Finding Resilience

Change and Uncertainty in Nature and Society

Brian Walker

• Publisher: CSIRO PUBLISHING
• Year: 2019
• ISBN:
  9781486310791
• Topic: Biological Sciences
• Subtopic: Science General
• Index: Biological Sciences

Floods, fires, famines, epidemics and disasters of all kinds are on the increase, and as their frequency rises so does the call for greater resilience. But what does that mean? The word is used differently in psychology, ecology, economics and engineering and runs the risk of becoming meaningless jargon. This would be most unfortunate because, if we are to successfully navigate very real and dangerous global trends, it is resilience that needs to be understood and fostered.

Finding Resilience is international in scope and unravels how ecosystems, societies and people cope with disturbance and adversity. An authoritative but plain English account which is based on the experiences of researchers, the fascinating stories from around the world reveal what resilience is, how it works in different kinds of systems, how it is expressed, and how it can be gained and lost.

PART I

What’s it all about?

What’s it all about, Alfie?

Is it just for the moment we live?

What’s it all about when you sort it out, Alfie?

Are we meant to take more than we give?¹

1

Connections in a changing world

Where are we heading?

It’s hard to grasp the enormity and timescales of the changes that have happened since our world began, and it’s particularly hard to understand how they relate to what is happening now. One way of trying to do it has been by compressing the history of Earth into a year, highlighting the major events and changes as the year unfolds. An interesting version of this is to imagine a year-long movie of Earth, beginning at the time it first condensed into a globe. The movie would be made up from one composite picture per year portraying the whole surface of Earth in one frame. It would have around 4.6 billion frames (the age of Earth) and, if the speed of the projector is such that the movie begins at 1 second into the new year and finishes on the stroke of midnight on 31 December, the following is what you would see.

For the first 3 days in January, the Earth is a boiling mass in which denser substances sink into a molten core (which still exists). As the atmosphere thins and cools, the surface crust forms. Water vapour accumulates in the atmosphere, stabilising temperatures. Condensation leads to rain, the hydrological cycle develops and on 4 January the oceans form (all this took close to 50 million years).

At the end of January, the big event in Earth’s history occurs as the first signs of life appear: tiny, simple organisms, primitive bacteria. Invisible at first, they multiply and diversify. The seas become full of these primitive bacteria, which develop and grow using energy from chemical interactions. They begin to change and become more complex as evolution gets underway.

In the latter half of May, there is another stupendous change. It begins with an imperceptible green dot inside a bacterium in the vast expanse of the primordial ocean soup: the first appearance of chlorophyll. This amazing molecule reflects green light and absorbs blue and red, using this energy to combine carbon dioxide and water into sugar, and releasing oxygen as a by-product. Evolution leads to multicellular organisms and in mid-June a new kind of chlorophyll first appears in green algae, and then in higher plant species as they evolve and diversify and invade the land. By early August, terrestrial Earth has become green, changing from having an atmosphere practically devoid of oxygen to one containing around 20%.

Over the next three and a half months (through to the middle of November), a great deal of biological activity is apparent with the evolution of millions of different species, and from 13 October until 13 November (400 million years), the world looks completely white as it goes through a long ice age. This is ‘snowball Earth’, with the coldest temperatures ever experienced. A host of species go extinct, but evolution takes off again and life diversifies. On 25 November, a flash of light is followed by a momentary darkness over the world as a murky layer fills the atmosphere. An asteroid has crashed into Earth and a host of species go extinct.

On 1 December, there is another asteroid impact. About 70% of species go extinct and late on that day the first vertebrate animals appear on land. On 11 December, the next asteroid impact occurs (the biggest catastrophe for life that Earth has known) causing around 95% of species to go extinct. On 12 December, reptiles appear and soon the age of the dinosaurs begins during the warmest period for life on Earth. Another catastrophic loss of species happens on 15 December, and on 18 December India collides with Asia, throwing up the Himalayas, and the first mammals appear, followed shortly by the first recognisable birds, as the dinosaurs continue to thrive in the middle of their 135 million year reign.

