the days are getting shorter, and the sun is no longer generously sharing its warmth with the earth, one of the most beautiful seasons of the year is coming – autumn. Like a mysterious sorceress, it changes the world around and fills it with juicy and unusual colors. The most remarkable of these wonders happen to plants and shrubs. They are among the first to respond to the changes in weather and autumn. They have three months ahead of them to prepare for winter and part with their main jewelry – leaves. But first, the trees will surely please everyone around them with their shades of colour and crazy colors, and fallen leaves will carefully cover the ground and protect the smallest inhabitants from severe frost.
Trees and shrubs in the fall. Autumn changes
In autumn, some of the most important changes in the life of trees and shrubs take place: changes in leaf colour and leaffall. Each of these phenomena helps them to prepare for winter and survive such a harsh time of year.
For deciduous trees and shrubs, one of the main problems during the winter season is lack of moisture, so in autumn all the nutrients begin to accumulate in the roots and core, and leaves fall off. A leaffall not only helps to increase moisture reserves, but also to save them. The fact is that the leaves evaporate the liquid very much, which is very wasteful in winter. Coniferous trees, in turn, can afford to use needles also in the cold season, because the evaporation of liquid from them is very slow.
Another reason for leaffall is the great risk for the branches to be broken under the pressure of the snow cap. If fluffy snow fell not only on the branches themselves but also on their leaves, they could not withstand such a heavy burden.
In addition, many harmful substances accumulate in the leaves over time, to get rid of which is obtained only with leaffall.
One of the recently solved puzzles is the fact that the deciduous trees, placed in a warm environment, and thus do not need to prepare for the cold, also drops the leaves. This suggests that the deciduous fall is not so much about changing seasons and preparing for winter as an important part of the life cycle of trees and shrubs.
Why do leaves change colour in autumn?
Trees and shrubs in the autumn. Autumn changes
As autumn comes, trees and shrubs decide to change the emerald colour of their leaves to brighter and more unusual colours. In this case, each tree has its own set of pigments – “paints”. These changes are due to the fact that the leaves contain a special substance, chlorophyll, which turns light into nutrients and makes the leaves green. When the tree or shrub begins to store moisture, and it no longer reaches the emerald leaves, and the sunny day becomes much shorter, chlorophyll begins to break down into other pigments, which give the autumn world of scarlet and gold tones.
The brightness of autumn colours depends on the weather conditions. If it is sunny and relatively warm outside, the autumn leaves will be bright and motley, and if it often rains, brown or dull yellow.