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HomeMy WebLinkAboutSupplemental_Tree Survey ReportTree  Survey  Report   Lift  1A/  Gorsuch  Haus   April  26,  2016   PROVIDED  BY:   Jason  Jones   Board  Cer,fied  Master  Arborist  #RM-­‐0734B   Aspen  Tree  Service  Inc.   Carbondale,  CO  81623   (970)  963-­‐3070   mtnjones@gmail.com   Summary   I  have  been  asked  by  Design  Workshop  to  analyze  and  comment  on  the  tree  resource  located  on  the  site  of  the  LiX  1A/ Gosuch  Haus  property  located  at  the  base  of  Aspen  Mountain.    The  site  is  being  considered  for  re-­‐development  and   there  are  numerous  trees  on  and  around  the  property.  While  it  is  in  the  best  interest  of  the  landowner  and  community  to   retain  as  many  trees  as  possible  while  developing  any  site,  it  is  important  that  the  trees  chosen  to  be  retained  can   tolerate  site  impacts,  will  not  present  an  elevated  level  of  hazards  to  the  property  or  its  users,  and  will  exist  as  long  term   assets  to  the  community  and  the  property.  I  have  visually  observed  the  trees  and  reviewed  the  plans  for  the  proposed   new  building  footprint  and  construc,on  and  determined  that  all  of  the  trees  on  the  site  would  require  removal  to   complete  the  planned  development  as  proposed.      I  have  provided  an  inventory  and  evalua,on  of  all  of  the  significant   trees  to  be  used  in  determining  planning  and  in  procuring  necessary  tree  removal  permits  from  the  City  of  Aspen     A  total  of  18  trees  with  total  diameter  of  243  inches  are  being  proposed  for  removal.    U,lizing  the  City  of  Aspen’s   formula  pertaining  to  tree  mi,ga,on  values,  a  total  of  $189,827.13  in  value  has  been  calculated  If  all  of  the  trees  being   requested  for  removal  were  mi,gated  at  full  value.    Due  to  factors  rela,ng  to  tree  health,  structure,  aesthe,cs,   placement  and  contribu,on  to  the  site,  it  is  my  opinion  that  the  individual  values  of  some  of  the  trees  that  are   designated  for  removal  would  likely  be  reduced  or  eliminated  upon  review  from  the  City  Forestry  Department.    There  are   three  trees  on  this  site  that  are  very  large  diameter  and  are  responsible  for  over  $120,0000  of  the  mi,ga,on  amount.     These  trees  are  in  overall  poor  condi,on  and  it  is  my  opinion  that  these  trees    should  not  carry  such  a  high  value  and  I   would  advise  the  ownership  to  request  a  reduc,on  in  this  amount  when  applying  for  tree  removal  permits.        Once    a  final  site  plan  is  developed,  trees  that  are  required  for  removal  are  iden,fied,    and  review  of  the  permit   applica,on  by  City  Forestry  department  is  performed,  a  precise  mi,ga,on  cost  could  be  determined.    It  should  be  noted   that  the  cost  of  new  trees  as  part  of  the  re-­‐landscaping  on  the  site  would  be  generally  applied  towards  mi,ga,on.  Any   difference  in  the  amounts  would  then  be  due  as  a  cash  payment  to  the  city  before  a  tree  removal  permit  could  be   released.   Methodology   I  ini,ally  met  with  Jessie  Young,  Landscape  Architect,  with  Design  Workshop  on  March  29,  2016  .    We  reviewed  the   property,  discussed  the  plans  for  construc,on  and  she  pointed  out  all  of  the  the  trees  on  the  site.    I  then  visited  the  site   with  an  assistant  on  April  23rd  to  perform  my  assessment.   I  was  provided  with  a  site  map  with  tree  loca,ons  and  es,mated  diameters  at  the  ,me  of  our  ini,al  mee,ng.    I  then   performed  a  visual  inspec,on  on  each  tree  located  within  the  boundaries  of  the  property.    I  re-­‐measured  each  tree  at   approximately  4.5  feet  above  ground  level  with  a  diameter  tape  to  obtain  an  accurate  Diameter  Breast  Height  (DBH).  I   rounded  diameter  down  to  nearest  whole  inch  on  all  trees.    I  was  provided  a  base  map  from  which  I  numbered  and   labeled  each  tree  on  the  map.    