chapter 44 - population ecology (lecture 3) Flashcards
the study of how populations interact with each other and their abiotic environment
ecology
a type of research where you take the unknown and make it known
basic research
a type of research where your work is used to directly help humans
applied research
an island in the arctic where 19 officers were sent to watch out for any russian offensive missions
there were 29 reindeer sent over with the soldiers to provide them with food. the reindeer population exceeded 6000 and then died out in the 1980’s
saint matthew’s island
a group of individuals of the same species
population
vital statistics used to describe populations, such as size, density, distribution, and age structure
demographics
the number of individuals in some specified area of a habitat; how clustered the population is, etc.
density
the three types of population density are
clumping, near uniform, and random
a distribution of the population where:
- there is safety in numbers
> safe reproduction
> non-motile babies
- brought together in search of resources
clumped
a distribution of the population where:
- nesting at a happy medium (safety & space)
- need for resources (spread out evenly)
- provides a decrease in competition
near uniform
a distribution of the population where:
- resources are random, or there is a uniform and steady flow of them
- individuals don’t care about each other
- chance plays a big factor
random
the most common type of population density distribution is
clumping
list two ways to measure approximate population size
- capture-recapture method (tagging()
- taking a sample, then extrapolating
population ___________ adds individuals, while ___________ subtracts them (think movement)
immigration, emigration
new births do not count as “________,” only immigration does
arriving
an interval in which the number of births is balanced by the number of deaths
- assume no change as a result of migration (immigration and emigration balance out)
- population size remains stable
zero population growth
per capita means
for each individual
the rate of growth (positive or negative) on an individual basis; total number of events in a time interval divided by the number of individuals
per capita rates
the formula for calculating the per capita rate is…
number of births divided by population size
b
birth rate
d
death rate
r
net reproduction per individual per unit time
G
population growth over time
N
number of individuals in a population
the combining variable of per capita birth and death rates is called…
- used to calculate the rate of growth of a population
- assuming that the rates are constant
r
the exponential growth equation is…
G=rN
a graph or curve that depicts how population growth expands by ever-increasing increments during successive intervals
- the larger the population, the more individuals there are to reproduce
exponential growth
assume that there is a ___% mortality rate between each stage of reproduction
25
populations grow exponentially as long as the per capita death rates are ______ than the per capita birth rates
lower
the human population now exceeds __ billion; and it is continuing to grow exponentially
7.6 billion
the average annual increase in population is
1.26
the maximum rate of increase per individual under ideal conditions; varies between species; is rarely reached in nature
biotic potential
human biotic potential
- at some point there is a glass ceiling
2-5%
factors that constrain a population’s size and slow or stop it from growing.
ex: food, mates, and competition with other organisms for resources
limiting factors
__-__ million people die every year from starvation
13-18
_ ______ people are malnourished
1 billion
limiting factors become more intense as population size increases
- the logistic growth equation (s)
density dependent
examples of problems that occur as population size increases are…
disease, competition, parasites, toxic effects of waste products, sickness
factors that are unaffected by population size
density independent
K
carrying capacity
the maximum number of individuals that can be sustained in a particular habitat
- logistic growth occurs when population size is limited by this
carrying capacity
the logistic growth equation is…
G=(rmax)(N)
a j-shaped curve correcting into an s-shape
- depicts how as the population increases, the reproduction decreases
- population growth slows due to carrying capacity
logistic growth
rmax
maxiumum population growth rate/
a phenomenon that occurs when the population grows so exponentially it surpasses K, and the population crashes as it hits the glass ceiling
overshooting capacity
