Ecology

unit 8 ap bio flashcards

Ecology

the scientific study of the interactions between organisms and the environment

Biomes

areas that are defined by temperature and precipitation

Population

groups of individuals of the same species in a given area

Community

all organisms in a given area

Ecosystem

all organisms and the abiotic factors with which they interact

Abiotic Factors

nonliving factors

ex. soil, sunlight, rainfall

Biotic factors

living organisms that impacts the environment

ex. plants, algae, amphibians

Biosphere

global ecosystem

Density

the number of individuals per unit area or volume

Dispersion

pattern of spacing of the population

Clumped Dispersion

for safety or is around a limited resource

Uniform Dispersion

result of toxins secreted of territorial birds

Random Dispersion

in the absence of special attractions

Type 1 Survivorship Curve

low death rates in young/middle age group, high rate in old age

few offspring, high parental investment

ex. humans

Type 2 Survivorship Curve

constant death rate over lifespan

ex. hydra, reptiles, rodents, and birds

Type 3 Survivorship Curve

high death rate among young

no parents- make many and hope one or two sruvive

ex. fish, plants

K-Selected

species that are on the Type 1 curve

high offspring survival, common parental care, fewer offspring

high competition, density dependent population regulation

R-Selected

species that are one the Type 3 Curve

little offspring survival, rare parental care, more offspring

little competition, density independent population regulation

Biotic Potential

the maximum rate a population could grow under ideal conditions

influenced by reproduction age, number of reproductive periods, and how many offspring an organism is capable of reproducing

Carrying Capacity (K)

max number of individuals that an ecosystem can sustain

influenced by environmental conditions

Logistic Growth

population growth in which the population hovers over and under the carrying capacity

Exponential Growth

population size continues to grow over time

Density Independent Factors

occurs regardless of population size

ex. natural disasters

Density Dependent Factors

directly related to population size

ex. competition for food, waste build-up, predation, disease

Community Ecology

study of how groups of different species interact with each other and with their environment in a particular habitat or ecosystem

made up of population diversity and density

Richness

the number of different species

Relative Abundance

number of individuals within each species

Dominant species

the most abundance species, has the most biomass

Keystone Species

exerts the most influence on species

Bottom-Up Structure

influence from lower to higher trophics

the abiotic environment, such as climate or nutrient availability, drives the structure and dynamics of populations within a community.

changes in the environment can have direct and indirect effects on the abundance, distribution, and interactions of populations, which in turn can affect the structure and function of the entire community.

Top Down Structure

removes predators, affects trophic levels below it

predators play a dominant role in regulating population dynamics within a community

Principle of Competitive Exclusion

now two species can occupy the same niche because one will outcompete the other

Predation

+ and - relationship in which the predator is + and the prey is -

When prey population increases, predator population increases

When prey population decreases, predator population decreases

Aposematic Coloration

coloration or patterning in animals that serves as a warning signal to potential predators, indicating that the animal is unpalatable or poisonousM

Batesian Mimicry

harmless species resembles a poisonous one

Herbivary

+ , - relationship in which organism eats part of a plant

+ is the consumer, they have specialized teeth and modified digestive systems

- is the producer

Symbiosis

a biological interaction between two or more different species that can benefit one or both parties involved

paratism, mutualism, commensalism

Paratism

one species benefits, one is harmed

(+,-)

Mutualism

both species benefit

(+,+)

Commensalism

one species benefits, one is unaffected

(+,0)

Gross Primary Productivity

amount of light energy converted to chemical energy

Net Primary Productivity

energy used by producers for cellular respiration

Food Chain

one trophic level to the next

producers → herbivores → carnivores

only 10% passes to the next level

Ecological Succession

the sequential building and rebuilding of an ecosystem

Primary Succession

occurs when a patch of land is created or exposed for the first time, or there were no previous organisms on it

there is no soil

soil building = slow

Secondary Succession

occurs on land that had been previously occupried

There is soil already present, so it is much faster

course after fires or clear cutting

Nitrogen Cycle

nitrogen is transformed and recycled in the environment

nitrogen is transformed and recycled in the environment

Bacteria converts nitrate back into nitrogen gas

Eutrophication

a body of water, such as a lake, river, or coastal area, becomes rich in nutrients, particularly nitrogen and phosphorus.

there is excess nitrogen in lakes due to runoff

causes the overgrowth of algae, so the algae dies and it uses up O2

Greenhouse Effect

a natural process, enables life on earth and gases trap heat to warm the atmosphere

Global warming

there is too much greenhouse, too much CO2, and excess heat is trapped

Ozone

O3

protects from UV rays

CFCs in aerosols and refrigerants deplete O3 by removing an oxygen

Invasive Species

they have no natural predators in a new environment, so they can quickly come and outcompete the native species

Biological Control

crop rotation, natural pest enemies, natural plant toxins, insect birth control

Biomagnification

Higher trophic levels have greater number of toxins than lower levels

if one organism in a lower trophic level gets a toxin, and they get eaten, the higher trophic organism will have a greater number of toxins in their system

Toxins

antibiotics and hormones given to animals/consumed by humans

Water cycle

continuous process of water movement on, above, and below the surface of the Earth.

