May 27, 2020 / University of Helsinki published news (in Finnish only) about the results of the Kevo warming experiment.

May 21, 2020 /  Our first paper reporting results from the Kevo warming experiment was published in Nature Communications. In this paper, we show how the seemingly low insect herbivory in a Subarctic mountain birch forest ecosystem can drastically reduce its CO2 uptake potential. This indicates that insect herbivores may significantly dampen the improving C sink capacity of Subarctic ecosystems if their abundances will increase with warming as predicted.

December 6-7, 2019 / Juha and Tuukka visited the Kevo site to move the most sensible measuring devices indoors for the mid winter.


October 21, 2019 / This is the end. After five years of measuring tree growth and behaviour in the birch kin experiment, we took the final measure of over 1100 trees and closed the study. People involved in this merry one-day exercise were Juha, Amaia, Jouni Laakso, Heikki Helanterä and Matti Rousi.


September, 2019 / Amaia has been collecting the quartz sand bags that were buried in soil under the trees in the birch kin experiment. The bags are used for estimating the growth of mycorrhizal fungal hyphae. It seems to work, this young Amanita muscaria fruiting body is tightly attached to the bag!

Kärpässieni ja mykopussi

August 19-21, 2019 / Another, late summer survey of VOC emissions in Viikki by James Blande, Hao Yu and Adedayo Mofikoya. Juha and Tarja examined leaf herbivore damages.


August 12-16, 2019 / Juha and Tarja, together with Oscar Franken from Vrije Universiteit Amsterdam, collected soil samples from the Kevo experiment to examine soil microbial and faunal responses to warming.


22 July, 2019 / Amaia Gonzaga Roa, from the Autonomous University of Barcelona (UAB), arrived and started examining vole damages at the birch kin experiment in Viikki. Amaia will be with us until the end of the year.


June 10-12, 2019 / Hao Yu, Henna Toppinen and James Blande from the University of Eastern Finland visited the birch kin experiment in Viikki to collect VOC emissions. Whether trees adjust their VOC emissions in relation to their neighbors is one of the most interesting questions in the experiment.


April 27-29, 2019 / Spring was coming and the plots in Kevo appeared from under the snow. Juha and Tuukka turned the warming on. Soon after a thunder strike broke parts of the system, but we got them fixed.


March 27-28, 2019 / Juha, Tarja and Sinikka attended the kick-off meeting of Arctic Avenue, a new spearhead research project between the University of Helsinki and Stockholm University. The project offers great opportunities to strengthen and build new collaboration with Stockholm researchers (photo of the participants of the meeting in Suomenlinna by Tarmo Virtanen).

January 21, 2019 / Polar nights are finally over! Ilkka Syvänperä checked the vole situation and secured fences in our site.

December 8-10, 2018 / Juha and Tuukka closed down the Kevo heating experiment for the mid  winter.


November 29, 2018 / Tarja’s popularizing science article (in Finnish) about our research was published in #muutos.

November 20-21, 2018 / Juha had a talk at the Arctic Research Leads to New Solutions symposium in Helsinki. The ARKTIKO program, funded by the Academy of Finland, is ending and it is time to get all our data collected at the Kevo warming experiment and the international transplant study published. The video made of the ARKTIKO program activities tells of our birch research as well!

October 22-24, 2018 / Field season 2018 is nearly over. Tarja went to Kevo and measured  CO2 flow once more with Ilkka Syvänperä. Days are already short, but the weather was nice and crisp. Polar nights are here soon.

The sun is nearly at its zenith in this picture!

September 18, 2018 / Tarja’s blog posting (in Finnish) about birch autumn leaf colors and aphids was published in #muutos.

August 27-31, 2018 / A workshop was organized by the Turku University Biodiversity Unit to celebrate the 60 years of Kevo field station. The meeting brought together people working in the same area with interlinked questions.

Kevo 60 Workshop participants 29082018_EV

August 24, 2018 / Sinikka returned from a field trip to Iceland with bags full of soil and plant samples. The trip was successful except that sheep had eaten half of the litter bags placed on the ground in early spring. Arthropod samples were in good shape though.


August 14, 2018 / YLE news reported of the faith of mountain birch forests under warming climate and our results in the Kevo heating experiment.