Late on Christmas night, the fifth (most recent) extinction event occurs and about three-quarters of the world’s species disappear. The dinosaurs die out and an explosion of mammal species begins.

On 31 December, at ~4.30 pm, the first bipeds emerge in the subtropical regions of Africa: ape-like creatures walking upright on two legs. Just after 8 pm, the first member of our genus, Homo erectus, appears, and at 11.35 pm, just 25 minutes before the end of the year, Homo sapiens appears. This species spreads rapidly through the continent and some in the northern part of Africa soon cross into Europe, replacing (probably exterminating) the pre-human Australopithecus africanus populations that arrived there earlier. Homo sapiens radiates through Europe, evolving into different races adapted to different environments, and by ~12 minutes to midnight people have reached Asia.

After ~6 pm, the world goes through many glaciation episodes (17 in the last 2 million years)² and it reaches its most recent maximum glaciated phase at 2 minutes to midnight. Within 50 seconds, with just one minute and 10 seconds of the year left, the ice sheets retreat and Earth is again in a warm phase.

At 1 minute to midnight, the world is a beautiful sight – the continents are covered by forests, savannas, sweeping grasslands and deserts, seas teem with marine life, each with their uniquely adapted forms of plants and animals. With 30 seconds to go, some little blotches appear: the first signs of human settlements. As the seconds tick by, they grow in size and become more numerous. With 3 seconds to midnight, the Holocene epoch begins: the last 12 000 years when Earth’s climate has been more stable and benign for longer than ever before, allowing Homo sapiens to really flourish.

It seems like the camera is speeding up and, with just 2 seconds to go, the Industrial Age arrives. Forests disappear, vast swathes of cultivated land appear, and the number and size of cities, and their murky palls, explode. As the sizes of cities increase, so, too, on a microsecond timescale, do the intensities of fires crammed together like a fireworks display. All this in the last 2 seconds of the year. It took more than 10 000 human lifetimes for the world’s population to reach 3 billion (in 1960). It has since reached 7.5 billion within one lifetime.

Earth is now in the ‘Anthropocene’: an epoch when human activities are significantly affecting ecosystems and climate. And in the last fraction of the last second the rate of change is still increasing, ever faster and more extensive than anything since the movie began – barring the asteroid impact that obliterated most of life on Christmas eve. The movie ends abruptly.

If the movie could run on into the future for just one more second, what would we see? Quo vadimus – where are we going? Or, as Latin scholars would point out, a more accurate translation is ‘where are we rushing to?’

Connections with nature

As primates, we have been co-evolving with the ecosystems in which we live for over 10 million years. We split from our nearest relatives, chimpanzees, ~6 million years ago and the genus Homo has been around for ~3 million years. The genes that govern our physiology and behaviour evolved over all this time to adapt us, physically, behaviourally and emotionally, to the environment and the ecosystems we live in. We are tightly linked to the nature of these ecosystems and to the other species that share them, from microbes to mammals, and a key part of our success has been our ability to sense and respond to these other species and to the environment in which we evolved.

Our bodies have evolved to connect us physiologically to the physical environment, although we are largely unaware of it and respond to its signals subconsciously. We accept without question the marvellously intricate mechanisms that allow our pupils to dilate and contract in response to changing light intensities and our bodies to maintain an even temperature. Our sensory and emotional connections are also mostly subconscious responses dictating how we feel and behave, but sometimes our conscious parts kick in and thinking about the signal can either enhance or reduce the response, depending on how serious it actually is. We can also be made aware of environmental signals as memories, which can strike us quite forcibly. I still vividly remember one such incident.

Just before sunset, in the hazy light of an African evening in spring, I drove down the escarpment of the Zambezi valley into the Mana Pools game reserve. I was with a botanist friend, Tom Muller, on our way to set up a research project on what was happening to the vegetation on the Zambezi River alluvium, following the construction of the Kariba dam. There was concern that the altered flow and flood regimes were changing the ecology of the alluvial ecosystems.

