Beautiful picture, are these a kind of poplar/aspen?
No, they are alders. On the thicker ones to the left you can see the rougher bark. (-:
Very cool!!! :D I have always wondered what Alders looked like. I know cotton wood, poplar, black poplar (balm of gilead) various forms of willow, but alders I have always been curious about. Sadly, this means the tree growing here which I thought may be Alder... isn't and I am curious as to what it is....
This picture is one of a typical Alder brook forest (or so we call it here, at least), usually with creeks at the ground. They look different if they stand alone! So, yours could still be an Alder, too.