Several expletives escape my mouth as the monstrous gray poplar I’m cutting tilts in the wrong direction and pinches the bar of my chainsaw. I tug hard on the saw and push on the poplar, but I don’t have the leverage to move the tons of leaning tree. Finally, after several sweaty hours using winches, ropes, and a handsaw, I manage to topple the tree in the opposite direction I initially wanted to fell it in. It creaks and groans and crashes down hard, right onto the sheep fence! It takes another two hours to saw it up into firewood for sugaring, throw the limbs into a burn pile, and bend the fence back into shape as best as I can. Poplar is a very soft wood and easy to cut, it burns quickly which is great for boiling sap but not so great for burning in a woodstove to heat your home. Many people think of them as “junk” trees. My relatives that are New Hampshire natives call them “popple”, but they are also called white poplar, quaking aspen, and their scientific name is Populous tremuloides.
I’ve been clearing some of our land where a large poplar stand has grown for the past 60 or so years. It is in the middle of an open field on the edge of an old barn foundation and some of these trees are large, much bigger than I can put my arms around. They are also on the edge of our driveway and the limbs come crashing across it during some of our more intense New England storms. This causes some moments of panic when we are trying to get to work. So, my wife and I determined that we need to reclaim this section of field. I’ve read short facts and snippets about the biology of poplars. For example, white poplar mainly reproduce through root sprouts and this stand that I am cutting down are probably all genetically identical clones. Most of the trees in one stand are also all male or all female as well.
To get a better grasp on this particular group of trees I gathered some data on the poplar stand by counting growth rings of ten random trees and measuring the diameter at breast height of 10 random trees. Most of the poplar in the stand are bigger and I only found new saplings at the very edges of the stand out in the field. The sparse number of smaller trees in the undergrowth were mostly small maples and ash. The trees that I counted rings on ranged from 12 to 45 years old and were an average age of 29 years old. The diameters at breast height ranged from 6.4 to 19.4 inches (16.2 to 49.3 centimeters). I could tell that these poplars were fast growers, some of the growth rings measured 1/4 to 1/2 inch think. So, they were packing on quite a bit of girth in these years. It seemed to me that most of these thicker growth rings were when the trees were in their teens about 15-19 years old. This suggests to me that these were really good growth years or that these trees reach a critical mass with the number of branches and leaves at this age and are able to really take off and grow quickly.
While chopping these trees into movable bits, I’m intrigued by their shape and structure and I want to know more. Why do these trees grow so fast? Why do the grow where they grow? Can you figure out which tree is the original clone? Why do these trees seem to die when they get to a certain size? How old are the trees in my stand (I answered this one)? As I work clearing this spot, I will continue to do some research to learn more about the lives and deaths of white poplars.