Why do woodlands smell so good?

Walking through a woodland is a feast for the senses. You might catch the sweet perfume of wildflowers drifting on the breeze or the earthy aroma of damp soil after rain. These familiar smells can instantly transport you back to childhood memories, lift your mood and help you relax. But what is it that makes nature smell so distinctive and why do we find it so appealing?

How do smells work?

Every time you breathe in, you also inhale invisible airborne molecules released by the world around you. These molecules bind to sensory receptors inside your nose, which send electrical signals to the brain. The parts of the brain that receive these signals are also where memory is stored and emotions are processed. That’s why certain smells can trigger memories and emotions.

What are the different smells in a woodland?

Plants

Plants produce scents to attract pollinators and pest predators, or to deter pests. No two plants produce the exact same scent. Sweet and floral smells, like roses and elderflower, attract pollinators who are drawn to the sugary aromas.

Plants that are pollinated by flies and beetles usually produce smells similar to rotting flesh and dung. Titan arum, also known as corpse flower, is known as the smelliest plant on Earth because it releases a foul, putrid odour, similar to a dead animal, to attract pollinators to its female flowers.

Trees

Some trees have stronger scents than others. Conifers, such as pine, release aromatic compounds called terpenes, which give forests their distinctive fresh smell – the scent many people associate with Christmas trees. Broadleaf trees tend to produce subtler woody aromas.

Fungi

If you’ve ever noticed a rich, earthy smell while walking through a woodland in autumn, fungi are often part of the reason. As fungi break down fallen leaves and dead wood, they release compounds that contribute to the damp, earthy aroma associated with autumn walks.

Petrichor

Oh, and you know the smell of earth after rain? It’s got a name: petrichor. It’s the distinctive earthy scent produced when rain falls on dry ground, releasing a chemical compound called geosmin into the air. Scientists believe we might be really sensitive to this smell due to our evolution, as our ancestors relied on finding fresh water sources and rainfall to survive. It’s increasingly becoming more popular as a perfume ingredient.

Why can you smell more in warmer weather?

Spring and summer are filled with scents because many plants and trees produce more aromas during the warmer months. Flowers emit stronger fragrances to attract pollinators such as bees, butterflies and moths. Warmer temperatures increase the release of these scent molecules and help them spread more easily through the air, making them easier for us to detect.

As autumn arrives, the opposite begins to happen. Cooler temperatures mean air molecules contract together, leaving less space for odour molecules to travel as far or as quickly. Instead, the air becomes richer with the earthy aromas of fallen leaves, damp soil and decay.

Temperature isn’t the only factor. Many flowers have evolved to release their fragrance when their preferred pollinators are most active. Plants pollinated by bees and butterflies tend to be most fragrant during the day, while those that rely on moths often release their scents at night.

Can different smells in nature be good for you?

Scientists have found that certain natural compounds in the air could have positive effects on both our minds and bodies. For example, Streptomyces rimosus, a microbe found in soil, has been linked to improved mood and reduced stress when it is released in the air and inhaled. Meanwhile, forests are filled with phytoncides, natural chemicals released by trees and plants. These compounds have antifungal and antibacterial qualities and play a role in boosting your immune system by stimulating your body to increase white blood cells. Terpenes emitted by conifers have been shown to have anti-inflammatory, antioxidant, analgesic and anti-tumour properties. Terpenes are also found in essential oils, contributing to their distinctive aromas.

The idea that forests can benefit our health isn’t new. In fact, it was explored extensively in Japan during the 1980s. The Japanese government studied the benefits of being in nature and found that pine forests release phytoncides that are beneficial to human health. They also found that two hours of mindful exploration in a forest could reduce blood pressure, lower levels of stress and improve concentration and memory. These findings resulted in the introduction and promotion of shinrin-yoku or forest bathing as both a therapeutic practice and a form of preventative healthcare, encouraging people to immerse themselves in nature. The practice has gained popularity worldwide as nature therapy and a simple way to support wellbeing.

Our sense of smell is also closely tied to memory and emotion. A familiar woodland scent can instantly transport us back to a happy memory, creating feelings of comfort, calm and relaxation. Research from the University of Kent found that people often formed stronger emotional connections with specific woodland scents than with the woodland itself. Participants associated particular smells with meaningful memories, and these scent-triggered recollections helped evoke positive emotions and enhance their sense of wellbeing.

More than just a pleasant smell

From the sweet scent of wildflowers to the earthy aroma of petrichor after rain, woodland smells are far more than pleasant fragrances. They help plants survive, trigger powerful memories and emotions, and even support our health and wellbeing. So the next time you head out for a walk, pause for a moment and take in the scents around you – your mind and body might appreciate the woodland in a whole new way.

It’s perhaps no surprise that research funded by the Woodland Trust found 90% of respondents believe woodland biodiversity has a positive impact on their wellbeing. Protecting and restoring biodiverse woodlands doesn’t just benefit wildlife, it also helps preserve the rich tapestry of sights, sounds and scents that make spending time in nature such a rewarding experience.