Research Associate in Ecosystems Modelling and Climate Data, University of Oxford
Disclosure statement
Tobias Jackson receives funding from the Natural Environment Research Council. Sami Rifai receives funding from The Oxford Martin School, The Nature Conservancy & The Met Office.
The Amazon’s new record-breaking tree.
Tobias Jackson, Author provided
Sometimes even the largest natural wonders can remain hidden from
human view for centuries. The Amazon is a dense place, full of life
with new species of flora and fauna being discovered every other day. Now, using the same technology that takes driverless cars from A to B, we – led by Eric Gorgens and Diego Armando da Silva, and along with colleagues from Brazil, Swansea, Oxford and Cambridge – have discovered the tallest tree in the rainforest.
At 88m tall,
it dwarfs the previous record holders by almost 30m. And it’s not alone
either. The Guiana Shield of north-eastern Amazonia, which accounts for
nearly 9% of the world’s remaining tropical forests, may contain lots
of these gigantic trees. With each one able to hold as much carbon
as an average hectare of rainforest, our discovery means that the vast
jungle may be a greater carbon sink than previously thought.
We didn’t just stumble upon these trees while strolling in the
forest. Between 2016 and 2018, Brazil’s National Institute for Space
Research coordinated a project to laser scan large swaths
of the Amazon. This project scanned 850 randomly distributed patches of
forest, each 12km long and 300m wide. Seven of these patches contained
evidence of trees taller than 80m. Most of them were located in the area
surrounding the Jari river, a northern tributary of the Amazon. Map of the journey showing
waterfalls and landmarks. Black symbols are waterfalls, blue symbols
secondary rivers and red star the target sites.Eric Gorgens, Author provided
Even we were surprised by the mammoth tree heights that the scans
reported, so we set out on a journey to confirm the findings with our
own eyes, determine their species and, of course, climb them.
The journey
We set off by boat from Laranjal do Jari in north-eastern Brazil, in
humid 35℃ heat. The first stage of our journey took us to the village of
São Francisco do Iratapuru, a community who produce sustainable brazil
nuts. The community provided four boats and 12 people to guide us up the
river and through the dense and unforgiving forest.
Without their expert assistance we wouldn’t have cleared the hurdles
that followed – the first of which was the Itacará waterfall. It took us
all of the second day to haul the heavy wooden boats and all of our
gear around over land carpeted with thick vegetation to avoid it.
Beyond Itacará, the river ranged from 300m wide and serene to 30m
with rocks and rapids. We were relieved to see that someone had packed
plenty of spare propellers for the outboard motors – by the end of the
trip we had used every single one. At one point our propeller hit a
submerged rock and snapped, leaving us without power or steering just as
we were trying to force our way upstream through a section of rapids.
We crossed the equator on the third day and covered 70km, before
spending most of the next day waist deep in the river, hauling the boats
up through eight kilometres of rapids and rocks with ropes and hands.
Having travelled 240km in total, we finally arrived at base camp on
the sixth day. Many of the tall trees were pretty close to the river, so
we could visit them quite easily from our camp – although cutting
through the dense undergrowth was such tough work that we didn’t have
time to visit all of the target sites revealed by the laser data.
We spent the next few days collecting samples and taking measurements
of the trees. The highlight was our climber, Fabiano, shooting straight
up the trees to measure their height the old-fashioned way – by
dangling a rope from the top.
We found at least 15 giant trees, all of which were over 70m tall and
some easily topping 80 m. Surprisingly in this diverse tropical forest,
all these trees were of the same species – Angelim vermelho (Dinizia excelsa). This species is common in the Amazon, often used for timber because of its strong, albeit smelly wood. Previously, hoever, it was thought to grow to only 60m.
We don’t yet know how these trees managed to grow so much higher. As pioneer species
– the first to grow into any new areas or gaps in vegetation – it’s
possible that they took advantage of some past disturbance that cleared
part of the forest, perhaps caused by a storm or by human habitation.
The fact that they have survived so long and grown so tall must be at
least in part thanks to their sheer remoteness from urban areas and
industry.
Carbon colossus
The laser scanning technology that has enabled this and other recent mammoth tree discoveries
isn’t just a plaything for tree lovers. It allows scientists to map
forest structure and carbon storage in amazing detail and at
unprecedented scales, and so better assess their importance in the global carbon cycle.
A number of projects are also collecting repeat data, which will allow
us to monitor the changing health in vital forests like these.
In this case, our research suggests that the north-east of the Amazon could store far more carbon than previously thought. Each Angelim vermelho can store as many as 40 tonnes of carbon
– that’s between 300 and 500 smaller trees, while occupying the space
of only 20. And although we only visited 15 trees, this was a small
proportion of the trees the laser scanning data revealed, which was
itself covered only a tiny proportion of the Guiana Shield. So, there
are likely to be many more giant trees out there – and some may be even
taller than our record-breaker.
Read more:
Amazon fires: eight ways you can help stop the rainforest burning
In the current political climate,
there are plenty of reasons to worry about the Amazon, but there is
also still room for wonder. The fact that discoveries like these are
still being made – even while parts of the forest are being destroyed by
logging, burning and agricultural expansion – demonstrates how much there is still to learn about this amazing and mysterious ecosystem.
Sadly, it is likely that many unknown species in the Amazon will become extinct before we even discover them. We must do all we can to protect this majestic rainforest and the treasures – both known and undiscovered – it holds within.
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Jon Richfield
logged in via FacebookI covet those gorgeous trees. We live in some challenging clay…