Six months on, and I am back at Danum Valley Field Centre to
continue collecting data for my PhD thesis. And aside from the continuation of
my research project, a twist of fate ties this visit to the last. On one of my
final days here back in January, with my work coming to a close, and a sense of
entitled accomplishment, I allowed myself to lounge around and read the
magazines left by passing tourists and researchers. One of these was a
National Geographic where a photo editorial focused on the use of remote
sensing, or the collection of data using electronic sensors to reveal trends in
the world's geographic organisation. Along with images of satellite trajectories and shifting river beds, were images of tree crowns from above, their colours distorted so
as to appear in vivid technicolor, a Wonka-Oz-Dr.Seus-esque scene of pink and
purple.
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| Canopy of rainforest in Panama with colour indicating carbon uptake (green slow, pink fast). Photo by Gregory Asner, Carnegie Institution for Science |
These images were the work of Greg Asner and his colleagues
at the Carnegie Airborne Observatory, who use LIDAR (Light Imaging, Detection and Ranging) technology to scan huge
areas of the globe's surface, collecting terrifying amounts of data on its
composition. By flying a dual propeller plane shooting lasers down at whatever lies below, and
recording the returning light signal, the team are able to detect changes in
the chemical make-up of huge areas of the planet’s surface in a short amount of
time. Soaking in the images before me,
pictorial representations making seemingly complicated data incredibly easy to
interpret, I became inspired by how advanced techniques had made the collection
of information of global significance rapid and efficient. I also felt pity for
those who have had to spend years of repetitive fieldwork to gather a smidgen
of what was being shown here, collected in a single flyby.
And so back to this week, on the ground in Danum, where I
started my acclimatization by assisting others working here, getting used to
the heat and sweat, to the mosquito bites and wasp stings. Along with botanists
working on trees and vines, we trekked to plots of forest to record the size
and density of marked trees and lianas or vines. By repeating measures over
subsequent years, scientists can determine how a forest is evolving, either as
a result of its recovery from logging, or due to changes in global climate. For
there it is, a ghoulish presence hanging over everyone’s shoulder, a force which we would prefer to ignore, but whose ramifications will likely
impact on all of life on earth: human induced climate change as a result of
carbon emissions.
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| Botanist Julien Engel measures trunk diameter in French Guiana |
In recording tree growth, it becomes possible to determine
how a forest stores released carbon. Lianas and epiphytes too, long neglected
by scientists trying to see the woods through the trees, are now taken into
account as influencing not only forest recovery (their choking embrace
smothering trees and preventing their growth), but also in storing large
amounts of carbon themselves. Thankfully, international governments are
beginning acknowledge the threats of climate change. Carbon is now on the
global agenda, and with programmes such as the UN’s REDD+ promoting carbon
credit schemes and payment to countries for maintaining forest cover, trees
equate to top dollar. Carbon creditors, aiming to cash in on this emerging market
are placing large investments into projects which aim to strengthen
calculations of where carbon is stored and how much of it is there. And when
you require funds to fly a laser-firing plane across the globe, working for
such investors can prove highly tempting. And so, on my return to Danum, I bump
into Greg Asner himself, here with his colleagues to collect leaf samples to
enable a better calibration for future forest scans.
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| The CAO plane flying over the Sierra Navada, California. Photo by Gregory Asner, Carnegie Institution for Science |
The team take two approaches; firstly, using LIDAR, they can
calculate the height of the canopy from the ground, and its density, and thus an
estimation as to how much carbon is held by each tree. This approach, as Greg
says, pays the bills, and satisfies partner organisations interested in carbon
balances. But is also allows for flight plans to collect more data, using the
second approach of spectroscopy, or the analysis of different wavelengths of
light returning to the plane’s detectors. Different species of trees have
different chemical signals as a result of the physiological make up of their
leaves, which absorb and reflect varying levels of light. By collecting leaves
from trees which have been scanned, and identifying the species, you can have
an effective chemical fingerprint, in theory allowing future flybys to
determine not only carbon content, but also species diversity.
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| Dana Chadwick from CAO preparing leaf specimens |
The combination of traditional field techniques such as
specimen collection and identification, with more technologically advanced tools such as
LIDAR is making waves in how science is performed, and how
data is interpreted. Burgeoned by an increasing global conscience and demand
for this information, landmark projects such as the Carnigie Airbourne
Observatory are able to accomplish tasks which would previously have been
unthinkable, but which today are increasingly common. Tropical biologists are now often armed with drones and a GPS, in addition to measuring tools of tradition. With a serendipitous week of inspiration from fellow jungle researchers, I am ready to commence my next 3 months of fieldwork!
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