June 10-15, 2018 / What a hassle during this week! Juha, Tarja, Sinikka and two new French trainees, Titouan Dubo and Margot Fontaneau, joined Ninon in Kevo. Also Matti Rousi came for a visit and helped us with the field work. Sinikka sampled insects, Margot and Ninon measured soil respiration, while Tarja, Juha, Matti and Titouan went to three treeline gardens to select and mark the experimental trees for this summer. Measurements of CO2-flow were also carried out before Tarja and Juha went back to home. Titouan, Margot and Ninon were left in Kevo to take care of the basic measurements.


June 13, 2018 / Tarja’s blog posting (in Finnish) about spring phenology of birch was published in #muutos.

May 15-23, 2018 / Yearly variation in phenological events is huge! First buds are already opening, whereas last year we had over 60 cm snow-cover at this time of year in our Kevo field warming site. Tarja went to Kevo to surveye spring phenology together with our french trainee Ninon Fontaine. Ninon will stay at the research station to take care of all basic measurements and insecticide sprayings in our Kevo field site.


May 10-11, 2018 / Snow started to melt really fast this spring! Juha and Tuukka took a last-minute travel and went to Kevo to restart our heating system for the upcoming growing season.


December 8, 2017 / Tarja got a research grant from Kone foundation and will soon be #rohkeatekijä! Well done!

November 28-29, 2017 / Juha and Tuukka went to Kevo and closed our warming system for the harshest wintertime.


August 29-30, 2017 / Tarja went to Punkaharju common garden sites to survey herbivore and pathogen damage of common garden seedlings with Luisa Gheraldini while Elina Oksanen and Sarita Keski-Saari measured chlorophyll content of the saplings.


August 13-19, 2017 / What a busy week! Tarja and Kristiina surveyed herbivore and pathogen damage, measured CO2 flow together with Mika and Lauri, collected BVOCs with Rajendra Ghimire and started to follow leaf senescence in Kevo warming experiment. In the end of this week, Tarja went to Kolari field sites to survey herbivore and pathogen damage in common garden birch seedlings as well.

July 6-14, 2017 / Tarja visited Kolari common garden sites and measured the chlorophyll content of summer leaves in our birch seedlings. Thereafter she went to Kevo warming site to establish an experiment to study the effects of warming on pupal period of different origins and genotypes of Epirrita autumnata.

Pupae were sexed under the microscope

June 4-10, 2017 / Juha, Tarja and Kristiina went to Kevo warming site to start the field season 2017. Kristiina surveyed spring phenology while Tarja and Juha installed aluminum collars in each field plot. They also tested the system to measure CO2-flow between the ecosystem and the atmosphere together with Mika Aurela and Lauri Heiskanen before heading back to home. Kristiina was left to research station to take care of all basic measurements and insecticide sprayings in our Kevo field site.

Testing the measurement system for CO2-flow

May 31, 2017 / Extremely cold spring weather inspired people to give feedback to climate warming researchers about the importance of their work in Letters to the Editor -section of Savon Sanomat, a local newspaper in Kuopio region.

Society feedback in a local newspaper.

May 22-23, 2017 / Juha and Tuukka went to Kevo warming site to restart our heating and monitoring system for the upcoming growing season.

Heat is on again!

May 8-12, 2017 / Tarja went to our Italian common garden sites to measure leaf chlorophyll and assess herbivore/pathogen damage of birch seedlings while Juha was collecting samples for soil carbon and microbial analyses around southern Finland. Guess which one had the last laugh!

Field work in Italy and Finland in the second week of May.

February 24, 2017 / To properly recover from jet lag and the strain of the conference journey Tarja took part into Finland Ice Marathon competition and won Ladies 50 km series in ice biking.

palkintojenjako 2
Photo: Wille Markkanen and Taustamarkkinat,

February 11-19, 2017 / Tarja presented a poster entitled “The plant kin effects on arthropod communities and leaf damage in birch” in the Gordon Research Conference: Plant-herbivore Interactions in Ventura, California, USA.

Ventura Pier
Early morning jog to the Ventura Pier

November 6-9, 2016 / Juha and Tuukka went to Kevo warming site to remove the heating and monitoring system for the harshest wintertime.

