Historically, trees had a marked spiritual value and thus had significant importance for religions (many ancient civilisations worshipped the sun and the trees – the two drivers of life) and for meditation. Over time the value has evolved from a religious and spiritual one, though such value stretched back even to 96AD where Roman senator Tactius defined woodlands and groves as “sacred depositories” and “revered”, and not to be “profaned by the steps of men”. Similar religious values can be found in Norse mythology, where the Yggdrasil (Tree of Life), an ash tree depicted growing from the depths of the earth to the heavens above and containing all life within, was of significance to Norse culture. Even in modern times the religious values continue however, such as in Lithuania where great Pagan feasts are marked by the wearing of masks to celebrate the natural world. Not only this, but the spiritual importance of trees can be seen in literature, such as with the Ents in the Lord of the Rings book series.
Sometimes we can get lost in trying to quantify the benefits trees provide, and miss the more intrinsic values trees provide for us.
Source: Latham, J. (2015) The Development of Forest Conservation in Europe. In Kirby, K. & Watkins, C. (eds.) Europe’s Changing Woods and Forests: From Wildwood to Managed Landscapes. UK: CABI.