Searching for the Tree of Life Near the Gates of Heaven

The Xylom™
The Xylom™
Published in
15 min readDec 15, 2021

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The needles of Maire’s yew (Taxus mairei) are being harvested to produce Taxol, a chemotherapy drug (Courtesy of Sanjay Paudel)

नेपाली

I’m cramped on the back of a 160 cc Honda unicorn motorbike, speeding along an ill-pitched twisting road in rugged terrain 5200 feet above sea level, thinking about my final year internal exam on ecology and fisheries that I ditched for a supposed hassle in some remote jungle of central Nepal.

The rising sun painted orangey color splashes in the eastern sky, but I could see none of that. My vision was blurry. The rushing cold January air was freezing my ear. I guess there were few loose ends in this tiny woolen cap that I was wearing. Trying to cover it up, I end up freezing my hand. “God damn it!” Now I got another opening at the other end. I definitely regret wearing this tiny cap.

I tried to grab a hold of anything sticking out of the bike, but that was not possible. Instead, I grasped on to Prakash Paudel, the driver, at his back and constrained my body as best as I could to hide behind him. Surely, I couldn’t face the rushing morning air.

It felt uneasy risking the trust of professors and ditching the internal exam like that, but Prakash (I call him by his first name to distinguish him from the other Paudels at the organization), the lead surveyor for the day, convinced me that it’s all for the good cause. Priorities huh! After all, he himself bunked several of those for works like this. And he’s certainly not alone: there are few other daredevils like him at Greenhood Nepal, a science-driven non-profit conservation organization based in Kathmandu.

I remember Sanjay Paudel, a distant brother of Prakash from the same town who also worked at Greenhood Nepal, saying, ‘instead of howling over long texts and boring lectures, I could do the real work that matters.’ We studied in the same college, yet he barely attended any theoretical classes. His uncle Kumar Paudel co-founded the institute back in 2012 and Sanjay was fortunate to have identified his passion in this field early. So, for aspiring conservationists at Greenhood Nepal, morning rides like this are fairly common. They run miles in two-wheelers and find passion advocating for nature and its conservation.

A wild Maire’s yew plant in rural Nepal. (Courtesy of Sanjay Paudel)

Today, Prakash and I were headed towards Bhumidanda inside Panauti Municipality in Central Nepal to carry out a survey of Maire’s yew (Taxus mairei), a conifer that remains critically endangered within the nation. Not much is known about Maire’s yew, to the point that taxonomists spent years justifying its existence. It was thought once as a variant of the English yew (Taxus baccata), a European counterpart of the species which can be found in Southwest Asia, and then the Himalayan yew (Taxus wallichiana), another endangered species native to Himalaya and Southeast Asia. Only did a genetic assessment (DNA barcoding) comprehensively establish it as an independent species.

The previous day, Prakash had called me explaining that this population assessment was the first of its kind for the species: “There are supposedly very few numbers of Maire’s yew trees across the nation; this assessment will tell us just how many are left in the wilderness.”

‘Wow! Saving an endangered species.’ I was feeling adventurous in my pre-final, post-Nescafe caffeine high. Less than 24 hours later, I was cursing myself out on the Honda on my way to Bhumidanda. There is no time to lose and there is no turning back.

The roads to Bhumidanda were treacherous and bouncy. We crossed Panauti, the historic city center of the area, and headed southwest. There, hideous stone excavations had scarred massive hills, leaving behind felled trees, rubble, and lots of abandoned houses. The terrible impacts of anthropogenic influence have not only ruined the virgin forests and driven away locals but also increased the stakes of the survival of Maire’s yew as a species.

I tried to grab a hold of anything sticking out of the bike, but that was not possible. Instead, I grasped on to Prakash Paudel, the driver, at his back and constrained my body as best as I could to hide behind him. Surely, I couldn’t face the rushing morning air.

The road ran at the base of two tall hills. Adjacently, the Roshi river flowed with the full thrush, roaring over the region. We could hear the thunder of excavation works at one side, while the roar of the river echoed on the other. As we headed further upwards, we could see clusters of trucks and tippers, all lined up the road. Cold riverine air was throbbing us to the core. Dust stirred up by all the construction only further shrouded the looming hills claiming the majority of the skyline — what would have been a perfect environment for the natural growth of Maire’s yew.

After further 30 minutes on the motorbike, we reached Kalanti, a beautiful village where we would be meeting Bhim Daai (Daai means elder brother), our field guide. We stopped at a few locations asking locals about this species. They knew the basics about the species, yet we got awkward stares, sometimes suspicious. Forest assessments and conservation advocacy was supposedly elderly work. But now they see two young fellas holding a diary in one hand and a handheld GPS tracker in the other, questioning about A TREE. I mean, it may not have been convincing at all. We were questioned, and we assured them about our purpose.