Metal  tags  were  afached  to  the  north  side  of  each  tree  labelled.    Individual  trees  were   entered  into  the  afached  tree  inventory  worksheet  with  an  accurate  DBH,  condi,on  ra,ng,  and  a  maximum  mi,ga,on   value  based  on  the  formula  provided  in  the  City  of  Aspens  Title  13  ordinance  pertaining  to  health  and  quality   environment  sec,on  13.20.020.    This  ordinance  states  that  gambel  oak,  serviceberry,  and  chokecherry  trees  over  3   inches  DBH,  other  deciduous  trees  over  6  inches  DBH  and  conifer  trees  over  4  inches  in  diameter  will  require  a  permit   from  the  forestry  department  and  may  require  mi,ga,on  based  on  the  formula:  Basic  Value  =  $41.00  x  3.14  x  (D/2)2   Where:  D  =  the  diameter  of  the  tree  in  inches.      Trees  that  were  mul,-­‐stemmed  were  measured  at  4.5  feet  above  ground   and  calculated  as  if  they  were  two  individual  trees  and  then  added  together.   Condi,on  values  were  assigned  as  a  result  of  visual  indicators  such  as  the  presence  of  dead  limbs,  signs  or  symptoms  of   disease/insects,  or  structural  defects.    Details  of  the  condi,on  scale  are  as  follows:   1)A  healthy,  vigorous  tree,  reasonably  free  of  signs  and  symptoms  of  disease,  with  good  structure  and  form  typical   of  the  species.   2)Tree  with  slight  decline  in  vigor,  small  amount  of  twig  dieback,  minor  structural  defects  that  could  be  corrected.   3)Tree  with  moderate  vigor,  moderate  twig  and  small  branch  dieback,  thinning  of  crown,  poor  leaf  color,  moderate   structural  defects  that  might  be  mi,gated  by  regular  care.   4)Tree  in  decline,  epicormic  growth,  extensive  dieback  of  medium  to  large  branches,  significant  pathogen  ac,vity   or  structural  defects  that  cannot  be  abated.   5)Tree  is  in  severe  decline,  highly  hazardous  or  is  dead.   Limits  of  the  Assignment   My  inves,ga,on  is  based  solely  upon  the  informa,on  noted  on  my  visits  to  the  site  in  March  and  April  of  2016.    I  have   not  performed  any  laboratory  examina,ons,  studied  soil  composi,on  or  employed  any  other  diagnos,c  techniques   beyond  visual  examina,on  of  the  trees  and  the  site.    I  have  developed  general  conclusions  of  tree  health  and  provided   recommenda,ons  based  upon  these  observa,ons.     Observations   Site  Description   The  property  is  located  at  the  base  of  Aspen  Mountain  Ski  Area  and  currently  includes  a  chairliX  and  mul,ple   outbuildings  related  to  the  ski  resort.    The  boundaries  extend  up  the  slope  to  a  na,ve  woodland  area  and  push  to   condominium  complexes  on  either  side.    The  majority  of  the  site  is  not  heavily  treed  with  a  very  small  por,on  of  the  site   having  any  tree  cover.    A  total  of  only  18  significant  trees  or  tree  groups  exist  on  the  en,re  site  that  will  require  removal   to  complete  proposed  development.    None  of  the  trees  appear  to  have  received  any  maintenance  or  supplemental  care   but  have  adapted  to  the  na,ve  condi,ons  present  at  the  base  of  the  mountain.       SpeciEic  Tree  Observations   Each  tree  was  evaluated  visually  and  entered  into  the  afached  tree  inventory  worksheet.    This  worksheet  contains  the   tree  species,  condi,on,  and  es,mated  mi,ga,on  value  based  on  the  City  of  Aspen  tree  removal  ordinance  formula.       Trees  #60-­‐  Subalpine  fir  (Abies  lasiocarpa)-­‐  13  inch  DBH.  This  tree  is  located  on  the  slope  below  the  exis,ng  chairliX  and   is  growing  very  close  to  the  stairway  leading  up  to  the  liX.    The  tree  is  in  good  condi,on  but  will  require  removal  as  it   silng  directly  in  the  proposed  building  footprint.   Trees  #61-­‐64  Narrowleaf  cofonwood  (Populus  angus3folia  )  -­‐There  are  a  group  of  3  large  cofonwood  growing  next  to   the  exis,ng  liXline.    These  trees  are  in  the  mature  to  over  mature  category  and  all  have  notable  deadwood  and  structural   defects.  