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The accuracy of volunteer surveyors for obtaining tree measurements in tropical forests

  • Barnabas Harrison
  • Thomas Edward MartinEmail author
  • Abdul Haris Mustari
Research Article


Volunteer-led surveys are increasingly used to collect ecological information and may represent a means for obtaining the tree measurement datasets necessary to calculate carbon stocks in tropical forests in order to justify funding like REDD+. However, the accuracy of tree measurements collected by volunteers remains unassessed. Here, we examine how tree measurements collected by student volunteers vary compared to measurements collected by trained ecologists using identical methods. Measurements by both teams were collected at 11 habitat plots on Buton Island, Indonesia. Both teams counted similar numbers of trees per plot and obtained positively correlated circumference-at-breast-height measurement values at plot and individual tree scales of aggregation. Volunteer and ecologist-generated median carbon stock estimates differed by just 1.1%. We therefore suggest that with sufficient training and supervision volunteers can be used to obtain accurate tree measurement data for carbon stock calculations.


Citizen science Habitat Indonesia Rainforest REDD+ 



The authors thank Mick McCarthy and Bruce Carlisle for guidance, and Plume School, Sedburgh School, Coulsden College, Harrogate Ladies College and Newcastle College for their surveying efforts. We also thank RISTEK Indonesia for the necessary permits to complete this research, and two anonymous reviewers for their constructive and helpful comments.


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Copyright information

© Royal Swedish Academy of Sciences 2019

Authors and Affiliations

  • Barnabas Harrison
    • 1
  • Thomas Edward Martin
    • 2
    Email author
  • Abdul Haris Mustari
    • 3
  1. 1.LondonUK
  2. 2.Operation Wallacea LtdOld BolingbrokeUK
  3. 3.Faculty of ForestryDepartment of Conservation of Forest Resources and EcotourismBogorIndonesia

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