349 terms

Cumulative set 2/19

APES Cumulative Set of Vocabulary Terms
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Tragedy of the Commons
The tendency of a shared, limited resource to become depleted because people act from self-interest for short-term gain
Externality
A cost or benefit of a good or service that is not included in the purchase price of that good or service
Maximum sustainable yield (MSY)
The maximum amount that can be harvested without compromising the future availability of that resource
Resource conservation ethic
States that people should maximize resource based on the greatest good for everyone
Multiple-use lands
May be used for recreation, grazing, timber harvesting, and mineral extraction
Rangelands
dry,open grasslands
Forest
dominated by trees and other woody vegetation (if you got this wrong, that's really sad)
Clear-cutting
involves removing all, or almost all, the trees within an area
Selective cutting
Removes single trees or relatively small number of trees from among many in a forest
Ecologically sustainable forestry
has a goal of maintaining all species, both plants and animals, in a close to a natural state as possible
tree plantation
large areas typically planted with a single rapidly growing tree species
prescribed burn
a fire is deliberately set under controlled conditions
national wildlife refugees
the only federal public lands managed for the primary purpose of protecting wildlife
national wilderness area
set aside with the intent of preserving large tracts of intact ecosystems or landscapes
National Environmental Policy Act (NEPA)
mandates an environmental assessment of all projects involving federal money federal permits
Environmental impact statement (EIS)
outlines the scope and purpose of the project, describes the environmental context, suggests alternative approaches to the project, and analyzes the environmental impact
Timberland Conservation Program (TCP)
run by the California Department of Fish and Wildlife and is responsible for plant, fish, and wildlife conservation in the state of California, guided by knowledgeable and effective professionals who use science, collaboration, and outreach to accomplish their mission
Timberland Environmental Impact Report
addresses all aspects of an operation's proposed timber operations, including, but not limited to, timber harvest levels, silvicultural methods (how to reduce tree stress), harvesting practices, erosion control, site preparation, watercourse and lake protection, hazard reduction, fire protection, wildlife protection, logging road and landing practices, archaeological resource protection, and rare plant protection
Silviculture
the art and science of controlling the establishment, growth, composition, and quality of forest vegetation for the full range of forest resource objectives, ensuring the long-term continuity of essential ecologic functions, and the health and productivity of forested ecosystems
environmental mitigation plan
states how it will address the project's environmental impact
Endangered Species Act
an act from 1973 designed to protect species from extinction
suburb
surrounds a metropolitan center and has lower population densities compared with urban areas
exurb
similar to a suburb but unconnected to any central city or densely populated area, they don't have any major commercial place to boast of, and may also have large farm areas
urban sprawl
creation of urbanized areas that spread into rural areas and remove clear boundaries between the two
urban blight
As people move away from a city to suburbs and exurbs, the city often deteriorates, causing even more people to leave.
highway trust fund
pays for the construction and maintenance of roads and highways
induced demand
an increase in the supply of a good causes demand to grow
zoning
a planning tool developed in the 1920s to separate industry and business from residential neighborhoods and create quieter, safer communities
multi-use zoning
allows retail and high-density residential development to coexist in the same area
smart growth
focuses on strategies that encourage the development of sustainable, healthy communities .
stakeholder
people with an interest in a particular place or issue
sense of place
the feeling that an area has a distinct and meaningful character
transit-oriented development (TOD)
attempts to focus dense residential and retail development around stops for public transportation, giving people convenient alternatives to driving
infill
development that fills in vacant lots within existing communities, rather than expanding into new land outside the city
urban growth boundaries
place restrictions on development outside a designated area
eminent domain
a principle that grants government the power to acquire a property at fair market value even if the owner does not wish to sell it
Extinction
When the last member of a species dies
Inbreeding Depression
When individuals with similar genotypes, typically relatives, breed with each other and produce offspring that have an impaired ability to survive and reproduce
Endangered
Serious risk of extinction
Svalbard Global Seed Vault
Contains strong seed varieties in case of natural disasters
Extinct species
Existed as recently as the year 1500 but no longer today
Threatened species
Have a high risk of extinction in the future
Near-threatened species
Very likely to become threatened in the future
Least concern species
Wide and abundant
Intrinsic Value
worth independent of any benefit it may provide to humans
Instrumental Value
Value of an organism, species, ecosystem, or the earth's biodiversity based on its usefulness to us.
