How Can Plants Survive Drought?
Plants react to drought by conserving the water they have. Grass is a good example to explain this. During a drought, you will notice that the grass turns yellow and crispy. Believe it or not the grass is not dead. Instead, the grass has gone into “half sleep” and stops growing to conserve water. Water is crucial to a plant’s survival, from the smallest plant to the biggest oak tree in the forest. Water is imperative to the food process, called photosynthesis. They make it by the sunlight, water and carbon dioxide. Without water to assist this process the plants won’t grow and will eventually die. So to conserve the water they just “go to sleep”, so to speak.
Deciduous trees have their own drought survival mechanism. Their tactic is to drop their leaves early to conserve the water they have. All the leaves have an opening known as the stomata. When it rains the water goes in the opening; conversely, if there is too much water in the leaf some water goes out here in what is know as transpiration. During dry periods when there is a lack of water the leaves will close their stomata so they won’t limit the water they have. However if they loose too much water they will wilt.
During long periods without water, some of the trees will drop the leaves long before autumn and go dormant in an attempt to survive the droughts. Trees that will not drop the leaves each year, such as pines, hemlocks, and junipers, are better adapted to the droughts than the other trees. They simply retain water better, and don’t transpire as much.
We will discuss some best ways to preserve evergreens more as winter approaches.