Having left the paved road, we were bumping and lurching our way down along a dirt road, and near the bottom of the escarpment we entered a woodland of flat-topped acacias. A warm feeling of familiarity flooded through me. It was my first return visit to such an area after 4 years in Canada. The shapes of the trees were so familiar, contrasting sharply with the thinner, erect shapes of pines and firs in the forests of northern Saskatchewan. The light was fading when we came out on to the broad alluvial flood plain of the Zambezi. Our way became smoother as we entered the magnificent open woodlands of winter thorn trees. We drove slowly through this paradise for several kilometres, catching fleeting glances of the grey shapes of elephants in the gathering gloom.

It was almost dark as we descended into a small dry riverbed, seeing at close quarters the long grass of the riverine fringe in the Land Rover’s headlights. A band of cooler air accompanied by an unmistakable smell came through the open windows. I felt a prickly sensation, a thrill of familiarity and an absolutely wonderful feeling of being home.

‘Ah! Phyllanthus’ remarked Tom. In the gloom I nodded in agreement, savouring the moment.

Phyllanthus reticulatus is a shrub that grows along the banks of rivers and drainage channels in the low altitude subtropical regions, the ‘lowveld’, of southern Africa. In the still of the evening its small flowers open and, when cool air drains into the river channels after a hot day, the aroma of this plant fills the air in uneven bands and patches. It is like the smell of freshly peeled potato skins (giving rise to its common name, the potato plant) and for me it is the smell of Africa: the smell of that part of the world that means so much to me. Smells like this touch something inside most people who were born in and grew up in some part of the world with characteristic odours, and they trigger a psychological response that engenders a strong emotional tie with that environment. The Australian author Michelle de Kretser, who was born in Sri Lanka and lived her first 16 years there, described at a literary festival how smell was her dominant sense when she returned to Sri Lanka after many years, and still is: ‘the fecund rot of the tropics makes me feel completely at home’.³

There is a lovely example of how this sense led to a breakthrough in understanding animal behaviour. Arthur Hassler was a renowned and much-loved ecologist at the University of Wisconsin. He died aged 93 in 2001 and it was he who answered one of the great intriguing mysteries of nature: how salmon returning from the sea to breed are able to precisely identify the stream, and the very place in that stream, where they were ‘born’, after being at sea for several years. In the 1940s, Arthur identified what is known as ‘olfactory imprinting’. With their finely honed sense of smell, the very subtle differences from place to place enabled returning salmon to swim hundreds of kilometres, reversing the imprinted chain of smells recorded in their brains on the way down to the sea, to arrive back at the precise stream where they were spawned. It was on a visit back to a mountain stream in Utah where he grew up that Arthur noticed how the smells of the plants around him rekindled childhood memories. And he wondered if that happened to fish. It was the germ of an idea that eventually led his research to unravel just how finely tuned olfactory imprinting has become in salmon.

Sight and smell are just two of the ways we sense and respond to our environment: all five of our senses are capable of eliciting strong responses that identify and tie us to the place we were reared. Collectively, our responses to the environmental stimuli detected by these five senses strongly influence our mental wellbeing. Ask someone to identify, for each of the five senses, the thing that characterises best their part of the world, and you will get an interesting insight into that person. While the smell for me is the aroma of Phyllanthus, for a friend who spent his life in savanna rangelands it was the warm, moist smell of soil after the first rains. Sound for me is probably the gentle call of an African scops owl at night or, nowadays, after many years listening to them, the warbling of the Australian magpie in the early morning – as children’s author Pamela Allen so aptly captures it, the ‘waddle giggle gargle paddle poodle’ instantly recognised by all Aussie kids. Hippos grunting in the river and belly rumbles of elephants are great reminders for me, but, as evocative sounds, these bird calls pip them.

The positive reactions triggered in our five senses by environmental signals are those that identify us with the places we feel we belong, that we understand and where we are comfortable. However, we also experience strong negative reactions in each of the senses, and these are much more general. For good reason, wherever we were reared and now live, we all have a strong aversion to the smell and taste of rotting meat. With a few exceptions, we are scared by the looks and hissing sounds of snakes. The scream of someone in great pain thoroughly alarms us. The painful experience of touching a burning ember, or being hooked by a sharp thorn, makes us wary of them in the future. Our senses both connect us positively to our environment and protect us from it.