Provision
A good that humans can use directly
Native species
Species that live in their historical range
Exotic Species
organisms that are not native to a particular area
Alien species
Species that live outside their historical range
Invasive specieas
When an alien species spreads rapidly across large areas
Lacey Act
Prohibits the transport of illegally harvested game animals across state lines
Convention on International Trade in Endangered Species of Wild Fauna & Flora (CITES)
Controls international trade of threatened plants and animals
Red List
List of threatened species made by IUCN
Convention on Biological Diversity
An international treaty to help protect biodiversity
Edge Habitat
Where two different communities come together, typically forming an abrupt transition,
Biosphere Reserves
Protected areas consisting of zones that vary in the amount of permissible human impact
Endangered Species Act
Has prevented or altered some construction projects to accommodate threatened or endangered species
Marine Mammal Protection Act
Prohibits the killing of all marine animals in the US and import and export of body parts
Well-Being
The status of being healthy, happy, and prosperous.
Economics
How humans as individuals or companies allocate scare resources in the production, distribution, and consumption of goods and services.
Genuine Progress Indicator
A measurement of the economy that considers personal consumption, income distribution, levels of higher education, resource depletion, pollution, and the health of the population. WHILE gdp RISES, gpi STAYS STEADY.
Technology Transfer
Less developed countries adopt technological innovations developed in wealthy countries.
Kuznets Curve
As per capita increases, environmental degradation first increases and then decreases.
Leapfrogging
New technology develops in such a way that makes the older technology obsolete and unnecessary.
Microlending
Practice of loaning small amounts of money to people who intend to start a small business in less developed countries. Improves quality of life, increases income, increases confidence, empowers women and sound environmental practices, lowers fertility rate so the population stabilizes, and local markets develop so less fuel is used to transport goods.
Natural Capital
Resources of the planet such as air, water, and minerals.
Human Capital
Refers to human knowledge and abilities.
Manufactured capital
All goods and services that humans produce.
Market Failure
When an economic system doesn't appropriately account for all costs
Environmental Economics
Examines the costs and benefits of various policies and regulations that seek to regulate pollution and degradation.
Ecological Economics
Treats economics as a component of ecological systems.
Vaulation
Assigning monetary value to intangible benefits and natural capital.
Environmental worldview
encompasses how people think the world works, how they view their role in it, and what they believe to be proper behavior regarding the environment.
Anthropocentric Worldview
Human centered worldview. Considers that human beings have intrinsic value.
Stewardship
Subset of anthropocentric worldview that is the careful and responsible management and care for Earth and its resources.
Biocentric Worldview
Life centered. Humans are one of many species, all of which have intrinsic value.
Ecocentric Worldview
Earth centered. Equal value on all living organisms and the ecosystems they live in.
United Nations Environmental Programme (UNEP)
A group within the United Nations responsible for gathering environmental info and research and assessing environmental problems.
World Bank
Provides technical and financial assistance to developing countries to reduce poverty and promote growth.
World Health Organization (WHO)
A group within the United Nations responsible for human health, including combating the spread of infectious diseases and health issues related to natural disasters.
United Nations Development Programme (UNDP)
A program of the United Nations that works to improve living conditions through economic development.
Environmental Protection Agency (EPA)
A U.S. government agency that creates federal policy and oversees enforcement of regulations related to the environment,including science, research, assessment, and education.
Occupational Safety and Health Administration (OSHA)
A U.S. federal agency responsible for the enforcement of health and safety regulations in the workplace.
Department of Energy (DOE)
A U.S. government agency created in 1977 with the goal of advancing the energy and economic security of the United States.
Human Development Index (HDI)
A measure of economic well-being that combines life expectancy, knowledge, education,and standard of living as shown in GDP per capita and purchasing power.
Human Poverty Index (HPI)
A multidimensional measure of poverty, measuring longevity, knowledge, economic provisioning and social inclusion.
Command and Control Approach
Sets regulations for emissions and controls with fines and punishments
Incentive Based Approach
Financial benefits and incentives for lowering emissions.
