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.

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.

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.

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.  

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.  

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.

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.

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.

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.

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 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!

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.

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.    

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.

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.

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!

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.

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.

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.

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.

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)
 

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.

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.

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.

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.  

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.  

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.

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.

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.

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.

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 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!

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.

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.    

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.

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.

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!

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.

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.

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.

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.

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)