Field of Science

Oldest known tree

I was feeling a bit meloncholy this morning and I could not exactly figure out why. Was it the end of a sometimes frustrating, sometimes exhilarating year, or the realization that the celestial cambium has added another growth ring, and we along with it are another year older. Was it because Janice Joplin was singing Me and Bobby McGee on the radio? And then quite by chance while looking for one thing (the world's first forest) I found another.

A Norway spruce (growing in Sweden) has been identified as the oldest tree on Earth. Growing at a high latitude this is not the towering giant you might expect; it barely tops 13 feet tall. This part of the tree is not that old, and you can't find a set of growth rings you can count, but the woody root stock has been carbon dated to nearly 10,000 years old. That means this tree took root just about the time the Pleistocene glaciers were pulling back and uncovering this area.

10,000 years makes this tree the oldest living individual organism on Earth. A very impressive record, and somehow knowing this has cheered me up. Although this spruce grows in a tough area, it's primary problem is winter and winds. At this latitude and in such a sparse community, the most common environmental mishaps that threaten big, old trees (lightening, fire) are relatively rare. So by growing slow and low, it has survived millenia.

It's quite likely some clones have lived longer, much longer, but it is the clone that survives, not the individual organism. Because they reproduce asexually, while genetically the same, the members of a clone are not the origninal organism at all, but copies, so the genotype persists not the individuals. Some unicellular organisms may form clones millions of years old, but at what point have enough random changes been accumulated in different copy lineages of the originial genotype that we would judge them different organisms? I have no idea.

There are aspen and sagebrush clones that are estimated to be around 10,000 years old, but no part of the original organism persists, just the genotype. So for now a Swedish Norway spruce holds the longevity record.

2 comments:

Watcher said...

Great post. Would you mind if I included it in the next edition of Berry-Go-Round? I'd be very interested in anything else you'd care submit as well. adventureREMOVETHISbotanist@yahoo.com Thanks!

Dr A said...

DrA is always happy to contribute. If everyone were a botanist, or liked plants like a botanist, the world would be a better place. Actually I think everyone wants to be a botanist, but it takes some people longer to figure that out than others.