A tree’s rings don’t merely reveal the age of the plant — they can also recount a country’s history. In “American Canopy: Trees, Forests and the Making of a Nation,” author Eric Rutkow parallels the development of America with shifting attitudes toward majestic oaks, maples and sequoias.

Do we look at trees differently today compared with earlier times?
The book covers 400 years, and our attitudes have shifted 180 degrees in that time. The original European settlers viewed trees as an obstacle — something to be cleared. It’s not until 200 years later that you start to see a serious effort at conservation.

Where did your interest in trees begin?
It stemmed from an interest in hiking when I was a teenager. I spent a lot of time backpacking in the Catskills, the Adirondacks and the Delaware Water Gap. I became very interested in the historical stories about why these trees were there.

How much research did you do outdoors as opposed to indoors?
Most of the research required me to be in libraries, but whenever I wanted to sharpen my thinking, I would go on a tree walk. A few years in, I had to stop because I came down with a case of Lyme disease. I was able to catch it early enough that it wasn’t a big problem, but it’s only been recently that I’ve gotten back into backpacking again.

National Arboretum, 501 New York Ave. NE; Sun., 1 p.m., $12; 202-245-2726.