IELTS MASTER - Book 20 Reading Test 1

To Britain

Mark Rowe investigates attempts to reintroduce elms to Britain

A The elm is one of the most iconic trees in the British landscape. It is a hardy, fast-growing tree that can live for hundreds of years. However, in the late 1960s, a disease known as Dutch elm disease arrived in Britain. It was imported on logs from North America and was caused by a fungus that blocked the water-conducting vessels of the tree, causing it to wilt and die. The disease was spread by elm bark beetles that spread the deadly fungus. This time, the beetles carried a much more virulent strain that destroyed the vast majority of British elms.

B By the 1990s, it was estimated that over 25 million elms had died in the UK. The loss of the elm has had a significant impact on the landscape and biodiversity. The elm was a key component of hedgerows and woodlands, providing habitat for many species of insects, birds and lichen. For example, the white-letter hairstreak butterfly relies exclusively on elm trees for its survival. Since the epidemic, the population of this butterfly has declined dramatically.

C Today, elms still exist in the southern English countryside but mostly only in low hedgerows between fields. ‘We have millions of small elms in hedgerows but they get targeted by the beetle as soon as they reach a certain size,’ says Karen Russell, co-author of the report ‘Where we are with elm’. Once the trunk of the elm reaches 10-15 centimetres or so in diameter, it becomes a perfect size for beetles to lay eggs and for the fungus to take hold. Yet mature specimens have been identified, in counties such as Cambridgeshire, that are hundreds of years old, and have mysteriously escaped the epidemic. The key, Russell says, is to identify and study those trees that have survived and work out why they stood tall when millions of others succumbed. Nevertheless, opportunities are limited as the number of these mature survivors is relatively small. ‘What are the reasons for their survival?’ asks Russell. ‘Avoidance, tolerance, resistance? We don’t know where the balance lies between the three. I don’t see how it can be entirely down to luck.’

D For centuries, elm ran a close second to oak as the hardwood tree of choice in Britain and was in many instances the most prominent tree in the landscape. Not only was elm common in European forests, it became a key component of birch, ash and hazel woodlands. The use of elm is thought to go back to the Bronze Age, when it was widely used for tools. Elm was also the preferred material for shields and early swords. In the 18th century, it was planted more widely and its wood was used for items such as storage crates and flooring. It was also suitable for items that experienced high levels of impact and was used to build the keel of the Cutty Sark.

E ‘It’s a shame that we’ve lost the elm,’ says Dr David Elliot, Chief Executive of the charity Trees for Cities. ‘It was a magnificent tree and its loss has left a huge gap in our landscape.’ The charity is working to reintroduce elms to London and other cities. The project has many advocates. Amongst them is Peter Bourne of the National Elm Collection in Brighton. ‘I saw Dutch elm disease unfold as a small boy,’ he says. ‘The elm seemed to be part of rural England, but I remember watching trees just lose their leaves and that really stayed with me.’ Today, the city of Brighton’s elms total about 17,000. Local factors appear to have contributed to their survival. Strong winds from the sea make it difficult for the determined elm bark beetle to attack this coastal city’s elm population. However, the situation is precarious. ‘The beetles can just march in if we’re not careful, as the threat is right on our doorstep,’ says Bourne.

F Any prospect of the elm returning relies heavily on trees being either resistant to, or tolerant of, the disease. This means a widespread reintroduction would involve existing or new hybrid strains derived from resistant, generally non-native elm species. A new generation of seedlings have been bred and tested to see if they can withstand the fungus by cutting a small slit on the bark and injecting a tiny amount of the pathogen. The effects are very quick,’ says Russell. ‘You return in four to six weeks and trees that are resistant show no symptoms, whereas those that are susceptible show leaf loss and may even have died completely.’

G All of this raises questions of social acceptance, acknowledges Russell. ‘If we’re putting elm back into the landscape, a small element of it is not native – are we bothered about that?’ For her, the environmental case for reintroducing elm is strong. ‘They will host wildlife, which is a good thing.’ Others are more wary. ‘On the face of it, it seems like a good idea,’ says Elliot. The problem, he suggests, is that, ‘You’re replacing a native species with something that is potentially invasive. We need to be careful.’ Russell adds, ‘We have to accept that we’re not going to get back the English elm. We have to look at what we can get. The question is, what does the public want? Do they want an elm that looks like an English elm, or do they want a tree that functions like an elm?’ There is also the risk that the disease could mutate. ‘We’re bringing in trees that are resistant to the current strain of the disease, but the disease could evolve and attack them. Then we’re back to square one. But if we don’t do anything, we’ll never know if we might get resistance,’ says Elliot.

