Month: August 2014
As a member of the pea family, the Nootka lupin has root nodules for nitrogen fixation. We’ve also seen other peas, clovers and vetch plants capable of fixing nitrogen as we’ve travelled around Iceland.
Carnivorous plants, however, have a unique way of gaining nutrients which are not available in the soil. The butterwort (Pinguicula vulgaris) is quite common in a lot of the damp environments that we’ve visited. The succulent leaves are covered with tiny glands which secrete fluids containing digestive enzymes. Small insects are trapped on the sticky surface of the leaf, and are digested by the enzymes. The fluid is then absorbed back into the leaf along with essential nutrients such as nitrogen and phosphorus which have been released from the insect corpse.
Common butterwort has a pretty purple flower held on a long stalk to keep pollinating insects away from the danger of the leaves. At this time of year plants have mature seed capsules.
However, as well as producing seed, the Common butterwort can also reproduce vegetatively, producing offshoots and new plantlets.
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.
I spotted a yellowish line snaking through the heathland on the island of Hrisey in Eyafjordur and stopped to investigate. It turned out to be a large patch of of Alpine Clubmoss (Diphasiastrum alpinum).
When we looked closer these plants were releasing their spores and so with sun shining it seemed to be an ideal moment for David to talk about the giant tree fossil in the geology gallery!
One of the qualities which attracts visitors to Iceland is its wilderness, and all that open space can tempt people into testing their driving skills and the capabilities of their cars.
Unfortunately, as Guðbjörg Gunnasdóttir (Manager of Snæfellsjókull National Park) explained to me, these are very fragile environments which are easily damaged and susceptible to erosion. Soils tend to be loose, vegetation is very fragile and water can be channelled along tracks increasing soil erosion.
Tracks can take decades to recover and so the Environment Agency of Iceland is trying to raise awareness of this issue so that everyone can experience Iceland’s raw beauty.
We have seen quite a lot of evidence of old trackways on the Icelandic landscape. The one below was from our first day on the Reykjanes peninsula, where the compacted soil had been colonised by different species to those found in across the surrounding marshland.
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’…
View original post 157 more words
In many of the landscapes we’ve visited in Iceland we have found loose mounds of ash from eruptions, black sand dunes or debris from glacial meltwater streams. One plant which happily colonizes this unstable, well-drained ground is Lyme grass (Leymus arenarius), a tall grass with distinctive blue-grey leaves.
Clumps of this grass will spread, growing new shoots from underground rhizomes and so can create large swathes of vegetation across empty expanses of sands.
After the 1973 eruption of Eldfell in Heimay, Vestmannaeyjar, residents had to dig their town out of the tonnes of smothering ashes. To stop the material blowing off the volcano slopes and back into the town, they planted species such as this to bind the new surfaces together.
Lyme grass is tolerant of sea salt and tolerant of drought. It is found around Central and Northern Europe and has been introduced to many locations (such as N America). It is planted because of it’s ability or bind sand together, stabilizing environments such as fore dunes, but it’s spreading habit means that it can become invasive.
We visited the wonderful Arbaer open air museum in Reykjavik. Historic houses in need of love have been rescued and moved to the site of the Arbaer farm. Here they receive specialist treatment to restore them so that they can be preserved for people to enjoy.
One highlight particular highlight was the opportunity to see the turf roof houses, including the Arbaer farmhouse (the only building not to have arrived from a previous home).
This turf would help to insulate the house, trapping warmth inside for the residents; including the livestock. The stone walls of the barn also had turfs between the courses, stopping any potential draughts.
It made me think of the Norwegian fairy tale in ‘East of the Sun and West of the Moon’ about the husband who has to mind the house and decides to graze his cow on the roof.
While David Gelsthorpe stopped to collect some interesting basalt specimens, mine and Dmitri Logunov’s attention was drawn to this lovely juniper bush.
Growing over the rocks and through a mound of moss, this juniper has grown into a low-lying shape which gives it some protection from high winds and the winter snows.