Bio AP Ecology Terms

Ecology

The study of the interactions among living organisms and with their environment

Levels of ecology

Organismal, population, community, ecosystem, biome, biosphere

Habitat

The place where an organism makes its home, collects nutrients, and reproduces

Niche

The role or position that an organism occupies within an ecosystem (how need for nutrients is met)

Organismal

Single organism with all features

Population

Group of organisms of same species living in same place at same time

Community

All the populations of a species living in same place at same time

Ecosystem

A biological community and all abiotic factors that interact with it

Biome

A group of ecosystems that share the same climate and have similar types of communities

Biosphere

The layer of Earth that supports life

Intraspecific interactions

Interactions that occur within a species

Interspecific interactions

Interactions among various species

Biotic factors

Living organisms that an ecosystem is composed of

Abiotic factors

Non living things that an ecosystem is composed of

Biogeochemical cycles

Conservation and recycling of matter that comprises living organisms

Water cycle

Evaporation, condensation, precipitation, runoff into plants + uptake of water, cycle repeats

Carbon cycle

Deposited by respiration of living organisms, fossil fuel burning

Absorbed by photosynthesis and oceans

Nitrogen cycle

Deposited by bacteria and plants and accumulates higher up food chain, human fossil fuels / fertilizers \= runoff

Goes into atmosphere and repeats

Phosphorus cycle

Deposited by weathering of rocks and volcanic activity

Enters oceans through runoff

Dissolves in ocean water cycles or forms sediment on ocean floor

Eutrophication

Effect from fertilizer runoff

Saltwater and freshwater eutrophication

Nutrient runoff causes excess microorganismal growth (depletes oxygen levels and kills ecosystem fauna)

Predation

Hunting of prey by its predator

Cycles of population growth and decline based on amount of food and amount of predators

Herbivory

Consumption of plants by insects and other animals

Defenses against herbivory

Mechanical defenses, chemical defenses, and physical appearance

Mechanical defenses

Cause physical pain to predator or prevents consumption

Thorns on plant, hard shell on turtles

Chemical defenses

Produced by organisms

Poison in foxglove

Physical appearance

Body shape, coloration, etc.

Avoid being detected by predators (chameleon)

Camouflage

Avoiding detection by blending in with the background

Aposematic coloration

Coloration that warns predators that organism not good to eat

Predator experiences toxic chemicals or unpleasant taste after

Batesian mimicry

Harmless species imitates warning coloration of a harmful one

Mullerian mimicry

Multiple species share same warning coloration and all have defenses

Competitive exclusion principle

Two species cannot occupy the same niche in a habitat

Different species cannot coexist in a community if competing for same resources

Resource partitioning

Species shift niches so they no longer compete

Results in character displacement

Character displacement

Two populations diverge in characteristics

Symbioses

Close interactions between individuals of different species over an extended period of time

Impacts abundance and distribution of associating populations

Commensal relationship

One species benefits from interaction while other neither benefits nor is harmed

Birds nesting in tree

Mutualism

Two species benefit from interaction

Parasitism

Parasite benefits, but host is harmed

Parasite

An organism that lives in or on another living organism and derives nutrients from it

Host

Organism being fed upon

Species richness

Listing of the species within a community

Species diversity

Listing of species in a community and the abundance of each species

Diversity index

Simpson's diversity index is one way to measure richness and diversity

Keystone species

A species whose presence is key to maintaining biodiversity within an ecosystem and upholds a community's structure

Invasive species

Non-native organisms that threaten the balance of an ecosystem / habitat

Primary succession

Succession of species where newly formed / exposed land is colonized by living things

Secondary succession

Succession of species where part of an ecosystem in disturbed and remnants of the previous community remain intact

Pioneer species

Species that contribute to primary succession by breaking down minerals into usable nutrients

Climax community

A stable community of organisms in secondary succession

Autotrophs / producers

Organisms that capture and use energy and inorganic nutrients to produce organic compounds

Heterotrophs / consumers

Organisms that consume preformed organic nutrients and tissues of other organisms

Food chain

Represents a single path of energy flow

Food web

Represents many paths of energy flow

Trophic level

An indicator of feeding level (primary producer, primary consumer, secondary consumer, tertiary consumer, etc.)

Primary productivity

All consumers are dependent on the productivity of producers

Ecological pyramids

Show parameters across trophic levels (population, biomass, energy)

Pyramids of numbers

Either upright or inverted

Visualization of ecosystem in terms of population

Pyramids of biomass

Measures amount of energy converted in living tissue at different trophic levels

Pyramids of energy

Always upright

Visualization of energy flow from producers to consumers

10% rule

Energy is lost at each trophic level

Each level has 10% of energy of previous level

Biomagnification

The increasing concentration of toxic substances in organisms at each trophic level

Climate change

The broad range of changes seen across the planet

Greenhouse effect

Cause of climate change

Certain emitted gases block heat from escaping and warm up the planet

Demography

Statistical study of how populations respond to fluctuations in quantity

Population size (N)

The total number of individuals in a population

Population density

The number of individuals within a specific area or volume

Mark and recapture

A method of counting the population of mobile organisms by marking a sample and capturing a new sample later on

Species dispersion patterns

Show the spatial relationship between members of a population within a habitat at a particular point in time

Uniform, random, or clumped dispersion

Uniform dispersion

Population is evenly distributed across the habitat

Random dispersion

Population is randomly distributed across the habitat

Clumped dispersion

Population is grouped in a specific area of the habitat

Density-dependent factors

Density of population affects growth rate and mortality

Density-independent factors

Influences mortality in a population regardless of population density

Exponential growth

Growth of a population with unlimited resources

J-curve

Logistic growth

Population growth decreases as resources become depleted

S-curve

Population growth rate

The number of organisms added in each reproductive generation

Death rate

Number of organisms that die during a particular time interval

Birth rate

Number of organisms that are born during a particular time interval

Zero population growth

Population size is unchanging because death rate is equal to birth rate

Biotic potential

The maximal growth rate for a species

Carrying capacity

The maximum population size that a particular environment can support

Survivorship curve

A graph of the number of individuals surviving at each age individual plotted versus time

Type 1 - humans
Type 2 - birds
Type 3 - trees

Fecundity

The potential reproductive capacity of an individual organism

K-selected species

Species selected by stable, predictable environments

R-selected species

Have a large number of small offspring in unpredictable environments

Age structure

Proportion of a population at different age ranges / can be represented in a diagram

Behavior

The change in activity of an organism in response to a stimulus

Innate behaviors

Behaviors that have a strong genetic component and are independent of environmental influences

Learned behaviors

Result from environmental conditioning and are modified by learning

Behavioral biology

The study of biological and evolutionary bases for such changes

Ethology

An extension of genetics, evolution, anatomy, physiology, and other biological disciplines

Reflex action

An involuntary and rapid response to stimulus

Kinesis

The undirected movement in response to a stimulus

Taxis

The directed movement towards or away from a stimulus (response to light, chemical signals, or gravity)

Fixed action pattern

A lasting series of movements elicited by a stimulus

Migration

The long-range, seasonal movement of animals

Foraging

The act of searching for and exploiting food resources

Selfish behavior

Only individual animal in a group benefits from its actions

Altruistic behavior

One animal's actions benefit another animal

Cooperative behavior

Both animals in a group benefit

Signals

Animal communication using stimuli