Why do some plants shed their leaves in the fall?

There are two reasons why plants shed their leaves. The first reason is the inability of the leaf cells to survive the frost. There are no special substances inside the cells, like in conifers, that prevent water crystallization and cell destruction. Therefore, it is easier for plants to shed leaves than to develop adaptations to preserve them. In addition, photosynthesis is slow in winter. The second reason is the elimination of unnecessary substances and toxins. This is how the plants get rid of unnecessary substances. Therefore, the leaves change their color.