2023
At the Gothenburg university research infrastructure, Skogaryd Research Catchment (SRC), not only is research conducted but also education. Every year different courses from environmental and Earth science programs, from University of Gothenburg and other universities, visit SRC for one or several days.

This week, the first-year students of the Environmental Science program visited SRC, as part of their base course in Environmental Sciences. They learned about the different ecosystems within the catchment, how greenhouse gases are measured by different methods and about the SITES Water program at the station. One topic that was discussed is how the lateral export of carbon contributes to the understanding the carbon sink-source strength of ecosystems and its importance for the landscape carbon balance.

An important part of science education is field work. Therefore, the students visited two of the research locations at SRC to see instrumentation and the large-scale experiments conducted. At Följemaden, the students were shown the rewetting of a peatland, that has been drained and under agricultural and forest management for 150 years. Among the topics discussed was, can we turn a greenhouse gas source back into a sink? At the central forest area, the students looked at the selectively harvested stand, which is comparing a clearcut and a stand with an extended rotation period. The students discussed, how does the carbon and greenhouse gas balance differ between the management options? The discussion also touched on more general questions regarding forests and forest management. As always, students were curious and had valuable question, stimulating a lively discussion.
Several inflows to Lake Bolmen are of interest to study to understand the brownification of the lake. The inflow river, Ryds Å, entering the lake south east of Bolmen, flows through an old peatland, Äspenäs. The peatland is thought to have an impact on the color of the water. There is no previous data on the brownification of Ryds Å, nor about its contribution of brown-colored water to the lake. In general, the available data on the hydrology of the river and its catchment are very sparse. It is therefore necessary to acquire such data to analyze how the peat area is affecting Ryds Å, its contribution to brownification in the lake, and the relationship between them.

This fall, two Master students in Environmental Engineering at Lund University, Emelie Ström and Frida Karlsson Öhman, will look further into this topic. The aim of their Master thesis is to quantify the brownification of Ryds Å. Further relevant parameters concerning the water quality in Ryds Å, such as pH, temperature, turbulence and chlorophyll, will also be quantified. The project will thereby consist of field work, including taking water samples and making a flow analysis, and laboratory work at the research station SITES Bolmen. The laboratory work includes filtration and spectrophotometry.
Emelie and Frida started their field work this week at Bolmen Research Station, and will continue there the next four weeks. They are in guidance of their assistant supervisor, Clemens Klante, Research Manager at SITES Bolmen Research Station, and their supervisor at Lund University, Professor Magnus Larson.
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.
SITES has three Thematic Programs that strengthen the collaboration within the network of stations in remote sensing, water monitoring and aquatic mesocosms. The Thematic Programs facilitate comparison between climate zones, landscape elements and management systems and offer open data from long-term monitoring and experimental installations.
This month the SITES AquaNet Thematic Program is featured, a standardized and open infrastructure to run mesocosm experiments across five SITES lakes spread across Sweden. The mesocosm enclosures are equipped with sensors and a data logging system as well as greenhouse gas chambers to measure environmental parameters in real-time (as seen in the image below for the mesocosm enclosure at Lake Erken). In addition to having access to the mesocosm equipment, SITES AquaNet also offers users technical support from qualified station personnel to run mesocosm experiments, established protocols to standardize both field and laboratory work and open access to data from previous AquaNet experiments as well as time series data in the lake and connecting stream(s) measured in the SITES Water monitoring program.
Link to Data: https://meta.fieldsites.se/objects/cX_V_MJ05R_QU1pnyzqEKqt9
In 2017, SITES AquaNet conducted a pilot experiment across the five AquaNet lakes. The experimental tests investigated the interactive effects of bottom-up (a reduction in light availability) and top-down (fish predation) disturbances on the stability of plankton community composition (bacterio-, phyto- and zoo-plankton) and ecosystem functioning. The graph shows sub-hourly oxygen data generated from sensors in the Lake Erken mesocosm experiment run in 2017, aggregated for the four treatments applied to the experiment (Control, Light, Fish, Light & Fish).
The results from the 2017 experiments at all SITES AquaNet stations are available as a data collection on the SITES Data Portal and published in Urrutia-Cordero et al. 2021.
This summer, drone flights were carried out by SITES Spectral over the Följemaden area in Skogaryd. The Följemaden area is part of a re-wetting experiment to investigate measures to reduce greenhouse gas emissions caused by soil drainage. The experiment was reported in a previous SITES news item. Starting this year, the area is part of a SITES Spectral monitoring area, and will be monitored by fixed spectral sensors, a phenological camera, and annual drone flights.
This summer, José Beltran (Lund University) carried out aerial mapping over the Följemaden area, covering 63 ha with the drone flying at 50 m altitude. Successful drone flights were also conducted at the Myckelmossen mire site and at the central forest in Skogaryd. SITES Skogaryd staff, Per Weslien and David Allbrand, are responsible for all the installations and maintenance of the instruments at the diverse Skogaryd catchment area in SITES, providing invaluable data to answer a range of questions related to ecosystem dynamics in a changing climate. The new SITES Spectral data from the Följemaden area, including processed data from the 2023 flights and the fixed sensors, will be made openly available through the SITES Data Portal.
On August 8th an Eddy Covariance (EC) flux tower was installed at Röbäcksdalen. This pilot project is a collaboration between Röbäcksdalen and Svartberget SITES stations, where the latter provides the tower, which is led by Matthias Peichl at the Department of Forest Ecology Management at SLU in Umeå. The location of the EC flux tower is on one of the larger fields at Röbäcksdalen station and is conveniently located near one of the SITES Spectral mast and between two of the sampling points in SITES Water. The land is used for feed production by the dairy farm operated by the Faculty of Veterinary Medicine and Animal Science at SLU, which is included in SITES Röbäcksdalen.
This is the first flux tower located in an agricultural system of the Boreal region in northern Sweden. Thus, it will deliver unique data that is expected to provide novel insights into how the carbon dioxide (CO2) ecosystem balance and water flux (e.g. evapotranspiration) vary during crop rotations on dairy farms and, on a more long-term basis, how climate change, and in particular warmer winters, will affect the carbon and water cycle of agricultural fields in the far north. This installment will provide unique complementary data to the measurements made within the SITES Water and SITES Spectral Thematic Programs, and is also the northernmost installment of an EC flux tower on agricultural lands in Sweden.
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.
SITES has three Thematic Programs that strengthen the collaboration within the network of stations in remote sensing, water monitoring and aquatic mesocosms. The Thematic Programs facilitate comparison between climate zones, landscape elements and management systems and offer open data from long-term monitoring and experimental installations.
This month the SITES Spectral Thematic Program is featured, an infrastructure for collecting spectral data for ecosystem measurements over terrestrial environments to a varying extends at all SITES stations. SITES Spectral data covers small to local scales by using fixed multispectral sensors mounted on masts or towers, phenologycal cameras and multispectral sensors mounted on Umanned Aerial Vehicles (UAVs). UAV drones are flown over targeted areas at the SITES stations at least once per year during the peak of the active growing season. The UVAs are equipped with a multispectral sensor, a red-green-blue (RGB) camera and a thermal camera. Together, the equipment on the UAVs capture images in the visible and near-infrared wavelength. After the UAV flights are completed, spectral data are processed centrally by the SITES Spectral Thematic Program, resulting in data products, including orthomosaics, digital elevation models and point clouds over the UAV flight path. Data products from SITES Spectral are openly available for download on the SITES Data Portal.
The image below is from the SITES Spectral data products at Lönnstorp station.
The image shows an examples of processed UAV data from a flight over agricultural fields at Lönnstorp in 2020. The data products include a RGB orthomosaic (left), a false color composite of multispectral orthomosaic (center), and a radiometrically calibrated vegetation index (right).
The joint AquaNet and AQUACOSM-plus experiments at SITES Asa and Svartberget have been running for about a month now (details about the project start are reported here). Preliminarily results from the experiments (graph below) show the difference in specific conductivity (a proxy for salinity) across the three different treatments; 1) Control, where no salt is added, 2) Gradual, where small amounts of salt are added in increments over time and 3) Extreme, where a large amount of salt is added once at the start of the experiment. Data from automatic in situ sensors in each mesocosm and manual samples throughout the experiment will be assessed to see how different salinity disturbance regimes impact the function and composition of biological communities.
The participants at the two stations have been busy maintaining and sampling the mesocosm experiments, learning from and collaborating with participants from different countries, while at the same time enjoy the Swedish summer.
At Asa, the core team is comprised of Guangbin Gao (Sweden), Andrra Zhjeqi (Sweden), Judit Rodrigo (Spain), with Pablo Urrutia Cordero (Spain), Jana Isanta-Navarro (Sweden), Jing Li (Sweden) and Pepe Rodriguez (Canada) also participating in the experiment for several weeks. Niels Aagaard Jakobsen (Research Engineer at Asa Station) led setting-up the mesocosm infrastructure at the station, while Silke Langenheder (SITES AquaNet Lead) and Wilhelm Lönnqvist (Asa Station Manager) supported the experiment set-up and preparations.
When asked about his experience at Asa station so far, Guangbin Gao stated, “I am very lucky and pleased to participate in the AquaNet experiment at Asa. It is a complete system of ecological experiments. Here, through the application of high-frequency sensors and daily sampling, I learned how to build and operate the mesocosm facility. Of course, there is a great opportunity to communicate and collaborate with researchers from different countries.”
At Svartbergt, the core team is comprised of Erin Ford (Canada), Mary Mullins (USA) and Anusha Singh (Czech Republic), with support at the start of the experiment from Aidan Guttormson (Canada) and Shelley Arnott (Canada). In addition, SITES AquaNet staff (Ingrid Sassenhagen, William Colom Montero) and Svartberget Station staff (Johan Westin, Johannes Tiwari and Viktor Boström) helped with the set-up and preparation for the experiment at the station.
On behalf of the team at Svartberget, Mary Mullins, summarized the experience, “Here at the Svartberget station in Vindeln, we have been busy honing our field and lab skills in limnology! From collecting plankton samples to analyzing the water chemistry of the mesocosms, we are determined to discover the impacts of salinity on this unique ecosystem. Living at the station surrounded by nature has been just as wonderful as exploring the nearby towns and making friends during Midsummer Celebration.”
With only a few weeks left in the experiment, there are only a few salt additions and samplings left, and then it is time to clean and store the AquaNet mesocosms for future experiments. Once the teams are back at their home institutions and have had time to recover, it is on to the analysis and results. So stay tuned!
Wildlife cameras have received a lot of attention in the last decade, and many research projects and practical applications using camera traps are now running. Cameras are surrounded by high hopes that these methods will make various wildlife surveys more effective, for example, since they may replace some time consuming field work. A scientifically proper use of camera trap data may, however, be tricky, and the topic constitutes a research field in itself. Studied issues may, for example, concern which sampling design (distribution of cameras, set up at each plot etc.) to apply and which picture statistics are actually relevant for a given research question.

