Fall foliage meaning

The leaves of deciduous trees — the kinds of trees which change colour in fall, like aspens and oaks — turn from green to autumn colours when the chlorophyll inside them breaks down due to changing temperatures and less direct sunlight. With a lack of chlorophyll, pre-existing yellow xanthophylls and orange carotenoids pigments that help protect leaf tissue from UV damage are revealed.

Red and purple colours are caused by the creation of pigments called anthocyanins. In Alberta, red foliage is uncommon — likely because our fall season is much shorter than that of other Canadian regions and our trees prepare for winter far quicker. Even once winter has set in, shedding leaves — a phenomenon known as leaf abscission, beginning with the wearing down of chlorophyll — assists the environment by providing nutrients in soil.

The timing of leaves changing colour is because of the environment, but also partially down to genetics.

Fall foliage meaning in hindi

The genetic code of deciduous trees is what informs the colours they change, and when they change. Warm, long summers indicate a longer wait for leaves to change colour — along with increasing the number of wasps in the city, something we observed at the beginning of September. Pollution levels impact the timing of the leaves changing colour as well.

Tagged: alberta , calgary , Fall , fall semester , science. Graphic by Sylvia Lopez.