All  three  of  these  trees  lie  within  the  area  where  the  new  proposed  chairliX  will  exist  and  would  require  removal   for  the  project  to  occur  as  planned.  The  mi,ga,on  value  of  these  three  trees  when  using  the  city  of  Aspen  formula  totals   $120.082.25.    Upon  review,  this  amount  seems  unreasonably  high  due  to  the  condi,on  and  contribu,on  of  the  trees.     Addi,onal  considera,on  beyond  the  overall  poor  condi,on  of  the  trees  that  should  be  noted  is  that  the  large  diameter   these  trees  show  is  not  in  line  with  the  height,  spread  and  density  of  a  similar  diameter  tree  of  this  species.    It  is  likely   that  the  harsh  condi,ons  of  the  site  forced  these  trees  to  adapt  by  growing  shorter  and  without  much  spread  while   pulng  growth  energy  into  diameter  in  an  afempt  to  create  maximum  structural  integrity.    I  feel  that  the  mi,ga,on   value  of  these  trees  should  be  reduced  considerably  once  reviewed  by  the  City  of  Aspen  forestry  department.     Depending  on  the  ul,mate  mi,ga,on  values  assigned  by  the  city,  further  inves,ga,on  of  these  trees  may  be  warranted   to  show  extent  of  decay  in  each  of  these  trees.     Tree  #61-­‐  -­‐39  inch  DBH-­‐  Narrowleaf  cofonwood-­‐    Tree  number  61  is  the  largest    of  the  trees  in  this  group  but  has  a  large   co-­‐dominant  stem  and  other  notable  defects  within  the  canopy.    The  tree  has  a  very  large  diameter  in  comparison  to  the   crown  density  and  the  mi,ga,on  value  of  nearly  $50,000.00  seems  would  be  considered  in  my  opinion  extremely  high   considering  the  trees  condi,on  and  contribu,on  to  the  site  and  community.       Trees  #62  Narrowleaf  cofonwood-­‐  29  inch  DBH-­‐  This  tree  is  in  the  worst  condi,on  of  the  group  of  3  as  it  has  mul,ple   significant  decay  pockets  notable  from  the  ground  within  the  canopy  and  large  por,ons  of  deadwood.    I  have  included   photos  of  some  of  these  decay  pockets  within  this  document.    I  would  an,cipate  a  reduc,on  or  elimina,on  of  mi,ga,on   value  associated  with  this  tree  upon  review  by  the  City  of  Aspen  forestry  department.    I  feel  that  this  tree  is  hazardous  in   its  current  state  and  removal  would  be  recommended  regardless  of  the  site  development.     Tree  #63-­‐  Narrowleaf  cofonwood-­‐  37  inch  DBH-­‐While  this  tree  is  displaying  moderately  good  vigor  mul,ple  pockets  of   decay  and  past  branch  failures  are  notable  from  the  ground.    This  tree  would  also  be  likely  to  have  a  reduced  mi,ga,on   value  assigned  upon  review  by  City  Forestry.       Trees  #64-­‐65  -­‐  Gambel  Oak  (Quercus  gambelii)  -­‐4  inch  DBH  mul,  stemmed-­‐An  area  was  noted  on  the  site  map  that  was   denoted  as  “shrubs  to  be  removed”,  it  was  assumed  that  this  area  did  not  include  any  trees  above  mi,ga,on  size.    While   most  of  the  plant  material  in  the  group  consisted  of  less  than  6  inch  diameter  Rocky  Mountain  Maple  stems,  closer   inspec,on  of  the  grouping  revealed  some  gambel  oak  stems  above  the  3  inch  diameter  size  which  would  trigger   mi,ga,on  according  to  the  city  code.    These  stems  were  in  good  condi,on  and  were  growing  in  a  very  dense  na,ve   environment.       Tree  #66-­‐  Colorado  Spruce(Picea  pungens  )-­‐  8  inch  DBH.  This  is  growing  along  the  edge  of  the  ski  slope  near  the   Mountain  Queen  Condominium  complex.    This  tree  is  showing  signs  of  poor  vigor  and  stress  and  close  inspec,on   revealed  a  piece  of  string  embedded  within  the  main  stem  approximately  10  feet  up  from  the  base.    This  will  cause   mortality  and/or  structural  failure  of  the  tree  ul,mately.      Due  to  this  condi,on,  I  feel  that  it  is  likely  that  the  mi,ga,on   value  would  be  removed  for  this  tree  upon  review.       Tree  #67-­‐  Colorado  Spruce-­‐  10  inch  DBH-­‐    This  Spruce  tree,  just  below  tree  #66  is  in  fair  condi,on  and  is  showing  signs  of   low  vigor  likely  related  to  soil  compac,on  and  other  stressful  site  condi,ons.    