Some of these questions are now studied at Grimsö in a joint SITES and FoMA project. The project uses data from the SITES camera survey (32 cameras in a regular grid in the research area) in combination with another type of camera set up at the same plot. The study focuses on the importance of camera position and will try to quantify the differences (number of photos, which species appear, etc.) resulting from varying set ups. The camera trap data will also be used to evaluate an artificial intelligence software for automatic species recognition in pictures via comparisons to interpretations made by experienced wildlife ecologists. The automatic process is usually fast, but its precision is still being discussed.
SITES offers good possibilities for various method evaluation studies as well as for projects searching for biological data, since numerous datasets are freely available. For onsite studies or experiments at Grimsö, via SITES, external projects may also receive support with fieldwork, checking equipment, etc.
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.
Bolmen Research Station, is an associated station to SITES AquaNet – an associated station benefits from SITES coordinated activities, in this case SITES AquaNet, and has access to SITES network and knowledge and the ability to mobilize and openly share station data via the SITES Data Portal. Bolmen Research Station is located in Tiraholm, by Lake Bolmen in Hylte municipality. The research at the station primarily focuses on environmental monitoring, fish conservation and management, water conservation and the effects of climate change on freshwater ecosystems.
Bolmen has participated in several SITES AquaNet experiments, including the first pilot experiment in 2017. This month, data from the 2017 AquaNet pilot experiment at Bolmen is featured. The experiment investigated the interactive effects of bottom-up (a reduction in light availability) and top-down (fish predation) disturbances on the stability of plankton community composition (bacterio-, phyto- and zoo-plankton) and ecosystem functioning. The experiments consisted of a fourfold replication of a full-factorial design with no disturbance (control), light reduction as a press disturbance (constant), fish predation as a pulse disturbance (temporary) and press and pulse disturbances combined. Each mesocosm enclosure was equipped with sensors and data logging system to measure in real-time environmental parameters, such as dissolved oxygen, temperature, photosynthetic active radiation, Chlorophyll a (as seen below), phycocyanin and turbidity.
Link to Data: https://meta.fieldsites.se/objects/fFHR9J_5xa-Bm2bxm0gz1J2E
The results from the 2017 experiments at all SITES AquaNet stations are available as a data collection on the SITES Data Portal and published in Urrutia-Cordero et al. 2021.
The graph shows sub-hourly Chlorophyll a data, from the mesocosm experiment run in 2017 at Lake Bolmen, aggregated for the four treatments applied to the experiment (Control, Light, Fish, Light & Fish). As evident in the graph, Chlorophyll a concentration fluctuated over time with differences in responses between the four treatments. The photo displays the AquaNet platform and mesocosm enclosures on Lake Bolmen, where each mesocosm is equipped with sensors, all connected to a central data logging system.
At Stordalen, a replanted clear-cut site within the SITES station Skogaryd Research Catchment, a new 16 m high tower has been installed for continues monitoring of greenhouse gas emissions. The tower overlooks a young plantation forest, replacing a smaller tower that has been outgrown by the trees. At Stordalen, researchers from Lund university are measuring the net ecosystem exchange (NEE) of carbon dioxide (CO2) at a clear-cut forest site using the time-tested Eddy Covariance (EC) method. The measurements started in 2012 directly following clear-cutting and have been running continuously since then. As the vegetation grows taller, the tower must be raised for continuous measurements above tree canopy. The tower was already raised in 2015 and now it is time for an even taller tower.
Forests can play an important role in climate change mitigation, as they store huge amounts of carbon in their biomass and soil and thus, can be a sink for atmospheric CO2. Rotation forestry, with clear-cutting and replanting, is the most common silvicultural practice in Sweden, but there is an intense debate about its role in climate mitigation and its ability to contribute to long-term sequestration of carbon from the atmosphere. The clear-cutting at the end of the rotation period causes large emissions of CO2 for several years, as the soil respiration from decomposition of organic matter in the soil exceeds the CO2 uptake by the seedings/young trees. Eventually, the increasing tree growth will return the forest to being a CO2 sink, but many uncertainties remain regarding the recovery time of the carbon balance after clear-cutting. It is crucial to better understand which factors influence the time it takes until the CO2 uptake by photosynthesis equals the emissions by respiration (point of carbon balance) on an annual scale and what additional time is needed before the initial carbon losses are compensated for (carbon compensation point).
Preliminary results for the first decade after clear-cutting, indicate that Stordalen is a large CO2 source to the atmosphere, and has not yet reached the point of carbon balance on an annual basis. Since Stordalen has moist soil conditions, a large fraction of birch trees has been left at the site to help promote the growth of the planted spruce trees. These birches have been partially removed on several occasions. This complicates the data interpretation, and it is important to account for these harvesting operations when assessing the recovery time of the carbon fluxes at Stordalen. Ultimately, the measurements at Stordalen might contribute to the formulation of new ecological and economic goals, management plans and policies that guide the future use of the Swedish forests.
The next round of the joint AquaNet and AQUACOSM-plus experiments are kicking-off! This time around the experiments will take place at Asa Research Station and Svartberget Research Station with a focus on functional and compositional consequences of different salinity disturbance regimes on plankton communities. The experiment is a follow up to the GLEON Salt experiment in 2018 and will run from mid-June to the end of July.
Through AQUACOSM-Plus, international project participants are supported through Transnational Access (TA) to travel to and carry out the experiment at the SITES AquaNet mesocosm facilities. SITES staff support in the preparation of the experiment and AquaNet platform set up; this includes connecting many small wires to a data logging system so that each mesocosm is equipped with high frequency sensors measuring, e.g., dissolved oxygen, temperature, photosynthetic active radiation, chlorophyll, phycocyanin and turbidity.
On June 12, 2023, the TA participants and SITES staff met at SITES Erken Laboratory to officially kick-off the experiments. The group discussed the experimental set up details and got hands-on training of the sampling scheme, using the AquaNet platform on Lake Erken as a test case. This week the group will separate into two cohorts; one group travels south to Asa Research Station, while the other travels north to Svartberget Research Station.
The mesocosm experiments will be identically run at the two stations, which are both located in forested catchments. The contrast between geographical location (57.17N and 64.26 N), lake area (0.52 km2 and 0.04km2) and trophic status (Oligratrophic and Mesotrophic), respectively for Feresjön at Asa and Stortjärn at Svaretberget, will provide an interesting comparison for the study.
The Abisko Scientific Research Station field season started in earnest on June 1st. The station will be fully occupied in July, and the occupancy will remain high even in August and September. The ten-bed field hut in Latnjajaure will have researchers on-site throughout the summer.
The Director of the Swedish Polar Research Secretariat, Katarina Gårdfeldt, and parts of the government agency's advisory council recently visited the station. They also went to the Stordalen mire area near Torneträsk, about ten kilometres from Abisko. They were shown around and informed about ongoing continuous measurements, such as greenhouse gases, and current research projects.
Alisa Heuchel started as the new laboratory manager at the Abisko Scientific Research Station in May. In September, Alisa Heuchel will defend her thesis in forest genetics. Although her job at the station will involve different tasks, she will bring many experiences from her PhD studies, including laboratory work. Read an interview with Alisa here.

Within SITES Water, the raft on Lake Almbergasjön was towed out and installed. The lake is located approximately 14 kilometres east of Abisko, and the raft measures temperatures at 24 different depths in the water column, as well as oxygen levels and conductivity. A station on the shore complements the measurements that collect data on wind direction, wind speed, air pressure, temperature, relative humidity, net shortwave and longwave radiation, and the water level in the lake.
Abisko Scientific Research Station has resumed pollen monitoring and is now part of the nationwide pollen surveillance. This means pollen is collected on-site and sent to the Environmental Archaeology Lab at Umeå University for analysis.
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.
SITES has three Thematic Programs that strengthen the collaboration within the network of stations in remote sensing, water monitoring and aquatic mesocosms. The Thematic Programs facilitate comparison between climate zones, landscape elements and management systems and offer open data from long-term monitoring and experimental installations.
This month the SITES Water Thematic Program is featured, which builds a unique long-term and well-coordinated measurement program where hydrological, physical, chemical, and biological parameters within lakes and streams are measured at seven SITES stations. As part of SITES Water, lake platforms are equipped with automated high frequency sensors that measures weather and climate variables above the lake (e.g. air temperature, humidity, wind speed) as well as physical variables within the lake (e.g. temperature, oxygen). The lake water temperature is measured at different depths, i.e. lake profile, which allows for the thermal structure of the lake over the year to be determined. The thermal structure of a lake plays an important role in the biogeochemical cycling and subsequent greenhouse gas emissions from the lake.
Link to Data: https://meta.fieldsites.se/objects/iHSmt3sLan6AhIm_DO5tV1h6
The graph shows sub-hourly water temperature at different depths in lake Erssjön over the year in 2020. Early in the year, the water temperature at different depths in the lake was similar but as air temperatures warmed in the spring, a thermal stratification formed, where the warm surface water of the lake disconnected from the cooler bottom water. As the air temperatures cooled in the fall, the lake mixed and the water temperatures in the lake at different depths became similar again. The photo shows the lake platform on Erssjön, which is equipped with meteorological sensors above the lake and in situ aquatic sensors below the lake.
On April 24-25, 2023, fourteen researchers, PhD and Master students gathered at Lake Bolmen to start up the international research collaboration within the EU network AQUACOSM-plus and the national infrastructure SITES AquaNet. The study will use mesocosms to investigate how lake ecosystems are affected by browning and eutrophication. The research project is taking place simultaneously at three locations in Sweden, and Bolmen Research Station was the first to go.
The group included Silke Langenheder – SITES Erken Laboratory and AquaNet coordinator, Ingrid Sassenhage – SITES Erken Laboratory, Antonia Liess – Halmstad University, Johanna Sjöstedt – Lund University, Nusret Karakaya - Bolu Abant Izzet Baysal University, Anna Lupon– CEAB-CSIC, Susana Bernal – CEAB-CSIC, Inge Elfferich – Cardiff University, Antonija Kulaš – University of Zagreb, Kadir Yıldız – Bolu Abant Izzet Baysal University, Kevin Jones – Lund University, Eline van Dam – Lund University, Franka Hemme – Lund University and Juha Rankinen – Bolmen Research Station. At a later date Eugènia Martí – CEAB-CSIC and Nuria Carabal de Antonio - Universidad de Valencia will join the Bolmen team.