Green Tax
Tax places on environmentally harmful activities or emissions.
Triple Bottom Line
Must take into account 3 factors economic, environmental, and social when making decisions.
UN Millennium Declarations
Eradicate extreme poverty and hunger, achieve universal primary education, promote gender equality and empower women, reduce child mortality, improve maternal health, combat HIV, malaria, and other diseases, ensure environmental sustainability, and develop a global partnership for development.
United Nations (UN)
An institution dedicated to promoting dialogue among countries with the goal of maintaining world peace.
Matter
anything that occupies spacd and has mass
Mass
measure of the amount of matter it contains
Atom
the smallest particle that can contain the chemical properties of an element
Element
A pure substance made of only one kind of atom
Periodic Table
lists all of the elements currently
Molecules
Particles comtaining more than one atom
Compounds
Molecules that comtain more than one element
Atomic Number
the number of protons in the nucleus of a particular element
Mass number
total number of protons and neutrons in an element is known at its
Isotopes
Various kinds of atoms are called
Radioactive Decay
The spontaneous release of material from the nucleus
Half-life
the time it takes for one half of the orginial radioactive parent atoms to decay
Covalent Bonds
componds are said to be held togther by
ionic bonds
the attraction between oppositely charged ions forms a chemical bond called
Hydrogen Bond
weak chemical bond that forms when hydrogen atoms that are covalently bonded to one atom are attracted to another atom on another molecule
Polar Molecule
one side is more positive and the otherside is more negative
Surface Tension
results from cohesion of water molecules at the surface of a body of water and creates a sort of skin on the waters
Capillary Action
happens when adhesion of water molecules to a surface is stronger than cohesion between the molecules
Acid
a substance that contibutes hydrogen ions to a solution
Base
a substance that contributes hydroxide ions to a solution
pH
a measure of how acidic or basic a solution is
chemical reaction
A change in which one or more substances are converted into new substances.
Law of conservation of matter
which states that matter connot be created or destroyed; it can only change form
Inorganic Compounds
Are compouds that either do not contain the elemnt carbon or do not contain carbon, but only carbon bound to elements other that hydrogen
Organic Compounds
are compounds that have carbon-carbon and carbon-hydrogen bonds
Carbohydrates
are compounds composed of carbon, hydrogen, and oxygen aroms
Proteins
are made up of long chains of nitrogen-containing organic molecules called amino acids
Nucleic Acids
Organic compounds found in all living cells
DNA
the genetic material organisms pass on to their offspring that contains te code for reproducing the components of the next generation
RNA
Translates the code stored in the DNA and allows for the synthesis of proteins
lipids
are smaller biological molecules that do not mix with water
Cell
highly organized living entity that consists of the four types of macromolecules and other sunstances in a watery solutions, surrounded by a membrane
Energy
The abiloty to do work, or transfer heat
Electromagnetic Radiation
a form of energy that includes, but is not limited to, visible light ultraviolet light, and infrared energy, which we perceive as heat
Photons
A massless packet of energy that carries electromagnetic radiation at the speed of light
Joule
the amount of energy used when a 1-watt light bulb is turned on for 1 second- a very small amount
Power
the rate at which work is done
potential energy
stored energy that has not been released
kinetic energy
the energy of motion
Energy
ability to do work, or transfer heat
chemical energy
potential energy stored in chemical bonds is
temperature
measure of the average kinetic energy of a substance
First law of thermodynamics
energy cannot be created or destroyed
Second law of thermodynamics
when energy is converted from one form to another (transformed), the quantity of energy is the same, but some energy gets lost as heat (ability to do work)
energy efficiency
the ratio of the amount of work that is done to the total amount of energy that is introduced into the system in the first place
energy quality
the ease with which an energy source can be used for work
entropy
randomness in a system
open system
echanges of matter or energy occur across system boundries
closed system
matter and energy exchanges across system boundries do not occur
inputs
additions to a given system
outputs
losses from the system
system analysis
an analysis to determine inputs, outputs, and changes in a system under various conditions
steady state
whether inputs equal outputs, so that the system is not changing over time
feedback
the results of a process feed back into the system to change the rate of that process
negative feedback loops
a feedback loop in which a system responds to a change by returning to its original state, or at least by decreasing the rate at which the change is occuring
positive feedback loop
feedback loop in which change in a system is amplified
biosphere
the region of our planet where life resides
Ecosystem
Particular location on Earth distinguished by its particular mix of interacting biotic and abiotic components.
