Every fall leaves of trees change the saturated green color for bright red and yellow shades. Leaves did not fall down yet, and the wood already "lilac, gold, crimson". What it is connected with? They did not dry up yet why lost the color?
Instruction
1. For a start it is worth remembering for what reason the leaves have green coloring. It is caused by existence in plants of such important substance as a chlorophyll. The pigment which is responsible for photosynthesis is continuously developed by all plants until temperature allows them to do it, that is practically all summer.
2. Then begins to become cold a little. Somewhere leaves change color in the middle of August. Production of a chlorophyll in leaves stops. The red and yellow pigment always contained in plants, but until then a large number of a chlorophyll did not allow it "to be shown" therefore color of a leaf was green. But now, when the pigment is not made for photosynthesis any more, the leaf changes the color.
3. But some leaves red, and some yellow. What caused this distinction? Biologists consider that the reason that the red pigment – anthocyan – is developed by plants mostly in the fall. In the summer it is practically not made in leaves. Anthocyans protect leaf cages from freezing in cold time, also interfere with overheating of a leaf in the hot afternoon, frighten off parasites.
4. Some areas of the planet dress yellow color in the fall, Europe treats them, and others in red is, mainly, America and Asia. Scientists tracked migrations of plants which are connected with movements of animals in these territories far back in the past, and came to a conclusion that the theory about wreckers is right.
5. The fact is that in America and Asia the migration of the animals trying to run away from cold (and together with them and plants whose seeds were on wool and in a dung of animals) happened, generally from north to south, and in Europe mainly from the East on the West. It is already more difficult as temperature in this direction not too strongly changes therefore many ancient trees in Europe died out. Parasites who ate them died along with trees as they depended on them. A paradox, but in general the number of wreckers for trees decreased therefore the European trees almost do not need protection against them.
6. There is one exception which confirms this hypothesis. In the Scandinavian countries, bushes which till fall become red, but not yellow as other trees of the region grow low. These trees have a long story, in cold times when their "relatives" died out, they hid under snowdrifts and therefore they kept "the" parasites. Therefore now these bushes are forced to paint leaves in red color to be protected from them while trees, younger in terms of evolution, stand yellow in the fall.