THE phrase “Big Science” brings to mind rockets, telescopes and
particle accelerators. When it comes to grand scientific gestures—and
the cash that goes therewith—those who wield field glasses and butterfly
nets in the name of terrestrial ecology seldom get a look in. Which is
surprising, as the habitat they study, namely dry land, is the one
actually occupied by humanity. But a group of American ecologists, led
by David Schimel, intend to correct this state of affairs. They plan to
shake up terrestrial ecology, and introduce it to the scale and sweep of
Big Science, by establishing NEON, the National Ecological Observatory
Network.
Finding the money for this project, which will be based in Boulder,
Colorado, has not been easy, but after a decade of discussion and
planning, America’s National Science Foundation managed to persuade
Congress to earmark $434m, the price of a modest space probe, to set it
up. The operating budget will be around $80m a year.
Dr Schimel’s team is thus now starting to wire up the landscape.
Ground has already been broken at three sites—in Colorado, Florida and
Massachusetts. Eventually, 60 places across the country will be covered
simultaneously. Once this network is completed, in 2016 if all goes
well, 15,000 sensors will be collecting more than 500 types of data,
including temperature, precipitation, air pressure, wind speed and
direction, humidity, sunshine, levels of air pollutants such as ozone,
the amount of various nutrients in soils and streams, and the state of
an area’s vegetation and microbes.
Crucially, these instruments will take the same measurements in the
same way in every place. By gathering data in this standardised way,
and doing so in many places and over long periods of time, Dr Schimel
hopes to achieve the statistical power needed to turn ecology from a
craft into an industrial-scale enterprise. The idea is to see how
ecosystems respond to changes in climate and land use, and to the
arrival of new species. That will let the team develop models which can
forecast the future of an ecosystem and allow policymakers to assess the
likely consequences of various courses of action.
Tower records
NEON’s researchers have divided America into 20 domains (see above),
each of which is dominated by a particular type of ecosystem. Each
domain will have three sets of sensors within it. One set will be based
in a core site—a place where conditions are undisturbed and likely to
remain so—that will be monitored for at least 30 years. The other two
sets will move around, staying in one place for three to five years
before being transplanted elsewhere. These “relocatable” sites will
allow comparisons to be made within a domain.
Every site, whether core or relocatable, will have a sensor-laden
tower that reaches ten metres above the existing vegetation. In an area
of a few tens of square kilometres around this tower, the researchers
will place further sensors in the soil and in local streams, to measure
temperature, carbon-dioxide and nutrient levels, along with rates of
root growth and the activities of microbes. These sensors will indicate
how efficiently different ecosystems use nutrients and water, how
vegetation responds to the climate, and how carbon dioxide moves between
living things and the atmosphere. That will help those who seek to
understand the carbon cycle—and with it, the consequences of
greenhouse-gas-induced climate change.
To complement these ground-based measurements, which can focus on
only a limited area, the team will conduct aerial surveys once a year at
each core site, looking at things like leaf chemistry and the health of
forest canopies, and will also look down on them with satellites. In
addition, NEON’s researchers can deploy a specially equipped aeroplane,
fitted with lidar (an optical version of radar), a spectrometer (to
measure chemical compositions) and a high-resolution camera, to assess
the impact of natural disasters such as floods, wildfires and outbreaks
of pests.
This aerial-surveillance system will be put to the test in a project
that started on August 21st, when a team led by Tom Kampe and Michael
Lefsky began studying the causes and impact of what has come to be known
as the High Park fire. Between June 9th and early July this fire burned
across 36,000 hectares (90,000 acres) of Colorado. Dr Kampe and Dr
Lefsky will fly NEON’s aeroplane over both the burned area and some
adjacent unburned stands of forest. They will record plant species,
forest structure, ash cover, soil properties, river sediment and the
overall topography of the burned area.
One particular question they plan to address is whether the behaviour
and severity of the High Park fire was affected by the spread of
mountain pine beetle, a pest that is rapidly overrunning Colorado
because its breeding season has been extended by the warming climate.
Repeated aerial surveys over the coming years will also give the
researchers insight into how vegetation recovers from fires, how the
beetles affect this process, how erosion and sedimentation affect the
region’s water resources, and whether fire creates opportunities for new
species to invade.
So many data, of course, require a lot of number crunching. Indeed,
it might be argued that what truly distinguishes Big Science from the
small stuff—as astronomers and physicists have known for decades and
biologists discovered in the aftermath of the Human Genome Project—is
not the amount of money involved but the volume of data that needs to be
processed. When fully operational NEON is expected to generate 200
terabytes a year. That is four times as much as the
Hubble space telescope, a reasonably big piece of science, churned out in its first two decades.
NEON, then, truly does represent a shift by ecologists towards
bigness. No doubt that will change the practice of the subject, just as
astronomy, physics and genetics changed when they became big. The days
of field glasses and butterfly nets may thus be numbered. But no one
doubts that in those other cases, the change was for the better. The
chances are, that will be true for ecology as well.