- ”This is a very exciting and important research project where we collect data from several locations in Sweden to try to figure out how the transport of nutrients and organic matter connected to different run-off scenarios may affect lake ecosystems and their water quality. Bolmen Research Station is first out and later in the the week we start the experiment in Skogaryd outside Gothenburg and the following week in lake Erken outside Uppsala”, explains Silke Langenheder, Professor in Limnology at Uppsala University and coordinator for SITES AquaNet in Sweden.
The researchers will use the mesocosm infrastrucutre to study how greenhouse gases, bacteria, algae and zooplankton in the lake are affected by increased brownification and eutrophication. The mesocosms (large floating containers) are placed in a floating platform on the lake and filled with lake water, which means that they have the naturally occurring ecosystem and the water chemistry that exists today.
- ”Climate change, variations in precipitation and how we use the land around the lake affect both the quantity and quality of the lake water, and by studying various factors that affect our lakes, we can prepare for the challenges of the future”, says Juha Rankinen, Station Manager at Bolmen Research Station.
Lake Bolmen is the most important source for drinking water production in south-western Sweden and both the quantity and the quality of water are topics that are becoming more and more relevant, both nationally and internationally. In the last two IPCC reports, water is highlighted as the central part of the climate change and mitigation measures.
- ”The experiment will last for six weeks and we will have five PhD/Master students placed at Bolmen to be able to take samples and analyze them daily. All the data we collect is then reported to SITES AquaNet and thus gives researchers throughout the world the opportunity to work with it. This collaboration between the research stations provides incredible advantages and opportunities for researchers and universities to take big steps forward”, continues Juha.
This news item was adapted from the original article in Swedish:
https://forskningsstationbolmen.se/uppstart-av-aquacosm-pa-forskningsstation-bolmen/
Youtube clip of experiment at Bolmen: https://youtu.be/PZBvv4S_g50
Linda Groot Nibbelink has recently started as Field technician at SITES Lönnstorp research station! Welcome to the SITES Community, Linda!
To get to know Linda, we asked for her to introduce herself to the SITES Community:
Hi! My name is Linda Groot Nibbelink. I grew up in Goes, a rural town in the Rhine delta in the Netherlands. I studied International Land and Water Management at Wageningen University & Research and Organic Agriculture & Agroecology at BOKU in Vienna, Austria and at University of Hohenheim, Germany.
Besides theoretical knowledge of agriculture, I gained practical experience by working and volunteering at organic, biodynamic and conventional fruit orchards, horticultural farms and dairy farms in Europe. Last year I did a full season internship at a plant breeding institute in Switzerland, where I worked with developing new pea varieties. After several years of moving around the continent, I decided to settle down with my partner in Lund.
At SITES Lönnstorp Research Station, my role will be to perform measurements and assessments in the experiments at the station. I will also be involved with data handling, management of experiments and taking care of samples that are collected.
What I love about working at Lönnstorp is that it allows me to combine working with my hands and with my mind. At the same time, it gives me the opportunity to learn the specifics of agriculture in Sweden and gain practical experience with field experiments.
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.
Wildlife monitoring is an important part of the activities at Grimsö Wildlife Research Station. A large part of the monitoring was initiated during the 1970’s, but new data series have been added over time as methods have developed. The continuous surveys focus on topics such as population dynamics, reproduction, life history traits and body measurements and include monitoring of, e.g., moose, roe deer, red fox, voles and starlings. For example, red fox (Vulpes vulpes) reproduction has been monitored since 1973 by identifying fox litters. Around 200 fox dens are checked annually within the Grimsö Wildlife Research Area and the dens with observed reproduction are summed to mirror the total number of fox litters for that year. The variation in the local fox abundance is related to the vole population cycle and is a key factor for the dynamics of several small mammal populations across Scandinavia.
Link to Data: https://meta.fieldsites.se/objects/09RC_nAwv6h0wauAY8dwFHR_
The graph shows the number of fox litters at Grimsö between 1973-2021, with variations over time mainly related to vole cycles. The extra low numbers in 1985-1986 were due to an outbreak of scabies (sarcoptic mange) that regulated fox populations more or less throughout Sweden during the late 1980's and into the 1990's.
Over the past few months, the SITES Water Thematic Program and the associated openly available data, has been featured in several events.
In December, Marcus Wallin (SITES Water Thematic Program Lead) presented a poster about SITES Water at the Hydrology Days 2022, hosted by Svenska hydrologiska rådet SHR. The theme of the event was "Freshwater: from source to sea", covering the broad spectrum of water from bio(eco)logical, physical and chemical, and society. The meeting took place in person this year at SLU Uppsala, after two years of being online, and offered a great opportunity for SITES Water to connect to academic researchers beyond SLU, including Uppsala University, Stockholm University, KTH, as well as to institutes and companies, including Swedish Environmental Research Institute, Tyréns AB and SMHI.

On the 2nd of March, an all day seminar titled, Hur beräknar vi Sveriges växthusgasbalans i skog, mark och vatten? - Nuvarande klimatrapportering och framtida möjligheter. (Translating to, How do we calculate Sweden’s greenhouse gas balance in forest, land and water – current climate reporting and future opportunities) brought together researchers and different stakeholders, e.g. governmental authorities, municipalities, private companies with interest in Sweden’s greenhouse gas balance. The focus was on the Land use, Land use change and Forestry sector, and how the national greenhouse gas balance is reported. The seminar also included presentations concerning greenhouse gas fluxes that are not covered in the national reporting and development of new measurement and modelling methods. Several SITES researchers as well as SITES collaborator, ICOS, presented during the seminar. It was obvious after the day that data generated within SITES are essential for improving our understanding of Sweden’s greenhouse gas balance.
Later in March (the 20th and 22nd), the third internal water seminar series at SLU took place. SLU has a strong and broad expertise on water, but is spread out across different faculties, departments and campuses and thus, the water seminar series is an opportunity to connect water research at SLU as a whole. This year’s program focused on early career scholars, where Blaize Denfeld (SITES Deputy Director) presented SITES Water in the context of her PhD and PostDoc research at multiple SITES Stations including Erken, Svartberget, Skogaryd and Röbäcksdalen.
Major efforts have been made lately among SITES stations and by the Secretariat to upload data generated within the SITES Water program to the SITES Data Portal. These data include meteorology, water chemistry from lakes and streams, lake temperature and oxygen profiles, lake water level and stream discharge. The SITES Water data is now openly available on the SITES Data Portal and more will be uploaded soon.
A handful of the external research projects at Grimsö focus on large scale evaluations of practical techniques to manage wildlife-traffic problems. These projects are led by Grimsö but conducted in collaboration with several national and international stakeholders, including, e.g. the Swedish Transport Administration (Trafikverket), Interreg Sweden-Norway and the Norwegian BaneNOR. Many issues concerning wildlife and traffic are complex but with growing importance in the last decades, both due to denser populations of large mammals and continued increase in traffic volumes. More information about the projects and innovative solutions to reduce wildlife collisions in traffic can be found at Om projektet – Vilt och Trafik.

One of the current projects, “Viltvarning vid järnväg” (translating to “Wildlife warning near railroads”), focuses on identifying techniques to scare animals away from railroad areas using sounds. This is being explored as an alternative to exclusion fences and wildlife passages, as it has the potential to be a more flexible and less expensive solution. One design being tested is called a MASS unit (Movement Activated Scaring System) and uses infrared (IR) sensors to detect movements, which in turn activate speakers that send out various sounds (horns, voices etc.) at a high volume (>70 dB) to scare away animals.

