Why do leaves of different sizes and shapes?
2017-09-26 19:55
Why do leaves of different sizes and shapes?
Leaf size of trees depends on a simple formula: they grow so large, so far as the available water but not so large that the whole plant has overheated.
So, water is needed for growth. And the sun? Leaves collect the sunlight and through photosynthesis turn them into food. But if the direct sun light very much, photosynthetic engine begins to rotate too quickly and risk burning out, reports Rus.Media.
So when it comes to leaf size, plants are a simple algorithm: water for growth and sunlight for food. Somewhere in between — a good balance, in which the sheet grows the desired size with its unique set of environmental conditions.
Having examined 7 thousand plants around the world, Australian scientists have found a new variable in mathematics of nature. Not only the risk of overheating controls the growth of leaves, but also cold of the night. “You are these two ingredients together — the risk of freezing and the risk of overheating, and this helps to model the size of leaves around the world,” says Ian Wright of Macquarie University in Sydney (Australia).
In fact, plants are much more afraid to catch a cold than to get too much sunlight. And since conditions vary greatly, and also varies the size of the leaves.
But in response to another question, scientists believe much less why leaves look the way they look, and not otherwise? Why are pine leaves different from, say, fern? Of course, nature came up with this whole kaleidoscope of colors and patterns not just in order to get people excited. It turned out that neither the sun nor the cold night air did not indicate plants as “dress”. Rather, it is a “family affair”, well-established and is genetically transmitted. Form leaves of the tree — the reaction to his long-term ecological and evolutionary history.
A 2003 study scientists Macquarie University provides that the leaf shape also has a functional value. The right sheet should be ideally suited to the environment surrounding the plant. And for plants it is a matter of life and death.
The corners of the leaves, for example, play a role in how captured sunlight. Acute angles reduce the amount of light which can hold the sheet. Notched leaves can cast shadows on themselves. Round leaves, on the contrary, have a higher ability to capture light and carbon”. There are a few basic rules on the “design” worksheets. The letter must be sufficiently open to capture the sunlight for photosynthesis. Also the email should have the form to stomata — pores could absorb enough carbon dioxide to fuel the process. Here size plays a key role. Like solar panels, large leaves they produce as much sunlight as you can. Small leaves are afraid of too much sunlight and try to stay as close as possible to each other in the cold.
Each species tries to make the letter such that it was ideally suited to his environment. Otherwise the plant is waiting for the end.
Research of the Department of agronomy Iowa state uses ficus Benjamin as an example. Growers who sell ornamental plants often poluchayut complaints: “I bought a ficus Benjamin, brought home, and all its leaves fell off, one of them.” Their answer is simple: “Just take care of it. The leaves will grow again.” And the leaves did come back — just was a different size, shape and density than before. The fact that these plants grow leaves that are perfect for a particular situation even if this situation is moving from living room to the bedroom.
For survival a plant cannot afford to be perfect. Beauty is a byproduct of functional perfection.