There is a heat wave in the UK as I write, but I am wearing a fleece, cagoule and waterproof over-trousers and wishing I had brought a wooly hat and gloves too. I am standing beside a stream 350 m north of Oslo, at an altitude of about 1000 metres, in the Rondane National Park in Norway. We are at the tree line here, and there are still patches of snow on the hillsides around us. At my feet I can see low shrubby growths of the dwarf birch (Betula nana), a classic feature of “tundra” vegetation, interspersed amidst expanses of light-coloured lichens.
The mountains of the Rondane National Park, Norway, seen from the Nedre Dørålseter Turisthytte, July 2013.
I am here to help a colleague, Susi Schneider with some fieldwork and, in the process, to learn the Norwegian approach to ecological assessment. However, my travels around Europe have already taught me that differences in scientific approach have to be set into broader contexts of environment and culture, and the patches of moose droppings scattered amongst the lichen are enough to remind me of the many differences that exist.
The streams in the upper part of the Atna River, which drains this part of the national park have extensive covers of a slippery, brown growth. If you remove a stone and run your fingers through it, it has a slimy, viscous feel. The overall visual effect is, frankly, off-putting but this is an entirely natural phenomenon: an alga called Hydrurus foetidus. Under the microscope, the yellow-brown cells can be seen to be arranged in rows within this mucilage, branching at intervals to give a feathery appearance. Hydrurus belongs to a group of algae called Chrysophytes, which are related to the diatoms, yet also distinct in many ways. It can be found in the UK but only in the depths of winter in remote places. It is much more common in Norway, even in July, partly because it is further north and partly because there are so many near-pristine streams here.
Hydrurus foetidus in the Atna River, Rondane National Park, Norway. Left hand image shows Hydrurus smothering a submerged cobble; right hand image shows the mucilaginous growths on a stone removed from the water.
Susi’s conductivity meter gives us an extremely low reading, just 4 microSiemens /cm, meaning that this stream water is about as pure as distilled water and we both wonder out loud how any organism can find the sustenance to grow here. There must, we presume, be occasional flushes of nitrogen, phosphorus and the other building blocks of life, perhaps following rain showers, one of which had soaked us a couple of hours earlier. In any case, most of the biomass that we can see is the slimy mass around the cells, composed of carbohydrate, the most basic product of photosynthesis. The recipe is simple: shake stream water with the carbon dioxide that is found naturally in the air (a turbulent stream is ideal for this purpose), then pour the mixture through the Hydrurus cells. The result, judging by the number of midge larvae feeding on it, is delicious.
Hydrurus foetidus at two different magnifications under the microscope. 250 micrometres = a quarter of a millimetre. Photographs by Chris Carter.
This still leaves us with a conundrum: that the goal of the EU legislation to which both Norway and the UK are signatories is natural or near natural ecosystems yet here we have just such an ecosystem albeit one distinctly lacking in aesthetic appeal. Nature is not only red in tooth and claw: it can also be brown, slimy and somewhat unappealing to the naked eye. Quite how we convince the lay public of this is something I still haven’t fully solved.