But our five senses are being dulled in civilised man. For our sense of smell we have 5–6 million receptor cells high in our nasal passages (dogs have over 200 million) and we can potentially distinguish more than 10 000 different odours. But we can’t all do that. Not only do we differ genetically in how well we can potentially smell things, but, for many of us, our potential sense of smell is poorly developed. We have not probed our sensory abilities nor used our senses in wide ranging ways. The old adage ‘use it or lose it’ applies well to the use of our senses. The average city dweller of today contrasts sharply with the remarkable abilities of Kalahari Bushmen and Australian Aboriginals who have grown up in natural ecosystems: not just living in them but living as a part of them and reliant on them. A colleague, Doug Williamson, once described to me an incident that captures this contrast.

He was in an open Land Rover on a sandy track in Botswana on the way to Deception Pan in the Kalahari. Behind him was a young San (Bushman) girl about 10 years old, sitting next to her father. They were travelling in a four-wheel drive at ~25 km an hour and the girl was leaning on the side of the Land Rover looking down at the road. Suddenly she called out to her father in an excited voice, in their distinctive ‘click’-sounding language. The driver stopped. They all got out and walked back to check something in the track. The girl’s father confirmed that yes, indeed, it was the spoor of uncle so-and-so. Uncle so-and-so hadn’t been around for some months, which was why the girl was excited. Neither of the white men in the vehicle could make out the distinguishing marks the Bushman pointed out. It was difficult enough to see that it was a footprint. On arrival at Deception Pan, however, there was uncle so-and-so, full of smiles and not in the least surprised his niece had identified his footprint while travelling at 25 km an hour.

Our emotional responses to environmental signals are no less intricate than are our physical and physiological responses. We share the emotional part of our brains with all other vertebrates – the oldest ancestral part, the stem at the base of our brain, sometimes called the reptilian part. The large conscious (human) part of our brain is for rational thought. Our essential ‘humanness’ depends on both conscious and subconscious responses to environmental stimuli. The two parts of our brains are strongly connected and the growing numbers of emotionally ill people in the developed world highlight how important it is to do something about the connection. The emotional responses triggered by environmental stimuli confirm that we have evolved as a part of the ecosystems in which we live, and in all the truly amazing complexity of the human brain our emotional wellbeing is still responsive to, and in fact dependent on, the ‘ecosystem’ we’re in.

This does not mean we have to stop all progress and keep ecosystems in exactly the state in which humans first saw them. In fact trying to do that – the preservationist philosophy – is a recipe for disaster. There are many changes we can make without upsetting our emotional links to ecosystems. Few people, ecologists included, could tell if they were in a pristine ecosystem or not. Three hundred years ago, much of Scotland was forested and looked like most of Sweden does today. People transformed it by clearing the forest. Water levels rose as a consequence, the forests were replaced by heathlands, and the present Scots love and identify with the heather and heathlands that now predominate.

What hasn’t changed is humankind’s basic relationship with ecosystems. We are all part of and connected with the ecosystems we live in. They may have the essential characteristics of the kinds we evolved in and affect us in positive ways, or they may have been so radically degraded or changed as to affect us negatively. Living in a congested city can do that. Either way, we respond in an intuitive way to the environment we’re in.

Our response to the stimulus of being attacked by a predator, for example, has evolved over millions of years. It’s a highly complex mechanism involving a sudden spurt of adrenalin into the blood that gives an instantaneous increase in heart rate and puts our bodies into the best possible state for rapid flight or fighting back. The problem in modern society is that this response is triggered by all s...

Table of contents

• Cover
• Title
• Copyright
• Contents
• Acknowledgements
• Part I What’s it all about?
• Part II Encountering resilience in nature
• Part III The nature of resilience in society
• Part IV Nature, society and resilience
• Part V A way forward
• Epilogue: What it’s all about
• Glossary
• Endnotes
• Index