Autotroph
organisms that can make their own food
Producers
Autotrophs. Uses solar energy to produce usable forms of energy with photosynthesis.
photosynthesis
Plants use the sun's energy to convert water and carbon dioxide into sugars
6CO2 + 6H2O + light --> C6H12O6 + 6O2
Cellular Respiration
Process that unlocks the chemical energy stored in cells of organisms.
aerobic respiration
Respiration that requires oxygen, glucose + O2 ==> energy
anaerobic respiration
Respiration that does not require oxygen, glucose ==> energy, produces lactic acid
Consumers or Heterotrophs
Incapable of photosynthesis. Must get energy from consuming other organisms.
herbivore
organism that obtains energy by eating only plants (producers)
Primary Consumers
Incapable of photosynthesis, consume producers (zebras)
Carnivore
organism that obtains energy by eating animals
Tertiary consumers
carnivores that eat secondary consumers (bald eagle)
Secondary Consumers
Eat primarily consumers. Carnivores. (lions)
Trophic Levels
Successive levels of organisms consuming each other.
Food Chain
Sequence of consumption from producers to top level of consumers.
Food Web
Food chains that take into account the complexity of nature and show all connections between organisms.
Scavengers
Carnivores that consume dead animals
Detritivores
Organisms that specialize in breaking down dead tissues and waste products
Decomposers
Fungi and bacteria that complete the breakdown process by recycling the nutrients from dead tissues and wastes back into the ecosystem.
Gross Primary Productivity (GPP)
Total amount of solar energy that the producers in an ecosystem capture via photosynthesis over a given amount of time.
Net Primary Productivity (NPP)
Energy captured minus the energy respired by producers.
Biomass
Total mass of all living matter in a specific area
Standing Crop
Total biomass present in an ecosystem at a particular time
Ecological Efficiency
Proportion of consumed energy that can be passed from one trophic level
Trophic Pyramid
Represent the distribution of biomass among trophic levels. Decrease by about 10 percent each time
Biogeochemical Cycles
Movement of matter within an between ecosystems.
Hydrologic Cycle
Powered by the sun. The pathways water takes as it travels through Earth's spheres/systems.
Transpiration
Plants release water from their leaves into the atmosphere
Evapotranspiration
Combined amount of evaporation from land and transpiration.
Runoff
Water moving across land surface and into water bodies, eventually reaching ocean.
Evaporation
Solar energy heats liquid water and it becomes a gas.
Condensation
Water vapor goes from a gas to liquid often to form clouds
Carbon Cycle
The movement of carbon through Earth's spheres/systems. Largest reservoir is rock/geosphere. Largest sink is the ocean.
Limiting Nutrient
A nutrient whose amount available limits growth of organisms.
Combustion
Burning organic fuels releasing carbon dioxide
Photosynthesis
Producers/autotrophs capture the energy of sunlight and store it in sugars.
Macronutrients
Needed by organisms in large amounts. Nitrogen, phosphorus, potassium, calcium, magnesium, and sulfur.
Nitrogen Cycle
The movement of nitrogen through Earth's spheres/systems. Largest reservoir is the atmosphere.
Nitrogen Fixation
Bacterial organisms convert N2 into ammonia NH3.
Nitrification
Bacteria convert ammonium NH4+ into nitrite NO2- and then into Nitrate NO3-
Assimilation
Process where producers incorporate elements into their tissues
mineralization
the process by which fungal & bacterial decomposers break down organic matter found in dead bodies & waste products & convert it into inorganic compounds
Ammonification
Bacteria (decomposers) in soil and water break down biological nitrogen compounds into ammonia.
Denitrification
Bacteria in oxygen poor soil and stagnant water convert nitrate into nitrous oxide N2O and nitrogen gas N2
Leaching
Nitrate transported through the soil with water.