This type of camera monitoring results in massive amounts of pictures, by far exceeding what can be handled and analyzed manually. Several automatic solutions, e.g. software & artificial intelligence (AI), for this are nowadays under test, where one tricky part is to obtain reliable and accurate identifications of species in the pictures. Depending on the position of the animal this may be more or less problematic, and in some situations impossible to achieve proper identifications. A separate part of the mentioned projects is to test software based on a machine learning processes using several different pictures of known animals, that vary in position, distance from the camera, etc. The raw data from the picture analysis shows a probability measure for which species are shown. At present, a cut off-level is often applied for an acceptable level of identification (e.g. 90%, but varies due to study aims). After removal of potential pictures showing humans, the raw data gets stored on a common platform between the Swedish Transport Administration and the project, where then AI is used to classify animals to species.
The collaborative work in this project among authorities, consultants and researchers, combined with the scientific evaluation of the methods tested, is a good example of how SITES stations can be utilized broadly.
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.
At Skogaryd Research Catchment, the mire Mycklemossen is equipped with an automatic weather station, which provides high-frequency meteorological data. This includes air temperature, relative humidity, air pressure, wind speed and direction, incoming and outgoing shortwave radiation, incoming and outgoing longwave radiation, net radiation, albedo and precipitation. Below the mast, snow and water depth as well as soil temperature and soil heat flux is measured. In addition to SITES, ICOS-Sweden and other research projects include greenhouse gas flux measurements, stream flow and chemical analyses at the mire Mycklemossen, making it one of a few mire sites where data can be combined to determine the Net Ecosystem Carbon Balance.
Link to Data: https://meta.fieldsites.se/objects/rHd5M1DWZcGtyM8XWS_fqsmJ
The graph shows sub-hourly (30 mins) wind speed measured 2.2 m above the mire Mycklemossen over the year in 2021. The photo shows Mycklemossen, a pristine poor fen mire with bog characteristics and having shrub encroachment.
"Accelerating change to solve the water and sanitation crisis" is the theme for the World Water Day 2023. Within the SITES Water long-term measurement program, data on hydrological, physical, chemical, and biological parameters within lakes and streams across SITES stations is made openly available to the user community to address a broad range of scientific questions relevant to solving the water crisis.
In celebration of World Water Day, the AQUATIC data from LAKE ERKEN has been updated including quality controlled data for 2022. The data covers a broad range of data types on chemical and physical variables for the lake and the streams surrounding it. Extensive time series can be found under the following link:
METEOROLOGY
Meteorological data Malma Island
CHEMISTRY
Lake Chemistry
Stream Chemistry (Filter on all stream sampling points)
LAKE PROFILING
Lake Temperature Profiles (Filter on all water temperature profiles)
Lake YSI Profiles (Filter on all YSI profiles)
WATER BALANCE
Stream Inlet & Outlet discharge (Filter on discharge for In-&Outlet)
Lake Water Level
More data on AQUATIC BIOTA will follow soon, so keep yourself updated on the SITES Data Portal for new data uploads.
Data collected within SITES are freely available and can be used by anyone as long as the data is cited and acknowledged, following the instructions in the SITES data policy.
In March, it is still “low season” at Abisko Scientific Research Station. About ten researchers have been on-site during the winter, but the number will gradually increase during the spring. In May, larger groups will arrive as the field season begins in earnest. They will be at the station all summer, and thus it looks like it will be another intense field season.
Work is underway to replace the heating system from direct electricity to geothermal heating. In the summer, three 550-meter-deep holes will be drilled from which the energy will be taken. The goal is for all indoor work to be completed by 31 March. In total, 1,900 square meters of laboratory and office space are affected in the main building. New pipes are being laid into each space, and around 200 radiators are being installed on three floors.
At this time of year, propane and other supplies are transported by snowmobile to the five field huts; the Mire villa in Stordalen, Latnjajaure, Kärkevagge, Jieprenkiedde, and Lullihatjårro. The transports are made by snowmobile during the winter to avoid helicopter transport during the summer. Some shovelling is required to get into the cabins (as pictured).
Browning of surface water, rivers and lakes is a major problem that affects the ecosystem and the water quality. For example, increasing browning reduces biodiversity in lakes by reducing the fish population and therewith the food web. Browning also lowers the recreational value in tourism and requires higher effort to produce clean drinking water. Due to its complexity and the relatively young research field on browning in waters, the governing processes and their interrelationship are not fully understood yet. But to mitigate the effect of browning, these processes need to be understood and suitable measures needs to be taken.
Therefore, two research projects in the lake Bolmen area are ongoing. One is the FORMAS financed Blue innovation project with Lagan water council, Bolmen Research station and Lund University as partners. The second project is the EU Interreg North Sea region Blue transition project with 24 partners from 6 European countries, including the Swedish Geological Survey (SGU), Bolmen Research station/Sydvatten and Lund University. In both projects the purpose is to develop a toolbox for mitigation and verification of methods that have been tested to be efficient for reducing the browning of lakes. It is expected that these measures are transferrable to many other lake systems since the problem is widespread in Sweden as wells as in other countries.
One of the main aims is to establish a good communication channel between the property owners and stakeholders in the Lagan water region. That is done by organizing workshops, for example at Bolmen Research station, and regular reference group meetings with stakeholders. To understand the underground hydrogeological conditions and to adapt it on a large scale, geophysics in combination with other sensors and in-situ investigations will be used. That has been done already for reconnaissance purposes (photo above) to get information, for example, about the thickness of the soil layer and the depth of the bedrock (figure below). After identifying suitable test sites, a monitoring system will be setup to run over several years to investigate the influence of the browning on the hydrogeological system. Based on that, mitigation strategies and measures will be developed and tested in a latter step.
News item was written by Tina Martin - Researcher and project leader at Engineering Geology at Lund University.
Ingrid Sassenhagen has recently started as Research Engineer at SITES Erken Laboratory! Welcome to the SITES Community, Ingrid!
Ingrid is an aquatic ecologist and studies all things related to phytoplankton. During her PhD project at Lund University, she investigated dispersal patterns and local adaption in the freshwater raphidophyte Gonyostomum semen, the infamous Gubbslem. For the following postdoc positions, she moved to Texas and France, where she worked in the marine ecosystems of the Caribbean and the Southern Ocean. Back in Sweden, this time at Uppsala University, Ingrid worked again with freshwater phytoplankton and investigated fungal parasites that infect algal blooms.
She is excited about contributing to studies of plankton community responses to environmental change in the SITES AquaNet mesocosm facilities. She will help with coordinating the upcoming mesocosm experiments, which will run in parallel at SITES stations at Erken, Bolmen and Skogaryd. Ingrid will also help with the maintenance and installation of the sensors for the mesocosms, prepare materials and chemicals for the experiments, and analyze the resulting data. She is really looking forward to meeting all the other enthusiastic aquatic scientists that will be involved in the experiments. In her free time, she likes to dance salsa and swing, go swimming and sew clothes, but lately she has been spending a lot of time at various playgrounds with her toddler son.
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.
At Svartberget Research Station, within the Krycklan catchment, hydrological and biogeochemical monitoring takes place across the watershed. The highly instrumented and monitored watershed creates a field platform for ecosystem research with the possibility to study interactions within and between the different parts of the landscape. The SITES calendar post for March displays a part of the field platform; one example of the 19 total V-Notch weirs and flumes installed across the stream network. The weirs are equipped with sensors to measure, e.g. water temperature and stage height. Additionally, water samples are manually collected at the stream locations throughout the year (i.e. twice a week during spring flood, once a month during winter conditions and every second week, during the rest of the year) for biogeochemical analysis, including chemical variables within the SITES Water Thematic Program.
Link to data: https://meta.fieldsites.se/objects/FE1KELfYkAA3Ch8cGkSIGnfI
The graph displays dissolved organic carbon (DOC, top line), ammonium (NH4, middle line) and phosphate (PO4, bottom line) concentrations measured at Kallkälsbäcken stream measured throughout the year in 2021. The photo shows the V-Notch weir installation at Kallkälsbäcken.
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.
The year 2023 started with a new SITES period at Röbäcksdalen, but there are more new things happening at the station. From the first of January 2023, Röbäcksdalen SITES station is no longer managed under the department of Agricultural Research for Northern Sweden. After an organization change at SLU, the field station, which houses the majority of the SITES activities, is now part of the Department of Crop Production Science, while the dairy farm is part of the animal infrastructure at the Faculty of Veterinary Medicine and Animal Science.
The SITES activities at Röbäcksdalen are continuing as usual, and soon we will have even better possibilities to collect field data. Located in Northern Sweden, the long nights, cold weather and cloudy skies in winter at the station have presented problems for the solar panels operating the weather station and the sensors on masts. This in turn, often has resulted in data missing from November to January. However, in late November 2022, Röbäcksdalen was awarded a stipend from Kempestiftelserna to support a project to install electricity to the stations infrastructures. With this effort, starting in winter 2023-2024, hopefully the weather and spectral data sets can run without interruptions throughout the whole season.
There is a need to optimize forest management in order to contribute to climate change mitigation by enhanced ecosystem carbon storage. Rotation forestry is the most common silvicultural practice in Sweden, but there is an intense debate about its ability to contribute to long-term sequestration of carbon from the atmosphere. Due to the urgent need for nature-based climate change mitigation options, there is now considerable social and scientific interest in the use of continuous cover forestry (CCF), but its effects on carbon sequestration are largely unknown and need to be quantified urgently. Ongoing and future forestry projects are taking place at the Central Forest at Skogaryd Research Catchment (SRC) to address these unknowns.
Already this winter at SRC, a 60-year-old Norway spruce forest has seen some harvest activities, including different management techniques; clearcutting (Rotation forestry- RF), diameter-limit cutting (CCF) and unharvested with extended rotation length.
A new Formas financed project will make use of the harvested activities at SRC to study the effect of CCF on carbon fluxes and sequestration, compared to RF, by use of novel methodologies based on sap flux (trees’ water transport) and phloem stable isotopes. The goal is to determine whether, and by how much, carbon uptake capacity is sacrificed as forests grow older and if a selectively cut forest can compensate for the carbon stock lost following clearcutting by increased growth and, if so, how. The novel methodology will be compared to the time-tested eddy covariance method. Both methods estimate forest carbon uptake in photosynthesis, but the isotopic method also allows for determining how individual uncut trees respond to the selection cutting. This project will support rigorous, objective analyses of one of the most compelling social issues in Scandinavia: what is to be done with the forests?
With this project forestry professionals, private forest owners, policymakers and the public will be provided with information regarding the impacts of different forest management strategies on the productivity and carbon sequestration of forests. Ultimately, this could contribute to the formulation of new ecological and economic goals, management plans and policies that guide the future use of the Swedish forests.
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.
During the month of January most of Sweden is snow and ice-covered, although the duration and intensity of snow and ice has been declining over time due to ongoing climate change. The SITES calendar post for January displays this trend, as ice cover duration on Lake Erken over the past 80 years has been declining. At Erken Laboratory, visual observations of Lake Erken’s ice cover began in the 1940s and continues today, now with the assistance of a monitoring camera on Malma Island. This long-term ice-covered record is one of the most comprehensive in the world.
Link to data: https://meta.fieldsites.se/objects/QLqXw2wkqxXrr0ahsxeQaWbp
The graph displays the total number of lake ice cover days, i.e. days between the start of continuous ice coverage (> 75% of lake surface ice-covered) and the ice break-up of the observed lake area, over time on Lake Erken between 1941 to 2021. The photo shows Malma Island, where the lake monitoring camera as well as other monitoring sensors are located, and with the Erken Laboratroy in the very background.
On January 1 the SITES community not only welcomed in the New Year, but also a new, six-year funding period (2023-2028). By the time we gather for the SITES III Kick-off meeting Feb 8‑10 at Asa Station, the incoming SITES Director, Kevin Bishop, will have visited all SITES stations and the Thematic Programs. He is looking forward to kicking-off SITES III this year:
“Getting to know this infrastructure during my three months of “inskolning” has been an eye-opener to the amazing infrastructure built up during the first decade of SITES existence. Now, with a period of stable funding ahead, SITES can focus on what it is we are here for, providing scientists with access to well documented field sites where they have superb opportunities for doing excellent ecosystem research. I am looking forward to the meeting with many of you in Asa and working together to refine the plans for the coming years of SITES.”
- Kevin Bishop (SITES incoming Director)
2023
At the Gothenburg university research infrastructure, Skogaryd Research Catchment (SRC), not only is research conducted but also education. Every year different courses from environmental and Earth science programs, from University of Gothenburg and other universities, visit SRC for one or several days.

