I have, for quite a while, had an obsession with remote and extreme places, an obsession that has been strengthened as of late. While researches into this direction may seem to be merely a matter of trivia, they often highlight quite interesting facts that are of broad interest.
And so it is with my search for the world's most southerly tree. Having posed myself this seemingly trivial question, I was going to learn a lot about geography and biology. Before determining where the tree was, I had to determine where it was not. This part was fairly easy: the world's most southerly tree could not be in Africa, because the most southerly point of the African mainland is around 33 degrees south, practically subtropical. Australia, although a bit further south, is also out. And Antarctica, while obviously far south enough, has no trees, and for that matter, only two species of flowering plants. Having eliminated these possibilities, the two likeliest suspects were some point in South America, or else an obscure island lying somewhere in the Southern Ocean. There are some good candidates in the second category, such as Campbell Island, which is New Zealand's most southerly point, a small island that is uninhabited, but where a visiting British officer at some point decided to plant a tree, a Sitka spruce. The tree still stands, and is billed as the worlds loneliest tree. However, at 50 degrees south, Campbell Island is still further north than Tierra Del Fuego, the southernmost tip of South America. Tierra Del Fuego, which I of course knew of, but really didn't know about, is a fascinating place. The landscape is fractally complicated, consisting of a major island, deeply indented with long bays, and a series of outlying islands, also deeply indented, and with their own series of outlying islands. The major island, although it has a cool climate, is well-forested. The question of finding the world's most southerly tree seems to be finding how far south that tree cover extends. Apparently, the answer is that the world's most southerly tree grows on Hoste Island, the second largest island of the Tierra Del Fuego archipelago, and that it is of a species called Antarctic Beech. (Interesting enough, this assertion comes from wikipedia, which despite their incessant bleating about "factuality", does not actually have any references on this matter. However, there is a hardy beech tree that grows far south, so the assertion that it is this tree and this island seems reasonable, if not sure).
But to keep our skepticism, is there perhaps another tree growing somewhere south of Tierra Del Fuego? I think that such a thing should be taken as a good possibility, even if we don't have proof of it. Trees, much like cats, prefer warmth and comfort, but are quite hardy and able to adapt. I don't think it is impossible that on one of the many little tundra-like islands dotting the Southern Ocean, some krummholz-stunted willow is hanging on between two rocks, in a place where the three scientists who visit the island a year are unlikely to see. Such a thing is a possibility, but not a good one. There are two reasons for this: first, most of the islands around Antarctica are truly barren of any flora more complicated than grass, and second, these islands are not that far south. For example, South Georgia Island, which is a glaciated island with nothing more complicated than grass growing on it, is actually not that far south: about level with Tierra Del Fuego. None of the southern islands in any of the three oceans seem to go beyond the level of tundra. And that is perhaps the biggest surprise I had when investigating this, how truly different the northern and southern hemispheres are in terms of how far towards the pole vegetation extends. Prince Edward Island, part of South Africa in the Indian Ocean, has a tundra ecosystem even though it is at a latitude where vineyards are grown in Oregon. The South Sandwich Islands, a full 15 degrees further south, are tundra bordering on a truly polar climate and flora, even though they are at the same latitude as the panhandle of Alaska, a region of lush (if chilly) forests. And the actual Antarctic Peninsula extends beyond the Antarctic Circle, meaning that the northern reaches of the Antarctic continent are at about the latitude of Fairbanks, Alaska, an area that is quite well forested. In other words, the biggest surprise about my quest for the most southerly tree is how low its latitude is, compared to what I am used to in the northern hemisphere. If the hemispheres were close to being equal in climate, there would easily be trees growing on the Antarctic continent itself!
Update: I was asked if perhaps there may be a tree growing (artificially) somewhere in Antarctica. I queried our resident expert, who replied:
iceowl says I have personally not seen a tree. Though there is a greenhouse both at the south pole and McMurdo. Lots of plants. There might be a small tree in one of those greenhouses, but I really don't know. I'd bet all the bases have greenhouses though. Now, there is petrified wood in Antarctica, if that counts....