Scents of the Forests

For many, forests and woodlands are special places, some are considered sacred, and they are also associated with wellbeing. Being surrounded by trees, with the sounds of the air moving through the branches and leaves, or absolute stillness, can be a profoundly relaxing experience, and the diverse and complex scents of forest and woodland undoubtedly contribute to this feeling. It is recognised that being in touch with nature provides a sense of comfort and wellbeing. In this blog, I would like to talk about some of the scents of the trees that dominate these forests, and look at the role they may play in evoking such responses.

In my early days practising aromatherapy, I would use essential oils from coniferous trees such as pines, firs, cedars and cypress primarily to help alleviate pain, and debility, or aid convalescence, and to support the respiratory system, with perhaps less regard for their impact on mood. However, it was some interesting research conducted by Warren and Warrenburg in 1993 that began to change how I regarded the coniferous oils. They reported that the fragrance of Douglas fir had distinctly relaxing effects, said to be similar to those brought about by meditation. Now, Douglas fir (botanically, it is not a true fir) has a scent that is quite distinct from the other conifers, in that it has a slightly lemony, pineapple-like odour, with a very slight floral note. This is because it contains a significant amount of a compound called geraniol, which is not usually dominant in coniferous oils – it is named after geranium where it is an important constituent in the essential oil.

The better known pine oils have strong, penetrating, fresh coniferous odours – their dominant constituents are called pinenes, and these are the most abundant terpenes in the natural world. Pine oils and their pinenes are used in many household cleaning products, so often the scent of pine essential oil provokes comments about how its odour is reminiscent of disinfectant. Scots pine oil is obtained from the needles of a beautiful conifer, named after Scotland, where it forms part of the ancient forests. Pine has been used over the centuries by many peoples, from the Egyptians, Romans to the North American Indians, for its wood, as a medicine and incense. However, in a pine forest, it is the fresh resinous scent that will be noticed. This scent is often experienced as instantly refreshing on the mind and soothing on the emotions.

The first also have fresh coniferous fragrances, and their essential oils may have slight lemony notes, whilst lacking the slightly harsh notes of the pine oils. Most of the firs are characterised by similar constituents, including the pinenes. Recent studies have highlighted the importance of fir species to good health. For example, Satou et al. (2011) demonstrated that inhalation of the essential oil of a Japanese species of fir could reduce anxiety. This particular fir is prevalent in Hokkaido in Japan, where shinrin-yoku is practiced. Shinrin-yoku translates as ‘forest bathing’, or ‘taking in the forest atmosphere’, and the practice has been shown to have numerous and measurable health benefits. Tsunetsugu, Park and Miyazaki (2010) have been focussing on the ‘Therapeutic Effects of Forests’ project for several years now. They have been investigating the physiological effects of exposure to the ‘total environment’ of forests, including deciduous broad leafed forests as well as conifer dominated ones, and also the effects of certain elements (such as the odour of the forest as well as some essential oils derived from forest species, the sound of running streams, and the scenery) in relation to their physiological effects (including central and autonomic nervous system activity and biological stress markers). Their work has confirmed that shinrin-yoku can reduce stress, reduce blood glucose levels in diabetic patients, increase natural killer cell activity and immunoglobulins A, G and M, reduce feelings of hostility and depression and lower blood pressure. They suggest that shinrin-yoku is ‘forest medicine’ and the practice could make a significant contribution to human health. So, next time you take a walk in the woods, be aware of how you are feeling and the enormous benefits it can bring.

The Siberian fir is part of the traditional medicine in Siberia, helping to maintain health during the very severe winters. Matsubara et al. (2011) demonstrated that it can also be used to maintain health in a contrasting contemporary environment. Prolonged visual display terminal use can lead to problems such as mental fatigue, sleep disorders and anxiety – and inhalation of Siberian fir is pleasant, and can prevent these problems without affecting task performance. Many of us spend hours at the computer, so perhaps a few drops of Siberian fir in a diffuser will help offset any negative effects…

Three cedar essential oils are frequently used in aromatherapy – Atlas, Himalayan and Virginian. The Atlas and Himalayan types are true cedars, with woody, warm, slightly camphoraceous and resinous notes. The Atlas and Himalayan types are botanically close, and they are related to the famous cedar of Lebanon – the earliest cedar to be used for its volatile oil and for construction of temples. The high oil content in the wood meant that it did not decay, and it could also repel insects, including those that would attack the wood. Early Egyptian uses of cedar included embalming and perfumery, and also of course as an incense. Cedar is still used as incense and for healing in Tibetan medicine.

