OneThing23: when you’ve heard one population explosion, you’ve heard them all

Spectacular eastern Oregon high plains - the Zumwalt Prairie

Sometimes, what happens in Oregon has already happened somewhere else.  We’re just slow on the uptake. What’s occurring in eastern Oregon should remind readers of another plateau experience.  Click on the pretty picture of the eastern Oregon herd for an endeering story.

The story is proof positive, as Thoreau put it,  that once you understand the principle of an event, all news like it is just gossip . . . this news item about Zumwalt Prairie ought to trigger thoughts about the Kaibab Plateau, a classic case of a little knowledge is a dangerous thing.  Or the road to hell is paved with good intentions. Or knowing the right lever to press, but pressing in the wrong direction. Or . . .

Mostly, no one really understood how the Kaibab system operated as a natural organism – an undulating, multi-generational rhythm of vegetation, deer, and predators.  It’s the kind of exquisite relationships within a complex biota that takes centuries to find its balance. So, in the early 20th century, in an attempt to protect a dwindling herd, President Roosevelt and Congress created a preserve: protect deer, kill off predators. Dad gum, if it didn’t work. And work and work.  In about a decade or so, deer population soared from approximately 4,000 to 100,000. And then quickly, bitterly and pathetically, died off . . . seeking the natural set point for the region’s carrying capacity, about 30,000.

Basic Vensim model for the Kaibab Plateau

For systems modelers, the Kaibab Plateau problem is a prime problem for students to test their modeling mettle.  Once students have a rudimentary model, some truly wonderful learning can take place:  one can actually test out various policies on the habitat to see which is most effective.  What happens if one reduces/increase deer tags?  What happens if one allows predators to increase?  What happens if we want to protect the deer and kill off the predators? How long does it take for one policy to move through a complicated system?

For the last 20 years, various high school and college instructors have been creating computer models for students to think through the counter-intuitive qualities of the dynamic equilibrium of the Kaibab.  Here is the tale of carrying capacity, human intervention, and cuddly deer.

It’s a very rich model. Things move in the direction opposite from our passions and inclinations. And every high school student should know something about it.

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3 comments on “OneThing23: when you’ve heard one population explosion, you’ve heard them all

  1. Estimado Tim:

    Que interesante explicación e introducción a tan importante tema y que bonito artículo relacionado en la foto.

    Te felicito por tu gran capacidad de motivar a otros en este campo de la dinámica de sistemas.

    Te comento además que me fue aprobado un artículo en “System Dynamics Society” donde describo en detalle como desarrollar un laboratorio de aprendizaje para la diabetes para trabajar con nuestros jóvenes en el tema de la prevención y claro que esto también es útil para los adultos para crear conciencia en la comprensión de esta enfermedad y saber que hacer cuando la padeces.

    Que tengas un excelente día.


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