Autumn arrives and the trees begin to change color, going from being green to being yellow or brown or even red. Winter arrives and all its leaves fall, being naked and disappearing its intense colors. But wait a moment, there are green trees despite the cold outside, how can that be? Well, if you have ever asked yourself that question, the answer is that what you are seeing are the adaptations of plants to environmental conditions. According to this, deciduous plants and evergreen plants can be differentiated. In Green . We are going to talk about the differences between evergreen and deciduous plants in order to understand better why we see those contrasts of colors during the year.
What are deciduous plants
The deciduous or deciduous plants are those whose leaves come off when the unfavorable time arrives (usually winter). The unfavorable time is usually that in which there are fewer nutrients available and fewer hours of light.
Leaves are the photosynthetic organs par excellence in plants, that is, they are responsible for providing organic matter to the plant through photosynthesis. During the winter there are fewer hours of light and the plants cannot produce enough food, so the production of photosynthesis is less and finally, the leaf is lost.
The green color of the leaves is due to the presence of chlorophyll in plant cells. Normally the leaves before falling become yellow, which means that the plant has stopped producing chlorophyll. Thanks to chlorophyll, plants can make photosynthesis, therefore, if there is no chlorophyll, there is no photosynthesis.
In addition, plants have substances that regulate internal processes, plant hormones or phytohormones. The abcísico acid (ABA) is a phytohormone that intervenes in the processes of fall of the leaves. The plant detects that the environmental conditions are unfavorable and begins to synthesize ABA that is transported to the leaves when the leaves contain a large amount of ABA the leaf finally falls.
The fall of the leaves is an adaptation to the environment in which they live. Normally the Atlantic forests are deciduous.
The evergreens are those whose leaves do not come off during the worst times. These trees also change the leaves throughout their life, but they do not do it with the same frequency as the deciduous ones and also the change of the leaves does not have to happen at the unfavorable time. The perennial leaves are those that last at least two years in the plant.
Remembering the above, if the fall of the leaves is an adaptation to the environment, then the maintenance of the leaves in the unfavorable time is also. Change all the foliage, every year is a task that requires a great energy expenditure for the plant, and depending on the conditions in which you live can do it or not. Evergreen plants prefer to keep their leaves in winter during the unfavorable season because they need to feed at all times. However, the deciduous plants should make a great energetic effort to keep their leaves alive under unfavorable conditions, for that reason they prefer to get rid of them and enter a state of latency, and when the favorable season arrives and the environmental conditions are better They can grow their foliage again.
The evergreen plants must endure the bad environmental conditions of the unfavorable season. For this, they have developed a series of adaptations. Some leaves like those of the oaks are small and have hairs to avoid freezing in the cold winters and the loss of water in the hot summers. The pines, for example, have transformed their leaves into pointy, needle-shaped needles, which are also hard due to the presence of waxes that give them protection against the cold.
Normally evergreen plants are found in areas with constant climates whether they are cold or hot. For example, tropical plants or high mountain plants, both have evergreen leaves. However, the deciduous plants are located in climates where there are more favorable periods and others less favorable.
What are the marcescent and semi-deciduous plants
Finally, it is worth mentioning the existence of two more types of leaves. We could say that it is an intermediate state between the two previous ones: they are the plants of marcescent and semi-deciduous leaves :
- The plants of marcescent leaves are those that renew the foliage every year, but they do not do it in the unfavorable time. It is an adaptation to climates with late frosts. The leaves of these plants lose their functionality in the unfavorable period, however, they keep them throughout the winter until the new favorable season. This helps protect the new buds that will form the leaves. Once the environmental conditions have arrived, the new leaves push the previous ones and they fall.
- The plant’s semi-deciduous sheet are those that slow the growth of leaves when conditions become unfavorable. They can generate smaller leaves, change their color or throw them away for good. When the conditions improve, the growth resumes and they become green again.