A group of scientists has created an economical and successful technique for calculating soil carbon flux, which yields important information on the carbon budget of an ecosystem. The conventional approaches of collecting comprehensive data on soil carbon flux are costly or time-consuming, which leaves many regions devoid of vital information regarding fluxes during the night and after rainfall. The study team devised an inventive solution—the fluxbots—to deal with this problem.
Fluxbots are tiny instruments that measure soil carbon flux; they are a little bigger than a loaf of bread. As opposed to conventional techniques, which call for researchers to measure CO2 emissions manually using a sensor, the fluxbots have lidded devices that open and close according to a set timetable. This eliminates the requirement for ongoing supervision by enabling automated and continuous data collecting.
These fluxbots were placed by the researchers in a variety of open spaces and under trees at the Mpala Research Centre in Kenya.
The fluxbots collected hourly data for almost two months, yielding over 10,000 measurements of soil carbon flux. The study’s conclusions showed some intriguing trends, including lower carbon flow levels under tree canopies than in open spaces and higher levels at night. The researchers postulated that large herbivores like elephants can disturb the soil and increase flux levels and that moisture has a greater impact on soil carbon flow than temperature. Further results will be presented by the researchers at the AGU’s Annual Meeting in San Francisco in 2023. They reported their findings earlier this year in the Journal of Geophysical Research: Biogeosciences.
These fluxbots are especially helpful for areas in the Global South with insufficient data for carbon accounting because of their low cost. These nations frequently rely on measurements from other countries to estimate their carbon levels since they lack access to costly autonomous sensors. By providing an affordable means of gathering precise and geographically specific data, the fluxbots allow nations to carry out independent assessments and enhance their comprehension of carbon dynamics.
If fluxbots are further refined and enhanced—for example, by adding an adaptor collar to validate measurements—they could completely transform the field of monitoring soil carbon flux. For academics and policymakers trying to properly manage ecosystems and combat climate change, they are an invaluable tool because of their price, accessibility, and continuous data collection capabilities.
Elizabeth Forbes was most concerned about the $45,000 carbon dioxide flux chamber in her backpack when she discovered a gigantic spiderweb and its weaver at the Mpala Research Centre in the Kenyan savanna. She added that after gingerly taking off the backpack and placing it on the ground, I became frightened and attempted to remove the spider from me.
For her doctorate in ecology at the University of California, Santa Barbara, Forbes was studying the effects of massive herbivore loss on savanna carbon cycles. She decided that carrying a bulky, costly device would not be practical for extended field trips or close interactions with spiders, so she set out to develop a less expensive method of measuring soil carbon flux.
The rate at which carbon dioxide (CO2) is transferred from the atmosphere to the soil or soil carbon flux, is a crucial indicator of an ecosystem’s carbon budget. The soils on Earth contain vast stores of carbon, but microorganisms that breathe, soil fissures, and human actions like deforestation can release this carbon into the sky.
George Koech, an ecologist at Mpala, stated in an email that measuring soil carbon flux is essential to comprehending the dynamics of terrestrial ecosystems. In addition to providing microorganisms with their main source of energy, soil carbon has a significant impact on ecosystem production and soil structure.
However, it usually takes a lot of time or money to collect comprehensive data on soil carbon flux. Furthermore, established procedures aren’t ongoing. Expensive autonomous instruments should never be left unattended overnight in an area where animals could trip over them or cause flooding from rain. Kathleen Savage, a biogeochemist at the Woodwell Climate Research Centre, explained that you kind of have to watch after them. As a result, data on nocturnal and post-rainfall fluxes are lacking in many places.
According to Savage, who studies greenhouse gas fluxes from natural systems, a large portion of the field is looking at less expensive solutions where you kind of give up a little bit of the resolution, or how sensitive your sensor is, but you gain something more reasonably priced. Although she was not involved in the design of the new instrument, she has personally devised some of these inexpensive solutions.
Researchers manually drive a cylindrical collar a few centimeters into the ground to collect data on soil carbon flux. The CO2 that the soil is emitting is then captured and measured by placing a CO2 sensor on top.
Rather, Forbes and her associates designed a series of eighteen sealed apparatuses they refer to as fluxbots. Each one costs roughly $367 to build and is a little bigger than a loaf of bread.
Forbes, who is currently a postdoctoral research researcher at Yale School of the Environment, stated that the collar was the robot rather than needing to go around with the little sensor version and drop it on top of these collars. The robot was simply placed in the ground, and it opened and closed its lid according to a set timetable.