Biodiversity in farming and nature

By Dan Saladino, Food journalist and author of Eating to Extinction 2021-10-12 9 minutes read

In our efforts to feed a growing population we have destroyed vast amounts of the Earth’s biodiversity. We urgently need to preserve what diversity remains, for the future of our species, the planet, and our food.

Biodiversity in crisis

The rapid loss of biodiversity is now recognized as one of the most pressing issues of our time. The modern food system is a key culprit; to feed our growing population we have focused on a small number of high-yielding crop varieties and animal breeds, transforming landscapes, and plundering natural resources in the process. As a result, many varieties of plants and animal breeds have been driven towards extinction.

Yet we now understand that biodiversity provides the foundation for food security, human health, and the stability of our planet. We need to develop ideas that will transform our food system, repair at least some of the damage we have inflicted, and safeguard the diversity that remains. The world needs ambitious, transformative ideas.

Defining diversity – the infrastructure of life

Biological diversity or ‘biodiversity refers to the variety of all life on Earth, from bacteria to bison, plants to people. It is made up of three interconnected components:

  • Species diversity, the mind-boggling array of animals, plants, and micro-organisms in the world (of the 9 million or more estimated species on Earth, we’ve identified around 1.2 million).
  • Genetic diversity, the variety of genes contained within species. In seed banks around the world, for instance, are 469,000 unique samples of wheat, 251,000 of rice, 3,200 of bananas, and nearly 25,000 of potato. These varieties or cultivars are all adapted to their local environments and possess traits suited to different conditions, from drought to flooding, poor soils to diseases.
  • Ecosystem diversity, the variety of habitats on the planet, from the Arctic tundra to the African Savannah, from rivers to the deep sea.

All three components are in rapid decline. We now have overwhelming evidence that more and more animals, plants, and ecosystems are facing an uncertain future and that the primary driver for this is the food system. Agriculture is the single largest cause of biodiversity loss and habitat destruction, accounting for 80 percent of all land-use change globally.

Biodiversity under threat – living through the Earth’s sixth mass extinction

In the Earth’s history, five mass extinction events have occurred, including the one that ended the age of dinosaurs. Many scientists believe we are living through a sixth mass extinction; this time, humans instead of natural events are to blame.

The scale of the world’s biodiversity loss was laid bare in a United Nations report in 2019 which plotted two diverging trend lines: one, upward-sloping, for humans, the other downward-sloping, for everything else. The scientists concluded that one million animal and plant species are now threatened with extinction, with the human need for food and energy as the main culprits.

Driving this decline in biodiversity is not only the increased demand for food but, crucially, a growing appetite for a tiny selection of ‘staple’ crops. During the past half-century, a ‘global standard diet’ has been replacing the world’s diverse food cultures. The average eater now gets the bulk of his or her daily calories from just six sources: wheat, rice, sugar, maize, soybeans, and farm animals (meat and dairy).

Of the 6,000 plant species humans have cultivated for food, a mere nine now account for two-thirds of all crop production. From this small selection of crops, we focus on just a few varieties of each. The same is true of animals; while nearly 8000 local breeds of farm animals exist, only a tiny number of these are raised for global livestock production.

Insatiable demand for some foods is leading to large-scale loss of biodiverse landscapes. Between 1980 and 2000, 100 million hectares of tropical forest were lost, some to cattle ranching in South America, others to palm oil plantations in Southeast Asia.

The Cerrado, Brazil’s equivalent of the African savanna in the center of the country, has been transformed by an ingredient that makes possible the world’s growing appetite for industrially produced meat. The Cerrado is one of the planet’s richest centers of diversity, but already so much has been lost to monocultures of soy.

Risk to future food security

Relying on just a few varieties of a small number of crops and on a tiny number of animal breeds for our food makes us far more vulnerable to the major threats posed by climate change: drought, pests, and disease.

The ‘Green Revolution’ (the ambitious post-war project to feed the world with high-yielding crops) was made possible by the arrival of modern plant breeding and the development of synthetic fertilizer. While it succeeded in its main goal – of producing more calories and feeding people - we are now dealing with some of the adverse consequences. In little more than five decades, the rich diversity developed by countless generations of farmers was rapidly replaced by a smaller selection of new varieties; higher-yielding, genetically identical, and dependent on chemical inputs.

In 1920 in Turkey, close to the birthplace of agriculture 10,000 years ago, about 18,000 unique ‘landrace’ varieties of wheat were being farmed. Following the arrival of new, high-yielding dwarf varieties in the 1960s, 95 percent of that genetic diversity was lost. In the late 1950s, Sri Lankan farmers were growing at least 2,000 different types of rice, but by the 1990s this had been mostly reduced to just five.

When we discard locally adapted varieties that have evolved over millennia, and they disappear from farmers’ fields, we risk losing unique and valuable genetic traits. In fields of traditional landrace wheats, no two populations are the same, but modern bread wheat has been bred for uniformity. Each individual plant is a near clone of the other, developed to produce the maximum amount of grain and to be ready to harvest at the same time. This homogeneity increases the crop’s vulnerability to disease; a lethal fungus can more easily spread from one identical plant to another.

Old landrace wheat variety. Photo: Marek Studzinski

As our climate changes, scientists are turning to older landrace crop varieties in search of disease resistance and drought tolerance. This approach has been used before. In the 1960s, when a disease broke out in the wheat fields of the American north-west, plant breeders experimented with a Turkish wheat stored inside a seed bank. They discovered it had resistance not only to the outbreak but also fourteen other diseases affecting the crop. Tonnes of food and millions of dollars were saved.

