Please help me with my school project about oaks, beech, and willow trees!

[Jenny86]

I am working on a project for school. I was wondering if you could answer my question. I live in southwestern Pennsylvania and I've noticed that the oak trees and the American Beech trees keep their leaves longer in the fall. The beech trees just started to lose their leaves last week and the oak trees are holding the majority of their leaves. Why do oaks and beech trees hold their leaves longer in the fall than other trees? I've also noticed that the weeping willows' leaves were still green in the middle of November. They just started to turn yellow last week. Why do their leaves stay green for so long?

I'd greatly appreciate any help!!

 

[Youngbuck20]

Oaks also hold their deadwood. Im just finishing up with school and the best answer ive heard is because they do lol. Thats why, they just do. What do you have to do for this project?

 

[treemandan]

A deciduous is a tree that looses its leaves after the bud under the stem of the leaf has matured and pushes the leaf off. Oaks are generally not a fast growing tree and take a little more time for buds to mature. Where the leaf stem meets the bud is very sticky and provides shelter for the young bud to mature which can take all winter on oaks. A bud on a beech is very sticky and grows simular to an oak.
Willows are a vigorous fast growing tree and will continue to photosythesis as long as its sunny and warm enough which it has been. Grass will do this too. You can take a cut willow log, place it on the ground and it will grow a new tree.
It has been warm around here for this time of year lately.

 

[treeclimber101]

Warm temp. As soon as the cold weather such as frost hit it will shock the layer and kill the leave , sorta kinda I think !

 

[Youngbuck20]

A deciduous is a tree that looses its leaves after the bud under the stem of the leaf has matured and pushes the leaf off. Oaks are generally not a fast growing tree and take a little more time for buds to mature. Where the leaf stem meets the bud is very sticky and provides shelter for the young bud to mature which can take all winter on oaks. A bud on a beech is very sticky and grows simular to an oak.
Willows are a vigorous fast growing tree and will continue to photosythesis as long as its sunny and warm enough which it has been. Grass will do this too. You can take a cut willow log, place it on the ground and it will grow a new tree.
It has been warm around here for this time of year lately.

Ill buy it, thanks.

 

[mesupra]

Marcescence, is the term given for a tree that looses its leaves in the Spring Vs. Fall. Oak and Beech are both said to be marcescent. Its believed that one of the advantages is the inability for large mammals to browse on the buds during winter.

 

[Jenny86]

My project

For my project, we had to pick something that we were curious about in the science world. I saw that many oaks, beech, and even some maple trees still holding their leaves and I've always ondered why they kept their leaves for so long. I have to observe several trees and collect data (ex what color are the leaves, are they loosing any, location).

I observed to big oak trees in this one yard.They are both the same size and shape. One of the oaks lost almost all of their leaves, while the other one is completely full with leaves. I'm trying to figure out why this is happening. Any thoughts?

Thanks everybody for your help!! This is helping me so much!

 

[Pelorus]

All the best to you Jenny with your project.
The two oaks you have observed may be producing different levels of plant growth regulators, specifically abscisic acid and cytokinens. Also, an early hard frost may prematurely kill the leaves on other trees like maples, which can cause them to be retained on the tree.

 

[Treepedo]

At the area the leaf is attached to the stem is an abscission layer and a protective layer.

The stimuli is shortened days and cooler temps.

Auxin is produced less and ethylene more.

The ethylene sets the abscission layer up to promote the synthesis of of enzymes to digest
the cell walls in said layer. With wind or other loads the leaf is finally shed.

The reason some trees hold on to their leaves longer is most likely due to higher amounts of
auxin the leaf. How this happens could be environmental, genetics or combination of both.

Hope this helps.

 

[M.D. Vaden]

At the area the leaf is attached to the stem is an abscission layer .... SNIP ... How this happens could be environmental, genetics or combination of both.

Hope this helps.

For the original opening post question, I agree with this reply, and snipped it down to the point that seems the shortest concise answer.

The abscission layer is the main way they loose leaves, and that gradually changes toward autumn and winter. Genetics is a big reason. Likewise, out here, sweet gum loose their leaves later than many other trees, and that's just the way those trees are. It's their genetic makeup. It can vary a little bit when they do it, and that depends on each years weather variation. And in that regard, environmental is a given for the shift of many species fluctuating earlier or later as a whole.

...

 

[TreeGuyHR]

Another factor is the species of oak, and individual variation within species. Pin oak will tend to hold leaves longer than other oaks n the same area, such as black, white, and red oaks. Younger oaks tend to hold leaves longer than older oaks too.

If you look at a bunch of wild origin trees, you will see that they are all a bit different in overall crown shape, central leader dominance, bark texture, leaf color and size, and the length of time leaves are held. These are phenotypic characteristics -- how the tree looks, based partly on genetic variation and partly on the environment in which it is growing.

Trees from nursery stock, if the same variety (a preferred individual from a population that is cloned by cuttings or tissue culture), will look very similar if grown in the same environmental conditions (such as a nursery row). Once planted out, they will tend to diverge in how they look because of environmental influences and "disturbance history" -- everything from car bumpers to pruning history, insect or disease impacts, squirrel claw scratches, sapsucker holes, and pet urine.:msp_mad: