By Stephen Elliott, Chiang Mai University’s Forest Restoration Research Unit

At last year’s UN Climate Summit in New York, businesses and governments pledged to “speed up restoration” to convert 350 million hectares of degraded forestland back into forest by the end of the next decade – an area larger than India. This would have huge benefits for the climate, by storing carbon and taking pressure off primary forests ( But how could this be achieved, on such a vast scale, so quickly?

Despite major advances in forest restoration science and practice, over the past 2 decades, restoration of tropical forest ecosystems is still largely dependent on manual labour – hauling baskets of saplings long distances, over rough terrain, planting them and then returning frequently to control the weeds. Accessible land, near roads, is usually not available for forest restoration, since it is already used for agriculture. Achieving the UN’s ambitious target will, therefore, require making forest restoration both less arduous and more cost-effective.

We must begin to think outside the box. And at Chiang Mai University’s Forest Restoration Research Unit, we think that advances in drone technology and computer-aided plant recognition may contribute to the solution.

The potential for automating forest restoration tasks, by combining proven restoration techniques with emerging technologies is great. Drones, equipped with tree-species-recognition software, could be used to rapidly locate seed trees in dense forest or even collect seeds from the tree crowns with various interchangeable tools. They could also carry out aerial seeding, by dropping soluble “designer seed bombs”, containing seeds in hydrogels with fertilizers, symbiotic microbes and growth promoters, to maximize seed germination and seedling establishment. Combined with plant-recognition technology, drones might also be able to control weeds by spraying herbicides, whilst avoiding spraying trees, and accurately deliver fertilizer around establishing tree seedlings. These processes could be fully automated, by enabling drones to automatically recharge their batteries by landing on solar-powered inductive charging pads. Aerial monitoring of forest canopy closure is already possible, but advances in plant recognition software are now enabling assessments of the recovery of plant species diversity. Remote microphones and camera traps in restoration sites could be used to monitor recovery of forest bird and mammal communities.

A few years ago, all this was regarded as science fiction; but not anymore. Most of these technologies already exist … we just have to improve them and combine them in innovative ways with existing forest restoration science, to achieve the desired results.

So it’s time for a serious discussion. Otherwise, pledges to restore hundreds of millions of hectares of forest over the next 15 years become just a pipedream.

To this end, a short workshop session, “Automating tropical forest restoration – from the Stone Age to the drone age,” was included in the  6th World Conference on Ecological Restoration in August. Stephen Elliott introduced the concept of auto-restoration, followed by  Lauren Fletcher who introduced the participants to his start-up company BioCarbon Engineering, which is developing drones to carry out aerial seeding on large scales. Then, workshop participants identified and prioritised the obstacles to automating seed collection, aerial seeding, and tree maintenance (weeding and fertilizer application) and suggested research projects to overcome them – both ecological and technological.

Even though the crowded schedule of the SER congress allowed for only 90 minutes for the session, some clear conclusions were reached:

  • At present, the technology for auto-seed collection with drone-mounted tools is still some way off, but drones with imaging systems, to assist human seed collectors find seed trees and increase the efficiency of seed collection, seem more easily achievable. We should therefore focus first on drones to assist human seed-collectors.
  • The BioCarbon prototype site mapping and seed delivery drones are an excellent start, but the seed delivery technology must be made adaptable to the wide range of seed sizes of the various tropical forest tree species needed for ecosystem restoration.
  • The mechanics and aeronautics of seed delivery are progressing rapidly, but the ecological science needs more work, particularly understanding seed dormancy, developing seed storage methods and determining how the variously sized/shaped seeds of different tree species respond to aerial delivery, under various habitat conditions.

To mark the 20th anniversary of Chiang Mai University’s Forest Restoration Research Unit, we will also run a much more comprehensive workshop on Automated Forest Restoration, here in northern Thailand on 28-31 October 2015. Please come along if you are free to join us, or help us spread the word to your colleagues and social media contacts. We look forward to working with all those interested in this cutting edge merger of ecology and technology.

Automated Forest Restoration Workshop details are here:, and registration is here:

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