This  tree  may  be  considered  for  a  reduced   mi,ga,on  value  due  to  vigor  related  factors.     Tree  #68-­‐  Cofonwood-­‐12  inch  DBH-­‐  This  tree  is  showing  moderately  good  vigor  but  has  very  poor  structure  as  it  has  a   weak  branch  union  and  co-­‐dominant  tops.    It  is  possible  that  this  tree  would  receive  a  reduc,on  in  mi,ga,on  value  due   to  this  structure.       Tree  #69  -­‐Colorado  Spruce  12  inch  diameter-­‐  This  tree  is  also  in  fair  condi,on  with  very  poor  structure.    The  misshapen   top  of  this  tree  would  make  it  highly  prone  to  snow  load  damage  in  this  loca,on  over  ,me.    I  feel  that  this  tree  would   likely  have  a  reduced  mi,ga,on  value  assigned  as  a  result.   Trees  #70-­‐78-­‐  12,13,9,12,8,8,9,11,10  inches  DBH-­‐  This  grouping  of  spruce  trees  are  planted  very  close  together  along  the   east  border  of  the  property  and  the  pool  area  of  the  Caribou  Condominiums.    Most  of  these  trees  are  in  good  condi,on   but  two  of  the  interior  trees  have  been  shaded  out  by  the  trees  nearby  and  are  performing  poorly.    Upon  inspec,on  of   the  grouping,  I  would  recommend  that  trees  number  72,  9  inch  DBH,  and  number  75,  8  inch  DBH,  be  removed  regardless   of  the  need  for  construc,on  ac,vity.    I  would  therefore  expect  that  a  reduc,on  or  elimina,on  of  mi,ga,on  value  could   be  considered  by  the  City  Forestry  when  assigning  mi,ga,on  values  to  these  two  trees.   Conclusion   In  this  instance  it  is  clear  due  to  the  extent  of  development  occurring  on  the  site  that  all  of  the  trees  will  require  removal   in  order  to  complete  the  proposed  plans.    Many  of  the  trees  are  in  rela,vely  poor  condi,on  and  I  feel  that  it  is  likely  that   a  reduc,on  in  the  maximum  mi,ga,on  value  could  be  given  once  the  trees  are  reviewed  by  the  City  of  Aspen  Forestry   Department.    While  current  plans  show  a  total  of  37  new  trees  being  installed  to  replace  the  18  being  removed,  the  large   diameter  of  many  of  the  trees  makes  mi,ga,on  values  very  high  when  calculated  at  the  maximum  possible  amounts.     Due  to  condi,on,  placement  ,  contribu,on  to  the  site  and  other  factors  I  do  feel  that  it  would  be  reasonable  to  see  some   reduc,on  in  maximum  mi,ga,on  values  for  trees  on  this  project   Map of Site Tree  60 Trees  61-­‐63 Trees  64-­‐65 Trees  66-­‐67 Tree  68 Tree  69 Trees  70-­‐78 Tree Inventory Spreadsheet Lift%1%A/%Gorsuch%Haus Tree%Inventory Condition%Scale 1<Excellent 2<Good 3<Fair 4<Poor 5<Dead Maximum%mitigation%values% based%on%City%of%Aspen%Formula Tree$#Species D.B.H.Condition Comments $Mitigation$ 60 Fir 13 2 5,439.27$%%%%%% 61 Cottonwood 39 3 Co<dominent,% Decay%in%crown 48,953.39$%%%% 62 Cottonwood 29 4 Severe%decay%in% crown 27,067.59$%%%% 63 Cottonwood 37 3 Some%dieback,% Decay%in%crown 44,061.27$%%%% 64 Gambel%Oak 4,4 2 1,029.92$%%%%%% 65 Gambel%Oak 4,4 2 1,029.92$%%%%%% 66 Spruce 8 4 Very%poor% structure,%signs% of%stress,% embedded%rope% in%main%stem 2,059.84$%%%%%% 67 Spruce 10 3 Compaction,%thin% canopy 3,218.50$%%%%%% 68 Cottonwood 12 2 Vvery%Poor% structure%4,634.64$%%%%%% 69 Spruce 12 3 Poor%structure 4,634.64$%%%%%% 70 Spruce 14 2 6,308.26$%%%%%% 71 Spruce 16 2 8,239.36$%%%%%% 72 Spruce 10 3 Overcrowded,% shaded%out 3,218.50$%%%%%% 73 Spruce 12 2 4,634.64$%%%%%% 74 Spruce 11 2 3,894.39$%%%%%% 75 Spruce 10 3 Overcrowded,% shaded%out 3,218.50$%%%%%% 76 Spruce 12 2 4,634.64$%%%%%% 77 Spruce 14 2 6,308.26$%%%%%% 78 Spruce 15 2 7,241.63$%%%%%% 274 Total%Maximum% Mitigatin%Value 189,827.13$% Photos Photo  showing  trees  61-­‐63  growing  next  to  liX  line.    Note  visible  deadwood,  decay  pockets  and  diminished  crown   density  for  trees  of  such  large  diameter..       Tree  number  61-­‐  Note  excessive  decay  pockets  in  crown Tree  number  63  showing  significant  decay  in   crown. Tree  number  69  showing  poor  shape  and  structure