New Scientist - USA (2019-06-15)

14 | New Scientist | 15 June 2019

THE world’s ability to track rapidly

rising levels of greenhouse gases

has suffered a major blow with

the axing of a vital monitoring

scheme on a UK-governed island.

For 40 years, the US and UK have

been monitoring concentrations

of carbon dioxide and methane

on Ascension Island. The air-

sampling station is the only one

in the central Atlantic and one

of just a handful in the tropics,

providing crucial data about how

oceans are absorbing carbon

dioxide and the atmosphere’s

response to our emissions.

But the operation has been

downsized and will soon end

entirely, raising concerns in the

scientific community.

The UK’s Met Office, which runs

the programme in partnership

with the US National Oceanic and

Atmospheric Administration

(NOAA) and Royal Holloway,

University of London, has halved

the number of staff it sends to the

island from four to two as a result

of damage to the island’s only

runway, which limits flights.

That led the job of air sampling

to become a voluntary one and, in

late April, the Met Office took the

decision that it could no longer

assist NOAA with this task.

A key piece of equipment is

also no longer working. A machine

for measuring the composition

of the air, which was installed in

2010 and billed as “vital” and a

“major UK contribution to global

understanding of the greenhouse

gases”, hasn’t been calibrated for

two years and is now offline.

“Trying to model global

greenhouse gas budgets without

Ascension measurement is like

trying to ride the Grand National

on a horse with three legs,” says

Euan Nisbet at Royal Holloway.

The Met Office says it will still

support Royal Holloway in the

monthly job of collecting flasks

of air from the island and flying

them to the UK. But even that

monitoring will soon end, as the

UK research council that pays for

the work has decided it will no

longer fund the project beyond

April 2020.

Ed Dlugokencky at NOAA says

Ascension’s location and the

decades of data gathered there

make this a particularly bad blow.

“Long measurement series are

useful for looking at subtle

changes possibly caused by

a changing climate,” he says.

It is getting harder to maintain

a global air-sampling network,

says Dlugokencky. “Some

cooperating agencies who

originally contacted us two or

three decades ago to join our

network are now less keen to work

with us or are asking for financial

support to keep sampling,” he says.

The Met Office says the primary

task of its staff on the island is to

assist the UK Ministry of Defence

(MoD) there.

“With a smaller team, we have

had to critically review all of the

non-MoD work we carry out and,

unfortunately, we are no longer

able to assist NOAA with their

air sampling on the island due to

the task complexities and level

of training involved,” says Vicky

Smiley at the Met Office. ❚

FUNGI colonise the roots of most

land plants, forming elaborate

networks that hand over

phosphorus and receive carbon in

return. But it turns out these fungi

are savvy traders, taking advantage

of their partners by shuttling

phosphorus to nutrient-starved

areas where plants are willing to

give up more carbon than usual.

A single arbuscular mycorrhizal

network can be connected to many

plants, and vice versa, which gives

scope for wheeling and dealing.

Toby Kiers at the Free University

of Amsterdam in the Netherlands

was curious to see how the fungi

deal with resource inequality. How

do they adapt trading strategies

when phosphorus supply is patchy?

To find out, Kiers and her team

used differently coloured light-

emitting particles called quantum

dots to tag phosphorus, allowing

them to track its movement through

a fungal network connected to a

host root in a Petri dish.

Using a series of different dishes,

the team exposed separate fungal

networks to unequal distributions

of phosphorus. In one dish, the left

side of the network received 70 per

cent of the phosphorus while the

right got 30. In another, the left

got 90 per cent and the right 10.

In a control, it was a 50/50 split

(Current Biology, doi.org/c6xk).

After 60 days, the team saw two

clear patterns in the unequal dishes.

First, inequality stimulated trade.

The greater the disparity across its

network, the more the fungus

transferred phosphorus to the root.

Second, the fungus did this in an

unusual way. “We could see the

fungus was moving phosphorus

across the network to its lower-

resource side,” says Kiers. If the

resource-rich patch was on the right

side of the dish, for example, most

phosphorus ended up on the left.

This suggests the fungus shifts

its resources to the side of the root

bundle where they are scarce.

“Here, demand is higher, and the

plant is potentially willing to pay

more,” says Kiers. ❚

Daniel Cossins

Ecology

Carbon emissions

Adam Vaughan

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News

“Fungi take advantage of

their plant partners by

shuttling goods around to

where demand is higher”

Climate monitoring axed

A crucial air-sampling scheme in the Atlantic is ending

Fungi trade

with plants like

a stock market

Ascension Island is

a UK territory in the

middle of the Atlantic