The leaves of most plants are green for much of the year, but in autumn, they transform into a stunning array of colours, including purple, yellow, and red.

This change is due to several factors, primarily shorter days, longer nights, and temperature variations, all of which impact the chemical processes within the leaves.

Leaves contain several natural pigments, such as chlorophyll, carotenoids, and anthocyanins. The green colour of leaves is primarily due to chlorophyll, which is crucial for photosynthesis, the process by which plants convert sunlight into energy. Carotenoids, responsible for yellow and orange hues, are also present in leaves throughout the growing season. Anthocyanins, which produce red and purple colours, are typically produced in late summer and early fall.

As the days shorten and nights lengthen in autumn, the amount of light available for photosynthesis decreases. Consequently, the production of chlorophyll slows down and eventually ceases. Without new chlorophyll, the existing green pigment breaks down and fades away. This decline in chlorophyll allows the other pigments, carotenoids, and anthocyanins, to become more visible, resulting in the brilliant colours of autumn foliage.

Carotenoids are responsible for the yellow and orange colours seen in many autumn leaves. They are always present in the leaves but are usually masked by the dominant green of chlorophyll. When chlorophyll production stops, the carotenoids' colours emerge. Anthocyanins, on the other hand, contribute to the red, purple, and blue hues. Unlike carotenoids, anthocyanins are not always present in leaves and are often produced in response to the changing conditions of autumn.

Here are three types of trees that showcase the beauty of autumn foliage:

Maple Trees

Maple trees are tall, often reaching heights of up to 29 meters. They are renowned for their beautiful foliage and are commonly found in the northern temperate zone and tropical mountainous regions. The leaves of maple trees are particularly stunning in autumn, turning vibrant shades of red. Their unique shape and rich colour make them popular for decorative purposes such as bookmarks and specimens. As autumn progresses, the red leaves deepen in colour and eventually fall to the ground, creating a striking carpet of crimson.

Ginkgo Trees

Ginkgo trees are deciduous trees that date back hundreds of millions of years. They can grow up to 40 meters tall and are distinguished by their greyish-brown bark with longitudinal cracks and fan-shaped leaves. Ginkgo trees are typically found in natural forests at altitudes of 500 to 1,000 meters. The growth of ginkgo trees is relatively slow, with the trunk thickening over several decades. In autumn, the leaves of ginkgo trees turn a brilliant yellow, adding a splash of colour to the landscape. Their high ornamental value and unique leaf shape make ginkgo trees a beloved sight in autumn.

Sycamore Trees

Sycamore trees are deciduous and can grow to heights of 15 to 20 meters. They are characterized by their green or greyish-green bark and broad leaves, which are yellowish-green and bright when in full bloom. Sycamore trees thrive in warm, moist environments and are not particularly hardy. In autumn, the leaves of sycamore trees turn a rich yellow, creating a picturesque scene. The yellow leaves hanging on the branches resemble a solidified oil painting, while the fallen leaves create a golden carpet on the ground, transforming streets into vibrant, colourful avenues.

In autumn, these trees, among many others, undergo a spectacular transformation, showcasing nature's ability to create beauty through change. The seasonal shift not only provides a visual feast but also reminds us of the intricate processes and adaptations that occur in the natural world.