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Fr.om. januari 2020 publicerar SITES nyheter enbart på engelska

One of the tree seedling plots that has been established at Lönnstorp. Photo: Tarquin Netherway. One of the tree seedling plots that has been established at Lönnstorp. Photo: Tarquin Netherway.
A new project will investigate the role of plant traits and mycorrhizal on plant-soil feedback as well as on microbial community assembly and functioning during seedling establishment. Experiments will be done at the two SITES agricultural stations and therefore include agricultural land in southern and northern Sweden.

The project at Lönnstorp and Röbäcksdalen research stations aims to answer questions around the relative importance of different woody-plant traits, such as leaf and root habits, together with mycorrhizal associations (symbiotic root associations with fungi) for plant-soil feedback mechanisms (i.e. the growth response of plants when growing in a new soil habitat) and for structuring soil, root and leaf-associated microbial communities and their functioning.
 
To investigate this, seedlings of twelve different woody plant species, ranging from conifers, such as spruce, and yew to broadleaf species, such as birch and maple, will be transplanted. The different species associate with different mycorrhizal fungi. Some seedlings will be inoculated with forest soil and some will not. Seedlings will also be planted in soil from the station where they are not planted (i.e. some seedlings at Lönnstorp will be planted in soil from Röbäcksdalen and vice versa) to account for differences in abiotic and biotic factors between the two sites.
 
The growth of the plants will be measured over two growing seasons, during which leaf associated microbial communities and nutrient concentrations will be analyzed. At the end of the experiment rhizosphere soil will be collected to examine the chemical properties and the microbial communities.
 
The results will hopefully contribute to the knowledge about which traits of the plant-soil system are central in altering the growth habitat (negatively or positively) during afforestation. In addition, these results could give an indication of the implications on ecosystem processes such as carbon and nutrient cycling across different climates over the short term, together with unravelling basic ecological questions around the assembly of plant-associated microbial communities and their functioning.  
 
Text: Tarquin Netherway, Department of Ecology, SLU.
Developing shoot of Norway spruce at Asa. Photo: Martin Ahlström. Developing shoot of Norway spruce at Asa. Photo: Martin Ahlström.
Even though arctic winds have reduced the temperature outside, spring is on its way. And with the spring approaching, so is the seasonal start of the Phenology monitoring programme at Asa research station.  

Phenological observations are made on birch, spruce and pine trees as well as on bilberry and lingonberry bushes. Shoot development, autumn leaf colouring, leaf felling and flowering are followed as part of the phenological observations. The monitoring programme started in 2006.
 

Example data from Asa Phenological Monitoring

Relative number of flowers, unripe and ripe berries of lingon, according to phenology assessments made in Asa between 2006 and 2020. Lines represent the 15-year average (solid) and standard error (dashed) numbers. Left panel show number of flowers, unripe and ripe berries vs. date and right panel vs. temperature sum, calculated from air temperature at standard height from the meteorological station in Asa.
 

Relative number of flowers, unripe and ripe berries of bilberry, according to phenology assessments made in Asa between 2006 and 2020. Lines represent the 15-year average (solid) and standard error (dashed) numbers. Left panel show number of flowers, unripe and ripe berries vs. date and right panel vs. temperature sum, calculated from air temperature at standard height from the meteorological station in Asa.
 

Shoot development of Norway spruce, according to phenology assessments made in Asa between 2006 and 2020. Pink dashed lines indicate single year development, black lines represent the 15-year average (solid) and standard error (dashed) shoot development. Left panel show shoot development vs. date and right panel vs. temperature sum, calculated from air temperature at standard height from the meteorological station in Asa.
 

Shoot development of Scots pine, according to phenology assessments made in Asa between 2006 and 2020. Pink dashed lines indicate single year development, black lines represent the 15-year average (solid) and standard error (dashed) shoot development. Left panel show shoot development vs. date and right panel vs. temperature sum, calculated from air temperature at standard height from the meteorological station in Asa.

Photo: Ola Eriksson. Photo: Ola Eriksson.
At the Abisko Scientific Research Station (ANS) the vehicle fleet was recently expanded with an “ark”. Here, Magnus Augner, station manager, tells what an ark is and why it was acquired.

Up here in Norrbotten, an "ark" is a kind of living module, usually with a stove, which you pull out on the lake ice with a snowmobile. In the floor of the ark there is a hatch through which you can do ice angling, while you have a nice time in the warmth inside.
 
A few years ago, Håkan Grudd, deputy station manager, got the idea that arks might be something for our Antarctic expeditions. He contacted several manufacturers and in the end we decided on Järvsöarken. A special feature of their arks is that you can place a snowmobile inside the ark, which is a great advantage for transport and storage for a longer period of time.
 
