Soil Volume Structural Soils (Socash) 2008 Sept Miami Dade Ciab

Soil Volume Structural Soils (Socash) 2008 Sept Miami Dade Ciab

• 1.
  Soil Volume andUrban Forest Henry Mayer, Miami-Dade County Cooperative Extension Service Jimmy Socash, ASLA, JFS Design Inc. CIAB Miami, 2008
• 2.
  “Meeting the Goals of the Miami-Dade County Street Tree Master Plan” •Planning •Planting •Pruning •Education and Growth •Best Management Practices (BMP) ROOT ZONE GROWING AREA “Design the soil space under and adjacent to the hardscape to sustain root growth – good trees well connected to the ground only develop if the roots have room to grow” “Miami-Dade County Street Tree Master Plan” Page 7- March 2007
• 3.
  Trees Growing inConfined Soil Spaces are Prone to Toppling… …Rate of growth is greatly reduced…and… will be short- lived. “Better to plant a 50 cent tree in a 5 dollar hole than a 5 dollar tree in a 50 cent hole”
• 4.
  “The major impedimentto establishing trees in paved urban areas is the lack of an adequate volume of soil for tree root growth.” Urban Horticulture Institute December 2000
• 5.
  Tree Plantings withrestricted root zone areas
• 6.
  Comparative Soil Volumes BrownsvilleMetrorail Station
• 7.
  Roots grow wellbeyond canopy edge Dr. Ed Gilman, U of Florida • Trees that normally grow a very expansive root system can become stressed and grow poorly in urban landscapes where soil space is limited • The result can be poor tree health, damaged sidewalks and curbs, and other problems
• 8.
  How Much Soil? Larger Trees 1200 CF Soil Volume = 20’ x 20’ x 3’ depth 20” Trunk Diameter e e s iz f tre me ti o o volu Ra soil to More Soil JAMES URBAN, FASLA, ISA 20” Trunk Diameter Tree will require 20’ x 20’ x 3’ deep soil volume (min.).
• 9.
  Each Sq.Ft. of canopyrequires 1.5 Cu.ft of soil JAMES URBAN, FASLA, ISA
• 10.
  Trees with morerooting space survive winds better Campuses, Parks, Yards Yards, Parks Street trees, Parking lots, Yards 91% 73% survival 64% survival survival 0 to 3 m2 4 to 7 m2 > 7 m2 (0 to 39 ft2) (40 to 75 ft2) (> 75 ft2)
• 11.
  Plant the EasyPlaces First. 1 4 City of Sweetwater 2 3 Develop design options that plant trees in large soil resources. JAMES URBAN, FASLA, ISA CIAB project
• 12.
  “ARBORIST NEWS” INTERNATIONAL SOCIETYOF ARBORICULTURE (ISA) August 2008
• 13.
  “Downtown Kendall UrbanCenter District” “Street Trees: …minimum caliper of six (6) inches and a minimum clear trunk of eight (8) feet at the time of planting.” TYPICAL MINIMUM SIZE OF 18’ OVERALL HEIGHT SITE PLAN PROVIDES STREET TREES BUT… IN 3’ X 3’ SQUARES…(27 C.F. OF SOIL VOLUME )! WILL THESE TREES GROW? HOW LONG WILL THEY LAST? …7-10 YEAR AVERAGE!... WHERE IS THE 1200 C.F. OF SOIL VOLUME?
• 14.
  Cornell University 1. INCREASEROOT ZONE AREA… Use “CU Structural Soils” or “Deeproot Silva Cell” Applications 2. USE PERMEABLE PAVEMENTS…
• 15.
  “Deeproot Silva Cells”... JAMES URBAN, FASLA, ISA
• 16.
  Permeable Pavements… When integrated with “CU-Structural Soils” or “Deeproot Silva Cells” … “Vegetation is watered, reducing the need for irrigation … Ground water is recharged Water resources are preserved Stormwater runoff is reduced Stormwater runoff quality is improved.” www.CoolCommunities.org
• 17.
  Permeable Pavements… U.S. GREENBUILDING COUNCIL (USGBC) LEED (Leadership in Energy and Environmental Design) CERTIFIABLE “Pervious pavements can be made of concrete, asphalt, open-celled stones, and gravel, that are mixed in a manner that creates an open cell structure allowing water and air to pass through. For example, porous concrete can pass 3-5 gallons of water per minute, which is far greater than most conceivable rain events and highly effective in controlling storm water drainage. “ www.CoolCommunities.org
• 18.
  Tree Grates… …”The grate girdles the trunk... If the tree doesn’t die first, it may lift the grate and create a hazard for pedestrians.” “New Urban News” February 2005
• 19.
  Landscape code changesare oftentimes tedious and lengthy… Departmental Policy Decisions can bypass this…