2023 > 02
The soil organic matter (SOM) reservoir is one of the largest pools of global carbon (C), with a powerful ability to regulate atmospheric carbon dioxide (CO2) concentrations. For that reason, ‘carbon farming’, or the active regulation of SOM pools through different management practices, has become one of the most tempting solutions for climate change mitigation. While there are good reasons to expect that agricultural soils can store large amounts of C, there are also major knowledge-gaps regarding the fundamental processes governing C sequestration.

One of the main areas of uncertainty is the fate of C in deeper layers of soil. In a recent meta-analysis, deeper soil layers hold on average 47% of agricultural soil organic C stocks. However, due to logistical challenges, deeper agricultural soil horizons below ploughing depth have rarely been studied, and most research has been restricted to the topsoil. In ecosystems dominated by perennial vegetation it has been shown that although the concentration of C is usually low in deeper soil layers, the total C stock below 20 cm often represents more than half the soil C. To date, nearly half the agricultural C stocks remain largely unassessed. Deeper soil layers contain C that has a significantly longer turnover time, in some cases up to thousands of years, whereas the topsoil mainly consists of young OM. Thus, not only do half the agricultural C stocks remain unassessed, it is also likely that they accumulate C, with power to mitigate atmospheric CO2.

In a newly launched project, a group of researchers from Lund University will attempt to close many of these pressing knowledge gaps, by assessing the outcome of the different farming practices conducted in the unique availability of comparable perennial and conventional agricultural practices of the SITES Agroecological Field Experiment (SAFE) at Lönnstorp Research Station. Supported by Formas, over four years, Johannes Rousk, Lettice Hicks, Albert Brangarí and David Wårlind, will investigate the potential that agricultural practices have to increase deep soil carbon stocks, while also improving mechanistic understanding of the processes that determine soil organic matter persistence. Specifically, the team will determine how agricultural paradigms with perennial crops (Kernza), supporting deep rhizospheres, can provide a means to both store C and maintain fertility. The team sets out to test fundamental soil science theory, and will attempt to optimize the contradictive ecosystem services of mitigating climate change by storing C while maintaining soil fertility. The hypotheses to be interrogated include 1) conversion to perennial agricultural systems with deep rhizospheres will increase soil organic matter contents (via “the microbial carbon pump”), increase the retention time of organic matter (increasing its persistence), and reduce the nutrient content (N and P) locked in the stored organic matter, 2) belowground root input in perennial systems will trigger a rhizosphere priming effect, resulting in recovery of nutrients (N and P) from SOM throughout the profile (<1m). The team anticipates that perennial systems can make agricultural soils mitigate climate warming by storing C, more resilient to indirect effects of warming (drought), and maintain a nutrient supply conducive for a sustainable agricultural productivity.
News item written by Johannes Rousk (Lund University)
To kick-off the new and third phase of SITES, Asa Research Station hosted a meeting during 8-10 of February. More than 50 persons participated physically at the meeting with several representatives from each SITES station, the Thematic Programs, the SITES Secretariat and the SITES Steering Group.
An important part of the meeting was to discuss and agree on the strategy and goals for SITES III. During the first ten years the focus within SITES has been on building the infrastructure, starting up the three Thematic Programs and making data from the stations available. The value of SITES to the science community was evident in the “Cool Science” presentations, which focused on multi-station research during SITES II related to eDNA, lake greenhouse gases and soil organic carbon decomposition.
During SITES III, the core for SITES is to continue to have a well-functioning and sustainable infrastructure over time that supports high-quality research with easy access to the infrastructure and data from the stations. The strategic goals for SITES during phase III reflect this, categorized by three watchwords; Quality, Openly Available and Sustainable.
In addition to the strategical work, the Kick-off meeting also had presentations from the stations, a session on data and user engagements, focused discussions within each Thematic Program and guest speakers to talk about SITES international engagements with LIFEPLAN, ICOS/ACTRIS and eLTER. The group also heard about the interesting history of Asa Reserach Station and toured the field station.
A detailed summary of the SITES meeting will be featured in the March Newsletter, so stay tuned!
The SITES 2023 Calendar theme is “Data in Focus”. The openly available data produced within SITES and stored on the SITES Data Portal is the “golden thread” of the infrastructure, allowing users access to ecosystem data that covers diverse habitats and climate zones across geographical gradients in Sweden. Each month follow along as we highlight a unique SITES dataset.
In Northern Sweden, lakes can be ice-covered for many months of the year, and although the conditions in the lake during this time are cold and dark (depending on the snow and ice conditions), biogeochemical processes in the lake continue. The SITES calendar post for February displays this, as an oxygen gradient develops in Almbergasjön as ice forms, with oxygenated surface waters and oxygen-depleted bottom waters persisting until ice melt begins at the end of May.
At Abisko Scientific Research Station, as part of the SITES Water Thematic Program, lake biogeochemistry data during winter is collected by aquatic sensors deployed under the ice as well as manually by station staff. The SITES lake water biogeochemistry monitoring in Almbergasjön began in 2017 and continues today, providing valuable data to understand how a changing climate, including lake ice-cover decline, will alter lake biogeochemical processes in the future.
Link to data: https://meta.fieldsites.se/objects/plRSfwkbopYGhj2W31TBRKul