It involves the evaporation of water from the Earth's surface, the formation of clouds, precipitation, and the return of water to the Earth's surface through runoff or infiltration.

driven by solar energy and gravity, and it plays a crucial role in maintaining the Earth's ecosystems and supporting human life.

Carbon Cycle

The carbon cycle is the process by which carbon is exchanged between the atmosphere, oceans, and living organisms. Carbon is taken up by plants through photosynthesis and is then passed on to animals through the food chain. When organisms die, their bodies decompose and release carbon back into the atmosphere or soil. Carbon can also be stored in fossil fuels, such as coal and oil, which are released into the atmosphere when burned. Human activities, such as deforestation and burning of fossil fuels, have disrupted the natural carbon cycle and contributed to climate change.

Mulerian Mimicry

two or more poisonous species resemble each other

Behavior

the nervous system’s response to a stimulus, carried out by the muscular or hormonal system

helps animals obtain food, find a partner for sexual reproduction, maintain homeostasis

Taxis

more or less automatic, oriented movement toward or away a stimulus

Kinetic

a simple change in activity or turning rate in response to a stimulus

e.g. sow bugs are more active in dry areas

Signal

a change in another animal’s behaviors

visual, chemical, tactile, auditory

Communication

transmission and reception of signals

Pheromones

many animals communicate through odors and emit chemical substances

they are effective at low concentrations

Learned behavior

modification of behavior based on experiences

Habituation

involves the loss of responsiveness to stimuli that contain little or no information

Imprinting

includes a specific critical learning period and innate components are generally irreversible

sensitive period

water cycle

• evaporation → water evaporates from surfaces

• condensation → evaporated water turns into clouds

• precipitation → falls back to surface as rain or snow

• collection → rainfall collects into rivers, lakes and oceans

nitrogen cycle

• nitrogen fixation → conversion of atmospheric nitrogen (N₂) into ammonia (NH₃) by bacteria.

• nitrification → ammonia is converted into nitrites (NO₂⁻) and then nitrates (NO₃⁻) by nitrifying bacteria.

• assimilation → uptake of nitrates by plants to synthesize proteins and nucleic acids.

• ammonification → decomposition of organic matter releasing ammonia back into the soil.

• dentrification → conversion of nitrates back into nitrogen gas (N₂) by denitrifying bacteria, returning it to the atmosphere.

• importance → essential for plant growth and maintaining ecosystem balance.

carbon cycle

• carbon cycle → the process of carbon exchange among the atmosphere, oceans, soil, and living organisms.

• photosynthesis -lants convert CO2 into organic matter using sunlight.

• respiration → organisms release CO2 back into the atmosphere through metabolic processes.

• decomposition → breakdown of organic matter by decomposers releases carbon into the soil and atmosphere.

• fossil fuels → carbon stored in ancient organic matter is released through combustion.

• ocean absorption → oceans absorb CO2 from the atmosphere, regulating global climate.

• carbon sequestration → natural and artificial processes capture and store atmospheric CO2.

K

carrying capacity

r

growth ratesp

N

population size

ecotone

when two terrestrial biomes meet

vertical stratification

different layers of a biome

photic

regions where light can penetrate the water

aphotic

light cannot penetrate water, animals rely on chemosynthetic food sources, bioluminescent fish

benthic

bottom of seafloor

thermocline

areas of rapid temperature change, keeps nutrients cycling through the water, organisms have adapted to the thermocline

nutrient limitation

growth of organisms stunted due to a lack of nutrients

acid precipitation

• flower pH than normal rainwater due to the presence of sulfur dioxide and nitrogen oxides in the atmosphere

• harms ecosystems, damages buildings, affects water quality

• result of industrial emissions and can lead to soil degradation and can harm aquatic life

overharvesting

Definition: Depleting natural resources faster than they can replenish causes species extinction, habitat destruction, and ecological imbalance, especially in fisheries, forests, and wildlife. Sustainable management is essential to mitigate these effects and ensure long-term resource availability.

• depleting natural resources faster than they can replenish

• causes species extinction, habitat destruction, and ecological imbalance

• sustaining management is essential to mitigate effects and ensure long-term resource availability

genetic diversity

• definition → genetic diversity within a species or population.

• importance →crucial for adaptability and survival.

• influences → effects traits like disease resistance and environmental adaptability.

• high diversity → enhances resilience and evolutionary potential.

• low diversity → leads to vulnerabilities and increased extinction risks..