Plants, soil and microfauna – how does light quality affect forest ecosystems?

The Canopy Spectral Ecology and Ecophysiology group at the University of Helsinki doing field work (photo: Marta Pieristé).

During spring time when the canopy leaves emerge in deciduous trees in temperate forests, there is a drastic change in light quality reaching the forest understorey. In collaboration with the Canopy Spectral Ecology and Ecophysiology group (CanSEE) at the University of Helsinki, researchers from the University of Rouen (Université de Rouen) visited Lammi Biological station this summer to investigate how this drastic change in light quality reaching the forest floor affects the ecosystem as a whole.

Plants in the understorey utilise light signals as cues to help time when their leaves emerge, when they flower, how to tall to grow, how large to make their leaves, as well as affecting their photosynthesis, leaf pigments and root growth.

Over the last three years the CanSEE group led by Dr Matthew Robson has been characterising the changes in the composition of light that reaches the forest understorey, and examining how different plant species respond to the change in these light signals. However these changes seen above ground are only half the story.

How does this affect below ground processes? The properties of soil in close vicinity to plant roots are modified by a large range of processes that occur during plant growth, which in turn affect the rhizosphere microbiota. Plant roots not only contain compounds such as sugars and amino acids for soil microbiota, but also compounds for defence such as antimicrobials and nematicides. Furthermore, the uptake of ions in the soil by roots can drastically affect the pH of the soil.

Researchers Dr Estelle Forey and Marta Pieristé from the University of Rouen are now beginning to investigate these questions, and in collaboration with CanSEE group, seek to understand how light quality in the forest understorey affects the ecosystem as a whole.

After long term plots either blocking out different light signals were set up in 2016, the two research groups have begun to sample the changes that occur in plants, soil and microfauna when these plots are deprived of different light signals.

A filter blocking out blue light over plants in the forest understorey. These long term plots were set up in 2016, where the plants have been monitored over the course of two years (photo: Marta Pieristé)..
A filter blocking out blue light over plants in the forest understorey. These long term plots were set up in 2016, where the plants have been monitored over the course of two years (photo: Marta Pieristé)..
Right: Dr Estelle Forey and PhD student Craig Brelsford from CanSEE group taking soil core samples from the plots. These will then be analysed by for the content of the soil, and the composition of mircofauna inside (photo: Marta Pieristé).
Dr Estelle Forey and PhD student Craig Brelsford from CanSEE group taking soil core samples from the plots. These will then be analysed by for the content of the soil, and the composition of mircofauna inside (photo: Marta Pieristé).

The results from this work may be important in understanding how climate change will affect the forest understorey ecosystem. The date of canopy leaf out in spring is advancing at 2.5 days per decade since 1971 in temperate forests due to rising global temperatures. In turn, this means that the changes in light signals due to canopy shade in the forest understorey will occur earlier, and may have cascading effects on understorey species of plants, soil and microfauna.

Text: Craig Brelsford, PhD Student (Canopy Spectral Ecology and cophysiology (CanSEE) Group).

Photos: Marta Pieristé.

Environmental change on trophic interactions in the Baltic Sea

Eider duck has recently been classified as endangered within the EU (photo: Heikki Eriksson).
The eider duck has recently been classified as endangered within the EU (photo: Heikki Eriksson).

A new research initiative at Tvärminne Zoological Station (TZS) brings together long-term research projects and conducts field and laboratory experiments, all in order to understand the function of the Baltic food web and how it is affected by environmental change. The research focuses on a community module consisting of blue mussels, eider ducks and white tailed sea eagles. This module forms a central part of the Baltic ecosystem and contains a keystone species, a mesopredator and a top predator and it links the marine and the terrestrial environments. We investigate the direct and trophically mediated impacts of environmental change within this group of closely interacting species representing three different trophic levels. Special emphasis is put on the trophic interactions surrounding the eider duck and how these affect its population development. The eider populations are in precipitous decline and the species was recently classified as endangered within the EU. We hope to understand what processes are driving the eider populations and to mitigate potential threats.

Blue mussels covering the rocky bottom (photo: Kim Jaatinen).
Blue mussels covering the rocky bottom. The blue mussel is the main food item for eider ducks (photo: Kim Jaatinen).

In 2017 Kim Jaatinen (TZS) and Markus Öst (Åbo Akademi) conducted their traditional fieldwork studying the Tvärminne eider population. This season was especially interesting and worrisome: the research group recorded an all time low in the population’s offspring production. Normally the 12 km wide research area produces between 1000 and 2000 ducklings, but this year only a mere 41 ducklings were seen in the standard duckling survey conducted at the end of June. Predation by sea eagles plays a major role in this low production but also other causes are under investigation.