After some discussions, they built three arks for us, which were then adapted to our needs in Antarctica, with e.g. snow melter, stove that allows cooking and solar cells for charging batteries. In the field season 2017-18, we used them for the first time on an expedition and it was clear that this was a good concept for expeditions into "deep field", i.e. so far away from research stations that one has to be self-sufficient, with the exception of fuel depots. Each "two-people set" consists of two snowmobiles, an ark, and a snowmobile sled (for fuel, research equipment, food, etc.)
Photo: Ola Eriksson. Photo: Ola Eriksson.
Why snowmobile arks? A large cost and a clear environmental impact is the fuel that must be transported down to Antarctica in order to conduct all types of activities. Looking for light-weight solutions that also have a high level of security is always an important part of our development of Antarctic logistics. Being able to live "indoors" in a warm space, which does not take time to set up, makes life on expeditions much more comfortable and safer than living in a tent.
 
In order to primarily be able to show and test living in arks during field courses, we have also purchased an ark for ANS. This also provides possible support for researchers who want to be able to live in the field in winter, away from the station and our field cabins.
 
Version 2 of our ark is 20 cm wider than the first one, which means that the beds are now 60 cm wide instead of 50 cm. The ark is equipped with fire extinguisher, carbon monoxide alarm, fire blanket, lighting, solar cells, 12v battery, USB charging, inverter 230 V, stove etc. In short, a small well-equipped "caravan" for snowmobiles, where two people can live quite comfortably.
Research plot from a previous biodiversity experiment (Biodepth) at Röbäcksdalen. Photo: Cecilia Palmborg. Research plot from a previous biodiversity experiment (Biodepth) at Röbäcksdalen. Photo: Cecilia Palmborg.
A new project with field experiments in both Lönnstorp and Röbäcksdalen will investigate the effects of seed dispersal and plant arrival order on grassland vegetation, plant biomass and insect diversity.

Why do plants grow where they grow? Certainly, it is partly due to the environment of a particular site that will favour some species, while deterring others. However, even with knowledge of the local environmental conditions, it is notoriously difficult to predict vegetation compositions using environmental variables alone. This leads to the suspicion that more must be going on. Could chance or luck play a role in shaping the vegetation?

One way plants could experience luck is by having their seeds arrive early to a place that is open for colonization. The arrival time of seeds will depend on seed dispersal, which is known to be very stochastic and therefore a process where chance is involved. Arriving early typically comes with certain benefits, such as access to nutrients, water and sunlight, causing the early arriving species to be more likely to successfully establish. The arrival order of species at a site could thus be one factor that shapes the vegetation.

But how could this idea be tested? It is not possible to go to a field and figure out which of the species was first on the scene. That’s why experiments are needed. Judith Sarneel (Researcher) and Tamara van Steijn (PhD student) from Umeå University will work together with SITES in both Lönnstorp and Röbäcksdalen to set up large scale grassland experiments, starting this spring/summer. In their plots they will introduce a set of grassland species with varying arrival orders between the plots.

The development of the vegetation, as well as the effects on the insect community, above and below ground biomass and other parameters, will then be followed over the years to come.

The results could potentially be useful in restoration of grasslands. Specifically, when seed sowing is used as a restoration method, it would be possible to manipulate the order of sowing in a way that benefits the species that are deemed most interesting. 

Text: Tamara van Steijn.
Niklas Rakos drilling a hole in the ice for sampling the lake sediment. Photo: Erik Lundin. Niklas Rakos drilling a hole in the ice for sampling the lake sediment. Photo: Erik Lundin.
SITES is mapping lake sediments for the lakes included in the thematic programmes SITES Water and SITES AquaNet, to enable a better understanding of biogeochemical processes within the lakes. Sampling has now started at Lake Almbergasjön at Abisko Scientific Research Station.

Since the lake is still ice-covered, Abisko research engineers Niklas Rakos and Erik Lundin took the opportunity to collect a deep sediment core. Using a Russian corer, nearly 3 meters of sediment from Almbergasjön was collected.

The sediment core was sliced and sediment subsamples stored for later analysis (e.g. water content, C, N, grain size). The sediment mapping campaign on Lake Almbergasjön will continue later in 2021 with a sub-bottom profile survey and gravity core collection across the lake.
A sediment core from Lake Almbergasjön collected using a Russian Corer. Photo: Erik Lundin.
A sediment core from Lake Almbergasjön collected using a Russian Corer. Photo: Erik Lundin.
SITES sediment mapping
Sediment sub-bottom profiling has already been conducted and long and short sediment cores have been collected at Lake Erssjön (Skogaryd Research Catchment) and at Lake Feresjön (Asa Research Station). Sediment cores have previously been collected for Lake Tarfala and a high-resolution bathymetry map exists (Kirchner et al. 2019). A sediment sub-bottom profiling survey was conducted for Lake Erken in 2017.  
 
Read more about the sediment sampling in news articles on SITES web and in our newsletter:

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