You are in a lush forest. Sunlight filters through the bright green canopy, casting jagged shadows on the ground. The towering trees hang over delicate ferns, wild flowers and colorful mushrooms. A deer ducks behind a bush. But there are subtle signs of human intervention: small electronic devices that gather vital data about potential threats such as drought or pests and transmit them miles away.
Although technology has long been used to study animals and plants in forests, it is evolving rapidly – becoming smaller, smarter and more interconnected. Some devices are so small that they can be placed on a single sheet. “For the developers of such devices, the forest presents a completely new challenge,” says Ulrike Wallrabe, professor of microsystems technology. Here, the technology must withstand ever-changing conditions, from fluctuating temperatures to rain and snowfall, as well as curious creatures such as mice.
Once operational, the new generation of smart devices offers an unprecedented view of the forest. “Drones already monitor large areas of forest, but they cannot explain why one tree is thriving and another is in trouble,” says Wallrabe. “We need to understand what happens on a small scale and over time.”
Wallrabe and his research partners are working on a range of devices that will be deployed from the ground to the treetops, transmitting data from Germany’s Black Forest to their laboratories at the University of Freiburg. At the same time, scientists and engineers at other companies are also focused on making their devices discrete and, ultimately, self-sustaining.
Silvanet Wildfire Sensor
Time is of the essence when fighting forest fires. Sensors attached to the trunks “smell” telltale gases such as hydrogen and carbon monoxide, and alert firefighters in the first hour – before satellites or cameras can see open flames. German startup Dryad networks has built AI into its solar-powered sensors to ensure they can distinguish between real fires and, say, passing diesel trucks.
Treeway
Digital dendrometers relieve foresters from tedious work. As the trees grow, the elastic band wrapped around their trunk stretches and transmits data directly to a computer. U lightweight device from a Brazilian startup Treeway it can also be attached to saplings. It also contains a humidity and heat sensor, which provides insights into climate impacts on reforested areas.
The Guardian
What does it take to catch illegal loggers or poachers? A smartphone is a good start. Rainforest Connection’s recycled, solar-powered smartphone hear the sound of chainsaws or gunshots within a 1 mile radius. The recordings are transmitted to the cloud for analysis and alert local authorities in near real time. This device also provides insights into the distribution and behavior of animal calls.
BiodivX drone
As animals move through trees, they spread DNA through feces, skin, and hair. This innovative drone collects what is known as environmental DNA (eDNA) from leaves and branches, with particles that stick to their adhesive strips. Swiss scientists have programmed the drone to be able to navigate autonomously through dense forests and hover firmly around branches to take samples.
Leaf sensor
Wallrabe and his team at the University of Freiburg have developed a glass capsule which measures gas exchange between a leaf and its surroundings. It can detect specific chemicals that trees emit under stress, for example, in case of drought, infestation or disease. The capsule is transparent so that sunlight can reach the leaf without compromising its function.
Plant-e
When the sun is limited, most devices are powered by batteries. Plant-ea Dutch company that emerged from the University of Wageningen, makes use of a natural process: Plants produce organic material through photosynthesis; some use for growth, the rest ends up in the ground. Bacteria break down this material and release electrons that Plant-e uses to power its sensors.
The seed-dropping drones
To scale and accelerate tree planting efforts, many companies, including in the United Kingdom Dendra Systemshave developed to the point drones. These drones, loaded with an array of seeds, fly over target areas and release their precious cargo. This is particularly useful in remote areas that are difficult to access for humans. By recording the exact location of the drop sites, foresters can monitor the growth and health of the planted trees.
This article appears in the January/February 2025 issue of WIRED British magazine.
