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POPULATION ECOLOGY - Coggle Diagram
POPULATION ECOLOGY
is a subset of
Ecology
which is defined as...
the study of interactions between organisms and their environments
is
NOT
...
environmentalism
seeks to...
investigate the factors that influence the size, distribution, and other properties of natural populations
can be used to make decisions about how to manage a species (based on data from studies)
used to assess the effects of other human activities on wild species
describes the interactions between a...
POPULATION
...
defined as...
a group of organisms that interbreed with one another more often than they interbreed with other members of their species
Size
= the total number of individuals in a population
can be affected by...
emigration
or deaths
= subtracting from a population (departure of individuals who take up permanent residence elsewhere
immigration
or births
= adding to a population (arrival of new residents that previously belonged to another population)
zero population growth
= an interval in which the number of births is balanced by an equal number of deaths
growth
can be expressed as...
per capita growth rate
= per capita births (b) - per capita deaths (d) --> per capita growth (r)
multiplied by the number of individuals equals...
1 more item...
exponential growth
= a population's size will increase by the same proportion of its total in every successive time interval
Density
= the number of individuals per unit area or volume
Distribution
= the location of individuals relative to one another
has different patterns such as...
near-uniform distribution
random distribution
clumped distribution
can be statistically characterized. This is called...
Demographics
can be sampled...but it is very impractical to sample ALL MEMBERS of a population. Biologists utilize sampling estimates such as...
Plot sampling
= a method of estimating the total number of individuals in an area based on data from direct counts in some portions of the area
Mark-recapture sampling
= an estimate of the population size of MOBILE animals
how?
Animals are captured, marked with a unique identifier, then released. Later, scientists capture another group from the same population.
The proportion of the marked animals in the second sample is taken to be representative of the proportion marked in the population as a whole
growth rate
under ideal circumstances is its...
Biotic potential
i.e., food, shelter, other necessities were unlimited with no predators or pathogens
also has its limitations such as...
density-dependent limiting factors
(i.e., factors that cause birth rates to slow and death rates to rise) --> population growth decreases
e.g., predation, parasitism, disease, competition for limited resources
can result in...
logistic growth
i.e., when density-dependent factors affect population size over time so that a plot of numbers versus time yields an S-shaped curve
...after a certain point, a population that has experienced logistic growth will reach its...
Carrying Capacity (K)
intraspecific competition
(i.e., competition for a resource among members of the same species
ultimately results in some individuals failing to secure what they need to survive and reproduce
density-independent limiting factors
i.e., factors that are not affected by crowding
can also be impacted by the members'...
life history
i.e., the manner in which individuals allocate resources to growth, survival, and reproduction over the course of their lifetimes
can be investigated by focusing on...
cohorts
i.e., a group of individuals born during the same interval - from birth until the last one dies
can have various types of survivorship curves...
these curves are...
Type II
Type I
are species that exhibit
K
-selection
i.e., adaptive traits that provide a competitive advantage when population size is near carrying capacity
have large bodies and long generation time
e.g., large mammals
Type III
are classified as opportunistic species
i.e., short generation time and small body size
exhibit
r
-selection, because they maximize r
e.g., flies