Drones are clever carriers – delivery drivers or couriers, if you like – for a wide variety of ends, many peaceful but others not so. In recent years, they have been put to work in a variety of applications in forestry and their importance is growing all the time.

I am not a tech boffin – far from it – but for we mere down-to-earth mortals I thought it worthwhile to offer an overview of both the growing and changing scenario and the applications of unmanned aerial vehicles (UAVs) aka ‘drones’ in smart forestry and related environmental work.

With their appetite for abbreviations and acronyms, the term UAV is widely used in North American circles. On this side of the Atlantic, ‘drone’ is everyday parlance. 

Battlefield UAVs were first deployed in large scale for wartime surveillance in Vietnam, but would not come into their own in the public domain until much later.

The consumer market for UAVs really took off in 2015 and now, less than a decade later, you name it and almost everything can be done using one of these machines as an intelligent aerial carrier. They are no longer restricted to their original simple photographic survey work. 

READ MORE: Rest and Be Thankful: Drones scatter tree seeds on hillside above A83

Let’s consider a few tasks related to forestry and other forms of land management (no doubt I will have missed some other existing applications and new ones will come on stream soon). 

In modern forestry these machines are still useful in mapping forests to optimize activities, helping in counting trees and mensuration, spotting disease and fire outbreaks or transporting Light Detection and Ranging (LiDAR) gear.

The technologies open to drone users are far more efficient and cost-effective compared with many traditional ways of data collection. Additionally, agile drones can reach places that are dangerous or impossible for humans to reach safely or quickly. The technology is advancing rapidly too, with drones getting more powerful.

Drones are of course regularly used by organisations such as fire and rescue, police or mountain rescue, seen doing everything from locating lost souls or hazards to acting as loudspeakers to provide instructions or reassurance or shining a spotlight in the dark or low-light conditions.

ADVANTAGES

Forestry Journal:  A UAV sends images to a remote monitor on a forestry site. A UAV sends images to a remote monitor on a forestry site. (Image: Supplied)

Drones save time, resources and lives. One of the main reasons for their widespread use is their ability to traverse and manoeuvre through areas that would be too dangerous or distant for humans to be in. 

Unlike people, drones do not tire, so inspections can be carried out more frequently, adding to the safety, dependability, and performance – for as long as the batteries last.

Although flight time, payload and range are limited by battery capacity, this has improved tremendously. 

The agriculture, forestry and environmental management fields employ drones to carry out operations such as survey, pesticide spraying, crop assessments, field soil analysis, and plant health monitoring. These activities require controlled precision mapping of the area over which the operation is conducted. By using drones with the appropriate GPS built into their software, farmers and foresters can carry out these operations in a cost- and time-effective manner, reporting back with high degrees of accuracy.  

In industrial complexes such as oil and gas refineries, pipelines and flare stacks, drones can be used to monitor the location for potential hazards and notify the relevant authorities if threatening conditions are detected. 

For instance, the official railway infrastructure inspection system in Britain has been greatly enhanced by flying drones. Now routine procedures such as defect detection for things like landslides or leaning trees, all of which demand close attention to detect accurately, can be picked up on more rapidly. 

In forests and wildfire sites, drones equipped with cameras and GPS are invaluable for getting a birds-eye view and pinpointing outbreaks of disease, fire or windblow safely. 

The ease with which drones can be deployed and operated has allowed users from a wide range of backgrounds – be it technical or otherwise – to fly them. Over the years, the range of UAVs available has also become quite extensive. The availability of lower-cost drones that are easier to control is perhaps one of the many reasons they have become mainstream.

Operators do not need an extensive technical background to navigate a drone securely.

Drones can be used to provide surveillance and security to organizations. This reliability also makes it useful in detection, recovery and disaster missions by both the official and voluntary emergency services.

Drones can deliver lighter packages rapidly too – such as emergency medicines to distant or hard-to-reach outposts or inaccessible accidents.

Forestry Journal: An estimated 20 million birch seeds have been scattered on the hillside above the A83 thanks to Forestry and Land Scotland’s use of drone technology.An estimated 20 million birch seeds have been scattered on the hillside above the A83 thanks to Forestry and Land Scotland’s use of drone technology. (Image: Supplied)

The uses for drones seem endless. In forestry and land management, they provide quick, cheap and accurate information on disease and insect outbreaks, general survey techniques and resource mapping. You name it, there’s a drone for most jobs.  

Abroad, there are of course huge differences in scale and usage. In North American forests, modified heavy-payload drones have been employed to sow tree ‘seed pods’ successfully following extensive wildfires or insect devastation. These flying machines shoot missiles with pre-germinated seed at around five per second at a high enough velocity that they embed in the soil. Take-up or establishment rates are still poor compared with traditional manual planting, but can be employed on quite recent fire sites where embers are still smouldering or the chance of flareups in dead trees make life difficult or dangerous for planting by hand.