Landscape view of Bhumidanda and its periphery. (Saugat Bolakhe for The Xylom)

Fortunately, the research team from Greenhood Nepal had also been frequently here for the initial scoping and planning; the locals keep a close eye on who’s coming in and out of the village’s confines. Greenhood Nepal was not only planning to assess the distribution and abundance of the species: Reshu Bashyal, in charge of the project, told me that they wanted to educate locals regarding conservation and help them understand how to sustainably harvest the tree.

Bashyal started off wondering whether this novel approach, designed to touch multiple facets including advocacy and education, would convince townspeople to treasure the gifts of Maire’s yew. “We were doubtful, after all, we are all young and inexperienced,” She said. “But the Conservation Leadership Programme not only supported our project financially but also trained and groomed us for better.”

The organization advocated strongly and actually helped in halting an ongoing stone excavation work in an area dotted with Maire’s yew trees. “In the opposite face of this hill, around Chalal Ganesthan, there is a 300-year-old mairei tree”, Prakash told me. “We were lucky arriving for this survey in time that we got to learn about this three-century-old tree.”

A 300-year-old Maire’s yew perches atop an excavation site. (Sanjay Paudel for The Xylom)

The team filed a Complaint at the district forest division office and even reached out to “Hello Sarkar”, where genuine complaints can be lobbied to the national government. Thankfully the forest division office responded, allocating a conservation officer for the protection of the tree. They have compensated the owner to halt the excavation, barred the surroundings, and established a holding board to increase awareness of the tree.

For millennia, humans have looked at yews from afar as this double-edged sword of immortality and doom that they were unable to wield.

50 grams of yew needles could send a healthy adult to a literal heart-stopping, untreatable death. The finest ancient killing machines known to us were made from yews: English kings, Celts, Romans, Greeks, Egyptians, all the way back to a 5300-year-old unfinished bow in the Alps. Shakespeare even made a point to introduce yew needles into The Tragedy of Macbeth. On the other hand, the Celts also observed how shoots could seemingly grow out of a piece of “dead wood”; early Christians buried yew shoots with the deceased and used boughs of yew as ‘Palms’ at Easter. Rudolf Simek, Professor and Chair of Ancient German and Nordic Studies at the University of Bonn, even suggests that Yggdrasil, the sacred tree in Norse mythology, means “yew pillar”.

Everybody seemed to know how to kill with a yew, but no one was able to snatch life from the jaws of death. That changed when a young botanist named Arthur Barclay went on an excursion in the Pacific Northwest. As the American Chemistry Society chronicled in a National Historic Chemical Landmark dedicated to the moment in history,

On a hot August day in 1962 Arthur Barclay stood in Washington State’s Gifford Pinchot National Forest staring at a small stand of scraggly conifer trees. A Harvard-trained botanist, Barclay worked for the New Crops Research Branch of the Agricultural Research Service, an arm of the USDA. In the stand, at an elevation of 1,500 feet, Barclay spotted a twenty-five foot tall Pacific yew tree, Taxus brevifolia, which he designated B-1645 (so named because it was the 1645th plant sample collected by Barclay). Barclay and his three graduate student assistants collected two samples: PR-4959, stem and fruit; and PR-4960, stem and bark.

Barclay collected T. brevifolia, an evergreen, apparently because the strategy was to collect at random. Not much was known about the tree. It belonged to the genus Taxus, the yew, one of five genera in the Taxaceae family. The yew is native to the Americas, Europe and Asia. The Pacific yew, T. brevifolia, is a tree of medium height with reddish bark and flat, slightly curved needles about an inch long. It lives in the shade of giant conifers on the banks of streams, deep gorges and damp ravines. It has hard wood that is of limited use. It has few natural pests because most of it is poisonous. And, significantly for the future, the Pacific yew grows very slowly.

Barclay’s samples eventually landed almost 4500 kilometers (2850 miles) away at the Research Triangle Institute in North Carolina, because, again, nobody knew what to do with it. Fortunately, the duo of Dr. Monroe Wall and Dr. Mansukh Wani persisted, and in a decade-long process, successfully isolated a crystalline substance and named it Taxol — “tax” for Taxus and “-ol” for alcohol.

