The National Interagency Fire Center reported more than 58,000 wildfires in 2021. The largest among them, the Dixie Fire in California, burned 960,000 acres. 2022 likely won’t be much better, as climate change continues to boost wildfires’ frequency and intensity. Meanwhile, trees also have to deal with a litany of other dangers, chief among them deforestation, invasive species, extreme weather, and drought. Just this century, the U.S. has lost 15 percent of its tree cover. This is especially troubling given that the United Nations’ Intergovernmental Panel on Climate Change recommends adding 1 billion hectares of trees to help limit global warming to 1.5 degrees Celsius.
As scientists search for solutions, they may look to an increasingly ubiquitous piece of technology: drones. A number of companies have sprung up in the last few years that use cutting-edge drones and data analysis to sprinkle seeds across deforested areas. In the process, the companies say, they can restore ecosystems and help mitigate global warming.
“We’ve had trillions of tons of carbon that has been emitted into the atmosphere,” says Bryce Jones, CEO of Flash Forest, a Toronto-based drone-deforestation company. “We need to decarbonize, but we also have a problem with the excess carbon already in the atmosphere. So how do you pull that out? Forests are one of the best ways to do that.”
Founded in 2019, Flash Forest creates seedpods — a concoction that includes seeds, fertilizer, mycorrhizae, and “everything that we can think of that will help promote germination and resilience,” according to Jones. The seedpods are tailored to the forest environment in order to maximize biodiversity, then dispersed via a fleet of drones. “We have mapping technology that allows us to assess the site beforehand to determine the areas that we don’t want to fly and the areas that we do want to plant,” Jones says. The company claims it will be able to plant seeds at ten times the rate of humans.
The 22-person start-up has mostly worked in Canada, though they’re currently planning a pilot program in Hawaii. Jones says they’re on track to plant 300,000 trees this year, and the goal is to hit 1 billion trees, a commonly stated goal among drone-reforestation companies, by 2028.
That number might seem ambitious, and it has indeed elicited some eye rolls in the research world. But drone technology, and by extension the unmanned vehicles’ capacity for seed dispersal, is quickly improving, thanks to advances in battery life, mapping software, and remote-sensing capabilities. “The technology is developing very rapidly,” says John Innes, a professor of forestry at the University of British Columbia who also advises Flash Forest. “The drones are now at the point where they can work intelligently within the landscape.”
There’s research to suggest that drone reforestation can be quite effective. Most notably, a study published in June 2021 in the journal Remote Sensing determined that, while challenges such as seed survival and uncooperative weather patterns certainly exist, the practice does in fact have the potential to help mend forests. “It can help with reforesting larger areas, and areas that aren’t exactly safe for humans to go in and do tree-planting,” says study co-author Gabriella Richardson, a graduate research assistant at the University of Guelph. “It can also be cost-effective and quicker for large-scale reforestation.”
Richardson’s study also suggested that UAV operators act more transparently around issues of seed-survival rates and utilize open-source workflows to better encourage community engagement. “Getting lots of professionals from different areas to work on improving the technology, and getting academics involved in research on training, will make [the reforestation efforts] even better,” Richardson says.
Cascade Tuholske, a postdoctoral research scientist at Columbia University’s Earth Institute who led a 2017 study on mangrove loss in Honduras, agrees with Richardson’s recommendation for more transparency. “Like with any new technology, we need peer-reviewed research that assess how well drone reforestation actually works,” he says.
Drone reforestation companies must also deal with critics who say they’re placing too much emphasis on the number of seeds dropped, and not enough on exactly how many of them will actually take root. There’s also a national seed shortage at the moment, which makes a new high-tech experiment low on government agencies’ list of planting efforts. “We don’t have the seed to even meet the demands right now,” says Chief Stewart McMorrow, supervisor at the Cal Fire Reforestation Center. “If a drone company says, ‘Hey, give us ten times the normal seed you’d use to reforest an area’, we’re not going to do it.” (A spokesperson for the U.S. Forest Service said that while the agency is evaluating opportunities where drones could help reforest, “Thus far, survival and costs have not been optimal when compared with hand-planting.”)
Still, it appears some government agencies are onboard with the tech. In October 2020, the Federal Aviation Administration gave the Seattle-based company DroneSeed a green light to fly swarms of drones beyond the usual visual line of sight restrictions in areas of the West that have been burned by wildfires — the first such approval in the U.S. The company’s eight-foot UAVs were sent out to drop so-called seed vessels — a proprietary mix of nutrients, fertilizers, and pest deterrents — in California and Oregon forests that were burned by the August Complex and Holiday Farm fires, respectively. (DroneSeed says each drone can carry up to 57 pounds of seed vessels.)
The company’s CEO, Grant Canary, says the seeding effort is a three-part process. First, DroneSeed uses a small drone to survey the terrain and create a 3-D map. It then uses that data to remove any obstacles from the UAVs’ pre-programmed flight paths and rule out dropping seeds in areas where they wouldn’t thrive (for example, a gravel road). Finally, they send out a group of two to five drones to fly along the predetermined path and drop the seedpods (which include hot pepper among its ingredients, to deter rodents). “Then they’ll come back and get reloaded,” he says, “like a NASCAR pit crew.”
DroneSeed is taking steps to improve its seed count. In August 2021, it acquired SilvaSeed, a 130-year-old seed producer, in order to bolster its own seed supply. That acquisition appears to have paid off: One month later, DroneSeed raised $36 million in a series A funding round.
It’s no sure thing that companies like DroneSeed and Flash Forest can continue to improve their tech. But if they do, they seem likely to gain more government support. Cal Fire’s McMorrow says as much. “We support progressive technology,” he says. “We want to see drones work.”