Don't put away shovels yet
A man named Jack Walters designed a propellant system to shoot seedlings into the forest floor. It's a process that can be seen in nature. Nature does it in mangrove seeds that sprout into plants and literally plant themselves by an aerial process into the mud below by falling. But dropping living seedlings into a slash pile on a clear cut will not penetrate to the soil.
Aerial broadcasting of seeds is done in Australia on sites where the surface has been burned off, and these are distributed by small plane or helicopter. They drop seeds, or drop pelletized seeds, or drop pellitized germinated seeds, depending on the soil conditions, and now they are firing pellitized germinated seeds into the ground.
Seeding drones are used to spread 40,000 seeds a day in bushfire areas in Australia.
A company called Droneseed USA uses drones with LIDAR (an acronym of "light detection and ranging" or "laser imaging, detection, and ranging". LIDAR is a method for determining ranges by targeting an object or a surface with a laser https://en.wikipedia.org/wiki/Lidar) and aerial imagery into post wildfire landscapes for analyzing soil quality and determining which seeds go where. These methods over-use seeds.
Dendra Systems says they can spread millions of seeds in a few hours, and predict the planting of 500 billion trees by 2060: 120 seedpods per minute, pre-germinated seeds, using pressurized air.
AirSeed Technologies, efficient at post planting surveys. They can go back and survey for re-seeding and predict planting 100 million trees by 2024.
Looking at all these possibilities, however, planting a seed doesn't mean planting a tree.
FlashForest claims 1 billion trees by 2028, operating in B.C., Alberta, and Ontario. The company is using drones on post-burn sites, post-harvest sites, and grassy areas. It seems the post-burn sites are best and high severity burn sites are the best sites for drones.
Timing is everything in these planting operations, which now operate earlier in the season, depending on weather. They have been successful in areas with reasonably high precipitation. Wet summers are better.
Grassy areas are not effective, grass competes too successfully with the tree seeds, so they use pellets, and collect significant quantities of wild seeds, which seeds are then encased in a mixture (proprietary) in encasements, including moisture retention material. The germination rate is quite high, said Innes.
Drones are constantly improving, and the technology of drones tends to be evolving rapidly, with planting capacity increasing progressively at a rate of 1000 percent capacity growth over the past couple of years. They can distribute 100,000 seed pods per day depending on number of drones deployed.
Planting drones now carry LIDAR and other technology. Early drones had smaller capacity, 80 pods, now they have the capacity for a million pods per day using three operational drones. The pods are fired into the ground, velocity and height are variables. Current drones fly high, but in the future the drones will fly lower with obstacle avoidance technology.
They geolocate every pod fired. Germination success is closely monitored by surveys. Top-up flights will be undertaken at sites with low success rates. The goal is to produce growth out of 20 percent of the seed, wasting 4 out of 5.
The question is, will drones replace tree planters?
Drones are cheaper and faster and do replacement planting both faster and easier, but mortality rates are higher. Drones can work in areas where tree planters have problems, steep sites, high bug areas, and sites with health issues like fire areas with ash. There are sites in Alberta where drones are operating in the north because it's hard for tree planters to get in there.
Drones are catching up and AI is moving things ahead, LIDAR on drones is one of the amazing advancements. The pellets and germination success rates are improving. But there will always be room for tree planters, says Innes.
Tree planting involves intuitive practices by planters, and these sensitivities are being emphasized by drone companies. Drones are dropping seeds obtained from the wild, while in tree planting, improved seed stock comes from nurseries. Two hundred kilos of wild seeds were collected by FlashForest this year. There is no apparent problems with seed supply at present. B.C. has seed zones, and A class seed is expensive. Seed lines up with the area being planted and seed transfer rules apply to drone planters just as they do to tree planters. "We need to make sure the seed rules are being followed." Wastage could be an issue while trees produce huge volumes of seeds.
Drones are mainly deployed to try to get forest cover back into place. They aren't being used to make harvestable forests at present.
It will become a numbers game, and drones will reforest areas affordably that might not be planted otherwise. Furthermore, tree planters will be drone pilots.
Optimium sites for drones are post fire sites, whereas cut sites are less drone worthy with all the slash impeding successful seed placements. "Drones could still surprise us," says John Betts, "but don't turn in your shovels just yet, planters."
It will become a numbers game, and drones will reforest areas affordably that might not be planted otherwise. Furthermore, tree planters will be drone pilots.
Optimium sites for drones are post fire sites, whereas cut sites are less drone worthy with all the slash impeding successful seed placements. "Drones could still surprise us," says John Betts, "but don't turn in your shovels just yet, planters."
