You CANNOT be replaced… a lesson I learned from trophic cascades. #WanderlustEDU #EdChat

One of my first years teaching I was told that we could all be replaced… this was not a threat, nor was it directed at me personally, but offered as an insight into a perspective on the teaching profession. Young and full of energy, I fought this mentality believing it untrue and that I had to simply work harder to make a tangible difference. As I got older I began to resign myself to this fact: I was a replaceable cog in a machine. I could still be a good cog, maybe even a great cog, but alas… a cog. What I failed to realize was the complex level of interconnectedness each of us has. I recently had a lightbulb moment when learning about connectivity as it relates to a scientific phenomenon called a trophic cascade.

American zoologist Robert Paine coined the term trophic cascade in 1980 to describe reciprocal changes in food webs caused by experimental manipulations of top predators. A trophic cascade is an ecological phenomenon triggered by the addition or removal of top predators. This removal often results in dramatic changes in ecosystem structure and nutrient cycling. In a food chain, an increase/decrease in carnivores causes a decrease/increase in herbivores and an increase/decrease in primary producers such as plants and phytoplankton.

Look closely at all that is missing when the top carnivore is removed (after) (1)

For example, in North America the removal of wolves has been associated with an increase in white-tailed deer. Leading to a decline in plants eaten by the deer. In Yellowstone National Park, the loss of trees has been linked with the removal of grey wolves. From the 1880s-1920s wolves were the target of extermination from Yellowstone National Park. The decrease of wolves led to an increase in eating tree saplings by herds of deer and elk. A ripple effect occurred in Yellowstone leading to a decrease in trees, loosening the soil on river banks, meaning less trees for beavers to dam the rivers, meaning less pools where fish had lived… an exemplar trophic cascade. But all hope is not lost. Over the past decade, grey wolves have been re-introduced to Yellowstone National Park. The grazing patterns of elk have been re-altered allowing more saplings to grow, allowing for more trees to grow and thrive in Yellowstone.(2) (3)

Some would like to ruin my overly-romanticized view of the ecosystem’s symbiosis and how the re-introduction of wolves positively impacted Yellowstone, but we cannot deny that there is a real level of interconnectivity going on. While I do not propose each of us is a predator in the educational system, I will say we are having a real impact on those around us.  Sometimes the impact is intangible and unseen, perhaps even seeming unmeasurable, but eventually these connections manifest themselves in many ways: the social media poke we get from a student we had in class decades ago or a direct message asking for help and/or reminding us of our shared experience (Sept. 11 reminders always strikes a powerful cord with me). All of which stem from a level of connection we cannot see in the moment, a level of meaningful connection which says YOU CANNOT BE REPLACED.

Perhaps you have gotten into a slump resigning yourself to a cog-like mentality (I have been there too). You may not feel relevant, appreciated, or that you are making a difference. Now the time to re-introduce yourself to your WHY. You matter, your work matters!

Also, please know, you are NOT ALONE! Wolves live and hunt in packs, these social animals cooperate and are known to roam large distances (4). Our PLN’s too are the embodiment of social cooperation that extends to the entire world! Reach out, share, collaborate… 

Let’s Do This!

WanderlustEDU: An Educator’s Guide to Innovation Change, and Adventure.


  1. trophic cascade | Definition, Importance, & Examples | Britannica. (2021). In Encyclopædia Britannica.
  2. ‌Silliman, B. R. & Angelini, C. (2012) Trophic Cascades Across Diverse Plant Ecosystems. Nature Education Knowledge 3(10):44
  3. Wolf Restoration – Yellowstone National Park (U.S. National Park Service). (2011).’%20prey,late%201800s%20and%20early%201900s.
  4. Wolves 101. (2019). Animals.,do%20not%20eat%20in%20moderation.

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