Small unmanned aerial vehicles (micro-UAVs, drones) in plant ecology.
OBJECTIVE
Low-elevation surveys with small aerial drones (micro-unmanned aerial vehicles [UAVs]) may be used for a wide variety of applications in plant ecology, including mapping vegetation over small- to medium-sized regions. We provide an overview of methods and procedures for conducting surveys and illustrate some of these applications.


METHODS
Aerial images were obtained by flying a small drone along transects over the area of interest. Images were used to create a composite image (orthomosaic) and a digital surface model (DSM). Vegetation classification was conducted manually and using an automated routine. Coverage of an individual species was estimated from aerial images.


RESULTS
We created a vegetation map for the entire region from the orthomosaic and DSM, and mapped the density of one species. Comparison of our manual and automated habitat classification confirmed that our mapping methods were accurate. A species with high contrast to the background matrix allowed adequate estimate of its coverage.


CONCLUSIONS
The example surveys demonstrate that small aerial drones are capable of gathering large amounts of information on the distribution of vegetation and individual species with minimal impact to sensitive habitats. Low-elevation aerial surveys have potential for a wide range of applications in plant ecology.
Department of Biology, Portland State University, P.O. Box 751, Portland, Oregon 97207 USA.
Mitchell B
MB
Cruzan
Department of Ecology and Evolution, Stony Brook University, Stony Brook, New York 11794 USA.
Ben G
BG
Weinstein
Department of Biology, Portland State University, P.O. Box 751, Portland, Oregon 97207 USA.
Monica R
MR
Grasty
Department of Biology, Portland State University, P.O. Box 751, Portland, Oregon 97207 USA.
Brendan F
BF
Kohrn
Department of Biology, Portland State University, P.O. Box 751, Portland, Oregon 97207 USA.
Elizabeth C
EC
Hendrickson
Department of Biology, Portland State University, P.O. Box 751, Portland, Oregon 97207 USA.
Tina M
TM
Arredondo
Department of Biology, Portland State University, P.O. Box 751, Portland, Oregon 97207 USA.
Pamela G
PG
Thompson
aerial drone (micro-UAV, UAS); aerial survey; digital elevation model (DEM); digital surface model (DSM); orthomosaic; vegetation mapping
J Anim Ecol. 2008 Jul;77(4):802-13
18397250
Ecol Appl. 2009 Sep;19(6):1417-28
19769091
PeerJ. 2014 Jun 19;2:e453
25024921
Front Plant Sci. 2015 Jan 05;5:734
25601871