TREE TRAILS
Why I fell in love with the Eucalyptus tree
Fire can be damaging to several plants. But eucalypts embrace it. Today, Eucalyptus trees are one of the most widely cultivated around the world
A kookaburra sits on an old gum tree, watching as orange-blue flames flicker in the distance. Peppermints, stringybarks, mottled gum trees stand to attention as the air crackles, heavy with foreboding. The forest floor is heavy with organic litter and their bark peelings, perfect fuel for the wildfire advancing rapidly. The wind picks up in the east, aglow with what seems to be a floating candle. When it comes into view, its blurry details sharpen into a 4ft-long curled, hollow tube of flaming bark from a ribbon gum burning 20km away. As it nears, a stringybark’s peeling trunk snatches the baton of fire, which sprints up into the tree, spreading from branch to canopy, reaching for the kookaburra in its gum tree. It flees as black smoke chokes the bush.
Australian landscapes, biodiversity and fire are deeply interconnected. As Victor Steffensen puts it in his book, Fire Country: “…nature has created the balance of no-fire and fire-dependent systems to provide tolerance and courtesy between them through fire.” No strangers to this fiery rapport are the eucalypts.
Eucalypts encompass 7 allied genera of woody plants bearing tough, capsule fruiting bodies called gum-nuts. Most members of this group are equipped with at least one of the following fire-adaptive traits: lignotubers, ground-level woody organs that contain a cavalry of vegetative buds, food reserves and vascular tissue; epicormic buds, snug in the branches and trunks of older trees from which spring new growth; thick, heat-resistant bark; encapsulated, hardy seeds that drop from the canopy when triggered by heat, coaxed into germinating by smoke. Where fire can be damaging to several plants, eucalypts thrive, embracing it in their growth and reproductive cycles.
Australia has over 700 species belonging to the genus Eucalyptus, the most well-known of the seven genera. Outside the continent, few occur naturally, such as in Indonesia and New Guinea, with the Philippines being the furthest in its range. Today, Eucalyptus trees are one of the most widely cultivated around the world, having been introduced in India, New Zealand, South Africa, Thailand, the US. They are valued for their rapid growth, ornamental qualities, windbreak properties and timber.
It was only at university in North Queensland, from 2008 to 2010, that I began to take notice of Eucalyptus trees despite having seen them in numerous cities, protected areas and army land in India. The very first house I lived in during this time had a River Red Gum poking out of a corner by the road. This tree sits intact in my memory because on my first morning in Australia, it held aloft for me a noisy bouquet of Rainbow Lorikeets, a colourful welcome.
The First Nations Australians, also known as Aboriginals, have an intimate, symbiotic relationship with the land. Their ecological knowledge, bequeathed to generations, is a living inheritance that has shaped Australia, its animals and plants. Eucalyptus seeds, gum, sap and leaves are used in traditional medicine, as bush foods, while the roots can be tapped for water. The didgeridoo, an indigenous musical instrument, is made from living Eucalyptus trees hollowed by termites. During a field trip across the wet tropics of Far North Queensland for an ecotourism class, I learnt of sacred Eucalyptus trees like the red gum, yellow and grey box. Grandmother trees, the oldest in the ecosystem, stand sentinel to the ravages of time, ‘Scarred’ trees were scarified to make artefacts, shields, canoes. Carved trees marked interment grounds and initiation sites, while ‘Birthing’ trees were testament to birth or placenta burial sites. To the First Nations people, trees are connections to ancestors, holding stories, kinship and purpose.
Practically every class I took acquainted me further with Eucalyptus trees.
The trees are an important resource for so much of Australia’s wildlife. The iconic koala feeds almost exclusively on its young leaves, while the Yellow-bellied Glider, an arboreal marsupial, prefers the sap. Some birds, like the Forest Red-tailed Black Cockatoo, have a penchant for the seeds and a great many birds, insects, bats and marsupials, the nectar. The trees offer hollows and crevices, which are in great demand. Burrowing under the bark, several insect larvae, like that of the Bent-wing Ghost Moth, feed on the wood, leaving signs of their presence in the form of scribbles, tell-tale zig-zag lines on the bark.
My natural resource management class measured the carbon content in eucalypt- and acacia- dominated landscapes. Our research echoed the findings of others on Eucalypt biomes, that these habitats stored significant carbon in both the living and the dead biomass. This does change if you factor in their fire-proneness, but according to research published in 2011, the re-sprouting ability of Eucalypts after fires makes them more effective long-term carbon banks than fire-influenced plant communities on other continents.
In India, I presented these results in 2011 at a conference on climate change held by my alma mater. Here I was accosted by a participant, angry that my Australia-based study promoted an alleged ground-water depleting genus in India. And so, I learnt of our controversial history and the raging debate surrounding the plants, specifically Eucalyptus tereticornis, the forest red gum, and E. hybrid, the Mysore gum.
To put it simply, the debate had two aspects, an ecological one and a socio-economic one. The ecological argument, which for the most part has been debunked, was that Eucalyptus plantations sucked up a lot of ground water, actively suppressed the growth of other plants, absorbed more nutrients than native plants, and comprised monocultures resulting in decreased biodiversity. The second argument, the real issue, was that plantation schemes promoted by the social forestry sector excluded marginal and landless farmers, perpetuating socio-economic injustices. All of this comes down to the management of Eucalyptus plants, specifically, human agency in decision making. And so, my interpretation of the Eucalyptus debate is that the true issue lies with governance and management, not the plants themselves as is the case with most introduced species.
I fell in love with Eucalyptus trees when I was helping a PhD student from my lab set up camera traps for feral cats in a property called Mt Zero-Taravale. Dwarfed by the towering elevated forests of Rose Gum, Red Stringybark, alternating with valleys of the Forest Red Gums, Bloodwoods, White Mahogany and Moreton Bay Ash, Poplar Gum mixed with Melaleucas, I couldn’t resist walking up to these giants and hugging them. Like the First Nations People, I felt a deep kinship with them, a connection I couldn’t explain at the time.
I spent five formative years in Australia in what was the emotional equivalent of a trial by fire. I survived racism, loneliness, a non-existent career in wildlife conservation, disillusionment, shame and depression. I survived burning, just like those Eucalyptus trees. And just like the trees, I too began putting out new growth after the flames had ebbed.
Rithika Fernandes is a Hyderabad-based urban ecologist at ICLEI South Asia, working with local governments on building sustainable cities
Catch all the Business News, Market News, Breaking News Events and Latest News Updates on Live Mint. Download The Mint News App to get Daily Market Updates.
MoreLess
First Published:30 Jun 2022, 12:30 PM IST
- Top Gainers
- Top Losers
- 52 Week High