‘Plants adapt by their fragrances — these enrich the environment and our lives

Context: Plants express their needs through the release of aromatic chemicals. They emit fragrances for both attraction and protection.

What is the significance of various fragrances emitted by the plants?

For protection, a certain fragrance is released when a leaf is crushed or when someone walks on grass. This is sharp and green, called ‘green leaf volatiles’, a general class of molecules which allows plants to put out a message that they are being injured.

– When a caterpillar chews on leaves, many plants sense that and respond by emitting green leaf volatiles which attract predators that can consume the caterpillar.

– The same fragrance informs other plants of danger — the plants can’t move away but they can move some of their nutrients inwards, further down from where they could be chewed up, saving their sugars from herbivores.

Nature’s fragrances are very important to humans too: They give humans a strong connection with their environment, bringing joy to lives and provide an important and rejuvenating break.

– Under the practice of ‘forest bathing’ which originated in Japan — this means stepping away from our work and screens, going outside to a place with trees and plants and taking time to absorb the freshness, colours, textures and fragrances of that experience.

Fragrance deeply also enriches our memories. So many of our feelings get intertwined with fragrances.

Business of synthetic fragrances

Today, the business of synthetic fragrances amounts to millions.

In the past 200 years, scientists discovered how to extract individual scented molecules from plants and use them to create perfume.

It began with linalool, a significant part of lavender, initially extracted to create scent — what followed was synthesizing these molecules from something completely unrelated, like turpentine.

Quite frequently, the smells of nature in commercial products — flowery fragrances, for instance — have nothing to do with the environment. These are scientifically produced, they’re more uniform, less expensive and often less reliant on using fertilizers or fossil fuels.

Way forward

This world of fragrances faces threats today.

Plants are very responsive to environmental conditions. With climate change, extreme weather events like heatwaves, wildfires and droughts as well as habitat conversion, many plant fragrances which evolved over millennia could change.

Once, plants would blossom on seasonal cues, like the coming of rains at a certain time — today, with these patterns changing, the world of fragrances which enriches our lives could change too.

The world needs to act to preserve and protect the environment.

Source: This post is based on the article “Plants adapt by their fragrances — these enrich the environment and our lives” published in The Times of India on 4th June 22.