USDA Forest Service research ecologist Susan Meyer wants to know why a few plant species can grow in places where other species can’t survive. The gypsum-rich soil near St. George, Utah, is one such place. The soil is covered with a thick lichen crust that is easily crushed by hikers, grazing animals, and off-road vehicles. This fragile, inhospitable landscape is the only place where a threatened plant species known as the dwarf bear-poppy grows.
This handsome perennial plant has notched leaves that resemble claws and blooms with a profusion of delicate white flowers punctuated with bright yellow centers. Blooming in late April and early May, the flowers are especially beautiful when illuminated by early morning or late afternoon light. Due to their endangered status and fragile habitat, populations of dwarf bear-poppies have been difficult to count, much less study.
Meyer and her colleague Kody Rominger, a plant ecologist at Utah Valley University, recently tested the feasibility of using drone technology to study the poppy at the White Dome Nature Preserve, a site owned and managed by The Nature Conservancy. Their testing also expanded to Red Bluffs, an area of critical environmental concern managed by the U.S. Department of Interior’s Bureau of Land Management.
The scientists thought a drone might enable them to take a census of dwarf bear-poppy populations. A plant census counts actively growing individuals within a defined area that contains a known population of the target species.
“The first step in studying a threatened or endangered species is to find out how many exist,” said Meyer. “The plants grow on hillsides with sparse vegetation, so they show up clearly on drone images. Using drones seemed like an ideal, noninvasive way to study this beautiful plant.”
The unmanned aerial vehicle, called a “quad ‘copter,” captured images of the research landscape at 50 meters and then 15 meters away. The former provided a broad data set for the census, while the latter provided validation that the protocol was recognizing and counting poppy plants correctly.
The scientists recently published their research results in Remote Sensing. It is the first published study about the feasibility of using drone-based imagery for a census of an endangered plant species. The report concludes it is possible to get an accurate estimate of the population size of an endangered species like the dwarf bear-poppy, with no damage to the plant’s habitat whatsoever.
“We predict drones increasingly will be used by scientists for census purposes,” Meyer said. “We also predict that they will become a key tool in the management of fragile ecosystems. For that to happen, land managers will need training to operate drones and analyze the collected imagery.