This week, the first-year students of the Environmental Science program visited SRC, as part of their base course in Environmental Sciences. They learned about the different ecosystems within the catchment, how greenhouse gases are measured by different methods and about the SITES Water program at the station. One topic that was discussed is how the lateral export of carbon contributes to the understanding the carbon sink-source strength of ecosystems and its importance for the landscape carbon balance.

An important part of science education is field work. Therefore, the students visited two of the research locations at SRC to see instrumentation and the large-scale experiments conducted. At Följemaden, the students were shown the rewetting of a peatland, that has been drained and under agricultural and forest management for 150 years. Among the topics discussed was, can we turn a greenhouse gas source back into a sink? At the central forest area, the students looked at the selectively harvested stand, which is comparing a clearcut and a stand with an extended rotation period. The students discussed, how does the carbon and greenhouse gas balance differ between the management options? The discussion also touched on more general questions regarding forests and forest management. As always, students were curious and had valuable question, stimulating a lively discussion.
Several inflows to Lake Bolmen are of interest to study to understand the brownification of the lake. The inflow river, Ryds Å, entering the lake south east of Bolmen, flows through an old peatland, Äspenäs. The peatland is thought to have an impact on the color of the water. There is no previous data on the brownification of Ryds Å, nor about its contribution of brown-colored water to the lake. In general, the available data on the hydrology of the river and its catchment are very sparse. It is therefore necessary to acquire such data to analyze how the peat area is affecting Ryds Å, its contribution to brownification in the lake, and the relationship between them.

This fall, two Master students in Environmental Engineering at Lund University, Emelie Ström and Frida Karlsson Öhman, will look further into this topic. The aim of their Master thesis is to quantify the brownification of Ryds Å. Further relevant parameters concerning the water quality in Ryds Å, such as pH, temperature, turbulence and chlorophyll, will also be quantified. The project will thereby consist of field work, including taking water samples and making a flow analysis, and laboratory work at the research station SITES Bolmen. The laboratory work includes filtration and spectrophotometry.
Emelie and Frida started their field work this week at Bolmen Research Station, and will continue there the next four weeks. They are in guidance of their assistant supervisor, Clemens Klante, Research Manager at SITES Bolmen Research Station, and their supervisor at Lund University, Professor Magnus Larson.
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.
SITES has three Thematic Programs that strengthen the collaboration within the network of stations in remote sensing, water monitoring and aquatic mesocosms. The Thematic Programs facilitate comparison between climate zones, landscape elements and management systems and offer open data from long-term monitoring and experimental installations.
This month the SITES AquaNet Thematic Program is featured, a standardized and open infrastructure to run mesocosm experiments across five SITES lakes spread across Sweden. The mesocosm enclosures are equipped with sensors and a data logging system as well as greenhouse gas chambers to measure environmental parameters in real-time (as seen in the image below for the mesocosm enclosure at Lake Erken). In addition to having access to the mesocosm equipment, SITES AquaNet also offers users technical support from qualified station personnel to run mesocosm experiments, established protocols to standardize both field and laboratory work and open access to data from previous AquaNet experiments as well as time series data in the lake and connecting stream(s) measured in the SITES Water monitoring program.
Link to Data: https://meta.fieldsites.se/objects/cX_V_MJ05R_QU1pnyzqEKqt9
In 2017, SITES AquaNet conducted a pilot experiment across the five AquaNet lakes. The experimental tests investigated the interactive effects of bottom-up (a reduction in light availability) and top-down (fish predation) disturbances on the stability of plankton community composition (bacterio-, phyto- and zoo-plankton) and ecosystem functioning. The graph shows sub-hourly oxygen data generated from sensors in the Lake Erken mesocosm experiment run in 2017, aggregated for the four treatments applied to the experiment (Control, Light, Fish, Light & Fish).
The results from the 2017 experiments at all SITES AquaNet stations are available as a data collection on the SITES Data Portal and published in Urrutia-Cordero et al. 2021.
This summer, drone flights were carried out by SITES Spectral over the Följemaden area in Skogaryd. The Följemaden area is part of a re-wetting experiment to investigate measures to reduce greenhouse gas emissions caused by soil drainage. The experiment was reported in a previous SITES news item. Starting this year, the area is part of a SITES Spectral monitoring area, and will be monitored by fixed spectral sensors, a phenological camera, and annual drone flights.
This summer, José Beltran (Lund University) carried out aerial mapping over the Följemaden area, covering 63 ha with the drone flying at 50 m altitude. Successful drone flights were also conducted at the Myckelmossen mire site and at the central forest in Skogaryd. SITES Skogaryd staff, Per Weslien and David Allbrand, are responsible for all the installations and maintenance of the instruments at the diverse Skogaryd catchment area in SITES, providing invaluable data to answer a range of questions related to ecosystem dynamics in a changing climate. The new SITES Spectral data from the Följemaden area, including processed data from the 2023 flights and the fixed sensors, will be made openly available through the SITES Data Portal.
On August 8th an Eddy Covariance (EC) flux tower was installed at Röbäcksdalen. This pilot project is a collaboration between Röbäcksdalen and Svartberget SITES stations, where the latter provides the tower, which is led by Matthias Peichl at the Department of Forest Ecology Management at SLU in Umeå. The location of the EC flux tower is on one of the larger fields at Röbäcksdalen station and is conveniently located near one of the SITES Spectral mast and between two of the sampling points in SITES Water. The land is used for feed production by the dairy farm operated by the Faculty of Veterinary Medicine and Animal Science at SLU, which is included in SITES Röbäcksdalen.
This is the first flux tower located in an agricultural system of the Boreal region in northern Sweden. Thus, it will deliver unique data that is expected to provide novel insights into how the carbon dioxide (CO2) ecosystem balance and water flux (e.g. evapotranspiration) vary during crop rotations on dairy farms and, on a more long-term basis, how climate change, and in particular warmer winters, will affect the carbon and water cycle of agricultural fields in the far north. This installment will provide unique complementary data to the measurements made within the SITES Water and SITES Spectral Thematic Programs, and is also the northernmost installment of an EC flux tower on agricultural lands in Sweden.
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.
SITES has three Thematic Programs that strengthen the collaboration within the network of stations in remote sensing, water monitoring and aquatic mesocosms. The Thematic Programs facilitate comparison between climate zones, landscape elements and management systems and offer open data from long-term monitoring and experimental installations.
This month the SITES Spectral Thematic Program is featured, an infrastructure for collecting spectral data for ecosystem measurements over terrestrial environments to a varying extends at all SITES stations. SITES Spectral data covers small to local scales by using fixed multispectral sensors mounted on masts or towers, phenologycal cameras and multispectral sensors mounted on Umanned Aerial Vehicles (UAVs). UAV drones are flown over targeted areas at the SITES stations at least once per year during the peak of the active growing season. The UVAs are equipped with a multispectral sensor, a red-green-blue (RGB) camera and a thermal camera. Together, the equipment on the UAVs capture images in the visible and near-infrared wavelength. After the UAV flights are completed, spectral data are processed centrally by the SITES Spectral Thematic Program, resulting in data products, including orthomosaics, digital elevation models and point clouds over the UAV flight path. Data products from SITES Spectral are openly available for download on the SITES Data Portal.
The image below is from the SITES Spectral data products at Lönnstorp station.
The image shows an examples of processed UAV data from a flight over agricultural fields at Lönnstorp in 2020. The data products include a RGB orthomosaic (left), a false color composite of multispectral orthomosaic (center), and a radiometrically calibrated vegetation index (right).
The joint AquaNet and AQUACOSM-plus experiments at SITES Asa and Svartberget have been running for about a month now (details about the project start are reported here). Preliminarily results from the experiments (graph below) show the difference in specific conductivity (a proxy for salinity) across the three different treatments; 1) Control, where no salt is added, 2) Gradual, where small amounts of salt are added in increments over time and 3) Extreme, where a large amount of salt is added once at the start of the experiment. Data from automatic in situ sensors in each mesocosm and manual samples throughout the experiment will be assessed to see how different salinity disturbance regimes impact the function and composition of biological communities.
The participants at the two stations have been busy maintaining and sampling the mesocosm experiments, learning from and collaborating with participants from different countries, while at the same time enjoy the Swedish summer.
At Asa, the core team is comprised of Guangbin Gao (Sweden), Andrra Zhjeqi (Sweden), Judit Rodrigo (Spain), with Pablo Urrutia Cordero (Spain), Jana Isanta-Navarro (Sweden), Jing Li (Sweden) and Pepe Rodriguez (Canada) also participating in the experiment for several weeks. Niels Aagaard Jakobsen (Research Engineer at Asa Station) led setting-up the mesocosm infrastructure at the station, while Silke Langenheder (SITES AquaNet Lead) and Wilhelm Lönnqvist (Asa Station Manager) supported the experiment set-up and preparations.
When asked about his experience at Asa station so far, Guangbin Gao stated, “I am very lucky and pleased to participate in the AquaNet experiment at Asa. It is a complete system of ecological experiments. Here, through the application of high-frequency sensors and daily sampling, I learned how to build and operate the mesocosm facility. Of course, there is a great opportunity to communicate and collaborate with researchers from different countries.”
At Svartbergt, the core team is comprised of Erin Ford (Canada), Mary Mullins (USA) and Anusha Singh (Czech Republic), with support at the start of the experiment from Aidan Guttormson (Canada) and Shelley Arnott (Canada). In addition, SITES AquaNet staff (Ingrid Sassenhagen, William Colom Montero) and Svartberget Station staff (Johan Westin, Johannes Tiwari and Viktor Boström) helped with the set-up and preparation for the experiment at the station.
On behalf of the team at Svartberget, Mary Mullins, summarized the experience, “Here at the Svartberget station in Vindeln, we have been busy honing our field and lab skills in limnology! From collecting plankton samples to analyzing the water chemistry of the mesocosms, we are determined to discover the impacts of salinity on this unique ecosystem. Living at the station surrounded by nature has been just as wonderful as exploring the nearby towns and making friends during Midsummer Celebration.”
With only a few weeks left in the experiment, there are only a few salt additions and samplings left, and then it is time to clean and store the AquaNet mesocosms for future experiments. Once the teams are back at their home institutions and have had time to recover, it is on to the analysis and results. So stay tuned!
Wildlife cameras have received a lot of attention in the last decade, and many research projects and practical applications using camera traps are now running. Cameras are surrounded by high hopes that these methods will make various wildlife surveys more effective, for example, since they may replace some time consuming field work. A scientifically proper use of camera trap data may, however, be tricky, and the topic constitutes a research field in itself. Studied issues may, for example, concern which sampling design (distribution of cameras, set up at each plot etc.) to apply and which picture statistics are actually relevant for a given research question.

