Population Limitation and Regulation

Question 1

Define population regulation

Answer 1

tendency of a population to decrease in size when it is above a particular level, but to increase in size when below that level

Question 2

Define limiting factor

Answer 2

a process that produces a change in average or equilibrium population density (change in N*)

Question 3

Define regulating factor

Answer 3

a process that causes per capita mortality to increase or per capita reproduction to decrease with increasing population density
alters per capita rates!

Question 4

Explain disease as both a limiting and regulating factor

Answer 4

disease can cause a reduction in the equilibrium population density (limiting factor) changes N* from N1* to N2*
but can also cause an increase in per capita mortality (regulating factor)

Question 5

regulation implies _____ with increasing population density
while _____ factors influence population limitation

Answer 5

negative feedback
(density dependent birth or death rates)
density dependence is key for regulation!

density-independent
can affect equilibrium density

Question 6

Examples of biotic and abiotic factors of density dependent regulation

Answer 6

biotic = competition for space, resources, predation, parasitism
abiotic = disturbance, weather (increased density means more individuals left out in the cold
MAIN = 1. competition 2. predation 3. parasitism

Question 7

how can parasitism and diseases potentially regulate population density

Answer 7

disease transmission is often density-dependent

Question 8

explain bison as example of diseases regulating population density

Answer 8

bacteria that would induce spontaneous abortion, and only persists with populations about 200 individuals
with lower densities, it reduces the impact of disease

Question 9

how can predation potentially regulate populations

Answer 9

if predators focus on high-density patches

Question 10

How can cannibalism potentially regulate populations

Answer 10

cannibalism can operate in a density-dependent manner for example in larvae, they often kill others of the same until their density is 1 larva per 1-2L of water

Question 11

What are applications of regulation and density dependence

Answer 11

conservation and management (the bison)
fisheries
agriculture and biological control

Question 12

population regulation is critically important for both ___ and ___ ecology

Answer 12

basic and applied