52. 52. Carefully cutting away loose, damaged bark is called _______ _______.<br />bark tracing<br />
  53. 53. Soils that have been compacted or raised in grade are good candidates for soil _______.<br />aeration<br />
  54. 54. There is far more than an arborist can do to treat trees that have been damaged by construction than to prevent the damage (true/false).<br />What a dork!<br />
  55. 55. _______ is a technique that may be employed to lower the soil grade in steps.<br />Terracing<br />
  56. 56. (Easy) Sample Test Questions<br />When soils are compacted by construction equipment, trees usually decline because:<br />oxygen availability is reduced<br />the ability of the roots to absorb water and minerals decreases<br />root growth and expansion may be diminished<br />all of the above<br />
  57. 57. (Easy) Sample Test Questions<br />Arborists should be involved early in the construction planning process because:<br />tree preservation measures should be in the specifications<br />once construction has begun, it may be too late to save the trees<br />there is often little arborists can do to treat construction damage<br />all of the above<br />
  58. 58. (Easy) Sample Test Questions<br />A measure that can be taken to minimize compaction on a construction site is:<br />water the site thoroughly before equipment is brought in<br />permanently raise the soil grade to protect tree rots<br />spread a temporary, thick layer of mulch over the site<br />root prune the trees in advance<br />
  59. 59. (Easy) Sample Test Questions<br />If a significant portion of a tree’s root system has been removed during building construction, a step that will help preserve the tree is:<br />pruning one-third of the crown to compensate for root loss<br />a surface application of 10 pounds of soluble nitrogen per 1,000 square feet<br />construction of a tree well<br />none of the above<br />
  60. 60. (Easy) Sample Test Questions<br />Digging trenches in a wheel-spoke pattern and backfilling with organic matter or a more porous soil is called:<br />radial aeration<br />tunnel aeration<br />soil fracturing<br />vertical radiation<br />
  61. 61. Challenge Question<br />What actions can be taken if a tree is damaged by construction in violation of the written specifications?<br />
  62. 62. Challenge Question<br />Why may tree death and decline due to construction occur several years after construction is complete? <br />What are some of the signs and symptoms of construction damage that an arborist can look for following construction?<br />
  63. 63. Resources<br />Trees and Development: A Technical Guide to Preservation of Trees During Land Development; Matheny and Clark, 1998.<br />Root Injury and Tree Health; Watson<br />Missouri Department of Conservation Urban Forester: and<br />International Society of Arboriculture:<br />Treelink:<br />Building with Trees Workshops – The Arbor Day Foundation:<br />