By Liz Kalaugher
As suspected, on Monday morning the weather took a turn for the worse and we woke to pouring rain. After stocking up on a small plastic spade for taking soil samples (steel could skew the analysis results by introducing extra iron), it was time to head out to the test sites in the valley to the north-west of Saana fell. As we climbed, we left the trees behind, pausing only to sample blueberries, juniper berries and crowberries. The height of the juniper bushes shows the depth of snow in winter, as stems sticking above the snow repeatedly freeze and thaw, and tend not to thrive.
The test sites are staked out by wooden skewers, which as it happens are sold locally under the brand Saana sticks – Saana is also a Finnish girl’s name. Each site consists of a grid 8 metres wide and 20 metres long, with a skewer pushed into the ground every metre, apart from where reindeer browsing for lichen have knocked them over.
Miska Luoto, Julia Kemppinen and Pekka Niittynen of the University of Helsinki took a spadeful (roughly a handful) of soil from a depth of between 2 and 10 cm at 18 points across the grid before carefully replacing the turf. Meanwhile, I pushed screws into the ground at 4 m intervals so that researchers who want to repeat the surveys in 20 years’ time can find the right spots, as the skewers are unlikely to last that long.
Although it sounds easy, in some places the task proved tricky – the soil cover was thin and the rock beneath hard. But it did help to highlight how much conditions here change over small distances. Indeed, this is what the researchers are aiming to measure: how different conditions on a very local scale affect vegetation cover. By the time they’ve finished, they’ll have around 500 different measurements from each 1 metre grid square in their study, from 21 test sites that are 8 m x 20 m in size, giving a grand total of 3,360 grid squares.
After analysing the link between current conditions and vegetation, they’ll be better able to predict what will happen to vegetation as climate changes. While the local variation means it’s tricky to model vegetation on a grand scale, it could also be that some places are able to act as refuges for plants as conditions warm.
Not only did the soil depth change, but its colour did too. At one site, grid points just 10 m uphill had much redder soil than their counterparts below, indicating that it was richer in iron. In one case, vegetation 10 m down a slope contained ten times more species per square metre – 43 in total – than a grid square higher up.
The soil collected today will go back to the lab in Helsinki for analysis of its nutrient levels and pH.
As the rain cleared in the afternoon and we paused for the team to prepare more sample bags, we could see Sweden on the other side of Lake Kilpisjärvi and the Finnish customs station below us, a small distance from the Norwegian border. My mobile phone welcomed me to Norway; you’d think a Nokia might have a better idea of local geography.
- This trip was funded by a European Geosciences Union (EGU) Science Journalism Fellowship.