[John Mason]

See http://www.bbc.co.uk...onment-17235229 - isolated pockets of trees are thought to have survived the last glaciation on nunataks. Wow! That's weapons-grade tough!

Cheers - John

[Flatlander]

Yes - spotted that one - quite interesting. Do you really buy actual trees surviving, though? I can't read the full paper, unfortunately, so I can't see whether that is actually what they suggested (as opposed to what the BBC reported, which may well be different).

Are there any nunatak sites today in the Arctic (eg Greenland) that have live conifers? Some of the northern Taiga allegedly has very old trees (possibly older than those pesky Bristlecone Pines) which grow only very very slowly, but these aren't surrounded by ice sheets.

I can imagine that seeds could survive in a dormant state though - this seems quite likely. There are some classic arctic/alpine sites in Scotland that may or may not have been nunataks but retain a range of species not found anywhere else in the UK - Ben Lawers being the classic example. I'm not sure whether these are supposed to have survived in seed or plant form - I can't find a reference on the shelf.

Interestingly, Norway Spruce was once native to this country, but it didn't survive here, despite the ice not reaching the south coast.


I wonder how long it will be before you can take a portable DNA sequencer into the field? There will be a huge amount of ecological data to be had from this kind of research, but its still a bit expensive to sequence everything in sight. There was a recent project to sequence some of the Scots Pine on our local moors to see if they were 'original' (there are allegedly no "native" pines in England) but sadly it looks like they are continental imports.

[ldavidcooke]

Hey Guys,

Keep in mind, life usually finds a way. Even on the craggiest slopes, if there is a basin which can catch water and detris to create humus a seed can germinate. As long as there is sufficent light, food and water many forms of plants will adapt to what appears to be conditions beyond normal for that species.

(For instance in a region of a known temperature range of -25 to 10 deg. C, on a south facing slope melt water trickling down a sun warmed rock face can lift the temperature in a craggy face basin by more then 20 deg. ambient. This warmth can be just enough to allow a microcosom survive though the macrocosom conditions are untenible...)

[John Mason]

Love the idea of the portable DNA-sequencer, Tim!

LDC - agree, although it's a bit telling that the modern treeline even this far south is less than 600m ASL. That, however, may well have other reasons, a prime candidate being the intensive sheep-grazing on our hills (and red deer in Scotland) - both effective removers of young green saplings. One sees conifers planted higher than this although they are often sickly-looking things. But there would have been running water available on nunataks most of the year round. With glacial temperatures fluctuating 4-8C below those of the present day, there would have been plenty of above-zero days outside of the winter months...

Cheers - John

[Flatlander]

There are some Scots Pine near the car park at Cairngorm ski area (650-700m ASL) which were planted in the 1950/1960s in a sheltered area. These are perhaps 4 feet tall now! On the very tops there are dwarf willows and azaleas that creep along the ground, but I've never seen a pine that high up. There is a natural tree line on Creag Fhiaclach nearby which peters out into contorted and very small pines (mixed with juniper) at about 640m, though on S facing slopes the tree line might get up to 800m if undisturbed. That's certainly what SNH seem to imply:
http://www.snh.org.u...es/26.htm51.jpg

Mind you, if we compare modern climates, it is certainly less harsh in parts of W Norway (particularly with regard to wind) than higher up in Scotland, even if the summer maxes are a bit lower. I suppose it depends how far the ice reached out into the Norwegian Sea whether or not the same could have been true then.


PS I suspect the field portable DNA sequencer will arrive one day, and probably not very far off. T'other half is hoping it doesn't make field botanists redundant! (Somehow I doubt it). I think the first use of portable sequencers is going to be something a bit less useful and rather creepier - in airports.

There are also plans for miniature genome sequencers (only one-off shots at the moment) such as this one: http://www.wired.co....n-dna-sequencer . They reckon it will be possible to sequence an entire human genome in 15 minutes with 20 of them. From where we were 20 years ago, that is an incredible advance.

[scrapemedic]

One species survival versus possibly thousands becoming extinct is not conclusive evidence of the resilience of all life. If that was the case there would still be dinosaurs in the park; big ones, not just crocodiles or birds before anyone makes that connection.

[John Mason]

The other problem being that coniferous trees are not good eating.

"Only when the last tree is cut, the last fish is caught, and the last river is polluted; when to breathe the air is sickening, you will realize, too late, that wealth is not in bank accounts and that you can’t eat money."

Cheers - John

[Andy Mayhew]

Tim Prosser, on 04 March 2012 - 23:31, said:

I can imagine that seeds could survive in a dormant state though - this seems quite likely. There are some classic arctic/alpine sites in Scotland that may or may not have been nunataks but retain a range of species not found anywhere else in the UK - Ben Lawers being the classic example. I'm not sure whether these are supposed to have survived in seed or plant form - I can't find a reference on the shelf.

Never really given much thought to how the unique Lawers flora survived.