Botanists and crop breeders are also urgently searching the wild for seeds of other plants we may need, including those of ‘crop wild relatives. The race is on to find and save them before they go extinct. Their traits could give us options for the future.

Risk of zoonotic diseases

Science has allowed us to bank on just a few of the highest-yielding and fastest-growing animal breeds for our meat. Just three breeding lines now dominate global poultry production, and most pork is based around the genetics of a single pig, the Large White. In dairy, more than 95 percent of America’s dairy herd is based around one breed of ‘super cow’, the Holstein (and most of these can be linked back to a handful of males). This genetic uniformity leaves these animals – and us – vulnerable on a global scale. Creating larger and larger industrial units filled with thousands of genetically identical animals is also a perfect environment for zoonotic diseases to evolve and spread.

The Cavendish crisis – the clone banana under attack

The dangers of replacing diversity with monocultures are evident in a crisis facing the banana industry. Panama Disease has the potential to wipe out the Cavendish, the world’s most traded banana. While there are more than 1,500 varieties of bananas, nearly half of all global production is the Cavendish.

This variety was planted across several continents in vast monocultures because it was robust enough to be transported long distances and was high yielding. But because of the way the fruit has been bred, every Cavendish banana is an exact clone of the others. So, if a pathogen can attack one tree on a plantation, it can attack them all. Scientists are working against the clock to find disease-resistant genes to this disease in wild banana plants found in the birthplace of the fruit, Papua New Guinea. It could be that ancient DNA may help the Cavendish to protect itself.

Similar problems are facing other food crops, including Arabica coffee (the source of most of the world’s espressos and cappuccinos). Because almost all cultivated Arabica descends from a small number of plants smuggled out of Yemen in the 17th century, it has a much narrower genetic base than its wild relatives. Again, monocultures of this crop have left it vulnerable to disease. Like a stock portfolio with just a few holdings, crops grown this way become vulnerable to catastrophes.

Safeguarding the future

The importance of preserving biodiversity can be illustrated by the survival of a mysterious and endangered plant growing in southern Mexico. This rare type of maize, called Oloton, is grown by an indigenous community in a high-altitude village in Oaxaca. It oozes a strange mucus from aerial roots which scientists have discovered allows the plant to self-fertilize. In a world awash with synthetic nitrogen manufactured with fossil fuels, this maize may hold important clues for future food security. It is also a stark reminder of how indigenous people and their food and farming cultures have helped to preserve diversity. Often, it’s they who are the last defenders of fragile ecosystems.

Our own biodiversity loss: The human gut microbiome

A diverse diet is important for the health of our microbiome, which is made up of trillions of bacteria and other microbes that live inside our gut. Science is revealing how important the microbiome is for our health. The more diverse our diets, the more diverse our gut microbiomes become, which in turn brings benefits to our health. We each have the most selfish of reasons to preserve the diversity of our food; our own wellbeing.

Microbes, living in amazing diversity inside our gut, can weigh up to 2kg. Photo: Getty Images

To achieve food resilience, we need to think big and small.

All over the world, people are finding ways to change food systems and help preserve biodiversity. Some of these efforts are based on large-scale thinking aimed at reimagining agriculture; others are intensely local.

One of the most ambitious suggestions comes from E.O. Wilson. In his book Half Earth: Our Planet’s Fight for Life, he suggests protecting the planet by preserving huge areas, land left undisturbed by humans. The idea is that half of the planet’s surface should be dedicated to flora and fauna, the equivalent of World Heritage sites for biodiversity.

Change is possible on a smaller scale too. The Crop Wild Relative project in the UK is working with wheat’s oldest ancestors, hoping to recover some of the phenotypic plasticity that modern wheats have lost but which the plant’s wild ancestors still retain.

In the east of India, on a two-acre plot in Odisha, seed collector Debal Deb is growing nearly 1,500 different varieties of rice. Many have been collected from remote farms, passed down through generations, often saved by just one farmer. Deb’s collection includes a variety that’s flood-tolerant, capable of surviving after being submerged for weeks; another can grow in soil with high-saline soils.

Alex Atala is Brazil’s most celebrated chef. His ATA Foundation runs eight projects designed to help indigenous groups flourish by making use of their own culture and traditions, ‘It makes sense to protect the people who protect diversity’, he argues.

Also in Brazil, Leontino Balbo’s business, Native, produces 34 percent of the world’s organic sugar (75,000 tonnes annually). On land where farmers once depended on chemical fertilizers, pesticides have been exchanged for a system of natural pest and disease management in which naturally resistant crop varieties flourish.

In Mexico City, Francisco Musi and Sofia Casarin have founded Tamoa, a company that makes traditional tortillas using Mexican maize varieties. In doing this, they are working to protect Mexican landraces, many of which are disappearing, pushed out by imported American corn.

Founded in Italy, the Ark of Taste is an online catalog of endangered foods compiled by the Slow Food movement. So far, more than 5000 endangered foods from more than 100 countries have been put on the Ark. It’s testament to the many people the world over who are working to save their own local food traditions – and it gives us hope.

The word biodiversity has only recently gained currency because humans are in the process of destroying what it refers to. But as the work of organizations, scientists, thinkers, chefs, and activists reminds us, this moment of crisis also represents an opportunity to heal the planet and protect the generations to come.

This article is based on a longer report. Read the full report

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