Bird number NS1A6243m ready to go (photo: Heikki Eriksson).
One more eider female measured, sampled and ready to go (photo: Heikki Eriksson).
Young eider ducks (photo: Heikki Eriksson).
These less than a day old eider ducklings are ready to go to sea (photo: Heikki Eriksson).

The blue mussel study conducted by Mats Westerbom, Kim Jaatinen and Alf Norkko focuses this year on analysing the effects of climate change on the population dynamics of this species so central to the Baltic ecosystem. In addition to applying new analysis techniques to the long-term data, the group has continued work on monitoring recruitment of young mussels to the population. This year a new monitoring scheme was started, which aims at following spatial and temporal variations in the condition (i.e., meat content) of the mussels.

The findings of this year’s projects will all shed light on the impact we are having on the Baltic Sea and how its ecosystem will be affected. This knowledge may help us mitigate the bad influence we are having on our environment. Stay tuned for upcoming results!

A crushing wave. A typical element in the lives of the eider ducks and the blue mussels (photo: Kim Jaatinen).
A crushing wave. A typical element in the lives of the eider ducks and the blue mussels (photo: Kim Jaatinen).

Text: Dr. Kim Jaatinen, Tvärminne Zoological Station
Photos: Heikki Eriksson & Kim Jaatinen

Mobile nature observations at HiLIFE-stations

In order to introduce mobile data gathering tools, a web browser based visualization service was set up for the stations a few months ago. The service is aimed for any visitor at any of the stations; people can use their mobile devices to record their own nature observations. The observations made are visualized on a map below (fig. 1) in real-time. The idea of this project, besides introducing the tools, is to provide meaningful doing for different groups visiting or staying at the research stations. So far observations have been made by staff, researchers, different courses and sudden visitors.

Fig. 1. The mobile nature observations visualized on a map. A green marker means a positive observation and a red marker means a negative observation.

We used Open Data Kit –tools for data gathering and Google’s services in visualizing the data. All the tools used work seamlessly hand in hand. All the necessary tools have been installed and are available at the stations. Mobile data gathering tools can be used for example both in research and teaching purposes.

Using mobile devices for data gathering has some advantages against traditional field forms. With digital mobile forms, all kinds of data can be gathered simultaneously with one device. Besides of numeric data it’s also possible to record co-ordinates, take photos, record sound etc. With ready-made digital forms and pre-formatted answers to choose from, errors in writing down the data can be minimized. One big advantage is also that the data is sent directly to the server (or a spreadsheet) from the field. The forms work also off-line, which is very important in field conditions, also in a technologically advanced country like Finland there are numerous areas with no mobile data connection available.

Contact Lammi Biological Station for more information on the tools available. The nature observation system is at your disposal if you visit any of the five HiLIFE-stations.

There are also co-operation between Lammi Biological Station and some teachers around Finland. The idea is to use the mobile observation tools in school projects and public science projects.

5097pics / 12fph / 2min 43s

The Muddusjärvi Research Station differs slightly from the other four HiLIFE-stations for not having a large infrastructure and year round activities. The station belongs to the Faculty of Agriculture and Forestry, University of Helsinki and is situated in northern Finland in the village Kaamanen, 25 km from the city of Inari. The station operates with ca. 13 hectares of field and ca. 700 ha of forest and administrates also a 1000 ha lake area. The original purpose was to conduct research to support Lappish agriculture and other subarctic research for the Faculty. Since 1996, the usage of the station has been more or less project based and concentrated to the summer time. There is one permanent employer accompanied by the necessary summer help.

The Inari lowlands are among the best farming areas in the northern Lapland. Fields are situated near the water systems and therefore better sheltered from the frost. The soil is mineral soil ranging from fine sand / moraine to fine silt. The fields are low with organic material and the forests are flat dry coniferous forests. Reindeer are a regular sight.

In a future blog post we will write more about the recent research projects which have been conducted from the Muddusjärvi Research Station. The station provides an excellent base for smaller research activities and the station owned areas makes it easy to set up different experiments.

The title of this blog post comes from this excellent time lapse video from a local Inari based photographer Rauno Koivunen. The video shows the leaving of the ice cover from the lake Muddus which happened quite late this year.

SUBA-course in Kilpisjärvi

Subarctic ecology -course 2017

Situated in the distant north-western corner of Finland, Kilpisjärvi Biological Station is the youngest of biological field stations of University of Helsinki. The field station was established in 1964 and is famous for its unique location, surroundings and research activities based on long-term monitoring schemes, especially on phenology and population dynamics of the key species in arctic ecosystems.