Phosphorus Cycle
The movement of phosphorus through Earth's spheres/systems. Largest reservoir is rock/geosphere. Weathering of uplifted rocks contribute phosphates to the land and some phosphate make their way back to the ocean. It is NOT found in the atmosphere.
algal bloom
The rapid growth of a population of algae
hypoxic
deficient in oxygen
sulfur cycle
Cycle of how sulfur cycles through the earth's air, water, soil and living organisms.
disturbance
an event resulting in changes in population size or composition
resistance
a measure of how much a disturbance can affect flows of energy and matter in an ecosystem
resilience
the rate at which an ecosystem returns to its original state after a disturbance
Eutrophication
Excessive phosphates and nitrates in bodies of water. Leads to overgrowth of producers, followed by decomposers, and low oxygen conditions.
Watershed
All of the land in a given landscape that drains into a particular stream, river, lake, or wetland.
Restoration Ecology
study of and implementation of restoring damaged ecosystems.
Intermediate Disturbance Hypothesis
Ecosystems experiencing intermediate levels of disturbance are more diverse than those with high or low disturbance levels.
Provisions
Goods that humans can directly use.
climate
the average weather that occurs in a given region over a long period of time
weather
the short term conditions of the atmosphere in a local area, which include temperature, humidity, clouds, precipitation, and wind speed
troposphere
the layer of the atmosphere closest to Earth's surface, extending approximately 16 km (10 mi)
stratosphere
layer of the atmosphere above the troposphere, extending roughly 16 to 50 km (10-30 miles) above the surface of the Earth
albedo
the percentage of incoming sunlight that is reflected from a surface
saturation point
the maximum amount of water vapor that can be in the air at a given temperature
adiabatic cooling
the process in which the decrease of atmospheric pressure allows rising air to expand in volume and lower it's temperature
adiabatic heating
the process in which the increase of atmospheric pressure allows sinking air to decrease in volume and raise it's temperature
latent heat release
the release of energy when water vapor in the atmosphere condenses into liquid water
atmospheric convection current
global patterns of air movement that are initiated by the unequal heating of the Earth
Hadley Cell
the convection currents that cycle between the equator and 30 degrees N and S
intertropical convergence zone (ITCZ)
the latitude that receives the most intense sunlight, which causes the ascending branches of the two Hadley cells to converge
polar cells
a convection current in the atmosphere, formed by air that rises at 60 degrees N and S and sinks at the poles, 90 N and S
ferrell cell
convection current in the atmosphere that lies between Hadley cells and polar cells
Coriolis Effect
the deflection of an objects path due to Earth's rotation
rain shadow
a region with dry conditions found on the leeward side of a mountain range as a result of humid winds from the ocean causing precipitation on the windward side
gyres
large-scale patterns of water circulation that moves clockwise in the N Hemisphere and counterclockwise in the S Hemisphere
upwelling
upward movement of ocean water toward the surface as a result of diverging currents
thermohaline circulation
An oceanic circulation pattern that drives the mixing of surface water and deep water
el Nino; ENSO
a reversal of wind and water currents in the South Pacific
terrestrial biomes
geographic regions that have a particular combination of average annual temperature and annual precipitation and contain distinctive plant growth forms that are adapted to that climate
aquatic biome
an aquatic region characterized by a particular combination of salinity, depth, an water flow
tundra
a biome that is cold and treeless, with low-growing vegetation
permafrost
an impermeable, permanently frozen layer that prevents water from draining and roots from penetrating
boreal forest
a biome; are forests made up primarily of coniferous (cone-bearing) evergreen trees that can tolerate cold winters and short growing seasons
temperate rainforest
a biome; moderate temperatures and high precipitation typify this biome
temperate seasonal forest
a biome; warm summers and cold winters with over 1 m (39 inches) of precipitation annually
shrubland/Chaparral
a biome; is characterized by hot, dry summers and mild, rainy winters
Temperate Grassland/cold desert
a biome; cold, harsh winters and hot, dry summers characterize this biome
Tropical Rainforest
a biome; are warm and wet, with little seasonal temperature variation
Tropical Seasonal Forests; Savannahs
a biome; are marked by warm temperatures and distinct wet and dry seasons
Subtropical Desets
a biome; also known as hot deserts; hot temperatures, extremely dry conditions, and sparse vegetation prevail
Littoral Zone
is the shallow area of soil and water near the shore where algae and emergent plants such as cattails grow
Limnetic Zone
a zone of open water in lakes in ponds
Phytoplankton
floating algae
Profundal Zone
region of water where sunlight does not reach, below the limnetic zone in very deep lakes
Benthic Zone
the muddy bottom of a lake, pond, or ocean
oligotrophic
describes a lake with a low level of productivity
mesotrophic
describes a lake with a moderate level of productivity
