AP Bio: Ch.53: Population Ecology

study of the biotic and abiotic factors that affect population size, density, distribution, and age structure

a group of individuals of a single species that occupy the same area at the same time

density (amount of individuals) and dispersion (how it's spread out)

number of individuals per unit area or volume

births or immigration (organisms coming into a population); deaths or emmigration (organisms leave a population)

Trees 5,000/km^2

pattern of spacing among individuals of the population

clumped, uniform, and random

most common form of dispersion; individuals are found in patches, usually around a required resource; may increase the chances of survival

trees along a stream and flocks of birds around a pond

often the result of antagonist interactions between individuals

territories and spacing between desert plants

often the result of the absence of strong attractions or repulsions between individuals; these are not a common pattern

dandelion or any kind of flower

the study of the vital statistics that affect population size

birth and death rates

a graphic way to show birth and death rates in a population

Type 1, Type 2, and Type 3

low and early midlife deaths; high death rate in older age groups

humans and other large mammals (elephants)

constant death rate over the life span

annual plants and many prey species (rodents/rabbits)

high early death rates and low late deaths

trees, oysters, and frogs

traits that affect an organism's schedule of reproduction and survival make up it's life history

when reproduction begins (age of sexual maturation), how often the organism reproduces, and the number of offspring in each reproductive event

1. "r" or opportunistic species and 2. "K" or equilibrial species

producing as many offspring as possible

early maturation, many reproductive events, and many offspring

maximize reproduction so that at least a few offspring survive to the next generation; however, most offspring die (TYPE 1 SURVIVORSHIP CURVE)

having the most offspring survive

high parental care, late maturation, few reproductive events, and few offspring

maximize survivorship of each offspring; they have few offspring, but the most survive (TYPE 1 SURVIVORSHIP CURVE)

(change in population)= N (change over time) = t === b (birth rate) - d (death rate)

r is equal to the difference between birth rate and death rate

"r" species; it produces a J-shaped growth curve; only holds for ideal conditions and unlimited resources

describes how a population grows more slowly as it nears it's carrying capacity where resources become limited when the population is too large; it is a characteristic of the "k" species

carrying capacity

the maximum population size that a certain environment can support at a particular time

constant value

environment changes

"K"

density-dependent and density-independent factors

affect is related to the number of individuals in a population (N); as N increases, morality increases

competition for resources, territoriality, disease, and predation

affect is not realted to N; mortality is not related to population size; things that could affect population whether big or small

weather and climate; natural disasters like naturally occurring fires

no longer increasing exponentially, but it is still increasing rapidly

fallen by nearly 50% because of geographic transition--fewer people are having less kids

a population goes from high birth rates to high death rates to low birth rates to low death rates

not known