Some of these questions are now studied at Grimsö in a joint SITES and FoMA project. The project uses data from the SITES camera survey (32 cameras in a regular grid in the research area) in combination with another type of camera set up at the same plot. The study focuses on the importance of camera position and will try to quantify the differences (number of photos, which species appear, etc.) resulting from varying set ups. The camera trap data will also be used to evaluate an artificial intelligence software for automatic species recognition in pictures via comparisons to interpretations made by experienced wildlife ecologists. The automatic process is usually fast, but its precision is still being discussed.
SITES offers good possibilities for various method evaluation studies as well as for projects searching for biological data, since numerous datasets are freely available. For onsite studies or experiments at Grimsö, via SITES, external projects may also receive support with fieldwork, checking equipment, etc.
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.
Bolmen Research Station, is an associated station to SITES AquaNet – an associated station benefits from SITES coordinated activities, in this case SITES AquaNet, and has access to SITES network and knowledge and the ability to mobilize and openly share station data via the SITES Data Portal. Bolmen Research Station is located in Tiraholm, by Lake Bolmen in Hylte municipality. The research at the station primarily focuses on environmental monitoring, fish conservation and management, water conservation and the effects of climate change on freshwater ecosystems.
Bolmen has participated in several SITES AquaNet experiments, including the first pilot experiment in 2017. This month, data from the 2017 AquaNet pilot experiment at Bolmen is featured. The experiment investigated the interactive effects of bottom-up (a reduction in light availability) and top-down (fish predation) disturbances on the stability of plankton community composition (bacterio-, phyto- and zoo-plankton) and ecosystem functioning. The experiments consisted of a fourfold replication of a full-factorial design with no disturbance (control), light reduction as a press disturbance (constant), fish predation as a pulse disturbance (temporary) and press and pulse disturbances combined. Each mesocosm enclosure was equipped with sensors and data logging system to measure in real-time environmental parameters, such as dissolved oxygen, temperature, photosynthetic active radiation, Chlorophyll a (as seen below), phycocyanin and turbidity.
Link to Data: https://meta.fieldsites.se/objects/fFHR9J_5xa-Bm2bxm0gz1J2E
The results from the 2017 experiments at all SITES AquaNet stations are available as a data collection on the SITES Data Portal and published in Urrutia-Cordero et al. 2021.
The graph shows sub-hourly Chlorophyll a data, from the mesocosm experiment run in 2017 at Lake Bolmen, aggregated for the four treatments applied to the experiment (Control, Light, Fish, Light & Fish). As evident in the graph, Chlorophyll a concentration fluctuated over time with differences in responses between the four treatments. The photo displays the AquaNet platform and mesocosm enclosures on Lake Bolmen, where each mesocosm is equipped with sensors, all connected to a central data logging system.
At Stordalen, a replanted clear-cut site within the SITES station Skogaryd Research Catchment, a new 16 m high tower has been installed for continues monitoring of greenhouse gas emissions. The tower overlooks a young plantation forest, replacing a smaller tower that has been outgrown by the trees. At Stordalen, researchers from Lund university are measuring the net ecosystem exchange (NEE) of carbon dioxide (CO2) at a clear-cut forest site using the time-tested Eddy Covariance (EC) method. The measurements started in 2012 directly following clear-cutting and have been running continuously since then. As the vegetation grows taller, the tower must be raised for continuous measurements above tree canopy. The tower was already raised in 2015 and now it is time for an even taller tower.
Forests can play an important role in climate change mitigation, as they store huge amounts of carbon in their biomass and soil and thus, can be a sink for atmospheric CO2. Rotation forestry, with clear-cutting and replanting, is the most common silvicultural practice in Sweden, but there is an intense debate about its role in climate mitigation and its ability to contribute to long-term sequestration of carbon from the atmosphere. The clear-cutting at the end of the rotation period causes large emissions of CO2 for several years, as the soil respiration from decomposition of organic matter in the soil exceeds the CO2 uptake by the seedings/young trees. Eventually, the increasing tree growth will return the forest to being a CO2 sink, but many uncertainties remain regarding the recovery time of the carbon balance after clear-cutting. It is crucial to better understand which factors influence the time it takes until the CO2 uptake by photosynthesis equals the emissions by respiration (point of carbon balance) on an annual scale and what additional time is needed before the initial carbon losses are compensated for (carbon compensation point).
Preliminary results for the first decade after clear-cutting, indicate that Stordalen is a large CO2 source to the atmosphere, and has not yet reached the point of carbon balance on an annual basis. Since Stordalen has moist soil conditions, a large fraction of birch trees has been left at the site to help promote the growth of the planted spruce trees. These birches have been partially removed on several occasions. This complicates the data interpretation, and it is important to account for these harvesting operations when assessing the recovery time of the carbon fluxes at Stordalen. Ultimately, the measurements at Stordalen might contribute to the formulation of new ecological and economic goals, management plans and policies that guide the future use of the Swedish forests.
The next round of the joint AquaNet and AQUACOSM-plus experiments are kicking-off! This time around the experiments will take place at Asa Research Station and Svartberget Research Station with a focus on functional and compositional consequences of different salinity disturbance regimes on plankton communities. The experiment is a follow up to the GLEON Salt experiment in 2018 and will run from mid-June to the end of July.
Through AQUACOSM-Plus, international project participants are supported through Transnational Access (TA) to travel to and carry out the experiment at the SITES AquaNet mesocosm facilities. SITES staff support in the preparation of the experiment and AquaNet platform set up; this includes connecting many small wires to a data logging system so that each mesocosm is equipped with high frequency sensors measuring, e.g., dissolved oxygen, temperature, photosynthetic active radiation, chlorophyll, phycocyanin and turbidity.
On June 12, 2023, the TA participants and SITES staff met at SITES Erken Laboratory to officially kick-off the experiments. The group discussed the experimental set up details and got hands-on training of the sampling scheme, using the AquaNet platform on Lake Erken as a test case. This week the group will separate into two cohorts; one group travels south to Asa Research Station, while the other travels north to Svartberget Research Station.
The mesocosm experiments will be identically run at the two stations, which are both located in forested catchments. The contrast between geographical location (57.17N and 64.26 N), lake area (0.52 km2 and 0.04km2) and trophic status (Oligratrophic and Mesotrophic), respectively for Feresjön at Asa and Stortjärn at Svaretberget, will provide an interesting comparison for the study.
The Abisko Scientific Research Station field season started in earnest on June 1st. The station will be fully occupied in July, and the occupancy will remain high even in August and September. The ten-bed field hut in Latnjajaure will have researchers on-site throughout the summer.
The Director of the Swedish Polar Research Secretariat, Katarina Gårdfeldt, and parts of the government agency's advisory council recently visited the station. They also went to the Stordalen mire area near Torneträsk, about ten kilometres from Abisko. They were shown around and informed about ongoing continuous measurements, such as greenhouse gases, and current research projects.
Alisa Heuchel started as the new laboratory manager at the Abisko Scientific Research Station in May. In September, Alisa Heuchel will defend her thesis in forest genetics. Although her job at the station will involve different tasks, she will bring many experiences from her PhD studies, including laboratory work. Read an interview with Alisa here.

Within SITES Water, the raft on Lake Almbergasjön was towed out and installed. The lake is located approximately 14 kilometres east of Abisko, and the raft measures temperatures at 24 different depths in the water column, as well as oxygen levels and conductivity. A station on the shore complements the measurements that collect data on wind direction, wind speed, air pressure, temperature, relative humidity, net shortwave and longwave radiation, and the water level in the lake.
Abisko Scientific Research Station has resumed pollen monitoring and is now part of the nationwide pollen surveillance. This means pollen is collected on-site and sent to the Environmental Archaeology Lab at Umeå University for analysis.
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.
SITES has three Thematic Programs that strengthen the collaboration within the network of stations in remote sensing, water monitoring and aquatic mesocosms. The Thematic Programs facilitate comparison between climate zones, landscape elements and management systems and offer open data from long-term monitoring and experimental installations.
This month the SITES Water Thematic Program is featured, which builds a unique long-term and well-coordinated measurement program where hydrological, physical, chemical, and biological parameters within lakes and streams are measured at seven SITES stations. As part of SITES Water, lake platforms are equipped with automated high frequency sensors that measures weather and climate variables above the lake (e.g. air temperature, humidity, wind speed) as well as physical variables within the lake (e.g. temperature, oxygen). The lake water temperature is measured at different depths, i.e. lake profile, which allows for the thermal structure of the lake over the year to be determined. The thermal structure of a lake plays an important role in the biogeochemical cycling and subsequent greenhouse gas emissions from the lake.
Link to Data: https://meta.fieldsites.se/objects/iHSmt3sLan6AhIm_DO5tV1h6
The graph shows sub-hourly water temperature at different depths in lake Erssjön over the year in 2020. Early in the year, the water temperature at different depths in the lake was similar but as air temperatures warmed in the spring, a thermal stratification formed, where the warm surface water of the lake disconnected from the cooler bottom water. As the air temperatures cooled in the fall, the lake mixed and the water temperatures in the lake at different depths became similar again. The photo shows the lake platform on Erssjön, which is equipped with meteorological sensors above the lake and in situ aquatic sensors below the lake.
On April 24-25, 2023, fourteen researchers, PhD and Master students gathered at Lake Bolmen to start up the international research collaboration within the EU network AQUACOSM-plus and the national infrastructure SITES AquaNet. The study will use mesocosms to investigate how lake ecosystems are affected by browning and eutrophication. The research project is taking place simultaneously at three locations in Sweden, and Bolmen Research Station was the first to go.
The group included Silke Langenheder – SITES Erken Laboratory and AquaNet coordinator, Ingrid Sassenhage – SITES Erken Laboratory, Antonia Liess – Halmstad University, Johanna Sjöstedt – Lund University, Nusret Karakaya - Bolu Abant Izzet Baysal University, Anna Lupon– CEAB-CSIC, Susana Bernal – CEAB-CSIC, Inge Elfferich – Cardiff University, Antonija Kulaš – University of Zagreb, Kadir Yıldız – Bolu Abant Izzet Baysal University, Kevin Jones – Lund University, Eline van Dam – Lund University, Franka Hemme – Lund University and Juha Rankinen – Bolmen Research Station. At a later date Eugènia Martí – CEAB-CSIC and Nuria Carabal de Antonio - Universidad de Valencia will join the Bolmen team.

