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..