Forests have a complex relationship with climate change. On the one hand, they also absorb atmospheric carbon proliferating amidst changing climates. On the other hand, they can suffer from increased heat stress, degrading their carbon absorption capacity and drought resistance. With funding of around $10.5 million from the German Research Foundation, scientists in Europe are now instrumenting forests with new sensors to better understand how forests are affected by climate change.
Mixing forest science with the Internet of Things (IoT) technology, drones and other devices, Ecosense will try to shed light on the effects of climate change on the interactions between plants, soil and the atmosphere. These interactions vary by species, location, and forest stand, which refers to collections of trees in a forest that are fairly uniform in age, size, distribution, and other factors. The EcoSense initiative will bring new technologies to forest monitoring following efforts such as those at Harvard University wired forest.
In particular, the project will study the abiotic and biotic processes of forest carbon and water exchange, how the ecosystem responds to environmental stressors, enabling the prediction of process-based changes in ecosystem function and sustainability, according to a project scheme. Data from the real-time sensor network will be transferred to a database for deep learning analysis and simulation models to generate short- and medium-term predictions.
“Climate change is already having a huge impact on forest ecosystems. We are seeing an increase in tree mortality worldwide,” he said Christian Wernerprofessor of ecosystem physiology at the Institute of Earth and Environmental Sciences of the University of Freiburg, indicating the effects of the 2018 European drought on trees. “Currently, we have well-established models to predict overall ecosystem functioning under unstressed conditions, but we don’t understand when and why climate extremes such as heat waves or droughts push individual trees or patches of forest beyond their critical points.”
Internet of woody things
The research team will instrument several hectares of hilly Black Forest in southwestern Germany, covering forests of pure beech, pure spruce and mixed trees. Climate change in the forest can have wider repercussions; the wood is of economic and touristic importance to Germany, famous for its traditional farms, cuckoo clocks and namesake ham and pie.
The EcoSense toolkit may include carbon dioxide (CO2) sensors, camera drones, and other devices. The team will initially deploy commercially available devices and then, from 2024, replace them with newly developed microsensors, some of which will be energy autonomous, according to Ulrike Wallrabeprofessor at the Department of Microsystems Engineering at the University of Freiburg.
“We want to measure water flows, CO2 discriminated by isotopes2 and volatile organic compounds and stress markers, mainly photosynthetic efficiency by chlorophyll fluorescence from soils up into the atmosphere,” said Wallrabe. “The sensor network will include new, compact and, where possible, energy autonomous sensors that must be developed in the project”.
Daniel Kneeshawa forest and climate change researcher at the University of Quebec in Montreal who is not affiliated with EcoSense, said the project is looking at interesting metrics that should be useful to a wide variety of researchers.
“As the researchers suggest, what happens at the cellular scale when it scales can have profound impacts across regions,” Kneeshaw said, adding that he wants to know how EcoSense data will scale up and down. “A better understanding of the mechanisms will help us be better prepared for future changes. Having such networks all over the world and having scientists talk about the different networks [about them] will lead to even more solid results and interpretations”.
The EcoSense project aims to start publishing studies in 2023, but some groups affiliated to it have already started publishing the results. For example, a group that included Werner posted a paper on a wireless, self-contained chlorophyll fluorometer that measures the efficiency of photosynthesis in plants. With a range of 10 kilometers, the new device can be fixed anywhere on a tree and is low-power and relatively inexpensive.
In addition to its 4-year initial funding, EcoSense has an option of two 4-year extensions to gain a long-term perspective. Researchers have high expectations of meaningful results.
“Our special feature is the unique alignment of ecosystem research with microsystems technology. Distributed autonomous sensing principles will open a new door for ecosystem research,” Werner said. of the processes and interactions that drive carbon and water fluxes, including stress markers such as volatile organic compounds and chlorophyll fluorescence.
—Tim Hornyak (@robotopia), science writer