- ”This is a very exciting and important research project where we collect data from several locations in Sweden to try to figure out how the transport of nutrients and organic matter connected to different run-off scenarios may affect lake ecosystems and their water quality. Bolmen Research Station is first out and later in the the week we start the experiment in Skogaryd outside Gothenburg and the following week in lake Erken outside Uppsala”, explains Silke Langenheder, Professor in Limnology at Uppsala University and coordinator for SITES AquaNet in Sweden.
The researchers will use the mesocosm infrastrucutre to study how greenhouse gases, bacteria, algae and zooplankton in the lake are affected by increased brownification and eutrophication. The mesocosms (large floating containers) are placed in a floating platform on the lake and filled with lake water, which means that they have the naturally occurring ecosystem and the water chemistry that exists today.
- ”Climate change, variations in precipitation and how we use the land around the lake affect both the quantity and quality of the lake water, and by studying various factors that affect our lakes, we can prepare for the challenges of the future”, says Juha Rankinen, Station Manager at Bolmen Research Station.
Lake Bolmen is the most important source for drinking water production in south-western Sweden and both the quantity and the quality of water are topics that are becoming more and more relevant, both nationally and internationally. In the last two IPCC reports, water is highlighted as the central part of the climate change and mitigation measures.
- ”The experiment will last for six weeks and we will have five PhD/Master students placed at Bolmen to be able to take samples and analyze them daily. All the data we collect is then reported to SITES AquaNet and thus gives researchers throughout the world the opportunity to work with it. This collaboration between the research stations provides incredible advantages and opportunities for researchers and universities to take big steps forward”, continues Juha.
This news item was adapted from the original article in Swedish:
https://forskningsstationbolmen.se/uppstart-av-aquacosm-pa-forskningsstation-bolmen/
Youtube clip of experiment at Bolmen: https://youtu.be/PZBvv4S_g50
Linda Groot Nibbelink has recently started as Field technician at SITES Lönnstorp research station! Welcome to the SITES Community, Linda!
To get to know Linda, we asked for her to introduce herself to the SITES Community:
Hi! My name is Linda Groot Nibbelink. I grew up in Goes, a rural town in the Rhine delta in the Netherlands. I studied International Land and Water Management at Wageningen University & Research and Organic Agriculture & Agroecology at BOKU in Vienna, Austria and at University of Hohenheim, Germany.
Besides theoretical knowledge of agriculture, I gained practical experience by working and volunteering at organic, biodynamic and conventional fruit orchards, horticultural farms and dairy farms in Europe. Last year I did a full season internship at a plant breeding institute in Switzerland, where I worked with developing new pea varieties. After several years of moving around the continent, I decided to settle down with my partner in Lund.
At SITES Lönnstorp Research Station, my role will be to perform measurements and assessments in the experiments at the station. I will also be involved with data handling, management of experiments and taking care of samples that are collected.
What I love about working at Lönnstorp is that it allows me to combine working with my hands and with my mind. At the same time, it gives me the opportunity to learn the specifics of agriculture in Sweden and gain practical experience with field experiments.
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.
Wildlife monitoring is an important part of the activities at Grimsö Wildlife Research Station. A large part of the monitoring was initiated during the 1970’s, but new data series have been added over time as methods have developed. The continuous surveys focus on topics such as population dynamics, reproduction, life history traits and body measurements and include monitoring of, e.g., moose, roe deer, red fox, voles and starlings. For example, red fox (Vulpes vulpes) reproduction has been monitored since 1973 by identifying fox litters. Around 200 fox dens are checked annually within the Grimsö Wildlife Research Area and the dens with observed reproduction are summed to mirror the total number of fox litters for that year. The variation in the local fox abundance is related to the vole population cycle and is a key factor for the dynamics of several small mammal populations across Scandinavia.
Link to Data: https://meta.fieldsites.se/objects/09RC_nAwv6h0wauAY8dwFHR_
The graph shows the number of fox litters at Grimsö between 1973-2021, with variations over time mainly related to vole cycles. The extra low numbers in 1985-1986 were due to an outbreak of scabies (sarcoptic mange) that regulated fox populations more or less throughout Sweden during the late 1980's and into the 1990's.
Over the past few months, the SITES Water Thematic Program and the associated openly available data, has been featured in several events.
In December, Marcus Wallin (SITES Water Thematic Program Lead) presented a poster about SITES Water at the Hydrology Days 2022, hosted by Svenska hydrologiska rådet SHR. The theme of the event was "Freshwater: from source to sea", covering the broad spectrum of water from bio(eco)logical, physical and chemical, and society. The meeting took place in person this year at SLU Uppsala, after two years of being online, and offered a great opportunity for SITES Water to connect to academic researchers beyond SLU, including Uppsala University, Stockholm University, KTH, as well as to institutes and companies, including Swedish Environmental Research Institute, Tyréns AB and SMHI.

On the 2nd of March, an all day seminar titled, Hur beräknar vi Sveriges växthusgasbalans i skog, mark och vatten? - Nuvarande klimatrapportering och framtida möjligheter. (Translating to, How do we calculate Sweden’s greenhouse gas balance in forest, land and water – current climate reporting and future opportunities) brought together researchers and different stakeholders, e.g. governmental authorities, municipalities, private companies with interest in Sweden’s greenhouse gas balance. The focus was on the Land use, Land use change and Forestry sector, and how the national greenhouse gas balance is reported. The seminar also included presentations concerning greenhouse gas fluxes that are not covered in the national reporting and development of new measurement and modelling methods. Several SITES researchers as well as SITES collaborator, ICOS, presented during the seminar. It was obvious after the day that data generated within SITES are essential for improving our understanding of Sweden’s greenhouse gas balance.
Later in March (the 20th and 22nd), the third internal water seminar series at SLU took place. SLU has a strong and broad expertise on water, but is spread out across different faculties, departments and campuses and thus, the water seminar series is an opportunity to connect water research at SLU as a whole. This year’s program focused on early career scholars, where Blaize Denfeld (SITES Deputy Director) presented SITES Water in the context of her PhD and PostDoc research at multiple SITES Stations including Erken, Svartberget, Skogaryd and Röbäcksdalen.
Major efforts have been made lately among SITES stations and by the Secretariat to upload data generated within the SITES Water program to the SITES Data Portal. These data include meteorology, water chemistry from lakes and streams, lake temperature and oxygen profiles, lake water level and stream discharge. The SITES Water data is now openly available on the SITES Data Portal and more will be uploaded soon.
A handful of the external research projects at Grimsö focus on large scale evaluations of practical techniques to manage wildlife-traffic problems. These projects are led by Grimsö but conducted in collaboration with several national and international stakeholders, including, e.g. the Swedish Transport Administration (Trafikverket), Interreg Sweden-Norway and the Norwegian BaneNOR. Many issues concerning wildlife and traffic are complex but with growing importance in the last decades, both due to denser populations of large mammals and continued increase in traffic volumes. More information about the projects and innovative solutions to reduce wildlife collisions in traffic can be found at Om projektet – Vilt och Trafik.

One of the current projects, “Viltvarning vid järnväg” (translating to “Wildlife warning near railroads”), focuses on identifying techniques to scare animals away from railroad areas using sounds. This is being explored as an alternative to exclusion fences and wildlife passages, as it has the potential to be a more flexible and less expensive solution. One design being tested is called a MASS unit (Movement Activated Scaring System) and uses infrared (IR) sensors to detect movements, which in turn activate speakers that send out various sounds (horns, voices etc.) at a high volume (>70 dB) to scare away animals.