How stress affects our judgement

Some of the most important decisions of our lives occur while we’re feeling stressed and anxious. From medical decisions to financial and professional ones, we are all sometimes required to weigh up information under stressful conditions. But do we become better or worse at processing and using information under such circumstances?

My colleague and I, both neuroscientists, wanted to investigate how the mind operates under stress, so we visited some local fire stations. Firefighters’ workdays vary quite a bit. Some are pretty relaxed; they’ll spend their time washing the truck, cleaning equipment, cooking meals and reading. Other days can be hectic, with numerous life-threatening incidents to attend to; they’ll enter burning homes to rescue trapped residents, and assist with medical emergencies. These ups and downs presented the perfect setting for an experiment on how people’s ability to use information changes when they feel under pressure.

We found that when the firefighters were relaxed, they were good at processing information. However, when they were stressed, they became hyper-vigilant to bad news, even when it had nothing to do with their job (such as learning that the likelihood of card fraud was higher than they’d thought), and altered their beliefs in response. In contrast, stress didn’t change how they responded to good news (such as learning that the likelihood of card fraud was lower than they’d thought).

Back in our lab, we observed the same pattern in students who were told they had to give a surprise public speech, which would be judged by a panel, recorded and posted online. Sure enough, their cortisol levels spiked, their heart rates went up and they suddenly became better at processing unrelated, yet alarming, information about rates of disease and violence.

When we experience stressful events, a physiological change is triggered that causes us to take in warnings and focus on what might go wrong. Brain imaging reveals that this ‘switch’ is related to a sudden boost in a neural signal important for learning, specifically in response to unexpected warning signs, such as faces expressing fear. Such neural engineering could have helped prehistoric humans to survive. When our ancestors found themselves surrounded by hungry animals, they would have benefited from an increased ability to learn about hazards. In a safe environment, however, it would have been wasteful to be on high alert constantly. So, a neural switch that automatically increases or decreases our ability to process warnings in response to changes in our environment could have been useful. In fact, people with clinical depression and anxiety seem unable to switch away from a state in which they absorb all the negative messages around them.

It is also important to realise that stress travels rapidly from one person to the next. If a co-worker is stressed, we are more likely to tense up and feel alert ourselves. This phenomenon can be observed in other species too. For example, if a bird detects a predator, it will fly away, and the rest of the flock will follow, even if they haven’t seen the danger themselves. This mechanism allows information to be transmitted quickly through a group, which can be vital for survival.

Studies show that if we observe positive feeds on social media, such as images of a pink sunset, we are more likely to post uplifting messages ourselves. If we observe negative posts, such as complaints about a long queue at the coffee shop, we will in turn create more negative posts. In some ways, many of us now live as if we are in danger, constantly ready to tackle demanding emails and text messages, and respond to news alerts and comments on social media. Repeatedly checking your phone, according to a survey conducted by the American Psychological Association, is related to stress. In other words, a pre-programmed physiological reaction, which evolution has equipped us with to help us avoid famished predators, is now being triggered by an online post. Social media posting, according to one study, raises your pulse, makes you sweat, and enlarges your pupils more than most daily activities.

The fact that stress increases the likelihood that we will focus more on alarming messages, together with the fact that it spreads extremely rapidly, can create collective fear that is not always justified. After a stressful public event, such as a natural disaster or major financial crash, there is often a wave of alarming information in traditional and social media, which individuals become very aware of. But that has the effect of exaggerating existing danger. And so, a reliable pattern emerges – stress is triggered, spreading from one person to the next, which temporarily enhances the likelihood that people will take in negative reports, which increases stress further. As a result, trips are cancelled, even if the disaster took place across the globe; stocks are sold, even when holding on is the best thing to do.

The good news, however, is that positive emotions, such as hope, are contagious too, and are powerful in inducing people to act to find solutions. Being aware of the close relationship between people’s emotional state and how they process information can help us frame our messages more effectively and become conscientious agents of change.