“Striped berry rug – raidallinen marjamatto” is a revegetation experiment we founded five years ago (2013) in Kilpisjärvi, the subarctic northwestern corner of Finland. Our group – consisted of researches of Luke, the University of Helsinki, and Aalto University – combined the approaches of scientific study and bioart.
Bioart is a novel way to do art by creating works that employ living organisms and natural materials. It aims to evoke new kind of scientific and artistic thinking and discussion on the relation of humankind and nature. Our scientific goal was to study how the planted individuals of lingonberry and crowberry, representing southern and northern origins, survive, flower and spread in a very poor and bare ground in the north.
In the landscape, the result of the revegetation field would form a big “rug”, the Striped berry rug. The stripes of the rug were long parallel lines of rooted cuttings of lingonberry and crowberry (altogether 500 plants). Furthermore, we studied how these species respond to increased temperature and elevated CO2 levels in the greenhouse. The artistic goal was to depict the plasticity of growth architecture of plant individuals in extreme conditions.
Dwarf shrubs are used in phytoremediation of bare, disturbed or polluted soil because of their good regrowth potential and resistance to toxic elements. They can form large clonal patches with extensive rhizomes which facilitate rapid spreading and coverage of the bare soil. Our revegetation experiment is an example of ecological restoration of eroded soil based on natural materials and wild plants. Its goal is to enhance the interaction between plant and soil.
When plants find a rooting site, they start to produce new organic matter which activates microbial processes and helps to remediate the soil. From an aesthetic point of view, dwarf shrubs are important landscape elements expressing changing colour and growth with change of seasons.
The northern plants showed higher plasticity in growth form by allocating more biomass to rhizomes than the southern ones.
As expected, we found that the northern origins of the dwarf shrub species survived better than the southern ones in the northern field experiment. In addition, the northern origins showed higher relative growth rates than the southern ones, in response to increased temperature and CO2 level of the greenhouse experiment. Overall, the northern plants showed higher plasticity in growth form by allocating more biomass to rhizomes than the southern plants.
Today, northern ecosystems are under the influence of climate change. Recent climate scenarios predict the average temperature of Finland is increasing by 1–4 oC in summers and as much as 2–7 oC in winters. The frost period of the soil will shorten and the amount of precipitation in winters increase, whereas drought periods in summers will become more frequent.
The results of our project gave experimental support to the observations that northern ecosystems have already started to change, shown as greening trend in satellite images. The colour of arctic and subarctic tundra has turned greener as a result of spreading of ground layer vegetation. Increasing temperature activates biomass production of shrubs and dwarf shrubs and pushes the distribution range of plant species towards the north, which can result in the movement of whole vegetation zones.
The revegetation project was carried out in the years 2013–2016, and it was partly granted by the Finnish Bioart Society.