A trophic cascade is an ecological process which starts at the top of the food chain and tumbles all the way down to the bottom.
The video How Wolves Change Rivers, narrated by George Monbiot, begins with the sentence: "One of the most exciting scientific findings of the past half-century has been the discovery of widespread trophic cascades. A trophic cascade is an ecological process which starts at the top of the food chain and tumbles all the way down to the bottom".
The video progresses with the marvellous description of the reintroduction of wolves in the Yellowstone National Park in the United States in 1995. Wolves are believed by many to be sanguinary animals (causing much bloodshed).
However, as they indeed killed some of the deer and coyotes, they also provided means for rodents and birds of prey to have their way in the local ecosystem. Systems thinking can reveal the unanticipated role of wolves as ecosystem engineers.
Rejuvenating forest
The significant and unsuccessfully managed populations of deer were blocking the flux of energy in the local food chain.
By changing the behaviour of the deer that started avoiding certain parts of the park, wolves offered trees a chance to increase their size by five times in a short period, attracting many species of birds.
Beavers came too, feeding on the trees and managing their growth by building aquatic dwellings also used by hundreds of other creatures such as muskrats, otters, ducks, fish, amphibians and reptiles.
Bears were feasting on the increasing number of berries. Surprisingly, the behaviour of the rivers also changed - they meandered and eroded less, narrowed channels, increased numbers of pools and riffle sections that are great wildlife habitats.
A trophic cascade is an ecological process which starts at the top of the food chain and tumbles all the way down to the bottom.
The rejuvenating forest stabilised river banks, and less soil erosion occurred. Astonishingly the wolves not only restored the Park's local ecology but also changed its geography.
Today's story is, unfortunately, a degenerative one. An incredibly biodiverse ecosystem is systematically shattering because of a species that ignores its interconnectedness with the whole web of life.
Agricultural expansion
I was born in Brazil, the fourth biggest emitter of global warming gases, and perpetrator of severe deforestation. This is done in the name of profit: corporations cut down trees, contaminate soil and water, consume the majority of hydric resources and frequently run their activities on slave work.
The meat industry emits the same volume of global warming gases as all the cars, trucks, planes and ships of the whole planet together, and in countries such as Brazil, it is directly related to suspension in the rights of workers, indigenous peoples and other traditional communities.
Apart from areas for grazing cattle, the increase in soy production is driving agricultural expansion - essential for the highly profitable and poorly assessed activity of producing meat.
The world's 1.5 billion cattle are frequently vilified. A single animal produces more than a hundred various polluting gases, more than 100 kg of methane per year and consumes about 990l of water to outcome a litre of milk. Moreover, their manure causes "dead zones" in the ocean.
To get to know the issue in depth, it is necessary to understand its broader context.
Interconnected web
What would 'How Wolves Change Rivers' look like if we were to blame the deer? We would probably focus on their adverse effect and miss facts that open the doors to more systemic perspectives.
The delicately interconnected web of relationships of the Amazon rainforest took some millions of years to reach its current state.
A large tree's daily job is to pump up about 1,000 l of water to the atmosphere, where water encounters plant produced substances that facilitate its condensation and assures abundance in rain formation. That means that like ocean algae they "seed clouds" while the whole forest is the releasing agent of 20 billion litres daily - a number that exceeds the Amazon river's water flow by 3 billion litres.
Besides, the forest keeps the moving air humid and like a biotic pump sucks damp air above the sea back to the continent thus maintaining rains under any circumstances. The air currents carry all the water released into the atmosphere to the interior of the continent, forming a flying river.
Other services include the prevention of desertification by delivering humidity, stabilisation of the water cycle and determent of climatic events, such as tornados.
Extending limits
None of this is possible if the cattle becomes a substitute for trees - the result is a long-term blockage of ecological flows caused by the absence of the fundamental functions that plants perform, indicating their significance for the planetary climate system. Plants exist in an intimate relation to the water cycle, as well as to the carbon, nitrogen and phosphorus cycles at local and global levels.
Deforestation leads to extreme weather events, loss in biodiversity, habitats and the degradation of near and far environments, sooner or later. For instance, the meat consumption increase in Germany threatens South-American ecosystems, since two thirds of the soy fed to livestock in the European country comes from Brazil.
Unfortunately, we are not encouraged to learn the stories that lie behind what we consume. We can start to change this by expanding our education beyond the limits of linear causation - eco-systemic thinking ought to be thought in schools.
An outrageous environmental debt is neither transferred to the final consumer, not paid with money - we all pay it with the loss of human lives, malformation of foetuses, human intoxication by heavy metals, chronic diseases, cancer and the destruction of the very fundamental conditions for all life on the planet.
The so-called "business as usual" strategy destroys commons, often irreversibly.
Cause for optimism
The meat industry must be watched closely by civil society. While committing to be more responsible and transparent in their operations, giants like the Brazilian JBS must adopt production models based on the circular economy if they want to avoid being regulated by the government.
It might be challenging to grasp the interrelatedness of all life on the Earth in a world where nature has been commodified.
The overlooked disruption of local water cycles caused by environmental degradation can be compared to the failure of the circulatory system in the human body; we are failing the blood vessels of our extended body, the planet Earth.
Despite this, we can be optimistic because we carry the potential of being wolves, which means creating a niche for other species and giving life back by being who we are. Who knows which rivers we will change?
This Author
Rafaela Graça Scheiffer is a Brazilian biologist who recently concluded her MSc in Holistic Science at Schumacher College.
