Drones elevate ecological research, a new report out today reports, discussing their wide benefits.
Collecting large sample databases is fundamental for plant research, but it’s often tricky to collect data from broad sites by foot. Data collection can be a time sap, occur in dangerous areas, and even compromise the areas you are researching. However, a solution has been addressed today in a new review. Scientists are succeeding in using micro-unmanned aerial vehicles (UAVs), or drones as you and I know them, to conduct these field data experiments.
These drones elevate ecological research and would have nearly zero impact on the area of study, simply flying over the landscape and gathering inconspicuous aerial photographs for data.
Dr. Mitch Cruzan, professor at the Department of Biology at Portland State University and lead author of the review published today, says, “The potential of drone technology in research may only be limited by our ability to envision novel applications . . . . This technology has the potential for the acquisition of large amounts of information with minimal effort and disruption of natural habitats.”
In his study, Dr. Cruzan states that drones can amass years of data noninvasively, helping to monitor vital trends such as habitat restoration efforts, rare and threatened plant populations, agriculture surveys, and carbon storage measures. He believes that drone surveys can become the “holy grail of ecological data.” The capabilities of this technology for research are nearly limitless, with drone-captured data being paired with additional technology such as 3D rendering to reach a variety of scientific conclusions. The professor believes scientists can learn about plant health, phenology, reproduction, diseases, and human-mediated disturbances all from the safety and comfort of their labs.
Researchers can fly small drones along research areas of up to 40 hectares in size. The drones’ internal GPS system enables hovering over pinpointed locations and altitudes, collecting high-resolution images. However, this method is not impervious to problems – Cruzan warns researchers of “shadow gaps” when collecting data. Taller vegetation can obscure shorter vegetation, hiding it from view in aerial photographs. In order to get accurate data relating to each area, researchers must create overlapping images.
You don’t need to be David Bailey to operate a drone, but you do need some training in order to ensure your precious data is usable. The report talks about operator requirements and how to guarantee that your video feeds are aligned properly with camera stabilization, and using the right lenses for each area. Most importantly, it talks about metadata of the drone’s altitude, speed, and elevation for every captured image.
Following the data collection, georeferenced images are joined together into a digital surface model (DSM), which looks to us a little like a photo collage, to be analyzed. The GIS software classifies vegetation types, landscape features, and even individual species in the DSMs, using manual or automated, machine-learning techniques.
To test their concept, Cruzan and colleagues used drone technology for a landscape genetics study on the Whetstone Savanna Preserve in southern Oregon, USA. “Our goal is to understand how landscape features affect pollen and seed dispersal for plant species associated with different dispersal vectors,” says Dr. Cruzan. They flew drones over threatened vernal pools and then analyzed the images, claiming if they had manually researched these habitats, not only would it have taken hundreds of hours, they also may have compromised the ecological integrity of these highly sensitive areas.
Before drones, research teams used light detection and ranging (LiDAR) equipment. LiDAR uses remote sensing technology to capture aerial images, but has several pitfalls: it’s expensive, requires specialist equipment, requires flyovers, and is conducted at a much higher elevation. Due to this high elevation, LiDAR isn’t really useful for analyzing subtle differences in vegetation, a task drone research excels in with its low-altitude, high-resolution footage.
The drone method is not perfect, however. Drones, though more affordable, range greatly in quality, low-end models sporting much cheaper cameras offering lower resolution. Flight regulations limit drone use, so you must be mindful of any limitations before you embark on a drone study. Finally, if a researcher can’t identify plant species from data, they still must return to the field the old-fashioned way, collecting data on foot.
Dr. Cruzan stresses that, despite its limitations, robotic drones elevate ecological research incredibly flexibly, believing it a highly versatile addition to the more traditional methods of data collection. He states that “using a broad range of imaging technologies and analysis methods will improve our ability to detect, discriminate, and quantify different features of the biotic and abiotic environment.” As drones elevate ecological research increasingly, access to open-source software and better equipment will continue to advance ecological research.