The graph displays sub-hourly surface (light yellow) and bottom water (dark yellow) oxygen concentrations in Almbergasjön during winter from ice formation to ice melt in 2021. The photo shows station staff at Abisko Scientific Research Station drilling a hole in the ice on Almbergasjön in order to collect water samples for the routine SITES Water sampling program.
2023 > 02
The soil organic matter (SOM) reservoir is one of the largest pools of global carbon (C), with a powerful ability to regulate atmospheric carbon dioxide (CO2) concentrations. For that reason, ‘carbon farming’, or the active regulation of SOM pools through different management practices, has become one of the most tempting solutions for climate change mitigation. While there are good reasons to expect that agricultural soils can store large amounts of C, there are also major knowledge-gaps regarding the fundamental processes governing C sequestration.

One of the main areas of uncertainty is the fate of C in deeper layers of soil. In a recent meta-analysis, deeper soil layers hold on average 47% of agricultural soil organic C stocks. However, due to logistical challenges, deeper agricultural soil horizons below ploughing depth have rarely been studied, and most research has been restricted to the topsoil. In ecosystems dominated by perennial vegetation it has been shown that although the concentration of C is usually low in deeper soil layers, the total C stock below 20 cm often represents more than half the soil C. To date, nearly half the agricultural C stocks remain largely unassessed. Deeper soil layers contain C that has a significantly longer turnover time, in some cases up to thousands of years, whereas the topsoil mainly consists of young OM. Thus, not only do half the agricultural C stocks remain unassessed, it is also likely that they accumulate C, with power to mitigate atmospheric CO2.

