Paradox of Enrichment, explained.
The paradox of enrichment is the possibility that increasing resource availability destabilises a consumer–resource system instead of simply improving its stability.
Why it happens
A Rosenzweig–MacArthur model combines logistic prey growth with saturating predation. Growth, handling, conversion and mortality parameters are fixed; increasing carrying capacity above 7/3 destabilises the coexistence equilibrium for these values.
The paradox of enrichment is the possibility that increasing resource availability destabilises a consumer–resource system instead of simply improving its stability.
Read the result
Late-window minima and maxima describe the displayed trajectory. A low numerical population is not an extinction event in this deterministic model.
A worked example
Enrich a predator–prey system
Run carrying capacity one point five for two hundred model time units and inspect late population variation.
Increase capacity to six and restart from the same prey and predator indices to expose larger sustained oscillations.
Compare the late-window prey range and identify the saturating predation feedback rather than assuming more resources guarantee stability.
OPTIONAL DEEPER DETAILGo deeper: inside the model
Inside this model
A Rosenzweig–MacArthur model combines logistic prey growth with saturating predation. Growth, handling, conversion and mortality parameters are fixed; increasing carrying capacity above 7/3 destabilises the coexistence equilibrium for these values.
Where this idea is useful
A practical use
Assess feedback and variability before assuming that increasing resources always reduces the risk of a population trough.
A common misconception
“More available food always stabilises every population.”
In some consumer–resource systems, enrichment amplifies delayed interactions and destabilises coexistence. This is conditional, not a universal ecological law.
What this explanation leaves out
- Deterministic teaching populations use fixed parameters and numerical integration; no real species forecast or extinction threshold is supplied.
Where does the threshold seven-thirds come from?
It is the local stability boundary for the fixed growth, handling, conversion and mortality values in this particular Rosenzweig–MacArthur model.
Could improving an average resource level worsen the system’s lowest trough?
Associated thinkers
Associations marked provisional are awaiting source review.
Further reading
Explore the original research or the teaching reference behind this experiment.