eutrophic
describes a lake with a high level of productivity
Freshwater Wetland
a biome; aquatic biomes that are submerged or saturated by water for at least part of each year, but shallow enough to support emergent vegetation
Salt Marsh
a biome; a marsh containing nonwoody emergent vegetation, found along the coast in temperate climates
Mangrove Swamps
a biome; occur along tropical and subtropical coasts and contains salt-tolerant trees with roots submerged in water
Intertidal Zone
the narrow band of coastline between the levels of high tide and low tide
Coral Reefs
a biome; are found in warm, shallow waters beyond the shoreline, represent Earth's most diverse marine biome
Coral Bleaching
a phenomenon in which the algae inside the corals die which soon causes the corals to turn white
open ocean
deep ocean water, located away from the shoreline where sunlight can no longer reach the ocean bottom
Photic Zone
the upper layer of water that receives enough sunlight to allow photosynthesis
Aphotic Zone
the deeper layer of water that lacks sufficient sunlight for photosynthesis
Chemosynthesis
process in which bacteria deep in the ocean use the bonds of methane and hydrogen sulfide to generate energy
ecotone
an area where two or more habitat types come together; transitional plants & organisms are found here--fragile, with high diversity, alterations to these habitats can cause significant destruction of edge species
species richness
the number of species in a given area
species eveness
tells us whether a particular ecosystem is numerically dominated by one species or whether all of its species have similar abundances
phylogenies
the branching patterns of evolutionary relationships
evolution
a change in the genetic composition of a population over time
microevolution
the evolution below the species level, such as the evolution of different varieties of apples or potatoes
macroevolution
the process in which genetic changes give rise to a new species, genera, family, class, or phyla
genes
are physical locations on chromosomes within each cell of an organism; determines the range of possible traits that it can pass down to its offspring
genotype
the complete set of genes in an individual
phenotype
the actual set of traits expressed in that individual
mutation
an occasional mistake in the copying process of DNA produces a random change in the genetic code
recombination
occurs as chromosomes are duplicated during reproductive cell division and a piece of one chromosome breaks off and attaches to another chromosome
artificial selection
when humans determine which individuals breed, typically with a preconceived set of traits in mind
natural selection
the environment determines which individuals survive and reproduce
fitness
an individual's ability to survive and reproduce
adaptations
traits that improve an individual's fitness
gene flow
the process of allelles (genes) moving from one population to another
genetic drift
a change in the genetic composition of a population over time as a result of random mating
bottleneck effect
a reduction in the genetic diversity of a population caused by a reduction in its size
extinction
the death of every member of a species
founder effect
a change in a population descended from a small number of colonizing individuals
geographic isolation
when a subset of individuals from a larger population may colonize a new area of habitat that is physically separated from that of the rest of the population
allopatric speciation
a process of speciation that requires geographic isolation
reproductive isolation
when the geographically separated population becomes so different that even if the physical barrier were removed, they could no longer interbreed and produce viable offspring
sympatric speciation
the evolution of one species into two species in the absence of geographic isolation
genetically modified organisms
organisms that have had their genetic makeup modified by genetic engineering
genetic engineering
techniques in which scientists can now copy genes form a species with some desirable trait and insert these genes into other species
range of tolerance
limits to the abiotic conditions they can tolerate
fundamental niche
the suite of ideal conditions
realized niche
the range of abiotic and biotic conditions under which a species actually lives
species distribution
the areas of the world in which the species lives
niche generalists
organisms that can live in a variety of habitats or feed on a variety of species
niche specialists
organisms that are specialized to lie in a specific habitat of feed on a small group of species
mass extinction
events in which large number of species when extinct over relatively short periods of time
fossils
the remains of organisms that have been preserved in rock
sixth mass extinction
scientists have predicted/identified a new mass extinction is underway and an estimated 2-25 percent of species will go extinct; it is caused by humans
ecosystem diversity
the measure of the variety of ecosystems within a region
species diversity
the measure of the variety of species within an ecosystem
genetic diversity
the measure of the variety of genes within a species
population
composed of all individuals that belong to the same species and live in a given area at a particular time
community
incorporates all of the populations of organisms within a given area
population ecology
