I wanted to write a short blog highlighting what I think is a great attribute of traditional Japanese gardens: their environmental benefits and thus an important dimension for the continued and enhanced conservation efforts.
This first struck me because of an affinity I feel between them and a Site of Special Scientific Interest (SSSI) at home in England. That is, not to mention their beauty, and the mental and physical wellbeing they lend. It is thus termed because of its vast array of moss species. When taking your time to appreciate the many wonders of the Japanese garden, you may find that moss is a near constant feature, underlying and creeping in at the corners of the whole garden. Akin to this is lichen. A symbol of clean air, in the crowded cities of Japan I have been amazed to see its prolific growth saturating almost every surface – dripping from rough-barked branches, sprouting out of stony lantern heads and characterising the faces of many a beautiful rock.
Indeed one study comparing a Japanese garden to a park, secondary forest and a lawn assesses the species richness (the number of each species within an area) of bryophytes (including mosses) on the soil, humus, rocks and tree trunks. Despite being limited to one example of each landscape type in a single city, the study determines that the garden has, quite significantly, the greatest species richness of bryophytes. A positive relationship between species richness and the area of rocks and water was also identified. It is likely that this is because these components enhance the habitat for bryophytes – allowing them to grow and reproduce more profusely. They lack a protecting coat of wax that higher plants have to protect against moisture loss; therefore humid environments are more readily needed. These amazing species’ also have the ability to absorb water directly from air or rain, meaning that the more saturated the surrounding atmosphere is, the more vivacious that their forms flourish. Rocks in the garden were more profuse than in any of the other sites studied – these characterful crystalline clusters are an integral part of the traditional Japanese garden. Compositions in both dry and wet areas of the garden further multiply the livable space for bryophytes, mirrored in their greater variety.
Specific management techniques and intensity of the garden, which is different to that of parks, forests and lawns, is also thought to contribute to the species richness. For example, the intense care of traditional gardens in their weeding, pruning, clearing of fallen leaves, steppingstone pathways and restriction of areas from the public all aid in the profusion of bryophytes. Weeding and clearing allows light and air to their delicate surfaces. Similarly, the pruning of tree branches gives passage to the skin of the tree where they may decorate it in dancing patterns of texture and colour. Habitat is thus created for the humidity loving, rock and bark mineralizing lichens. Of these immense symbiotic beings, I have never seen before so alluring the intricacies of tactility and decoration in such miniature. In a silent ghostliness, they beckon inquisitiveness. I have to admit my joy in watching them shape-colour-shift in their dazzling array through the seasons.
Of their sap-veined hosts, old trees are another asset to the traditional Japanese gardens. It is now well known that such wood, as well as dead wood, serves to create a rich diversity of habitat for many species of plant and animal. They house may nooks, holes and microclimates within them. Usually dead trees would be removed, but as the above study also suggests, perhaps we can enhance the potential of these gardens for conservation by allowing them to stay. Trees further provide us with the very oxygen we inhale, calming and cooling it as it gravitates around them.
Beneath the charming aesthetics lies the source and food of their foundation: soil. These distinctive gardens, which have developed over centuries of culture, have also developed through their associations with the soil and its own deep, secretive ecosystem. What unique relationships may have formed between the plants, mycorrhiza, bacteria and other multitude of living edaphic creatures of this veiled underworld?
The history of native plant use may also prove a unique source of conservation for these species, as well as the life that stems from them. In the true emulation of nature that many of these garden styles achieve, perhaps their value for insect, bird and animal populations is largely undervalued.
Bodies of water in the form of slick ponds, tinkling streams and majestic waterfalls within these gardens further act to enhance the environmental qualities of these gardens. Water has an innate ability to cool in the hot temperatures of summer, and retain heat to reduce the frost damage of plants in winter. In the vast scope of a large city’s microclimate, such liquid glass is vital in creating equilibrium of climate.
The myriad of natural features that many a traditional Japanese garden embodies stands to provide us with a lot more than a beautiful sight for a weekend. Rooted in their original conception is the unspoken thought: conservation. They signify man coming closer to nature, its components and vital network of processes. They are an essential platform for developing our understanding and relationship to nature.