It was that time of
stillness in early spring when the snow has fled but the intractable greys and
browns of winter persist. I set out into the veil of hibernation, in search of
a restive spring. I
walked along Wilket Creek park in Toronto and amid the winter duff a great
gnarly white willow tree beckoned
... So,
I got closer and closer and closer...
What I
saw excited and intrigued. I saw moss, lichen, and fungi nestled in deep
crevasses of rope-like bark. The ridges were so deep that when I captured one
with my camera, the next one looked like another tree in the background. Seen
up close, the bark texture resembled bone and stone. In one huge crevice a
spider had made its web and had ensnared some unfortunate insect for its
dinner. In another cavern-like fissure, I saw the brilliant yellow-green of a
new lichen. Here, amid the “dead” bark, an entire community was stirring with the
freshness of spring. The different bark textures of trees attract different
species that live on it. The deep fissures and crevices on the bark of white
willow provide a wonderful haven for various epiphytes such as moss and lichen,
and many species of insects and spiders. The invertebrates, in turn, attract
birds that feed on them.
Willow Bark
The bark
of a willow plays a similar role as our skin for us. It protects the tree,
particularly its soft living and growing layer. Tree bark is also home to many species,
providing an important micro-ecosystem in the forest.
Willow
bark protects the living and growing layer called cambium. Every growing
season, the living cambium adds a new
layer of cells to the xylem, which it
surrounds. The outer edge of the cambium produces another layer of cells that make
phloem, which transports sugars from
the leaves to the rest of the tree. Outside that, most trees have a layer known
as the cork cambium, which produces
the cork – the tough outer layer of the tree. This outer layer is all that we
usually see of the bark.
Willow as Warrior
The bark
of many trees make chemicals that protect against fungal and insect attack.
Birch (Betula) bark is high in volatile
oils—which make it great for lighting fires—and is so waterproof and resistant
to decay that tubes of birch bark can still be found on the forest floor
after the wood inside has decayed. Bark of most oak trees (Querqus) is high in tannins, which are toxic and
protect the tree from insects.
The willow
has salicylic
acid in its bark, branches and leaves that helps mediate the tree’s
resistance against various pathogens. It does this by inducing the production
of pathogenesis-related proteins through a rapid signaling process. The acid helps mediate systematic
acquired resistance in which a
pathogenic attack on one part of the plant induces resistance in other parts.
The signal moves to nearby plants when the salicylic acid converts to the
volatile ester methyl salicylate. Willow communicates...
Willow as
Provider
Willows enact an
important ecological function by colonizing areas that have been disturbed and
undergoing successional recovery. Because they grow quickly and easily propagate using stem
cuttings, willows can also be used to vegetate stream banks to help prevent
erosion and sometimes to re-vegetate other types of disturbed lands.
Willows are also common food—especially in winter—for mammals such as deer,
moose, and rabbits, among others. Willows are also an important source of
nectar for bees in early spring when few other species of pollinators are flowering.
Willows are also a good source of
renewable energy, which may prove important in the future. The willow
biomass can be burned directly, or it can be chemically converted into more
easily portable liquid fuels such as alcohol or a synthetic,
petroleum-like mixture. Willow
twigs are flexible and have been used to weave baskets, for caning, and to make
woven fences and other lattices.
Willow as Healer
Willows have a long history
of medicinal use. Many cultures are known to have chewed willow twigs to relieve
pain and fever. The original
source from which salicylic acid was extracted was the bark of the white willow (S. alba), a
native of Europe. This chemical is used to manufacture acetylsalicylic acid
(ASA), an analgesic useful for treating pain, fever, and inflammation.
Willow as Magic
The magic and legends
associated with the willow tree are often bound up with water—its preferred habitat—and
the moon. Hecate, the Greek goddess was the moon and of willow, taught sorcery
and witchcraft. The priestesses of Helice, also associated with water, used
willow in their magic and witchcraft. The Greek poet Orpheus carried willow
branches on his adventures in the Underworld. With its ability to regrow from
pollarded trees and cuttings, the willow symbolizes renewal, growth, vitality
and immortality to the Chinese.
References:
Brown, R.W., Lawrence, M.J. & Pope, J. 2004. “Animals
– Tracks, Trails and Signs.” Hamlyn,
London.
Freedman, Bill. “Willow
Family (Salicaceae)—Economic and Ecological Importance of Willows. Online: https://science.jrank.org/pages/7398/Willow-Family-Salicaceae-Economic-ecological-importance-willows.html
Judd, Walter S., Christopher Campbell, Elizabeth A.
Kellogg, Michael J. Donoghue, and Peter Stevens. 2002. “Plant Systematics: A Phylogenetic Approach.” 2nd ed. with CD-ROM. Suderland, MD:
Sinauer.
Klein, R.M.1987. “The Green World. An Introduction to Plants
and People.” Harper and Row, New York.
Mitchell, A. 1982. “Trees of Britain and Northern Europe.”
Collins, London.
Puplett, Dan. “Tree Bark.” Trees for Life. Online: https://treesforlife.org.uk/forest/forest-ecology/tree-bark/
Steven, H.M. & Carlisle, A. 1959. The Native
Pinewoods of Scotland. Oliver & Boyd: Edinburgh.
Street, L. & S. 2002. “The importance of Aspens for
lichen.” In: Cosgrove, P & Amphlett, A. (eds.). The Biodiversity and
Management of Aspen Woodlands: Proceedings of a one-day conference held in Kingussie,
Scotland, on 25th May 2001. The Cairngorms Local Biodiversity Action Plan:
Grantown-on Spey.
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| Nina Munteanu |
Nina Munteanu is an ecologist and internationally published author of award-nominated speculative novels, short stories and non-fiction. She is co-editor of Europa SF and currently teaches writing courses at George Brown College and the University of Toronto. Visit www.ninamunteanu.ca for the latest on her books. Nina’s recent book is the bilingual “La natura dell’acqua / The Way of Water” (Mincione Edizioni, Rome). Her latest “Water Is…” is currently an Amazon Bestseller and NY Times ‘year in reading’ choice of Margaret Atwood. Nina's latest novel "A Diary in the Age of Water" will be released by Inanna Publications in 2020.
