Aspens are only white when your shooting them against a dense, dark background. Aspens are really a greenish/yellow color. In a scene like this...sure, you could print it very contrastly and make the tree's white...however with the white snow, it would not look right!
No worries, Shawn. When I first saw the image, I immediately thought it was an AA image. Great work... having grown up in Colorado, my favorite tree is the Aspen. I quite like the way you captured them.
I think in a print you'll be able to lift the aspens by a zone or so. Maybe a preflash would help keep detail in the snow while letting reduce the main exposure?
Thanks everyone. I didn't mean that I wanted the aspens to to be white in a print. I'm well aware of how that is achieved, I was simply a little surprised to see them in person, having only seen them in photographs prior to this... Thanks again. Best. Shawn