Lecture 31-Population Ecology Flashcards
A group of individuals of a single species living in the same general area.
Population
What is population ecology?
The study of populations in relation to their environment
Population ecology studies how biotic and abiotic factor influence what?
Density, distribution, size, and age structures of populations
The number of individuals per unit area or volume.
Population density
Population density is typically __________.
Estimated
Population dynamics deal with __________ and __________ within a population.
Addition, removal
Addition:
Birth and immigration
Removal:
Death and emigration
Addition = population __________.
Influx
Removal = population __________.
Outflux
What is population size affected by?
Birth, death, immigration, and emigration
Change in population size (N) during time interval (t) =
(Births + immigration) - (Deaths + emigration)
Average # per individual.
Per capita
Per capita birth rate equation:
B = bN
Per capita death rate equation:
D = mN
Per capita rate of increase equation:
r = b - m
Different populations exhibit different __________ __________.
Distribution patterns
The pattern of spacing among individuals within the boundaries of the population.
Dispersion
3 types of dispersion?
Clumped, uniform, and random
Aggregated in patches.
Clumped
Evenly distributed; result of antagonistic social interactions (territoriality).
Uniform
Position of individuals independent of others.
Random
Most common dispersion pattern:
Clumped
The maximum population size that a particular environment can sustain.
Carrying capacity (K)
What can carrying capacity be shaped by?
Energy, shelter, refuge from predators, nutrient availability, water, and suitable nesting sites
The study of vital statistics of populations and how they can change over time.
Demography
The data used in demography is captured through:
Census, mark-and-recapture, and sampling
Age-specific summaries of survival patterns of populations.
Life tables
Shows rate of survivorship for a cohort/population.
Survivorship curve
Describe a Type I curve.
Low death rates during early and middle life, and then curve down sharply among older age groups.
Describe a Type III curve.
Large/massive death rates for the young, then low for those few individuals that survive.
Describe a Type II curve.
Equal/constant death rate over the organism’s life span
This affects the future growth of the population.
Population age structure
Populations of all species have the potential to expand when resources are ___________.
Abundant
Population increase under ideal conditions.
Exponential population growth
An exponential population growth have what kind of exponential growth curve?
J-shaped
Exponential population growth is characteristic of populations that are:
Introduced to a new environment
When dealing with exponential population growth, there is no limit on __________, no __________, and no __________.
Resources, competition, and predators
What limits population growth?
Carrying capacity
Levels off as population size approaches carrying capacity.
Logistic population growth
Traits that affect an organism’s schedule of reproduction and survival.
Life history
Examples of traits that affect an organism’s schedule of reproduction and survival:
When reproduction begins, how often an organism reproduces, and how many offspring are produced
There is a __________ between reproduction and survival.
Trade-off
Interaction among organisms affects:
Population size fluctuation
