Carbon dioxide is essential for photosynthesis. The leaf stomata open to allow the intake of carbon dioxide, at this time the leaf tries to balance itself to live, as the water inside the leaf mixes with the air. In other words, the leaf needs enough sunlight and carbon dioxide to sustain itself for photosynthesis, but too much heat and water loss during this process poses a risk to the leaf. That is why the leaf tries to balance the process, which directly affects its shape.
For example, the so-called canopy of a tree and the leaves located at the top tend to be smaller, as they are located in the area most exposed to sunlight. The less the area of the leaves exposed to the sun’s rays, the less its size will be affected. So the leaves on the lower parts also tend to be larger.
Needle-shaped leaves, on the other hand, have a very low light-absorbing surface area. Therefore, it cannot capture a lot of sunlight energy for photosynthesis. They also have special pit-like “stomata” designed to prevent excessive water loss.
Coniferous trees are located in climates, especially those that do not receive a lot of rain, where careful conservation of water is an important survival criterion.
