Sunday, August 22, 2010

Aspens and Chernobyl: nature's resiliency and ability to survive or not

Turning from the wet to the dryside for a moment, have you ever noticed how trees like Aspens seem to change into their fall colors simultaneously? Like the drop of a hat, one moment they're green and the next moment they are a striking brilliant yellow - almost as if they were one tree rather than individuals.

Well, in essence, they are one tree. Certain species, particularly aspens, have the ability to sprout new trees from an expanding root network without the need for reproduction or fertilization. Call it botanical cloning. In fact, some groves of aspens constitute some of the largest single living organisms on the planet (there are some fungus experts that might argue who has the title, as there are huge underground fungi that grow in a similar fashion).

However, a group of Canadian researchers from British Columbia have determined through groundbreaking (no pun intended) DNA studies, that this ability of the aspen to "clone" itself is not everlasting. Their studies show that this method of propagation, like with other biological species, can produce genetic mutations with each succeeding tree which impacts its fertility and its ultimate life span. At some point the tree (or trees) must reproduce by more "traditional" means.

According to Howard Falcon-Long of the BBC News,
"Dr Ally's team found that genetic mutations gradually build up with each subsequent generation of clone, resulting in a decline in fertility. This means that the aspen cannot clone itself indefinitely, but eventually must reproduce sexually or die."

Here's a video I shot along California's eastern Sierras which contains scenes of aspen groves in the midst of changing to their fall colors. Imagine that many of the trees you see here are actually all part of the same tree.

On the other side of the globe, the effects of genetic mutation and biodiversity brought about by contamination have been the subject of a long study at Russia's Chernobyl nuclear facility. After four years of study in and around the plant's "exclusion zone," scientists from the U.S. and France have reported a decline in the number of mammals, insects, and reptiles. So, with environmental contamination events - like Chernobyl or, say, the Gulf oil spill - when left to its own devices, without human interference, nature does not necessarily heal itself or bring itself back to "normal."

According to a BBC News report, birds were heavily impacted by the contamination. "During their census work, [scientists Professor Timothy Mousseau] and Dr. [Anders] Moller have also examined the effects of radiation contamination on the animals. They say that these impacts are particularly obvious in birds. 'We think they may be more susceptible, after long migrations, to additional environmental stress.' explained Professor Mousseau."

The scientists are not without their critics. Though their motives or supporting data may be questionable, Ukrainian scientists have said the opposite is true: that without human influence, animals are thriving in Chernobyl. Professor Mousseau claims their evidence is totally anecdotal.

Nature has amazing ways to perpetuate life; backup systems, if you will, like the cloning and traditional reproduction methods of the aspens. But mankind's technology has been able to produce impacts that can overpower nature's ability to heal and come back strong. We must carefully monitor what happens in the wild, what happens in and around facilities like energy and oil drilling plants, and we must not drop the ball when it comes to following up on the effects of our mistakes.

Read about the aspens and Chernobyl in BBC News.

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