Question

Describe 3 reasons why deciduous trees when under stress might lose their leaves.

Answer 1

Three reasons for loosing of leaves under stress for deciduous trees are:

1. Deciduous plants include ash, aspen, beech, birch, cherry, elm, hickory, hornbeam, maple, oak, poplar and willow, which starts flowering during the period when they are leafless. The reason is, as this increases the chances  of pollination. When there is less leaves the pollinators like the insects can get attracted to the flower without any obstracles. This asures pollination and increases the rate of pollinations.

2. The deciduous plants lose their leaves in order to conserve water or for better survival of winter conditions. These plants starts loosing the leaves in autumn season so that they can be prepared for the coming dry winter season. Water is very important for plants to carryout all the functions, but due to the coming dry weather they adapt themselves by shedding leaves which needs water for survival.   

3. By loosing leaves the deciduous trees conserve energy for later events. When unfavorable weather is detected, stress hormones in the trees are triggered. This process is called abscission where the leaves sheds off actively from the tree by specialized cells. At the begining of the abscission process, this deciduous trees reabsorb important nutrients from their leaves and keep them for later use in their roots. Chlorophyll molecules are broken down to get nutrients and conserve it's energy. That is why the color of leaves changes from green to red to yellow.