the study of factors that cause populations to increase or decrease
population size
the total number of individuals within a defined area at a given time
population density
the number of individuals per unit area (or volume for aquatic organisms) at a given time
population distriution
a description of how individuals are distributed with respect to one another
sex ratio
the ratio of males to females
age structure
a description of how many individuals fit into particular age categories
limiting resource
a resource that a population cannot live without and which occurs in quantities lower than the population would require to increase in size
density-dependent factors
influences an individual's probability of survival and reproduction in a manner that depends on the size of the population
carrying capacity; k
population growth slowed as population size increased because there was a limit to how many individuals the food supply could sustain
Density-independent factors
have the same effect on an individuals probability of survival and amount of reproduction at any population size
population growth rate
the number of offspring an individual can produce in a given time period, minus the deaths of the individual or offspring during the same period
population growth model
mathematical equations that can be used to predict population size at any moment in time
intrinsic growth rate; r
under ideal conditions, with unlimited resources available, every population has a particular maximum potential for growth
exponential growth model
tells us that, under ideal conditions, the future size of the population depends on the current size of the population, the intrinsic rate of the population, and the amount of time over which the population grows
J-shaped curve
when populations are not limited by resources they exhibit a J shaped curve, an exponential growth model
logistic growth model
describes a population whose growth is initially exponential, but slows as the population approaches the carrying capacity of the environment
S-shaped curve
the shape of the logistic growth model when graphed
overshoot
when the population becomes larger than the spring carrying capacity
Die-off
population crash usually experienced after the overshoot of the carrying capacity
k-selected species
species that have a low intrinsic growth rate, which causes their populations to increase slowly until they reach the carrying capacity of the environment
r-selected species
species that have a high intrinsic growth rate because they reproduce often and produce large numbers of offspring
survivorship curves
graphs of distinct patterns of survival over time
Type I Survivorship Curve
shows a population where most individuals live to an advanced age
Type II Survivorship Curve
shows a population where all ages have a similar death rate
Type III Survivorship Curve
Most individuals die early in life (e.g., fishes, invertebrates, and plants).
corridors
strips of habitat that connect separated populations that the animal travels across
metapopulations
a group of spatially distinct populations that are connected by occasional movements of individuals between them
inbreeding depression
related individuals breed to produce an offspring that have trouble surviving and reproducing
community ecology
the study of species interactions, which determine the survival of a species in a habitat
symbiotic relationship
The relationship between two species that live in close association with each other.
competition
the struggle of individuals to obtain a limiting resource
competitive exclusion principle
states that two species competing for the same limiting resource cannot coexist
resource partitioning
where two species divide a resource based on differences in the species' behavior or morphology
predation
refers to the use of one species as a resource by another species
parasitism
a relation between organisms in which one lives as a parasite on another
pathogen
A microorganism that is capable of causing disease in a susceptible host
herbivory
interaction in which one animal (the herbivore) feeds on producers (such as plants)
true predators
typically kill their prey and consume most of what they kill
mutualism
benefits two interacting species by increasing both species' chances of survival or reproduction
herbivores
consumes plants as prey
commensalism
a type of relationship in which one species benefits but the other is neither harmed nor helped
keystone species
a species that plays a role in its community
ecosystem engineers
species that create or maintain habitat for other species
ecological succession
the predictable replacement of one group of species by another group of species over time
primary succession
occurs on surfaces that are intially devoid of soil
secondary succession
occurs in areas that have been disturbed but have not lost their soil
parasites
live on or in the organisms they consume
parasitoids
organisms that lay eggs inside other organims
predator-mediated competition
competition in which a predator is instrumental in reducing the abundance of a superior competitor, allowing inferior competitors to persist
pioneer species
organisms that have the ability to colonize new areas rapidly and grow well in full sunshine
theory of island biogeography
demonstrates the dual importance of habitat size and distance in determining species richness
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