Demography: vital statistics and quantitative description of a population
The most fundamental demographic measure of a population is the
number of individuals in a population.
Of particular interest is the number of individuals in a population over
Tropics environment relatively constant
Primary selective forces are biotic (predation and competition
Result: a lot of species but not always high abundance of each
Abiotic variation increases has you move from the equator
Tolerance of abiotic
Describes the gradual and continuous change in species composition
and community structure over time following a disturbance.
Ecologists have developed two main terms to describe community
o Primary succession
Newly exposed site th
The consumption of a live organism.
This distinguishes predation from scavenging and detritivory.
Types of predation
o Carnivory - an organism captures, kills, and consumes an
o Herbivory - consumption of a live plant by an animal.
o Both species benefit from the interaction.
o In mutualistic pollination systems, both plant and pollinator
benefit, the former by the transfer of pollen and the latter
typically by a nectar meal.
o There are several different typ
o Competition: Any interaction between two or more species
over a limiting resource that causes a decrease in the
population growth of at least one of the species.
o Competition can be intraspecific
Life history : any aspect of the developmental pattern and mode of reproduction of an
Life history strategies are those mechanisms by which organisms deal with or
circumvent potentially harmful interactions and maximize reproductive success.
Difference between exponential and geometric population growth
When a population breeds seasonally (often once a year) we say the population
Some species reproduce almost continuously and generations overlap. We say
Cohort Life Table
Follows a cohort of individuals from birth to death and used to
estimate the age-specific probabilities of survival.
Static Life Table
Accomplishes the same goal, but instead of following a cohort of
individuals from birth to death, da
Limiting Factors: Abiotic components that ultimately determine
the presence or absence of an organism in a given area
Law of the Minimum The success of an organism is determined by one
crucial ingredient in the environment that is in short supply
Law of T