When one species becomes the ecosystem's needle.
Nature is like a perfect puzzle, where every piece has its perfect place and importance to complete the picture. Remove that one piece and the picture will make no sense.
Everything is connected. We are all one.
I consider myself to be a spiritual person. However, I always frown upon a hippie-sounding one-love communication style. And “everything is connected” sounds kind of unreal, to be honest. What I had felt my entire life until a few years ago was disconnection. I felt disconnected from others, the world, and sometimes even from myself.
But what if I told you that actually, everything is connected?
Would you believe that oceans, forests, and deserts in different continents influence each other’s weather? What would you think if I told you that some species are ecosystem engineers? And that if you remove one specific species from an ecosystem, it unbalances everything else?
Well, brace yourselves. Our Earth is magic. Here are some facts:
Every year, sand from the Sahara desert flies 10000 km to the Amazon. There it feeds the rainforest flora through its phosphorus-rich nutrients, helping it to grow.
The Amazon creates its rain by increasing the humidity released from its trees.
Elephants are ecosystem engineers. By knocking off trees to reach fruits and leaves, they create space for other plants to grow. They also fertilize the land with their dung. Thanks to all that they increase the African forest biodiversity.
Wolves changed Yellowstone’s river and flora. When wolves were reintroduced in Yellowstone Park in the nineties, they changed the entire ecosystem composition. By decreasing elk numbers, new plants had the chance to grow thanks to the halt to overgrazing. As a result, the new vegetation affected the waterways. The beaver returned, as well as different bird species. Thanks to the dams created by beavers, even more species came back to the park, such as otters and reptiles.
Sea otters help fight climate change and help increase biodiversity. By predating on urchin populations, the kelp forests, which are a great carbon sink, have the chance to grow. And kelp forests provide habitat to other fish species…
These are only some of the astonishing facts about how ecosystems work. They reveal a complex picture, interconnections, and different roles played by specific species.
The Green World Hypothesis

Photo by Yujesh Maleku on Unsplash
Ecologists used to think that foundation species, such as plants, controlled the structure of an ecosystem. The amount of vegetation was considered the key to the number of herbivores and carnivores. Scientists thought that ecosystems worked from the bottom to the top. However, this theory didn’t explain why herbivores wouldn’t eat all the vegetation available and reach overpopulation and overgrazing.
In the early 1960s, scientists Hairstone, Smith, and Slobodkin reversed the theory by stating that predators were the ones allowing the world to be green, by controlling the numbers of herbivores. Hence, the Green World Hypothesis was born. The latter was confirmed by the work of ecologists Robert Paine and James Estes, who studied the effects of starfish and sea otters on ecosystems in the North Pacific. Both predators' species, at the top of the food chain, were affecting the entire ecosystem composition. By removing the predator, grazing species overpopulated and overgrazed the vegetation available. Hence, removing habitats for other species and decreasing biodiversity drastically.
What are keystone species?
A species that can regulate the entire composition of an ecosystem is called a keystone species. Keystone species are divided into ecosystem engineers, predators, and mutualists. The latter are considered cooperative species, interacting for mutual benefit in one ecosystem. Pain’s and Estes’ findings lead to the famous phrase “All animals are equals, but some animals are more equal than others”. Some species drive their ecosystems from the top-down and are vital for ecosystem services. By removing predators in several ecosystems around the globe, we have contributed to reducing ecosystems’ biodiversity. Species such as sharks, sea otters, bears, lions, wolves, but also elephants, mangrove trees, and bees are keystone species.

Photo by Gerald Schömbs on Unsplash
Understanding the different roles of species in a community has played a vital role in the theorization of new conservation practices and will help us restore entire ecosystems and their trophic cascades: the top-down processes of ecosystem services provided by keystone species. But even more importantly, ecology provides us with a clearer picture of how nature and ecosystems work. Nature is a perfect puzzle, where everything, every tiny piece plays its part. Some pieces are more important than others, but every piece seems to be relevant. Even if we are still far away from fully understanding how Nature works, some brilliant scientists have uncovered essential pieces of information that could guide us into a more balanced relationship with the wild. For centuries our species has seen predators as a danger to our survival, almost erasing them from our world. Furthermore, we continue to view other species as replaceable and merely a means to our ends. Our present instrumental view of the world has deep roots in cultures of control, dominance and subjugation. However, as we come to understand more and more about ecosystems, our survival seems to be tightly tied to other species' survival. Which brings us to re-evaluate our position in the world.
What if, instead of being at the top of the pyramid, we’re just one other piece of the puzzle?
If have a business and you care about conservation and sustainable development you can make your contribution by simply working with Natriarch! Find out more about our services on our performance marketing page.
Bibliography
Paine, R. T. (1995). A Conversation on Refining the Concept of Keystone Species. Conservation Biology, 9(4), 962–964. http://www.jstor.org/stable/2387008
Davic, R. D. (2003). Linking Keystone Species and Functional Groups: A New Operational Definition of the Keystone Species Concept. Conservation Ecology, 7(1). http://www.jstor.org/stable/26271938
Garibaldi, A., & Turner, N. (2004). Cultural Keystone Species: Implications for Ecological Conservation and Restoration. Ecology and Society, 9(3). http://www.jstor.org/stable/26267680
Sala, E., Charles III, K. o. G. B., & Wilson, E. O. (2020). The nature of nature: why we need the wild. Washington, D.C., National Geographic
NASA Science Editorial Team (2015), 'Desert Dust feeds Amazon forest', https://science.nasa.gov/science-news/science-at-nasa/2015/29apr_amazondust (Accessed: 07.11.2023)