Winter is coming

October 1, 2016 / To compensate for long days of sitting in a car during a road trip through Europe, Tarja took part in a trail marathon at Koli national park with a former group member Katarina Koikkalainen.


September 16-23, 2016 / Tarja and Timo Oksanen transported last common garden seedlings from LUKE Haapastensyrjä forest breeding unit to Northern Italy. Finally, our common garden experiment is ready for research use!

After a very long road trip through Europe and across the Alps the seedlings were finally planted on their right destination with our Italian colleagues.

August 10-12, 2016 / The seedlings were transported and planted into the common garden field sites in Punkaharju.

Can you locate our experimental seedlings?

July 19-22, 2016 / Tarja and Juha transported birch seedlings from LUKE Haapastensyrjä forest breeding unit to Northern Finland. The seedlings were planted into the common garden field sites in Kolari and the warming experiment in Kevo.

Having a road trip with birch seedlings to Finnish Lapland

June 26 – July 2, 2016 / The warming experiment was established in a treeline mountain birch forest near Kevo Subartic Research Station. Tuukka installed the heating and monitoring system, Juha and Tarja shoveled a ditch to install a vole fence around the experimental area, while the students, Katja and Kristiina, did all scientific work. Altogether 20 plots were established into intact ground layer vegetation. Seedlings of four birch species (B. pendula, B. pubescens, B. nana and B. pubescens subsp. czerepanovii), cloned from their northernmost populations, will be planted later into each plot. The plots will be exposed to a warming treatment (half of the plots is heated 2-3 °C above the ambient temperature using infrared ceramic heaters) and herbivore removal (half of the plots will be weekly sprayed using an insecticide) in a fully factorial 2×2 experimental design. In this design, the heating × herbivore removal interaction will reveal the role of herbivores in ecosystem responses and in the ability of birches to acclimatize to warming. The responses of B. pendula and B. pubescens, which currently have a more southern distribution, will tell of their future ability to colonize these treeline environments.

Finally it’s time to smile – work camp is over and we don’t have to tolerate those tormenting blackflies anymore!

June 8, 2016 / Common garden field sites in Kolari and Punkaharju have been fenced against moose, hares and voles.

Punkah 018
Hard work is over! Punkaharju site is awaiting for our experimental seedlings.

May 25-26, 2016 / Tarja, Juha and Janina presented posters at the 11th Finnish Plant Science Days in Turku.


May 24, 2016 / Tarja, Tihomir Simin and Sarita Keski-Saari established a growing chamber experiment to test the effects of different day lengths of Kolari and Florence on the seedling growth and physiology. Plant material, i.e. tree origins and genotypes are the same as will be planted on our common garden field sites (see poster above) in this summer. This experiment will help us to disentangle the effects of day length from the effects of warmer climate in our transplant experiment.

Plant welfare society

May 10-11, 2016 / Tarja, Juha and Viivi participated the annual ARKTIKO seminar at Hotel Rantapuisto in Helsinki and presented posters about transplant and warming experiments.

May 3-6, 2016 / Tarja and Helena established a laboratory experiment to test the effects of soil on the growth of the seedlings. Soils were collected from our forthcoming field sites in Kolari, Punkaharju and Florence (see poster below) and plant material, i.e. tree origins and genotypes are the same as will be planted on these sites. This experiment will help us to disentangle the effects of soil from the effects of warmer climate in our transplant experiment.

Ready for a few months growth competition!

26 February, 2016 / In between the establishment of decomposition trail Tarja took part into Finland Ice Marathon competition and won Ladies 50 km series in ice biking!

Palkintopallin pönöttäjä.jpg
1. Tarja Silfver 2. Eve Lahti 3. Ulla Tervo                                          © Ville Miettinen

February 23-26, 2016 / Tarja and Laura established a laboratory experiment of 240 Petri dishes to study the effects of growth environment and latitudinal shift on the decomposition of woody plant litter (we have earlier tested the effects on leaf litter decomposition). The plant material, or twigs were collected from a common garden experiment of transplanted trees, representing southern and northern silver birch provenances and genotypes.

Ready for a 6-month trial

February 1-4, 2016 / Juha and Tarja presented a poster in the Nordic OIKOS 2016 conference in Turku, Finland.