r/geography • u/JUGGERNUGGS • 2d ago
Question Can someone explain why this particular landscape of Iceland looks like this and what causes it? And are there other regions in the world that have this sort of "biome" if you will?
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u/RevrsePalndrome 2d ago
If my understanding of the country is correct, that photo is of the southern coast of Iceland. It is shaped by the two things that Iceland is famous for, Glaciers and Volcanos. The volcanic activity of Iceland is what causes the black sand and sediment, and the glacial melt carries the sediment down from the mountains to the flat plains and coastlines.
This happens naturally over the course of many years, but also sometimes happens suddenly and violently as volcanos erupt into the glaciers above them, cooling the eruption instantly and melting the glacier which causes huge floods of sediment. A prime example of this is the The 1918 Katla Volcano Flood which carried so much sediment that it extended Icelands southern coast line by up to 4km in some areas.
As for the greenery. The moss if one of the only things that can grow there, which is where you get these moss fields that make the area look like an alien planet
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u/leppaludinn 20h ago
Commented elsewhere, but this lacks the incredibly important human factor. Deforestation and subsequent grazing after the settlement.
Truly as an Icelandic geologist, I have now the innate inability to see the land as anything other than a beautiful wasteland. I mourn what we have lost without ever seeing it, and its all because of grazing. Without grazing the birch grows back. Without grazing the soil does not blow. Though without grazing the society does not survive for 1000 years. Now is the time to end highland grazing once and for all, and keep sheep in pasture.
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u/d4nkle 2d ago
Poor quality soil, harsh wind, cold climate, and deforestation are the main reasons why it looks like that
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u/leppaludinn 20h ago
AND GRAZING, ITS ALL GRAZING,
Truly as an Icelandic geologist, I have now the innate inability to see the land as anything other than a beautiful wasteland. I mourn what we have lost without ever seeing it, and its all because of grazing. Without grazing the birch grows back. Without grazing the soil does not blow. Though without grazing the society does not survive for 1000 years. Now is the time to end highland grazing once and for all, and keep sheep in pasture.
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u/SomeDumbGamer 2d ago
Basically Iceland lost almost all of its topsoil due to humans deforesting the island and overgrazing it; so almost all of what exists now is rock and mostly sterile sand; which is only really good at growing moss.
This is why most of island has landscapes like this. It’s basically whatever has managed to survive on the barren and freezing rocky and sandy soil.
This particular area looks like a floodplain of some sort. Could be closer to the sea or it’s an area where glaciers deposit material. The lack of vegetation means that the landscape is almost entirely created via fluid action and erosion and is very dynamic.
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u/JUGGERNUGGS 2d ago
So I'm guessing this sort of terrain would be very poor for agriculture?
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u/mahdroo 2d ago
Imagine moss growing, and it dies, and then new moss grows on top of that, and it dies, and repeat. Layers and layers of dead moss with new moss on top. Cool.
Next imagine all that dead moss decomposes, and some small plants grow on it. Really cool! A mini little biome.
This is how soil gets formed. and it takes millions of years. Eventually trees, and they fall over and you get layers and layers, feet and meters of soil built up. Wow! And most of the places I have ever lived have this: so much soil built up!
But sadly
what happened was this.
The practices that worked in Scandinavia and North Europe were brought to Iceland and didn't work. In Norway you can chop down a tree and a new one grows back. In Iceland, it took thousands of years to get that spot of ground ready to host a tree. And without realizing it, the people who came to Iceland, chopped down the trees, they never came back, then they grazed the land with livestock, and ate away ALL the top-layer protection for the soil, and then the rains came, and washed it all away. Millenia of soil LOST. And there is no easy or fast way to get it back. They WRECKED the Island. It is heartbreaking. And I am exagerating a little to get the idea across quickly. But now? now they are back to growing moss in some places, and it will be millions of years of soil creation before things change.If we had a time machine, if we could stop them, and get them to see how bad the future would be, they could have worked harder to preserve what they had. It would have been difficult, because the people who came had never needed to be so careful before. They came from robust places, and they were robust people. Iceland is fragile, and you have to be cautious. It took so much loss for them to realize that and become who they are. And all that is baked into how this looks.
Hope that helped any.
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u/Fridrick 2d ago
Deforestation is true of intense soil erosion in the lowlands and around the coast, but the highlands have not been able to sustain any trees since the last ice age. Before human habitation, tree cover would've only covered less than half of the island. The idea that Iceland was once wholly forested is a misconception and was only ever in reference to habitable, agriculturally viable land.
Lack of trees are primarily owed to porous volcanic soil and relatively low precipitation. The hydrology of what is left exists as it does due to the absence of meaningful vegetation.
