Why do deciduous trees lose their leaves and why?

Question

I am asking this for a school project. If you can please answer by the 9th of August. Thanks.

Answer 1

Trees lose their leaves in the fall due to falling temperatures and lessened hours of light and, possibly, a difference in the quality of the light reaching them. The light rays are weaker because of the angle of tilt of the Earth's axis. A ring at the base of the leaf's stem begins to thicken and shuts off the supply of nutrients to the leaf. The leaf dies and the area of the ring becomes brittle. Winds cause the leaf to move and eventually break near the ring. The major reason leaves fall off is to save the tree energy during a period of lessened light and less available water. Trees have to have water to draw in nutrients. The water passes up the tree until it gets to the leaves, where it exits by way of evaporation through the pores of the leaves. Without leaves, the tree hibernates, so to speak, until more light and warmth are available to begin the new cycle.

Hope this helps, but you need check everything I've told you here because it's been a few years since I studied the subject and I may not be totally correct.

Good luck on the project.

Answer 2

It is an adaptation for dealing with winters.

during the winter there is less precipitation overall in most areas where deciduous trees live. Even less of this actually penetrates the ground due to the fact that much of it falls as snow.

so in order to survive this decline in moisture, trees that require high quantities of water go dormant in order to conserve what water they do get.

Leaves are responsible for over 90 of water loss in trees. So they drop the leaves, which drastically reduces the amount of water required to survive the winter.

Deciduous trees do not go completely dormant, they will continue to grow roots through the winter, just at a much slower rate.

Hope this helps

Answer 3

I always understood it to be as a result of the shorter daylight hours in the fall, and a reduction in photosynthesis. But you better do some on-line research and get additional details, or dispell my recollection.

Good luck

Answer 4

a little tid bit that may be fun to add to your project is that because leaves are made of nitrogen and therefore they are nitrogenous waste when leaves drop their leaves it's like they go to the bathroom only once a year! (a botany teacher told me that )

Answer 5

You have the internet, why don't you just do your own school work. What is this country going to become, the children of today don't know how to research. :(

What are you going to write in your bibliography? Yahoo questions? Or do you know what a bibliography is?

Answer 6

like hibernation for plants. energy savings