Hello autumn

October 10th, 2013

Hello GrrenZoners,

is your neighbourhood look like this now?

For sure that’s how big part of Europe looks, but what with your places? Do you want to know what is going on with leaves now? Even if you can’t observe it in your country, it is good to know how Mother Nature is doing this beautiful trick with colors.

Why do leaves turn yellow and red? Firstly, we need to know why they are green.

Plants make food to grow via photosynthesis – converting carbon dioxide and water into sugars using the energy in sunlight. This energy is captured by chlorophyll, the green pigment found in leaves and green parts of plants. The sugars are transported around the tree and stored in the leaves.  Sunlight and warmth are necessary to produce chlorophyll, which is also destroyed by bright sunlight. In summer, it is continuously created to keep the leaves green.

When there is a lack of sunlight, chlorophyll is not produced. Crucial chemical pigment behind leaves turning yellow is carotene – the main pigment in carrots, which is also found in leaf cells in the growing season. This is a yellow pigment but it isn’t visible until the production of chlorophyll slows in autumn. As the green fades, the yellow carotene remains. Low temperatures also destroy chlorophyll so cold nights quicken the process of leaves turning yellow.

But what with red leaves?

As a tree prepares to shed its leaves in winter, a layer of cells form across the base of the leaf stalk which restricts the movement of sugars back into the body of the tree. Concentrated in the leaf, sugars react with proteins in the cell sap to produce anthocyanin, a purply red pigment that causes apples to turn red and black grapes purple. Crucially, the production of anthocyanin is boosted by sunlight, drought and temperatures staying above freezing.

According to the article from The Guardian: the perfect ingredients for vibrant autumn colours are cold – but not freezing – nights, dry weather and bright sunny days.

Yes, we have perfect conditions for colorful autumn here in Poland.

GreenZoners, tell us about your autumn:)

One Response to “Hello autumn”

  1. farid says:

    oui c’est exact, bienvenue l’automne, c’est un paysage magnifique

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