Earth & Environmental Sciences Area/Lawrence Berkeley Lab researchers make soil moisture measurements in Barrow, Alaska.

Earth & Environmental Sciences Area/Lawrence Berkeley Lab’s Baptiste Dafflon (right) and Craig Ulrich (left) make soil moisture measurements with a TDR and active layer depths with a tile probe. [Photo credit: Earth & Environmental Sciences Area (EESA)/Berkeley Lab]

Scientists studying Arctic ecosystems have long relied on established—yet limited—methods to help them understand how elements within an ecosystem interact with each other.

Now, researchers at Berkeley Lab’s Environmental & Earth Sciences Area (EESA) have led the development of a new approach for monitoring terrestrial ecosystems, and have used the system to discover new insights about how processes in different compartments of an Arctic Tundra ecosystem interact over space and time.

The research team developed a new strategy for autonomous monitoring of soil properties (using geophysical imaging), as well as land surface and vegetation processes (using a range of sensors). The strategy, which was deployed above and below the ground in an Arctic ecosystem, enabled rapid sampling over time at high resolution. It was used in research being conducted in Alaska as part of the U.S. Department of Energy Next-Generation Ecosystem Experiment-Arctic project.

Baptiste Dafflon collects monitoring data of an Arctic ecosystem using a UAV.

UAV used by Baptiste Dafflon (at a different study site) to collect monitoring data of an Arctic ecosystem . (Photo credit: EESA/Berkeley Lab)

“We needed a better approach to sense and quantify interactions between the subsurface, land, and vegetation, particularly in complex ecosystems like the Arctic that are subject to extreme perturbations—which includes annual freeze-thaw cycles—over short timescales,” said Baptiste Dafflon, EESA research scientist and the first author on a paper (published earlier this month in the Journal of Geophysical Research) that reported the study results. “For the first time, this strategy enabled a virtual window for visualizing how different compartments of an ecosystem interact and respond to environmental changes.”

In particular, the researchers’ analysis revealed seasonal interactions between soil water content and vegetation growth, and a variable relationship with permafrost conditions. In addition, the research team showed that these results can be applied to larger regions that they surveyed using an unmanned aerial system (UAS) and geophysical techniques.

The top photo shows the area monitored using above- and below-ground imaging, while the bottom figure gives an aerial view of the monitoring line.

The top photo shows the area monitored using above- and below-ground imaging, while the bottom figure gives an aerial view of the monitoring line. (Credit: EESA/Berkeley Lab)

“The study also suggests that it should be possible to use soil measurements to infer plant responses, and to use airborne vegetation imagery to estimate soil properties—over large scales and in a way that’s not invasive,” said Susan Hubbard, Berkeley Lab’s Associate Lab Director for EESA and the senior author on the paper.

The new monitoring approach is expected to be useful for addressing a range of questions at different sites. As part of its Watershed Scientific Focus Area, EESA is deploying a similar system in Colorado to explore how mountainous watersheds respond to hydrological perturbations, such as droughts, floods, and early snowmelt.

“The rapid advance of drone-based imagery, coupled with autonomous geophysics, land-based imagery, and telemetry, offers a whole new way to interrogate terrestrial ecosystems,” Hubbard said. “I believe the approach documented in this paper will become a new standard in years to come.”