Tuesday, November 08, 2011
Nature Notes: Color starting at the top
I've started noticing how most trees seemed to start changing colors at the top before the lower ones change.
There's an evergreen on the right hand side of the shot above so I'm only using the tree which fills in most of the shot to illustrate this top to bottom change over.
I can understand why trees often lose top leaves first because of the wind which would explain the one directly above but the wind wouldn't explain the direction of color change.
My largest oak tree won't fit into a shot so with the one above you only see the difference in the very top and middle of the tree but the bottom leaves have barely changed at all yet.
One reason I've probably not noticed this top to bottom color change as much in other years is because when you have a mix of evergreens and different trees like the shot above, there are so many different stages, as well as evergreens that don't lose leaves.
Above the colorful part is one tree and you can see that the lower leaves aren't as far along in the change as the top. The same is true in the next tree with the bottom leaves still being green and the top reaching full color.
From a different perspective the shot below shows how the different trees with green leaves rising above the colored ones would make it easy to miss this phenomenon.
The next shot is another one showing how different trees mixed together can explain why I have missed this top to bottom color change until I started looking for it.
It is getting quiet at the lake with far fewer water birds on the main part than almost any other time, although I am spotting spotting a fair number of ducks and geese in the coves.
I almost didn't recognize the titmouse on my deck below because they look so different when their feathers are fluffed out.
I know that trees start storing more nutrients in their roots during the winter which is part of the process of leaves changing colors and dropping off when day length, temperature and other factors change. But I don't know what explains why top leaves tend to change before lower ones. Please let me know if anyone has an answer to this question because I couldn't find one. Click for the home of nature notes.