This type of camera monitoring results in massive amounts of pictures, by far exceeding what can be handled and analyzed manually. Several automatic solutions, e.g. software & artificial intelligence (AI), for this are nowadays under test, where one tricky part is to obtain reliable and accurate identifications of species in the pictures. Depending on the position of the animal this may be more or less problematic, and in some situations impossible to achieve proper identifications. A separate part of the mentioned projects is to test software based on a machine learning processes using several different pictures of known animals, that vary in position, distance from the camera, etc. The raw data from the picture analysis shows a probability measure for which species are shown. At present, a cut off-level is often applied for an acceptable level of identification (e.g. 90%, but varies due to study aims). After removal of potential pictures showing humans, the raw data gets stored on a common platform between the Swedish Transport Administration and the project, where then AI is used to classify animals to species.
The collaborative work in this project among authorities, consultants and researchers, combined with the scientific evaluation of the methods tested, is a good example of how SITES stations can be utilized broadly.
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.
At Skogaryd Research Catchment, the mire Mycklemossen is equipped with an automatic weather station, which provides high-frequency meteorological data. This includes air temperature, relative humidity, air pressure, wind speed and direction, incoming and outgoing shortwave radiation, incoming and outgoing longwave radiation, net radiation, albedo and precipitation. Below the mast, snow and water depth as well as soil temperature and soil heat flux is measured. In addition to SITES, ICOS-Sweden and other research projects include greenhouse gas flux measurements, stream flow and chemical analyses at the mire Mycklemossen, making it one of a few mire sites where data can be combined to determine the Net Ecosystem Carbon Balance.
Link to Data: https://meta.fieldsites.se/objects/rHd5M1DWZcGtyM8XWS_fqsmJ
The graph shows sub-hourly (30 mins) wind speed measured 2.2 m above the mire Mycklemossen over the year in 2021. The photo shows Mycklemossen, a pristine poor fen mire with bog characteristics and having shrub encroachment.
"Accelerating change to solve the water and sanitation crisis" is the theme for the World Water Day 2023. Within the SITES Water long-term measurement program, data on hydrological, physical, chemical, and biological parameters within lakes and streams across SITES stations is made openly available to the user community to address a broad range of scientific questions relevant to solving the water crisis.
In celebration of World Water Day, the AQUATIC data from LAKE ERKEN has been updated including quality controlled data for 2022. The data covers a broad range of data types on chemical and physical variables for the lake and the streams surrounding it. Extensive time series can be found under the following link:
METEOROLOGY
Meteorological data Malma Island
CHEMISTRY
Lake Chemistry
Stream Chemistry (Filter on all stream sampling points)
LAKE PROFILING
Lake Temperature Profiles (Filter on all water temperature profiles)
Lake YSI Profiles (Filter on all YSI profiles)
WATER BALANCE
Stream Inlet & Outlet discharge (Filter on discharge for In-&Outlet)
Lake Water Level
More data on AQUATIC BIOTA will follow soon, so keep yourself updated on the SITES Data Portal for new data uploads.
Data collected within SITES are freely available and can be used by anyone as long as the data is cited and acknowledged, following the instructions in the SITES data policy.
In March, it is still “low season” at Abisko Scientific Research Station. About ten researchers have been on-site during the winter, but the number will gradually increase during the spring. In May, larger groups will arrive as the field season begins in earnest. They will be at the station all summer, and thus it looks like it will be another intense field season.
Work is underway to replace the heating system from direct electricity to geothermal heating. In the summer, three 550-meter-deep holes will be drilled from which the energy will be taken. The goal is for all indoor work to be completed by 31 March. In total, 1,900 square meters of laboratory and office space are affected in the main building. New pipes are being laid into each space, and around 200 radiators are being installed on three floors.
At this time of year, propane and other supplies are transported by snowmobile to the five field huts; the Mire villa in Stordalen, Latnjajaure, Kärkevagge, Jieprenkiedde, and Lullihatjårro. The transports are made by snowmobile during the winter to avoid helicopter transport during the summer. Some shovelling is required to get into the cabins (as pictured).
Browning of surface water, rivers and lakes is a major problem that affects the ecosystem and the water quality. For example, increasing browning reduces biodiversity in lakes by reducing the fish population and therewith the food web. Browning also lowers the recreational value in tourism and requires higher effort to produce clean drinking water. Due to its complexity and the relatively young research field on browning in waters, the governing processes and their interrelationship are not fully understood yet. But to mitigate the effect of browning, these processes need to be understood and suitable measures needs to be taken.
Therefore, two research projects in the lake Bolmen area are ongoing. One is the FORMAS financed Blue innovation project with Lagan water council, Bolmen Research station and Lund University as partners. The second project is the EU Interreg North Sea region Blue transition project with 24 partners from 6 European countries, including the Swedish Geological Survey (SGU), Bolmen Research station/Sydvatten and Lund University. In both projects the purpose is to develop a toolbox for mitigation and verification of methods that have been tested to be efficient for reducing the browning of lakes. It is expected that these measures are transferrable to many other lake systems since the problem is widespread in Sweden as wells as in other countries.
One of the main aims is to establish a good communication channel between the property owners and stakeholders in the Lagan water region. That is done by organizing workshops, for example at Bolmen Research station, and regular reference group meetings with stakeholders. To understand the underground hydrogeological conditions and to adapt it on a large scale, geophysics in combination with other sensors and in-situ investigations will be used. That has been done already for reconnaissance purposes (photo above) to get information, for example, about the thickness of the soil layer and the depth of the bedrock (figure below). After identifying suitable test sites, a monitoring system will be setup to run over several years to investigate the influence of the browning on the hydrogeological system. Based on that, mitigation strategies and measures will be developed and tested in a latter step.
News item was written by Tina Martin - Researcher and project leader at Engineering Geology at Lund University.
Ingrid Sassenhagen has recently started as Research Engineer at SITES Erken Laboratory! Welcome to the SITES Community, Ingrid!
Ingrid is an aquatic ecologist and studies all things related to phytoplankton. During her PhD project at Lund University, she investigated dispersal patterns and local adaption in the freshwater raphidophyte Gonyostomum semen, the infamous Gubbslem. For the following postdoc positions, she moved to Texas and France, where she worked in the marine ecosystems of the Caribbean and the Southern Ocean. Back in Sweden, this time at Uppsala University, Ingrid worked again with freshwater phytoplankton and investigated fungal parasites that infect algal blooms.
She is excited about contributing to studies of plankton community responses to environmental change in the SITES AquaNet mesocosm facilities. She will help with coordinating the upcoming mesocosm experiments, which will run in parallel at SITES stations at Erken, Bolmen and Skogaryd. Ingrid will also help with the maintenance and installation of the sensors for the mesocosms, prepare materials and chemicals for the experiments, and analyze the resulting data. She is really looking forward to meeting all the other enthusiastic aquatic scientists that will be involved in the experiments. In her free time, she likes to dance salsa and swing, go swimming and sew clothes, but lately she has been spending a lot of time at various playgrounds with her toddler son.
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.
At Svartberget Research Station, within the Krycklan catchment, hydrological and biogeochemical monitoring takes place across the watershed. The highly instrumented and monitored watershed creates a field platform for ecosystem research with the possibility to study interactions within and between the different parts of the landscape. The SITES calendar post for March displays a part of the field platform; one example of the 19 total V-Notch weirs and flumes installed across the stream network. The weirs are equipped with sensors to measure, e.g. water temperature and stage height. Additionally, water samples are manually collected at the stream locations throughout the year (i.e. twice a week during spring flood, once a month during winter conditions and every second week, during the rest of the year) for biogeochemical analysis, including chemical variables within the SITES Water Thematic Program.
Link to data: https://meta.fieldsites.se/objects/FE1KELfYkAA3Ch8cGkSIGnfI
The graph displays dissolved organic carbon (DOC, top line), ammonium (NH4, middle line) and phosphate (PO4, bottom line) concentrations measured at Kallkälsbäcken stream measured throughout the year in 2021. The photo shows the V-Notch weir installation at Kallkälsbäcken.
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.
The year 2023 started with a new SITES period at Röbäcksdalen, but there are more new things happening at the station. From the first of January 2023, Röbäcksdalen SITES station is no longer managed under the department of Agricultural Research for Northern Sweden. After an organization change at SLU, the field station, which houses the majority of the SITES activities, is now part of the Department of Crop Production Science, while the dairy farm is part of the animal infrastructure at the Faculty of Veterinary Medicine and Animal Science.
The SITES activities at Röbäcksdalen are continuing as usual, and soon we will have even better possibilities to collect field data. Located in Northern Sweden, the long nights, cold weather and cloudy skies in winter at the station have presented problems for the solar panels operating the weather station and the sensors on masts. This in turn, often has resulted in data missing from November to January. However, in late November 2022, Röbäcksdalen was awarded a stipend from Kempestiftelserna to support a project to install electricity to the stations infrastructures. With this effort, starting in winter 2023-2024, hopefully the weather and spectral data sets can run without interruptions throughout the whole season.
There is a need to optimize forest management in order to contribute to climate change mitigation by enhanced ecosystem carbon storage. Rotation forestry is the most common silvicultural practice in Sweden, but there is an intense debate about its ability to contribute to long-term sequestration of carbon from the atmosphere. Due to the urgent need for nature-based climate change mitigation options, there is now considerable social and scientific interest in the use of continuous cover forestry (CCF), but its effects on carbon sequestration are largely unknown and need to be quantified urgently. Ongoing and future forestry projects are taking place at the Central Forest at Skogaryd Research Catchment (SRC) to address these unknowns.
Already this winter at SRC, a 60-year-old Norway spruce forest has seen some harvest activities, including different management techniques; clearcutting (Rotation forestry- RF), diameter-limit cutting (CCF) and unharvested with extended rotation length.
A new Formas financed project will make use of the harvested activities at SRC to study the effect of CCF on carbon fluxes and sequestration, compared to RF, by use of novel methodologies based on sap flux (trees’ water transport) and phloem stable isotopes. The goal is to determine whether, and by how much, carbon uptake capacity is sacrificed as forests grow older and if a selectively cut forest can compensate for the carbon stock lost following clearcutting by increased growth and, if so, how. The novel methodology will be compared to the time-tested eddy covariance method. Both methods estimate forest carbon uptake in photosynthesis, but the isotopic method also allows for determining how individual uncut trees respond to the selection cutting. This project will support rigorous, objective analyses of one of the most compelling social issues in Scandinavia: what is to be done with the forests?
With this project forestry professionals, private forest owners, policymakers and the public will be provided with information regarding the impacts of different forest management strategies on the productivity and carbon sequestration of forests. Ultimately, this could contribute to the formulation of new ecological and economic goals, management plans and policies that guide the future use of the Swedish forests.
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.
During the month of January most of Sweden is snow and ice-covered, although the duration and intensity of snow and ice has been declining over time due to ongoing climate change. The SITES calendar post for January displays this trend, as ice cover duration on Lake Erken over the past 80 years has been declining. At Erken Laboratory, visual observations of Lake Erken’s ice cover began in the 1940s and continues today, now with the assistance of a monitoring camera on Malma Island. This long-term ice-covered record is one of the most comprehensive in the world.
Link to data: https://meta.fieldsites.se/objects/QLqXw2wkqxXrr0ahsxeQaWbp
The graph displays the total number of lake ice cover days, i.e. days between the start of continuous ice coverage (> 75% of lake surface ice-covered) and the ice break-up of the observed lake area, over time on Lake Erken between 1941 to 2021. The photo shows Malma Island, where the lake monitoring camera as well as other monitoring sensors are located, and with the Erken Laboratroy in the very background.
On January 1 the SITES community not only welcomed in the New Year, but also a new, six-year funding period (2023-2028). By the time we gather for the SITES III Kick-off meeting Feb 8‑10 at Asa Station, the incoming SITES Director, Kevin Bishop, will have visited all SITES stations and the Thematic Programs. He is looking forward to kicking-off SITES III this year:
“Getting to know this infrastructure during my three months of “inskolning” has been an eye-opener to the amazing infrastructure built up during the first decade of SITES existence. Now, with a period of stable funding ahead, SITES can focus on what it is we are here for, providing scientists with access to well documented field sites where they have superb opportunities for doing excellent ecosystem research. I am looking forward to the meeting with many of you in Asa and working together to refine the plans for the coming years of SITES.”
- Kevin Bishop (SITES incoming Director)
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