Ecology Study Guide

individual

1st level of organization in ecology

population

2nd level of organization in ecology

community

3rd level of organization in ecology

ecosystem

4th level of organization in ecology

biome

5th level of organization in ecology

biosphere

6th level of organization in ecology

a biotic factor

A LIVING component (organism) that shapes up the environment

an abiotic factor

An UNLIVING component (organism) that shapes up the environment

autotrophs

a name for organisms that make their own food

producers

another name for autotrophs

the sun

where an ecosystem initially gets its energy from

through photosynthesis to producers/autotrophs and so on

how an ecosystem gets its energy from the sun

consumers

a name for organisms that must eat to obtain their energy

heterotrophs

another name for consumers

carnivore

a type of heterotroph that mostly eats meat, or the flesh of animals

omnivore

a type of heterotroph that eats both plants and animals

herbivore

a type of heterotroph that eats plants

decomposer

a type of heterotroph that breaks down or eats decaying material for energy

detritivore

a type of heterotroph that eats on waste, organic matter, or detritus for nutrients and energy

The Competitive Exclusion Principle

A proposition that says no two species can occupy the same niche in the same ecosystem for too long.

Food Chain

A hierarchical series of organisms each dependent on the next as a source of food.

Food Web

A system of interlocking and interdependent food chains.

Photosynthetic/producers

What organisms are always at the start of a food chain/web?

Trophic level

The position of an organism in the food chain.

First level of the trophic levels __

_consists of producers, also known as autotrophs. They utilize solar energy through photosynthesis.

Second level of the trophic levels __

_consists of herbivores, who depend on producers for nutrients and energy.

Third level of the trophic levels __

_small carnivores and omnivores, who eat other animals and sometimes plants.

Fourth level of the trophic levels __

_consists of other, bigger carnivores, who eat smaller carnivores and animals

Fifth level of the trophic levels __

_consists of apex predators, who have no predators, who eat other carnivores and animals.

10% (Chemical energy)

What percent (%) of the energy in one trophic level is transferred to the next trophic level?

symbiosis

A close, prolonged association between 2 or more different biological species.

mutualism

a type of symbiosis where both species involved benefit to some extent with neither being harmed.

commensalism

a type of symbiosis where one organism obtains benefits from the other without harming or benefiting it.

parasitism

a type of symbiosis where one organism is benefited at the expense of the other, or the other is harmed in the process.

a limiting factor

anything that constrains a population's size and slows or stops it from growing

density dependent factor

a limiting factor that depends on population size

density independent factor

affect all populations regardless of the population size

density dependent factor examples

predation, competition, waste accumulation and disease

density independent factor examples

natural disasters like storms, floods and earthquakes, the climate and human activity

carrying capacity

How many organisms an environment can sustain properly without starvation and overcrowding

exponential growth

a population's per capita (per individual) growth rate stays the same regardless of population size, making the population grow faster and faster as it gets larger

population density

the concentration of individuals within a species in a specific geographic scale

primary consumers

are on the 2nd trophic level, also known as herbivores

secondary consumers

are on the 3rd trophic level, also known as small carnivores/omnivores

tertiary consumers

are on the 4th trophic level, also known as large carnivores

quaternary consumers

are on the 5th tropic level, also known as apex predators

bacteria

nitrogen fixation is mostly carried out by which organism?

logistic growth

a type of graph that has multiple phases of growth and is S shaped

no soil

primary succession occurs in areas with what?

climax community

what is formed at the end of succession?

_ just one step in a food chain

a trophic level is _

population

all of the organisms of the same species living in the same place at the same time is what?

community

all of the living organisms in an area

ecosystem

all of the living and nonliving parts of the environment

community only includes the living

what is the difference between a community and an ecosystem?

a community includes all the populations of different species (that live in the same place at the same time)

what is the difference between a community and a population?

keystone species

an organism that has an unusually large impact on the environment

niche

all of the resources used by an organism, its total way of life

habitat

a place where an organism lives

ecology

the study of interactions that take place between organisms and their environment

Ecology explains _

_ how living organisms affect each other and the world they live in

biome

a major regional or global community of organisms, characterized by the climate conditions and plant communities that thrive there. 

biosphere

the portion of earth that supports life

primary productivity

the rate at which producers make organic material

it gets lost as heat

where does the rest of the energy go when the available energy is available for the next trophic level?

biomass

the dry mass of all organisms

dispersion

pattern of spacing

random

a type of dispersion which is unpredictable and patternless

clumped

a type of dispersion which is patchy aggregation

uniform

a type of dispersion which is even spacing

age structure

relative number of individuals at each age

exponential growth

a type of graph that is continuous unchecked growth

quadrats

a method for determining population size that is when researchers mark off an area, and count the number of species in this small area.

indirect counting

a method of determining population size that is used for organisms that move around a lot or are difficult to see. 

mark and recapture

a method of determining population size that is when animals are captured, tagged, and released. 

biogeochemical cycles

materials cycle between the living and physical parts of an ecosystem

biogeochemical cycles examples

water, carbon and nitrogen

evaporation

water cycle step 1: sun heats earth, water evaporates and goes into atmosphere as water vapor

condensation

water cycle step 2: water condenses (gas to liquid) to form clouds

precipitation

water cycle step 3: water leaves clouds, falls on earth in many ways (EG rain)

percolation/infiltration

water cycle step 4: water enters soil and becomes groundwater

run-off

water cycle step 5: some water moves on the surface to rivers, lakes and oceans

transpiration

water cycle step 6: water released from plant leaves, returns to the atmosphere

the oceans (a whopping 97.2%)

where is the most water kept on earth?

nitrogen fixation

nitrogen cycle step 1: bacteria work with legumes (peas, beans, peanuts) to take nitrogen from atmosphere and convert it into soil

ammonification

nitrogen cycle step 2: decomposers convert organic nitrogen (nitrogenous waste deposited from animals and plants) to ammonia

nitrification

nitrogen cycle step 3: other kind of bacteria convert ammonia to nitrites + nitrates

denitrification

nitrogen cycle step 4: another kind of bacteria convert nitrites + nitrates to nitrogen gas

succession

changes in a community over time

primary succession

a type of succession where new sites/land is created

climax community

mature, stable ecosystem

secondary succession

a type of succession which occurs after human intervention or a natural disaster (soil is still intact)