RTI scientists Monroe Wall (right) and Mansukh Wani (left) were responsible for the discovery of Taxol. Interestingly, its structure is so complex that Wall and Wani almost went to press with the side chain of the molecule placed in the wrong position. (Courtesy of RTI International)

Taxol became a silver bullet within three decades since it was first tested on humans: it has made its way on the World Health Organization’s Model List of Essential Medicines to fight back against previously untreatable or hard-to-treat cancers of the ovary, breast, cervix, nasopharynx, and many more. However, under the mindful watch of the tree of life, where there is death there will always be death. To extract the life-saving alkaloid, harvesters at first had to use a large knife to cut bark from the Pacific yew, killing it in the process. According to one source, the bark of a 40-foot Pacific yew tree, which may have taken 200 years to reach that height, yielded barely half a gram of the drug. When Audrey Avansino became the first patient to receive taxol treatment at Stanford University in 1991, six 100-year-old yews were sacrificed in her stead, death by a thousand cuts.

And that became a problem when the rest of the world caught word of the miracle drug.

However, under the mindful watch of the tree of life, where there is death there will always be death. To extract the life-saving alkaloid, harvesters at first had to use a large knife to cut bark from the Pacific yew, killing it in the process. According to one source, the bark of a 40-foot Pacific yew tree, which may have taken 200 years to reach that height, yielded barely half a gram of the drug.

Opposition ratcheted up from environmentalists in the Pacific Northwest with the way Pacific yews were inventoried and harvested. To quickly know exactly where yews were, the U.S. Forest Service recruited and hired Oregonians with logging permits to cut the trees in Mount Hood National Forest and strip their bark. There was just such a booming demand for the miracle drug that forests managed by the United States federal government could no longer provide enough supply. Fortunately, Dr. Robert Holton struck gold at the turn of the century when he discovered a semisynthetic pathway to produce Taxol, earning him and Florida State University over 355 million dollars in royalties alone, the most ever generated by a university licensed technology. Nowadays, using Holton’s formula, yew needles are harvested to obtain 10-DAB III, the chemical precursor to Taxol.

A local dries Maire’s yew needles during the harvesting process. (Courtesy of Sanjay Paudel)

To maximize the production of Taxol, yews that have needles with higher natural concentration are preferred. The search for purity soon moved across half the globe to Nepal: it is suggested that anticancer drugs made from Maire’s yew are of the finest quality compared to those made from other yews. Rajendra Maden, writing (link in Nepali) for Himal Khabar, argues that Maire’s yew when sold in the name of English yew or Himalayan yew, makes a large price difference. For a species whose history is built on a taxonomic identity crisis, this presents a big conundrum: more demand means more money for local harvesters but more stress on the Maire’s yew’s abundance in the wild.

In 2012, Nepalese botanist Ram Chandra Paudel led a research team, which collected sets of morphological, molecular, and climatic data to clarify the taxonomy and distributions of yews in the Himalayan region. It clearly delineated the availability of three species of Taxus in Nepal — Himalayan yew, West Himalayan yew (T. contorta), and Maire’s yew. The research comprehensively concluded the availability of Maire’s yew around the three districts of Central Nepal including Sindhuli, Kavrepalanchowk, and Makawanpur. Researchers hypothesized that Maire’s yew was more threatened than others.

But its proper assessment was lacking. Nepalese government data shows that on an annual basis Nepal exports around 45,000 kg tons of yew needles regardless of species, yet they have no idea exactly how much of that consists of Maire’s yews. Despite being listed under CITES appendix two that regulates its international trade, few seem to be concerned about specifically how this endangered plant is harvested. Few folks know about it, very few cultivate it, and even fewer conserve it. Until recently, nobody knows where they are, and how many are there left in the wild.

In Nepal, those who know where the yews are don’t know how valuable they are, while those who see the tree’s value simply don’t know where they are.

Bhim Daai (left) talks to another local. (Saugat Bolakhe for The Xylom)

Bold voice, talkative, blackish lips, Bhim Daai is a typical rural Nepali. We first met him at the village’s milk station, where he sold a can of buffalo’s milk. Aluminium can on one hand and a cigarette on another, he waved us hello. Prakash recognized and greeted. We passed by his small yet typical hut. He was welcoming enough to offer us a morning Dal Bhaat and we were hungry enough to devour. Tightening our shoelaces, we braced for the walk. Khurpa — a short-handled cutting tool — in his right, Bhim Daai led the way. We had a simple job: find the trees, measure their width, tentative height, and their location.

The sloppy roads were meandering and bushy. Three days back, the forest had received heavy snowy rain and our path was sure not straight. Cutting the messy shrubs, clearing the prickling bushes and hard tree branches, Bhim Daai struggled to make way. We dove deep into the forests for an hour and then finally encountered our first tree of the survey.

The tree was probably ten to twelve meters tall, its needless spread like that of a fern. It was the first time that I encountered this very species; it appeared nothing out of the ordinary, but I would later know that there is more than that meets the eye.

