By Sue Crowley, executive director

Happy Halloween Ripples Readers!  This year’s Halloween is turning out to be wet and overcast with plenty of winds blowing the leaves through open areas, yards, down the trails, and beyond.

I was driving up I-43 toward Green Bay yesterday, and it struck me how many trees I had noticed that had shed most of their leaves except for some clusters on the very tops of the trees.  Now you know you are following a forester, a birder, a wildlife watcher, or plant enthusiast when the car in front of you seems to be suspect in either maintaining a consistent speed or veering slightly outside of its designated lane. The reason is this (me included): we tend to practice “moving-vehicle-tree-identification” (or of whatever natural element has caught our eye)! One loves a challenge at 70 mph.  Anyway, the trees I noticed were most likely cottonwoods or aspen (also known as popple). They looked a bit like candles with the flickering yellow leaves on top resembling flames. 

I wondered why the leaves at the top had not dropped, while all the rest had made their way to ground.  I honestly do not know the answer and found it curious to think that the top leaves seem much more exposed to the bluster of autumn than those lower down.  One hypothesis is that these top leaves are most definitely sun leaves versus those lower down known as shade leaves. Sun leaves tend to be smaller and thicker.  They do not need to be as broad to capture the sun’s rays, and they develop a thicker blade (the main part of a leaf) and perhaps the petiole (the leaf stem) that attaches to the tree. This thickness may mean it takes a bit longer to activate the cells in the abscission layer, which causes the leaf to leave the tree. 

Well, that’s my story for this Halloween.  Stay safe and enjoy the beauty of leaves all around.

Photo credit: Getty images, marekuliasz