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Pre-treated seeds are encapsulated in a protective shell to survive being fired pneumatically into the ground from a height by a drone. Clay pellets or gel packets are sometimes required. Some companies add chilli to the capsule to make it distasteful to clever foragers like squirrels or passing birds, which might otherwise swiftly end the seed’s survival chances. Planting sites are targeted by this ‘eye in the sky’ rather than simply broadcasting stock from planes.

Besides pinpointing wildfires, specialised drones can be used to limit them through controlled burns. A specialised drone propels a stream of flaming petrol or other fuel on to the treeline or drops self-igniting ‘dragon eggs’ – similar to ping-pong balls or turtle eggs, these are filled with inflammable liquid which ignites on impact with the ground.

Managed properly, controlled fires can burn away overgrown forests and create fire breaks, so assisting the prevention of deadly and destructive wild megafires.

Closer to home, an article in a recent FJ described the use of drones in detecting lurking rhododendrons to be sprayed in Scotland, while Forestry and Land Scotland is experimenting with a technique new to it – broadcasting an estimated 20 million birch seeds that have been scattered on the hillside above the A83 at Rest and be Thankful, using drone technology to prevent landslip.

An up-and-coming application in the UK has been operating drones mounted with both daytime and thermal cameras in wildlife management work, including of many foresters’ favourites, deer. Thermal cameras mounted on drones pick up infrared waves from heat-emitting objects such as warm-blooded animals even in the dark or mist.

DISADVANTAGES

Forestry Journal: Drone technology is advancing all the time. Pictured here is an example of one in use in forestry from 2016.Drone technology is advancing all the time. Pictured here is an example of one in use in forestry from 2016. (Image: Supplied)

As with any evolving technology, drones have their downsides too. Although UAVs have become ever more complex and efficient by incorporating the latest advancements in technology, there is always space for refinement and to diversify.  

Although maybe of less immediate relevance in forestry, privacy is a major hurdle as apparently drones can be hijacked or manipulated. That represents a security risk.

They can trespass into no-fly areas such as airports and military zones. While convenient surveillance is an advantageous use of drones, it can become a disadvantage with severe consequences when done by third parties. While measures such as ‘geofencing’ can restrict the movement of UAVs into unauthorised zones such as airports, there is still more that might be done to protect both public security and individuals’ privacy. 

It seems that the central control system of a drone can be attacked and so hackers can take over control of it. Private and confidential information can be extracted and then corrupted or completely damaged.  

Forestry Journal: Technologies open to drone users are far more efficient and cost-effective compared with many traditional ways of data collection.Technologies open to drone users are far more efficient and cost-effective compared with many traditional ways of data collection. (Image: Supplied)

Much has been done to refine the accuracy of drone control within the ever-changing complexity of the airspace. This manoeuvrability becomes even more vital when drones are used in heavily populated areas or within open tree stands. Drones need to operate at a level that eliminates any risk of harm to both surrounding infrastructure and people.

RULES AND REGS

Forestry Journal: A crop like this can be a challenge to assess on foot, but it’s a breeze for a drone.A crop like this can be a challenge to assess on foot, but it’s a breeze for a drone. (Image: Supplied)

As the use of drones by the public has soared – and following scares with too-close-for-comfort incidents at airports caused by hobbyists – the Civil Aviation Authority in the UK introduced rules and regulations for flying larger UAVs weighing over 250 grammes as well as for model aircraft. Full details and an ebook can be found on the CAA website together with hints on training. 

Key pointers include:
• Never fly more than 120 m (400 ft) above the surface
• Always keep your drone in view
• Never fly in an airport’s flight restriction zone without permission.

If your drone has a real camera or weighs 250 g or more then you need to register with the CAA. Anyone flying such a drone needs to pass a test and get a flyer ID from them.

At the time of writing, there is no distinction between flying drones commercially and for pleasure or recreation in the UK. This means that an approval just to operate commercially is not required. However, all commercial drone flights do require valid insurance cover.

You may also need a permit to fly drones in some visitor-rich or well-visited state forests in the UK.

THE FUTURE

Over the past decade, drone technology has advanced leaps and bounds, to the point that units equipped with remote sensors such as infrared, LiDAR and AI software can not only observe but also compile and analyse detailed data profiles on large forested areas.

Emerging technologies are continuously offering new ways in which drones can be used for smart farming and precision agriculture and to a lesser extent in forestry and other land management disciplines.  The collection of real-time data offers opportunities for natural resource managers to significantly reduce their costs and boost findings or yields.

There are several companies developing prototypes of automated drone systems.

Another skill set that companies are evolving is using drones in autonomous ‘swarms’, allowing them to work in unison to complete tasks. So one drone say detects an infected area in a forest and alerts a second equipped to spray or treat it. 

Here at home, a rapidly growing number of companies now offer contracted-out services with professional drone operators and training courses, turning what was once a hobby into a business.  

I suspect we may soon see home deliveries to your very own doorstep, mini-landing pad or flat roof, if they have not already been trialled commercially. Might we soon see home deliveries of take-away meals by drone? After all, in some UK cities autonomous robots now deliver pizzas straight to your door.  

Forgive the pun but is ‘the sky the limit’ for drones in the era of smart forestry?