In a newly launched project, a group of researchers from Lund University will attempt to close many of these pressing knowledge gaps, by assessing the outcome of the different farming practices conducted in the unique availability of comparable perennial and conventional agricultural practices of the SITES Agroecological Field Experiment (SAFE) at Lönnstorp Research Station. Supported by Formas, over four years, Johannes Rousk, Lettice Hicks, Albert Brangarí and David Wårlind, will investigate the potential that agricultural practices have to increase deep soil carbon stocks, while also improving mechanistic understanding of the processes that determine soil organic matter persistence. Specifically, the team will determine how agricultural paradigms with perennial crops (Kernza), supporting deep rhizospheres, can provide a means to both store C and maintain fertility. The team sets out to test fundamental soil science theory, and will attempt to optimize the contradictive ecosystem services of mitigating climate change by storing C while maintaining soil fertility. The hypotheses to be interrogated include 1) conversion to perennial agricultural systems with deep rhizospheres will increase soil organic matter contents (via “the microbial carbon pump”), increase the retention time of organic matter (increasing its persistence), and reduce the nutrient content (N and P) locked in the stored organic matter, 2) belowground root input in perennial systems will trigger a rhizosphere priming effect, resulting in recovery of nutrients (N and P) from SOM throughout the profile (<1m). The team anticipates that perennial systems can make agricultural soils mitigate climate warming by storing C, more resilient to indirect effects of warming (drought), and maintain a nutrient supply conducive for a sustainable agricultural productivity.
News item written by Johannes Rousk (Lund University)
To kick-off the new and third phase of SITES, Asa Research Station hosted a meeting during 8-10 of February. More than 50 persons participated physically at the meeting with several representatives from each SITES station, the Thematic Programs, the SITES Secretariat and the SITES Steering Group.
An important part of the meeting was to discuss and agree on the strategy and goals for SITES III. During the first ten years the focus within SITES has been on building the infrastructure, starting up the three Thematic Programs and making data from the stations available. The value of SITES to the science community was evident in the “Cool Science” presentations, which focused on multi-station research during SITES II related to eDNA, lake greenhouse gases and soil organic carbon decomposition.
During SITES III, the core for SITES is to continue to have a well-functioning and sustainable infrastructure over time that supports high-quality research with easy access to the infrastructure and data from the stations. The strategic goals for SITES during phase III reflect this, categorized by three watchwords; Quality, Openly Available and Sustainable.
In addition to the strategical work, the Kick-off meeting also had presentations from the stations, a session on data and user engagements, focused discussions within each Thematic Program and guest speakers to talk about SITES international engagements with LIFEPLAN, ICOS/ACTRIS and eLTER. The group also heard about the interesting history of Asa Reserach Station and toured the field station.
A detailed summary of the SITES meeting will be featured in the March Newsletter, so stay tuned!
The SITES 2023 Calendar theme is “Data in Focus”. The openly available data produced within SITES and stored on the SITES Data Portal is the “golden thread” of the infrastructure, allowing users access to ecosystem data that covers diverse habitats and climate zones across geographical gradients in Sweden. Each month follow along as we highlight a unique SITES dataset.
In Northern Sweden, lakes can be ice-covered for many months of the year, and although the conditions in the lake during this time are cold and dark (depending on the snow and ice conditions), biogeochemical processes in the lake continue. The SITES calendar post for February displays this, as an oxygen gradient develops in Almbergasjön as ice forms, with oxygenated surface waters and oxygen-depleted bottom waters persisting until ice melt begins at the end of May.
At Abisko Scientific Research Station, as part of the SITES Water Thematic Program, lake biogeochemistry data during winter is collected by aquatic sensors deployed under the ice as well as manually by station staff. The SITES lake water biogeochemistry monitoring in Almbergasjön began in 2017 and continues today, providing valuable data to understand how a changing climate, including lake ice-cover decline, will alter lake biogeochemical processes in the future.
Link to data: https://meta.fieldsites.se/objects/plRSfwkbopYGhj2W31TBRKul

The graph displays sub-hourly surface (light yellow) and bottom water (dark yellow) oxygen concentrations in Almbergasjön during winter from ice formation to ice melt in 2021. The photo shows station staff at Abisko Scientific Research Station drilling a hole in the ice on Almbergasjön in order to collect water samples for the routine SITES Water sampling program.
Latest News
- December Data in Focus: Ten years of stream discharge from Asa’s Feresjön inlet stream
- Data Retreats Continue, on to Bolmen
- Welcome Joel Gräsman to Asa Research Station!
- Data retreat at Grimsö brings three SITES stations together to develop common cleaning scripts
- November Data in Focus: Lönnstorp Research Station soil temperature data
- New advanced drones tested in SITES Spectral Thematic Program
- Transitioning from Summer to Winter Sensors in the Abisko Area
- SITES Erken provides a venue for bringing groups together to explore monitoring instrumentation, da…
- GreenLeaFood and Green2Feed – Two projects that use SITES Lönnstorp Research Station facilities
- October Data in Focus: Precipitation dynamics at Röbäcksdalen Field Research Station