community and population ecology

native

from the ecosystem

nonnative

die off

naturalized- become established, reproduce, but don’t become invasive

invasive- aggressively displace native spaces

why and how do nonnative species become invasive

no predator

better able access resources

another limiting factor is not present

indicator species

their presence or by their absence indicates an environment condition

moss= bad soil

algal bloom= presence of excess nutrients

keystone species

niche has a major impact on an ecosystem by impacting many other niches

ex; otter

foundation species

habitat creating species

coral reef

Law of competitive exclusion

no two species can occupy the same niche

resource portioning

dividing up resource to reduce competition

predation

predator and prey

predators and prey adaptations

speed, eyesight, smell, size, armor, agility, camouflage, chemicals, and mimicry

parasitism

one organism benefits other is harmed

commensalism

one organism benefits and other is neither hurt nor helped

mutualism

both benefit

what influences the diversity in an ecosystem

latitude: higher latitude= less diversity

Pollution

NPP

habitat availability and conditions

time

climax community

one in which population remains stable in balance with each other and their environment

primary succession

long time starts on bare rock, typically linches and mosses (pioneer species), make soil, then early successional plant species, grasses, then mid-successional plant species shrubs, late successional plant species trees; first pines, then hardwoods

secondary succession

begins in a disturbed area

catastrophic natural 

fire, landslides, storm damage, volcanic eruptions

catastrophic human caused

fire, deforestation

gradual natural

climate change

gradual human caused

climate change, invasive species, salt on crops over grazing

inertia/ persistence

resistance to disturbance

consistency

ability to remain unchanged

resilience

ability to recover from disturbance

clumping and what are reasons for clumping

staying together in groups

safety and resource

uniform

random

species richness

number of difference species per unit area

species evenness

relative abundance of the different species per unit area

population change

Population Change=(Births−Deaths)+(Immigration−Emigration)

new population

New Population=Initial Population+Births−Deaths+Immigration−Emigration

population density

Population Density=Total Population/Land Area

carrying capacity

the maximum population an ecosystem can sustain

biotic potential

reproductive capacity of a species

intrinsic rate of increase

capacity for growth with no limits

minimum viable population

lower limit of species population that will survive in the wild

environmental resistance

factors that limit r

what are variable K and r

K: carrying capacity

r: rate of increase

exponential growth

logistic growth

what happens when N>K?

it means the population size (N) has exceeded the carrying capacity (K) of the environment.

population cycles

stable

cyclic

Irruptive

Irregular

predator prey population cycles

one is high other is high

one is low other is low

what is the purpose of reproduction?

is to leave your genes for the future

r strategies

lots of offsprings

independent early

reproduce early

little parental care

small

don’t live long at birth

K strategies

large

reproduce late

lots of parental care

live a long time at birth

few offsprings 

independent late

Type 1

Type 2

type 3