The Nootka lupin was brought to Iceland to help to restore degraded soils. It’s use began in the 1960s when the Icelandic Forestry Service used lupin to fertilise newly-planted forest areas. As a plant which needs a sunny spot, lupins could not thrive once the trees grew tall enough to create shade. After this it was then sown by the Soil Conservation Service to help to improve soils.
Soil erosion is a considerable problem for Iceland. At the time of settlement, Iceland was actually more vegetated, with habitats such as forests, grasslands and willow tundra. Before the Vikings there were no grazing animals in Iceland (the Arctic fox was the only mammal) but with the people came the sheep, goats, cows and horses.
Centuries of sheep farming are thought to have taken their toll on the land putting an intense pressure on fragile grazing lands. Woodlands suffered when sheep could graze the regenerating shoots from felled birch and willow trees, preventing the formation of coppices. In addition, from the 16th to the 19th centuries, the climate became harsher slowing vegetation growth, and land was lost to disasters such as meltwater outwash caused by volcanic eruptions under glaciers.
Lyme grass and lupins can both grow in loose soils and help to combat erosion.
Hrísey is the second largest island in Iceland (after Heimaey off the south coast) and it was looking magical in the sunshine. The island’s name comes from the Icelandic word for the dwarf birch (Betula nana), hrís, suggesting that this was common here at the time of settlement. On this visit I found several clumps, but it’s been a much more prominent part of the vegetation in other places we’ve visited.
The island has not been grazed by sheep since 1974 and is now covered by low-growing shrubs and heath-land plants such as heather, crowberry, bilberries, mountain avens and woolly willow. The island is a birdwatching destination as over 40 species are known to breed there.
However, I was particularly interested in a plant new-comer, the Nootka lupin (Lupinus nootkatensis).
Introduced from Alaska for land reclamation, the Nootka lupin has taken to Iceland and has naturalized in many parts of the country. The lupin changes soil chemistry as it has root nodules containing nitrogen fixing rhizobacteria. Rhizobacteria fix nitrogen from the air, making it available for the plant to utilise and leading to soil enrichment. On the island of Hrísey, another introduced species, Cow Parsley (Anthriscus sylvestris) has started to grow within the patches of lupins where the soil is more nitrogen rich.
Many of the patches of lupins we found on Hrísey had been cut back, perhaps to try to decrease their vigor and allow light to reach the ground. Lupins grow taller than the low heathland plants and can shade them out, but they do not colonise vegetated heath as rapidly as bare ground so cutting may maintain the size of a patch. Cutting had spurred some of the lupins into some late-season flowering and so I collected some examples for the Manchester Museum herbarium.
Lupins are a bit like marmite, however, and so while some people hate them, others think they are a welcome addition to the flora. They are undeniably pretty and I would think that the bumblebees like them too. On Hrísey we spoke to Júlla, manager of the Júllabúð store…..definitely a fan.
Today I was delighted to have the opportunity to meet Starri Heiðmarsson, the Head of Botany for the Icelandic Institute of Natural History. As well as looking after the herbarium (which is based in Akuyreri), Starri is a lichenologist who spoke to us about his interesting research focusing on seashore lichens.
Earlier this year, I listened to the lichenologist Professor Nimis explaining the concept of nunataks to students of the University of Manchester in the Italian Alps and it is incredible (and quite sobering) to find out that scientists in Iceland are able to study colonisation of emerging nunataks as the Icelandic glaciers retreat.
However, while in Iceland I am specifically looking at the consequences of introducing invasive species in fragile environments (and collecting specimens of the Nootka lupin as an extreme example) and so I took the opportunity to explore this story further in conversation with Starri.
While Dmitri recorded his findings from a discarded cup (see below), I saw an opportunity to see what was growing along the edges of the marsh next to us. This included two species of cotton grass which were very striking (Common cotton grass and Scheuchzer’s cotton grass), marsh cinquefoil and bog bean, along with 3 introduced species brought to Iceland by human activities (Colt’s foot, groundsel, Common valerian).
One of the stories I really want to explore while here in Iceland is that of the introduced plants which have naturalised in the Icelandic countryside, focusing in particular on the Nootka lupin (Lupinus nootkatensis).
On the second day of our field trip to Iceland, we visited the interesting site lying in the southern municipality of Reykjavik, called Garðabær, which literally means ‘Garden Town’. We walked around the beautiful Lake Urridavatn surrounded by boggy meadows full of sedge, dwarf bushes (like blue berry) and cotton grass (see on the photo).
On the meadow side of the path to the lake we found a plastic cup thrown by someone a few days ago. Incidentally, the cup, which was partly filled with rain water, became a deadly trap to insects and spiders. Having inspected the content of the cup I found two specimens of crab spiders (Xysticus sp.; male and female), one specimen of the ground beetle (family Carabidae) and one harvestman (family Phalangiidae). So, the cup ‘worked’…
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