I can't see pines (or other plants) migrating upslope in order to survive a Glacial by growing above their normal range though? So a nunatak seems unlikely. Though possibly a sheltered valley that due to climatic/topographical reasons didn't become glaciated?

But as regards seeds surviving in a dormant state - that's certainly a possiblity, especially given other recent news:

Ancient plants back to life after 30,000 frozen years

[John Mason]

No. I prefer my fish fresh, not sweating like old gelignite in their plastic packaging. It's an argument for whoever manages the supermarket to be more clued-up about demand though!

Cheers - John

[Flatlander]

A bit more information...

At least one ice-free refuge is supposed to have been on Andøya Island, which is not likely to have been a nunatak in the sense pictured or described in the article. Presumably its proximity to the sea kept the ice sheet from invading it completely. It is quite low lying, the highest point being 700m. So on a nice sheltered, S facing slope.....that's a maybe.

Agreed that seeds are likely to be a better survival mechanism during particuarly harsh conditions. If one can survive 30,000, then why not 100,000...

Regarding the UK flora, I found this:
http://www.tandfonli...550870802338610

It suggests that most of the Arctic/Alpines did not survive in situ but were left behind after a northward migration from a refuge further south, although two species do have Scottish variants (like the Norwegian spruce trees) - particularly Saxifraga cernua (which is extremely rare).

[John Mason]

Not sure where Vill is taking this thread but no I do not feel guilt. If you must have the grim details, there is only one supermarket here and it only has a small section with "fresh" fish which tends to get sold pretty quick. There are two excellent fish-stalls on the Wednesday street market both of which are best visited first thing unless one has a compulsive urge to queue and both of which are gone early afternoon, sold out. I buy herrings off the one sometimes as you don't tend to get them on rod-and-line but the rest is all purchased by the many people who don't catch their own.

I wonder if your local Superstore has such a good track-record - though the lads I know on the WSF forum reckon the mackerel sold by such places are not fit to be used for bait! We're a fussy lot, us anglers, you see...

Cheers - John

[ldavidcooke]

Hey Tim,

As to seeds, generally the glacial ice flows would sweep/scour the surfaces clean and bear large bolders down stream. Seeds on the ground would likely provide an instant of lubrication before being smeered across the rocky bedrock..., or pushed hundreds of miles south or out to sea...

[Flatlander]

ldavidcooke, on 05 March 2012 - 17:09, said:

Hey Tim,

As to seeds, if the progress of the ice were to sweep/scour the surfaces clean and bear large bolders down stream with the flowing ice. Seeds on the ground would likely provide an instant of lubrication before being smeered across the rocky bedrock..., or pushed hundreds of miles south or out to sea...

Not in the ice free areas! The question is whether or not a growing plant survived in an ice free area, or whether the seeds survived in a deep freeze in the same place, until conditions became more suitable. It seems to me (especially given Andy's post) that the latter is more likely, but unless someone can find a 12kyr old tree somewhere in a Norwegian peat bog, we are unlikely to be able to prove it one way or another.

[andre]

Very interesting. There are some issues though with seed surviving under an ice sheet. As the flowing ice dynamics is supposed to sweep the sediments out towards the ocean, where they spend the rest of the time being named Heinrich events.

But if the Weichselian glaciation events were nothing more than giant mountain glaciers, sure why not.

On the other hand that would add maybe some five to ten more meters to the deficiency of the total ice volume and sea level lowering during the last glacial maximum.

[John Mason]

I guess we could do with having the abstract of the paper in question:

It is commonly believed that trees were absent in Scandinavia during the last glaciation and first recolonized the Scandinavian Peninsula with the retreat of its ice sheet some 9000 years ago. Here, we show the presence of a rare mitochondrial DNA haplotype of spruce that appears unique to Scandinavia and with its highest frequency to the west—an area believed to sustain ice-free refugia during most of the last ice age. We further show the survival of DNA from this haplotype in lake sediments and pollen of Trøndelag in central Norway dating back ~10,300 years and chloroplast DNA of pine and spruce in lake sediments adjacent to the ice-free Andøya refugium in northwestern Norway as early as ~22,000 and 17,700 years ago, respectively. Our findings imply that conifer trees survived in ice-free refugia of Scandinavia during the last glaciation, challenging current views on survival and spread of trees as a response to climate changes.

Cheers - John

[NileQueen]

John Mason, on 05 March 2012 - 13:22, said:

The other problem being that coniferous trees are not good eating.

"Only when the last tree is cut, the last fish is caught, and the last river is polluted; when to breathe the air is sickening, you will realize, too late, that wealth is not in bank accounts and that you can’t eat money."

Cheers - John

What? Are you out of your cotton-picking mind, John?!! If you had been a mastodon, you would see them (spruce anyway) as scrumptious. You don't think any animals eat pine?
It's not all about you and your dinner John :-P

[NileQueen]

Re: seed preservation: see the news about the Silene seeds that were resurrected
http://www.inquirebo...-years-208.html