arc 2/3 summative study guide (terms)

exponential growth

under ideal conditions, a population can increase rapidly over a relatively short amount of time

(J SHAPED)

ex. birth and immigration

logistic growth

period of slow growth following a period of exponential growth before leveling off to a stable size (reaches carrying capacity)

(S SHAPED)

1. resources are abundant at first, and the population grows quickly

2. resources and growth reduce

3. population levels off to a size the environment can support

boom and bust

population grows exponentially, can exceed the resources available (boom)

=

rapid decline in population, higher death rates (bust)

density-dependent factors

environmental conditions or events whose impact on a population is affected by the population's density

simple terms: things in the environment that affect a group of living things depending on how populated they are

-exert a stronger influence on larger, more densely populated groups of organisms

-help define the carrying capacity

-can alter birth and death rates

ex. competition, predation, disease, parasitism, etc

density-independent factors

environmental influences, often abiotic, that impact a population's size, regardless of density

simple terms: non-living things that affect a population, no matter how crowded they are

ex. natural disasters like floods, wildfires, droughts, hurricanes, etc

ex. some human factors like pollution and habitat destruction

limiting factors

an element in the environment that restricts the growth, distribution, or abundance of a population or organism, determining the ecosystem's carrying capacity

carrying capacity

the maximum population of a species that an environment can hold indefinitely without being damaged or degraded, determined by factors like food, water, shelter, and predation

simple terms: the max population an ecosystem can hold before things get bad

disturbances

events that change communities, remove or destroy organisms from communities, or alter resource availability

ecosystem resilience

an ecosystem's ability to recover from disturbance

succession

a sequence of biotic changes that restore a damaged community or create a community in a previously uninhabitable area

simple terms: changes to make an unlivable community into a livable community

primary succession

the establishment and development of an ecosystem in a previously unhabited area

ex. rocks

secondary succession

restoration of an ecosystem in an area where soil was left intact (soil still on the ground)

-responds faster than primary

-sometimes new plants come and increase biodiversity

what makes a graph scientific?

clearly and accurately communicates scientific data

niches

the role of an organism in its habitat, or how it makes its living

multiple niches = competition = bad

species harmony

balance between an ecosystem, all interacting

stable ecosystems

-biodiversity

-niches

-species harmony

-resistance to disturbances

-abundance of resources

-consistent/predictable climate

what causes fluctuations in population size?

-births/deaths

-emmigration/immigrations

-carrying capacity

-density-dependent and independent limiting factors

-disturbances

trophic cascade

an ecological process that happens when the removal or addition of a top predator triggers a chain reaction that impacts other species throughout the ecosystem, cascading down the food web to affect lower trophic levels, from prey populations to the plants they eat

keystone species

organisms that have a disproportionately large effect on their ecosystem relative to their abundance

if they are removed, the ecosystem would collapse