POPULUS TREMULOIDES
Also known as white poplar, golden aspen, mountain aspen, quaking aspen, or Quakies, Populus tremuloides is a truly amazing organism. It rarely reproduces sexually as a flowering plant, and when it does it does so only after a severe fire or under the most ideal climatic conditions. More commonly this cool climate clonal spreads through its creeping subsurface rhizomes. As it does so, Quakies shoots up what appears from above ground to be many independent trees. What may seem to be a whole forest of thousands of individual trees is actually a single organism. (Of course, this is not unlike a mushroom whose mycelium might spread as a silky web one millimeter thick for an acre or more below foot, only to be seen when its fruiting bodies erupt out of the earth.)
Aside from their interesting growth and reproduction, this tree is really a fountain of resources as well. While being the most widely distributed tree in North America – stretching from its dense populations looking out over the Arctic Ocean and spreading across virtually all of Canada, to more isolated populations all the way south into Central Mexico – it's also a resource for almost every creature that comes upon it. Everything from moose to bison, beaver to vole, and a whole menagerie of insects feed on its leaves, shoots, bark, and wood. And of course these trees aren't just food but are also hunting ground upon which creatures forage for their food. Many creatures also live in and on and make use of this tree's constituents for the construction of their dams, lodges, dens and nests.
Despite all this trauma visited upon it, Populus tremuloides appears virtually indestructible. While the clones, the individuals trees above ground, die off all the time or are decimated by a herd of goats, say, the underground mass typically remains untouched and can even go dormant for a century or more if it's not happy with its current situation. As well, more than merely being physically separated from the beasties that would harm it, and while above ground clones are also susceptible to illness, the parent appears impervious to disease and pests, and even more vicious attacks with modern herbicides. Farmers and foresters regularly attempt to kill these colonies in a desire to clear the land for more valuable plantings. And they so commonly fail. Killing the golden aspen is a serious undertaking. If you've ever tried to dig up the root system of a sizable tree you know why people resort to blowing them up with dynamite when that's an option. But you can't do that with this tree. Why? Well, take the root system of an oak, willow, or cedar tree (which may be five square metres) and multiply that by ten or even as much as a hundred thousand! Seriously. I kid you not. To wipe that out with one blast you'd need a military-grade tactical warhead. And as long as there is some surviving section of root you still might end up with a poplar forest in no time.
Well, how big are these tree/colonies? There's a colony of Populus tremuloides, technically a single male, living in Utah, named the Trembling Giant. He's labelled "giant" because his subsurface rhizomal mat encompasses an area of roughly forty-three hectares (that's the size of Vatican city or something around eight times the base of the Great Pyramid at Giza.) And as you'd imagine, all this area translates into some serious mass. This bachelor is truly massive, having earned himself the distinction of being the heaviest known organism on the planet, weighing in at six thousand metric tons. For scale, that's about forty-five blue whales. That's big.
But this is only part of the Giant's greatness: he also happens to be the oldest living organism, estimated to be perhaps eighty thousand years old. Yes, that's right, eighty thousand! I write "perhaps" because there's a running debate about his age. Some claim he could be as young as five thousand and others argue he's far more ancient – orders of magnitude more ancient. Extreme estimations place him in the realm of one-million-years-old. Of course, with this guy, unlike other trees, you can't just take a core from its trunk and count rings as done with other trees as it's composed of many trees of differing age. Some have attempted to date the colony by taking into account a range of factors including regional environmental conditions, its size and the rate of growth of its rhizomes (which differs between individuals based on things like sex and elevation), as wells as by looking at its DNA and that of ones of known age and then comparing the mutations that differentiate them. But there are limits and flaws with each dating method and so the debate continues. Sadly, it appears the Trembling Giant is dying. Old age? Disease? Environmental disturbance? Ennui? No one knows why.
So, many more questions remain about this truly amazing organism.