Since 1986 a field course on subarctic ecology has been a steady part of the stations summer program and one of the most traditional field courses for students of Ecology and Evolutionary Biology. (Well, the first course was held in 1980 but was put to halt for two years because of the stations renovation work). For sure the course structure has seen many changes and co-teachers during its +30 year history, but it is still more or less driven by the field station’s manager, Professor Antero Järvinen, and concentrates on the main characteristics of subarctic nature.

Recently the course has been held for up to 15 students, lasting 10 days during the end of June and the first half of July. The combination of excellent surroundings, introductory and advanced lectures, small-scale course studies and variety of field excursions has made this course one of the most anticipated field courses among the students. Every course is unique, since the students themselves are one of the key contents, as every student gives a presentation, chosen from a list of given topics, in a student seminar or during a field excursion.

SUBA 2017 students in the field.
The joy of outdoor learning! Despite the variable weather conditions, the students enjoy their time in the field (photo: Aki Aintila).
The surroundings for this field course are unique. Students examining Lapland Rosebay (Rhododendron lapponicum) at Saana fell, with the Malla strict nature reserve in the background (photo: Aki Aintila).
The surroundings for this field course are unique. Students examining Lapland Rosebay (Rhododendron lapponicum) at Saana fell, with the Malla strict nature reserve in the background (photo: Aki Aintila).

The starting point for the course is the conditions that organisms face in these arctic latitudes; how the ecological features and limiting factors shift as the importance of biotic factors (e.g. predation, competition between species) decrease and the importance of abiotic factors (average temperature, extreme variations of weather conditions) increase, how organisms have adapted to cope with the extreme conditions and how to exploit the resources available. Furthermore, the theoretical background highlights the role of key species and, naturally, the long-term changes, both in the climatic conditions and species’ population dynamics.

The hotspot of Finnish fell flora is located in Kilpisjärvi. Students observing Silene wahlbergia in Malla strict nature reserve (photo: Aki Aintila).
The hotspot of Finnish fell flora is located in Kilpisjärvi. Students observing Silene wahlbergia in Malla strict nature reserve (photo: Aki Aintila).
“The field excursion and teaching species 
identification in the field were the best part 
of the course.”
Surveying bird nests has been part of the course since 1986 (photo: Aki Aintila).
Surveying bird nests has been part of the course since 1986 (photo: Aki Aintila).

But there’s no better way to put theory into practice than sending the students to the field. As a starter, the students collect data for small-scale course works in a small study area nearby the station. The topics have varied, from surveying bird nests to collecting spiders, but the focus is on field methodology, standardizing, sampling and observing the nature from scientific perspective. Step by step, the excursions tend to get broader, from full day hikes to the nearby fells (mountain) or visiting the Norwegian fjords with their own wildlife. The course also visits the bog areas situated 100 km south of Kilpisjärvi, especially the palsa bog areas, introducing the students to another important habitat type of arctic ecosystems.

Visiting a glacier and the glacial throughs (U-valleys) is the excursion that many students hold as the highlight of the course (photo: Aki Aintila).
Visiting a glacier and the glacial throughs (U-valleys) is the excursion that many students hold as the highlight of the course (photo: Aki Aintila).
“Teaching was really inspiring and teachers gave 
attention to every student. Each teacher on the 
course is a firm expert of one’s own field.”

Species identification is another important aspect on the course. The purpose is to mainly give general education, as different habitats are characterized by their species compositions. Of course, the background and purpose of species identification skills and mastering species communities were dealt with, since knowing the different bird calls or leaf structures can be essential when working with experimental or plain monitoring studies. But “picking up the cool stuff” and highlighting the specialties of this particular region is also important.

Eurasian Dotterel (Charadrius morinellus) is one of the special birds that breed only in the fell range (photo: Aki Aintila).
Eurasian Dotterel (Charadrius morinellus) is one of the special birds that breed only in the fell range (photo: Aki Aintila).

For sure every hue and detail cannot be observed during a single course, but it’s also about exciting and inspiring the students. What a way to familiarize a new generation of students for the function of field stations, biodiversity monitoring and scientific examination than offering hands-on experiences and chances to witness the atmosphere of this one-of-a-kind environment. Field courses like this are also important for recruiting new people for the field stations – and field station based teaching also serves its crucial part on university-level education.

“During the field excursions I realized how 
unique the nature in this part of Finnish Lapland 
really is. Many thanks to the organizers!”

Text and photos: Aki Aintila

The author has worked as a co-teacher on the course since 2013. More pictures and stories from this course are available his blog ( in finnish):
http://hulluparoni.blogspot.fi/2017/07/suba-2017-feat-mallan-linjalaskennat_19.html