Thursday, January 29, 2009

Reader questions invited

Reader questions invited

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One of the great pleasures of writing “Environmental Almanac” is the way it puts me in touch with people who share both an interest in the natural world and a concern for how human activity affects the rest of life on earth.

As I research segments, I have the opportunity to talk with scientists whose research is expanding human comprehension of everything from the soil beneath our feet to the atmosphere around us. I also talk with planners, policy-makers, engineers and others who are working to enable us to live well without imposing burdens on others around the world or in the future.

I also enjoy hearing from readers, whether they stop me to share a bird sighting, compare notes on bike routes, or speculate about the potential for wind and solar power to resolve the problems created by our current reliance on fossil fuel.

Over time, and with encouragement from others, I have wondered whether it would be possible to use “Environmental Almanac” to bridge the gap between readers and researchers by adding an occasional question-and-answer component to the column.

As I envision it, this might include using this weekly forum to investigate two or three questions on specific topics. For example, a while back when I ran a column on oak trees in Urbana that predate European settlement [click here to see it], a listener from Sidney emailed to ask how she might determine the age of mature oaks in her yard. I forwarded her question to University of Illinois Extension Forester Jay Hayek, who provided a reply that I found informative and entertaining, and one I thought other people might be interested to read as well.

Following is that exchange:

I was very interested in the article on ancient oaks as I have two very old Bur oak trees in my yard. I live in Sidney and my 2 story house has been in the family since 1909. In a family picture dated 1912, these two oak trees were already towering above the house. How do I safely determine the age of the trees?

Hayek's reply: There are three generally adopted methods to determine tree age: cut the tree down and count the annual rings; use an increment borer to extract a small core of wood and count the annual rings; or know approximately when the tree was established. Seeing that one rarely wants to cut down a healthy tree merely out of curiosity, an increment borer or historical data might be used to answer the question.

I'm not an advocate of using an increment borer on yard trees due to the small chance that infection may enter the wound made by the instrument; it’s not likely, but possible. Large prairie-borne bur oaks still alive and thriving in the prairie region of central Illinois have been estimated to be between 175-350 years old. My advice, use a best guess estimate of 150-275 years.

Of course it may be that readers are curious about broader topics, in which case a single question could also be the point of departure for a separate column.

So if you have a question about the natural world, or you would like to learn more about research on environmental questions taking place at the University of Illinois, send me an email at Otherwise, you could always just stop me the next time you see me birding or riding my bike.