The reblooming of Antarctica

Discuss with friends or co-workers where they would go and what they would do if given access to cheap and effective time travel, and the answers are usually painfully expected. Well, they are if the idea is not to influence the timestream in any way. Get up next to the big stage at Woodstock to watch Jimi Hendrix. Check out the grassy knoll in downtown Dallas in November 1963. Sip champagne at the Battle of Hastings. Oh, you might have a few people who want to go further back, but only so far as to see a dinosaur or two. All of time and space to play with, and we’re still desperately limited to human experiences and human timescales. (Not that there’s anything wrong with this. If given the opportunity, and knowing that (a) I was going to change our current history irreparably if I made any changes and (b) I was never returning to my own time, I can think of lots of entertainment. Joining the French Resistance in 1942, for instance.)

However, were some madman with a blue box to give me an opportunity to visit any place and any time in Earth’s past, for a full day, I can think of two options. The first is to find a nice hilltop around 108 million years ago, and enjoy a picnic dinner while watching the asteroid impact that produced the crater Tycho on the moon. The other would be to drop off anywhere in Antarctica about 50 million years ago and go sightseeing. Not only would I see things never viewed with human eyes, but I’d probably see lots of things that aren’t even suspected. First and foremost, flora unlike anything else on our planet, then or afterwards.

The popular perception of Antarctica as a frozen, alien waste contains a lot of truth, but we’ve only known the continent for a little over two centuries. With 98 percent of its surface covered in ice, kilometers’ worth in some areas, precious little other than the coasts, the famed Dry Valleys, and some areas in the Transantarctic Mountains, the vast majority of Antarctica has been icelocked for longer than the genus Homo has existed. Because of the ice coverage, most of the continent’s features are obscure. To put it another way, Antarctica has a lake the size of Lake Ontario in North America, and it was only discovered in the 1990s.

(And before I start, I’d like to apologize to any and all Antarctic researchers and explorers reading this, because I feel your pain. I imagine you’re as sick and tired of references to H.P. Lovecraft’s “At The Mountains of Madness” and John Carpenter’s remake of The Thing, coming from people who think they’re the first individuals in the history of human civilization to ever make the connection, as I am to references to Little Shop of Horrors. Aside from legitimate reasons for doing so, I won’t bring up either for the rest of this essay.)

Naturally, that ice doesn’t prevent palaeontologists from making new discoveries, but it definitely gets in the way. Hints of the geological and palaeontological richness of Antarctica’s past keep emerging, particularly with dinosaur discoveries in the Nineties and Aughts (most notably with the Jurassic theropod Cryolophosaurus), but almost nothing is known about Antarctica’s animal life after the dinosaurs became extinct. Floral knowledge is even worse: thanks to pollen analysis and some fossils in accessible deposits, Antarctica was one of the last holdouts for the Wollemi pine until about maybe 5 million years ago. Today, only two flowering plants still live on Antarctica, mostly because so little of the continent ever reaches temperatures amenable to growth. For all intents and purposes, Antarctica is an entire continent above the tree line.

It also needs to be said that palaeontological evidence still only gives hints of Antarctica’s former zoological and botanical bounty. It’s possible to make informed assumptions about certain lifeforms based on studies of South America, Australia, and New Zealand, based on their former connection through the supercontinent Gondwana. For instance, just looking at carnivorous plants, considering their distribution through the rest of Gondwana’s territory and on pollen analysis of Australian sites, Antarctica probably had its own selection of sundews, butterworts, and bladderworts. Judging by their current distribution through the Pacific Rim, particularly in Tierra del Fuego, the triggerplants (Stylidium) may – may – have considered Antarctica home before the continent froze. The problem, though, is that without some sort of fossil proof, this is all supposition. Carnivorous plant fossils other than pollen are incredibly rare because they generally lived (and continue to live) in areas hostile to fossil preservation, and any surmisals on what survived where before the antarctic glaciation depends upon finding fossils that aren’t, as mentioned before, under two kilometers of ice.

In a strange way, this ties directly into important concerns over introducing the seeds of potentially invasive plants to Antarctica, because the one last time I’d like to visit for a day would be Antarctica 30 million years from now. One way or another, whether it’s by anthropocentric climate change, a change in the ocean currents that help keep Antarctica’s temperatures stable, or the continent’s gradual tectonic shift north, Antarctica is going to thaw. At that point, the whole land surface is the cliched but appropriate blank slate. As recent news concerning Silene stenophylla raised from 30,000-year-old seeds, some native plant seeds might survive the freeze and sprout again. Human-transported seeds could very easily get established, and will probably become extremely invasive for a time. The biggest vectors of new flora, though, will be the ones that have been around for millions of years: water, wind, and birds. And they’re going to go nuts.

This won’t be a sudden change, and we definitely aren’t going to see forests at McMurdo Sound in our lifetimes even if Antarctica’s entire ice sheet melted tomorrow. Most of northern North America is still recovering from the last big glaciation in the Pleistocene, with many soils still being nutrient-poor: some theories about the wide range of the purple pitcher plant Sarracenia purpurea compared to its relations lie with its encouraging animal life such as mosquito larvae and rotifers as a replacement source of nitrogen. (As such, if you’ve ever been to Newfoundland and Labrador, you’ll understand why S. purpurea is the official floral emblem and provincial flower. S. purpurea is perfectly suited for the bogs of Newfoundland, Ontario, and Michigan, as well as the Pine Barrens of New Jersey.) And North America wasn’t covered with ice for 5 to 15 million years, the way Antarctica has been. Once it thaws, the whole continent will gradually green up, and all of those plants will most likely be descendants of traveling seeds dropped within the last few hundred years. With Antarctica remaining an island continent as Australia gradually runs into Asia and produces a whole new run of mountain-building, comparable to India’s formation of the Himalayas, I’d love to see what the forests of Queen Maud Land look like in another geologic era or so.

Comments are closed.