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Proceedings of International Conference on Climate Change, Biodiversity and Ecosystem Services for the Sustainable Development Goals : Policy and Practice 27-29 June 2016 at the Sirindhorn International Environmental Park, Cha-am, Phetchaburi, Thailand

B.  Phenological  Metrics  of  Teak  Plantation Based  on  the  phenological  metrics  extracted  from  TIMESAT  program,  SOSs  varied  among  these  three  years,  which  started  at  96,  152  and  80  day  of  year  (DOY)  in  2009, 2010  and  2011,  respectively  (Table  1).  SOS  in  2010  was  delayed  compared  to  other  years.  El  Niño  in  2010  may  contribute  to  this  change  in  phenology  (Fig.3,  4). relationship  with  minimum  temperature  and  precipitation  (r=0.81  and  r=0.64,  p<0.0001,  respectively)  (Fig.8).  These  results  imply  that  growing  season  might  start  when  temperature  decreases  with  precipitation  increases  during  April  to  May.  Thus,  the  results  suggest  that  climate  variables  such  as  precipitation  and  temperature  were  the  main  controlling  factors  for  NDVI,  corresponding  to  plant  phenology.  However,  more  analysis  on  this  relationship  is  needed  to  be  conducted  at  teak  plantations  with different  topographic  and  climate  conditions,  in order  to  test  the  hypothesis  that  precipitation  and  temperature  control  teak  phenology  and  obtain  further  understanding  on  phenology  and  climate  variation,  especially  under  the  context  of  climate  changes.  IV.  CONCLUSIONS In  this  study,  four  years  time  series  of  MODIS  NDVI  image  were  processed  with  cloud  removal  in  order  to  investigate  the  phenological  variations  driven  by  climate  variability.  From  the  results,  we  concluded  that: - Processed  MODIS  NDVI  was  able  to  capture  the  changes  of  phenology  of  a  teak  plantation  in  this  study. - The  SOS  of  teak  plantation  was  delayed in  El  Nino  year,  with  significant  effects on  the  variations  of  LOS  during  four years  in  this  study.  - Teak  forests  NDVI  have  a  stronger  relationship  to maximum  and minimum temperature  than  precipitation.  - Further  analysis  on  phenological  metrics  (such  as  comparison  with  photographs  and  field  sensor  data)  in  relation  to  meteorological  variables  is  required  for  further  understanding  of  the  relationships  between  teak  plantation phenology  and  climate  variation,  especially  under  the  context  of  climate  change. Table  1  Phenological  Metrics  of  Teak  Plantation  Period  2009-2012 Year SOS (DOY) EOS (DOY) LOS (Day) 2009-2010 96 (April) 60 (March) 324 days 2010-2011 152 (May) 63 (March) 264 days 2011-2012 80 (March) 22 (Jan) 295 days On  the  other  hand,  EOSs  in  2009,  2010  and  2011  were  on  60,  63  and  22  DOY,  respectively.  As  a  result  of  the  changes  in  SOS and  EOS,  LOS  in  2010  with  El  Niño  was  about  264  days;  shorter  than  in  2009  and  2011 by  about  60  and  31  days,  respectively.  In  general,  analysis  from  phenology  metrics  shows  that  LOS  of  teak  plantation  ranged  between  264  and  324  days.  SOS  occurred  from March  to  May  while  EOS  occurred  in  January  or  March  of  the  following  year.  The  patterns  of  teak  forest  phenology  extracted  from  MODIS  NDVI  are  consistent  with  those  previously  reported.  Yoshifuji  et  al.  14  concluded  that  canopy  duration  of  tropical seasonal  forest  is  about  300-320  days.  C.  NDVI  and  Its  Response  to  Climate  Variables The  Spearman  correlation  coefficient  between  NDVI  (8  day  period,  250 m  resolution) and  climate  factors  was  calculated.  Results  indicate  that  NDVI  was  significantly  and  negatively  correlated  with  maximum  temperature (r=-0.85,  p<0.0001),  positively  correlated  with  precipitation  (r=0.51,  p<0.0001)  in  the  period  of  April-May  (Fig.7).  During  EOS  (October  to December),  NDVI  had  a  significant  and  positive 278 Proceedings  of  the  International  Conference  on  Climate  Change,  Biodiversity  and  Ecosystem  Services  for  the Sustainable  Development  Goals  (SDGs):  Policy  and  Practice  27-29  June  2016,  Cha-am,  Phetchaburi,  Thailand


Proceedings of International Conference on Climate Change, Biodiversity and Ecosystem Services for the Sustainable Development Goals : Policy and Practice 27-29 June 2016 at the Sirindhorn International Environmental Park, Cha-am, Phetchaburi, Thailand
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