Bhim Daai and Prakash clear the way to carry out the Maire’s yew census. (Saugat Bolakhe for The Xylom)

Prakash unrolled the measuring tape, letting me handle one end of it. I went round circling the base of the tree trunk. He noted down its overall circumference in his diary. It wasn’t exactly possible to measure the precise height of the tree, so we made an educated guess.

“What do you think, 20 feet, Bhim Daai?” Prakash asks.

“Probably 18 to 20 feet.” Bhim Daai mumbled.

Prakash opened up his tiny GPS and waited for a minute or so to let it acclimatize. Clicking at its protruding joystick, he navigated through the device and scribbled in his diary the exact longitude, latitude, and elevation of the location. This only took 5 minutes for each tree encountered, but the process continued for the whole day.

“Isn’t it boring, Saugat?”, Prakash had asked me around mid-day.

“Nah”, I hid my lethargy. “Come on! I agreed to do this. It’s going good, man.”

As we plumbed through the sloppy hilly terrain the whole day and the following, less than 30 mature trees were recorded. We would record one tree here and another would be a kilometer away. Thankfully, Bhim Daai had known all about them.

Some yews in the wild were cut down, and it was concerning. To the researchers at Greenhood, it became evident that the species lacked systematic and sustainable harvest guidelines. There were unique challenges. The full growth of Maire’s yew took decades and its natural way of reproduction is hard since both the male and female trees would need to be nearby. Further, locals don’t know much about their buyers and are forced to obey the price that the dealer sets. On the other hand, pharmaceutical companies have been cultivating yews in nurseries, but that reduces the involvement of locals and again puts them at the mercy of a global conglomerate.

In Nepal, those who know where the yews are don’t know how valuable they are, while those who see the tree’s value simply don’t know where they are.

The Greenhood team wanted to straighten things out. In this process, as Bashyal informed and Prakash elaborated, they learned about indigenous knowledge surrounding the species and included relevant knowledge in the document. But still, the nursery-based cultivation may establish a reasonable population but what about the wild?

The Greenhood Nepal team talks to locals working in a yew nursery. (Courtesy of Kumar Paudel)

Kumar Paudel argues that there can be many consequences of uninformed rapid cultivation. First, it may result in haphazard cutting in the wild as a single host tree can produce thousands of propagules. Second, the propagated plants lack genetic diversity. This has the potential to cause inbreeding depression, a condition that reduces the biological fitness and plants immunity against disease and pests, and ultimately increases the likelihood of extinction.

Bashyal informed that the team is working for dynamic modes of advocacies and awareness. The team had published the first draft of the harvesting guidelines and ‘are working for its further revision and editions.’

Hiding in the shade of a big tree, the three of us were putting those concerns away for our afternoon lunch though. We rested our bags and opened our packs of dry WaiWai noodles, and packs of wrapped mango juice — a typical afternoon lunch in the wilderness. The conversation shifted. It was a delight to listen to Bhim Daai and his unique perspective in everything ranging from daily livelihood, farming, to kids, marriage, and everything.

Two hours later, we were nearly done for the day. On our way back, we passed his home. Ishwori Vauju — Bhim Daai’s wife — was working in the nearby farmland all day by herself. Bhim Daai had a lot of responsibility beyond being handsomely paid to point foragers towards the cash-growing trees. He owned four big buffaloes, eight goats, and few chickens. Sure, he led a busy farm life.

Waving us goodbye, Bhim Daai rushed to join his wife. The afternoon had turned into dusk; night fell faster in the jungle.

On my latest visit to Greenhood, Sanjay excitedly showed me an animation video clip and a video magazine. ‘We wanted to carry out a school workshop but the pandemic happened and you know the rest’, Sanjay said. To compensate, the team had come up with a digital way of advocacy: the latest development of the leadership project. The animation portrayed a boy that conversed with a mairei tree. And the tree responded with a typical motherly Nepali tone. They are planning to feature it in their coming workshops and have released it through their social media handles.

Looking ahead, Bashyal is confident in the team’s ability to empower locals in sustainable harvest of the highest quality yews and to conserve the existing number in the wild. “We can do more research on it. We can educate and empower more locals about it. And hopefully that may drive change.”

For a tree that has saved so many lives, making sure that it lives is the least one can do in return.

Saugat Bolakhe is an aspiring science writer based in Nepal. As a graduate of Zoology from Tribhuwan University, he is interested in writing about evolutionary biology, climate change, and conservation biology. Saugat loves music and you may occasionally find him screaming few Nepalese or English songs. He can’t dance that much but can sure do a backflip.

Alex Ip contributed research to this story. Originally published at thexylom.com

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