Although it is commonly called cedar, Virginian cedarwood essential oil is obtained from a species of juniper. The Virginian cedar tree is significant in Northwest/Pacific Indian tradition. According to the Cherokee, cedar wood holds powerful protective spirits. Pieces of cedar wood are placed in medicine bags, and also above the doors of homes to ward off evil spirits. Cedar wood was also used to make totem poles and ceremonial drums. In ceremony and prayer, cedar is burned –and in sweat lodges, cedar wood is used along with sage and sweetgrass, for purification. The Pacific Northwest tribes maintain that cedar brings in good energies whilst driving away evil and negative influences. Virginian cedarwood essential oil has a light, fresh, soft, resinous woody scent that is reminiscent of the forest environment – and it is often said that it can promote inner strength.

Cypress oil is obtained from the needles (leaves) of this iconic Mediterranean conifer. Cypress was widely used as incense in ancient Egypt and Greece, and it was also associated with the Underworld, and because of this it was, and still is, planted in graveyards. Therefore here there are mythical and traditional associations with the transition from life to death and re-birth, and consequently the scent of the oil is often suggested as a source of comfort and strength for those undergoing times of mental, emotional and spiritual transition.

However, not all forests are dominated by the aromatic conifers. The scents in deciduous woodland are quite different, as is the feeling evoked within their atmosphere. In many cultures, there are sacred groves. Celtic spirituality places particular significance on trees, and Druids consider the oak, ash and thorn to be especially important. In India, sacred groves are located in the Parinche valley in Mahasashtra. As well as having ecological significance, the sacred groves are important parts of village life. They are dedicated to deities and have significance to the local community. In these groves, ceremonies are conducted, festivals are held, medicinal herbs are collected – they are small, natural sanctuaries, with a wide variety of plant life (Waghchaure et al. 2006).

There are no essential oils from deciduous woodland trees that have been investigated in relation to their aromatherapeutic properties; however that does not mean that the deciduous woodland environment with all of its scents is not therapeutic for both the indigenous fauna as well as humans. The scent of deciduous trees, such as oak leaves, is described as a ‘green odour’. An animal study (Akutsu et al. 2002) demonstrated that inhalation of this green odour could positively influence the behaviour and physiology of rats with stress-induced hyperthermia.

So it would seem that although the greatest benefits could be gained from shinrin-yoku, because of our deep connection with the natural world, we can use the scents of the forest in our artificial environments to counteract stress and enhance wellbeing. They are also ideal scents to accompany meditation.

References

Akutsu, H., Kikusui, T., Takeuchi, Y., Sano, K., Hatanaka, A., Mori, Y. (2002) Alleviating effects of plant derived fragrances on stress induced hyperthermia in rats. Physiology and Behaviour 75, 355-360.

Matsubara, E., Fukagawa, M., Okamoto, T., Ohnuki, K., Shimizu, K and Kondo, R. (2011) The essential oil of Abies sibirica (Pinaceae) reduces arousal levels after visual display terminal work. Flavour and Fragrance Journal 26, 204-210.

Satou, T., Matsuura, M., Takahashi, M., Umezu, T., Hayashi, S., Sadamoto, K and Koike, K. (2011) Anxiolytic-like effect of essential oil extracted from Abies sachalinensis. Flavour and Fragrance Journal 26, 416-420.

Tsunetsugu, Y., Park, B-J. and Miyazaki, Y. (2010) Trends in research related to “Shinrin-yoku” (taking in the forest atmosphere or forest bathing) in Japan. Environmental Health Preventative Medicine 15, 27-37.

Waghchaure, C.K., Tetlai, P., Gunale, V.R., Antia, N.H. and Birdi, T.J. (2006) Sacred groves of Parinche Valley of Pune District of Maharashtra, India and their importance. Anthropology & Medicine 13, 1, 55-76.

Warren, C and Warrenburg, S. (1993) Mood benefits of fragrance. International Journal of Aromatherapy 5, 2, 12-16.

 Written by Jennifer Rhind