Concepts: Keystone species, and population cycle dampening.
Source: Science original research Report (April 5, 2013).
- Background: A keystone species is one that disproportionally affects its ecosystem*. Relationships between predator-prey are generally assumed to be cyclic insofar as their amounts reflect each other in a cyclic manner (e.g. many plants feed many herbivores that increase consumption, reducing plants, etc). Current models for cyclicism assume that cycles are mostly determined by delayed density dependence. Cycles can fade due to (1) noise, (2) environmental change, and (3) environmental change weakening the interaction between biotic entities that give rise to cycles.
- Results: In brief, 18 years of data show a reduction in voles’ winter growth rate. They use the data to rule out pathways 1 and 3, arguing for 2, as causing these effects.
PS. The term keystone species comes from “keystone” in an arch, which although being under the least amount of pressure in an arch, nonetheless the arch collapses without it.