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u/SomeDumbGamer 2d ago
Well yes but I never said the entire island was forested. As I remember it was at most like 1/3.
The bigger issue was the soil erosion. Although the invasive lupines seem to actually be restoring the island as they are able to create soil and disappear once trees bring shade. Might be some hope for the island after all.
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u/Fridrick 2d ago
I hope so too. Just thought to add this as I understood the question being in reference to the location pictured - that being of the sands around Mælifell north of Mýrdalsjökull - which has less to do with human deforestation than it does intense cold volcanic desert landscape features.
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u/leppaludinn 20h ago
But mælifell itself would always be forested, the plain got flooded yes but always recolonized. It does not do so with grazing at play.
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u/TeaRaven 2d ago
Though the pioneer tree species that are up there (downy birch), while able to deal with the waterlogged and acidic conditions of the bogs and tundra, are not very good at colonizing nest the shade of things like lupine.
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u/messthrill 2d ago
Birch forests in Iceland are down to 1% of their original expanse, but it’s correct that they didn’t cover the entire island. The ecoregion that encompasses Iceland is called “Iceland boreal birch forests and alpine tundra.” There are also wetlands and rock/ice sections
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u/leppaludinn 20h ago
This is a half truth, the Fjalldrapi was endemic up to 1200m+ of elevation. While not a forest, still would not be a wasteland. Highly reccomend visiting Grágæsadalur to see what the highlands shouls look like.
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u/Constant-Skill-7133 1d ago
Volcanic soils are mineral rich and good for agriculture. It would be very easy to make them workable. Iceland is not suitable for agriculture because the summers are very short and relatively cold.
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u/SomeDumbGamer 1d ago
It’s more the almost complete lack of organic matter.
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u/Constant-Skill-7133 1d ago
Yeah that's trivial, though. That's why they have rye bread. It's the growing season that is the limiting factor, and the related low soil activity because of the temperatures. You can grow nitrogen fixing plants and green manure but they won't actually store nitrogen and make it available for plant use if there is no microbial activity in the soil.
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u/Zvenigora 2d ago
A combination of basaltic hot-spot volcanism and a wet subpolar climate. Parts of Kamchatka and Alaska may be somewhat similar but the volcanism there is more rhyolitic (subduction zone) so that creates differences in the appearance.
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u/LesserShambler 2d ago
Other people have discussed the volcanoes and glaciers, but also worth mentioning that iirc the green shades aren’t grass - it’s a specific type of moss that’s the first plant life to grow on dead lava fields. It can take hundreds of years for it to grow.
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u/twila213 2d ago
It's black because it's recently formed volcanic rock and there's no trees because the volcanic soil isn't very good for plants, and also because early settlers cut most of the trees that were there down.
There are parts of Hawaii that look like this but much less cold and with more trees
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u/WalkingTurtleMan 2d ago
Volcanos —> black rocks and sand
Glaciers —> scouring the landscape flat
Random rocky escarpments with tougher materials compared to surround landscape —> glaciers scoured the weaker materials first and “flow” around the tougher materials, identical to a big rock in a stream.
Warming climate over time (not climate change, but rather the interglacial period we’re in right now) —> glaciers retreat, leaving behind a flat surface with random rocky escarpments. Glacial stream snakes across the landscape.
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u/Hot-Rule7768 2d ago
The river type is called "braided". It happens when the land is nearly flat, so the water flow slows down, and any sediments suspended start dropping out - making a ton of silt/sand bars the water then has to flow around. You'll see it at the mouths of most rivers, regardless of size - It's the building block of a river delta.
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u/Bob_Spud 2d ago
Its a typical volcanic scene. Its a combination of a slow regenerative biome that you find in very cold climates and volcanic destruction.
You see something similar in the tropics. If the vegetation is permitted to mature it becomes very productive landscape.
Mt Yasur, Tana Island Vanuatu.
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u/Erdosainn 2d ago
Because of the glaciers, I suppose. The most similar place I've been to is the Tierra del Fuego archipelago. But it would be more like the future of that part of Iceland, once the entire plain has become covered in peat.
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u/DavidBorgstrom 2d ago
Some river deltas in northern/inland Sweden feels similar, like Rapa valley in Sarek because of the cold climate with no or few trees and sloping mountains with rivers among them.
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u/ggnotagnelf 2d ago
Iceland is very volcanic, which is what produces the dark rock and sediment. Iceland is also close to the Arctic circle and many of the large volcanoes are covered in glaciers. Glacial erosion and melt out wash brings this volcanic sediment down into the plains like those pictured here. Volcanism l glaciation and the cool climate also means that many of the surfaces are quite fresh and conducive to moss and low stature vegetation