Resource Details

Using lightweight unmanned aerial vehicles to monitor troical forest recovery

Literature: Journal Articles

Zahawi, R. A., J. P. Dandois, K. D. Holl, D. Nadwodny, J. L. Reid, and E. C. Ellis. 2015. Using lightweight unmanned aerial vehicles to monitor tropical forest recovery. Biological Conservation 186. Elsevier Ltd: 287–295. doi:10.1016/j.biocon.2015.03.031.

Contact Info


Las Cruces Biological Station, Organization for Tropical Studies
University of Maryland (Dept. of Geography and Environmental Systems)
University of California Santa Cruz (Dept. of Environmental Studies)
Missouri Botanical Garden (Center for Conservation and Sustainable Development)



  • This study examines the ability of unmanned aerial vehicles (UAVs) to accurately monitor and measure secondary forest growth in southern Costa Rica. These UAVs may help to fill an important gap in our ability to measure and monitor the success of restoration projects in terms of measuring structural complexity and community composition in remote or mountainous areas where field-based monitoring is otherwise difficult. Using the 'Ecosynth' method, the UAVs simply combine aerial photographs from digital cameras with a computer software to create 3D models of vegetation. This UAV technology can be priced at $300-a few thousand dollars and is a more cost-effective alternative to LiDAR, which can be $20,000 for a single flight. 
  • In particular, this study compared the accuracy of UAV measurements/predictions to field-based measurements of canopy height, above ground biomass, canopy roughness, canopy openness, and frugivorous birds. Field-based measurements were conducted on 13 sites, each with three plots of a different restoration treatment (passive, active plantation, and intermediate "island" strategies).
  • Overall the Ecosynth canopy height was a strong predictor of field canopy height, although accuracy decreased with low canopy height associated with the passive restoration plots. Above-ground biomass was able to be estimated with Ecosynth, suggesting the potential importance of this methodology in being incorporated into REDD+ programs without adding large expenses. Parameters such as canopy openness and canopy height were successful in predicting frugivorous bird presence at an accuracy similar to those of the field-based measurements. While UAV and Ecosynth methodology is not a replacement for field-based monitoring, it can help researchers and landowners to monitor the progress of restoration projects at the local level, especially where field-based monitoring is difficult. 

Geographical Region

  • Southern Central America
  • Ecosystems

  • Montane Forest
  • Country

  • Costa Rica
  • This database is a work in progress, and we need your input to keep it up to date. Feel free to contact ELTI at to provide information on your own work as well as other projects and literature currently missing from the database.


    ELTI is a joint initiative of:
    Yale School of Forestry & Environmental Studies Smithsonian Tropical Research Institute