APES Midterm
Primary productivity
rate at which organic matter is created by producers in an ecosystem
Phytoplankton
Microscopic, free-floating, autotrophic organisms that function as producers in aquatic ecosystems
GPP (gross primary productivity)
The total amount of solar energy that producers in an ecosystem capture via photosynthesis over a given amount of time
NPP
(Net Primary Productivity): the energy captured by producers in an ecosystem minus the energy producers respire
Trophic levels
The hierarchical levels of the food chain through which energy flows from primary producers to primary consumers, secondary consumers and so on.
Conservation of matter
the principle stating that matter is not created or destroyed during a chemical reaction
Omnivore
A consumer that eats both plants and animals
Carnivore
A consumer that eats only animals.
Herbivore
A consumer that eats only plants.
First law of thermodynamics
Energy can be transferred and transformed, but it cannot be created or destroyed.
second law of thermodynamics
when energy is changed from one form to another, some useful energy is always degraded into lower quality energy (usually heat)
Energy pyramid
Shows the amount of energy that moves from one feeding level to another in a food web
10% rule
Only 10% of the total energy produced at each trophic level is available to the next level. The amount of energy passed up to the levels of the food pyramid reduces as you go up.
Food chain
A series of steps in which organisms transfer energy by eating and being eaten
Food web
a system of interlocking and interdependent food chains.
producers (autotrophs)
Organisms that make their own food
Ecological pyramids
illustration of the relative amounts of energy or matter contained within each trophic level in a given food chain or food web
Primary consumers
animals that feed on producers; ex. herbivores
secondary consumers
carnivores that eat herbivores
tertiary consumers
carnivores that eat secondary consumers
heterotrophs
An organism that obtains organic food molecules by eating other organisms or their by-products.
Reservoir
A large store of (water, carbon)
Organic
of, relating to, or derived from living matter, contains carbon
Inorganic
Not formed from living things or the remains of living things
Carbon cycle
The organic circulation of carbon from the atmosphere into organisms and back again
Carbon
C 6
Carbon sinks
places such as forests, ocean sediments, and soil, where accumulated carbon does not readily reenter the carbon cycle
Photosynthesis
Plants use the sun's energy to convert water and carbon dioxide into sugars and oxygen
Phytoplankton
Microscopic, free-floating, autotrophic organisms that function as producers in aquatic ecosystems
Cyanobacteria
Bacteria that can carry out photosynthesis
Cellular respiration
Process that releases energy by breaking down glucose and other food molecules in the presence of oxygen, releases CO2
Decomposition
A chemical reaction that breaks down compounds into simpler products.
Decomposer
An organism that breaks down wastes and dead organisms
Leaf litter
decomposing but recognizable leaves and other debris forming a layer on top of the soil, especially in forests
Detritivore
organism that feeds on plant and animal remains and other dead matter
Nitrogen
N 7
Nitrogen cycle
The transfer of nitrogen from the atmosphere to the soil, to living organisms, and back to the atmosphere
Nitrification
Conversion of ammonia (NH4+) into nitrite (NO2-) and then into nitrite (NO3-)
Nitrogen fixation
process of converting nitrogen gas (N2) in the atmosphere into nitrogen compounds that plants can absorb and use
Ammonification
fungal and bacterial decomposers use nitrogen-containing wastes and dead bodies as a food source and excrete ammonium (NH4+)
Denitrification
process by which bacteria convert nitrates (NO3-) into nitrogen gas (N2)
Impervious surfaces
surfaces that don't absorb water ex. roads, sidewalks, houses / buildings
Leaching
removal of dissolved materials from soil by water moving downwards
Assimilation
The process by which producers incorporate elements into their tissues
Phosphorous
P 15
Phosphorous cycle
The movement of phosphorous atoms from rocks through the biosphere and hydrosphere and back to rocks.
Phosphorus sinks
- Rocks and minerals
- Long-lived vegetation
- Dissolved PO4 ions, absorbed PO4 into particles, single-celled organisms
Hydrologic cycle
The cycle through which water in the hydrosphere moves; includes such processes as evaporation, precipitation, and surface and groundwater runoff
Hydrology
the study of water and its effects on and in the earth and in the atmosphere
Hydrosphere
All the water at and near the surface of the earth, 97% of which is in oceans
Groundwater
water held underground in the soil or in pores and crevices in rock.
Condensation
The change of state from a gas to a liquid (forms clouds)
Precipitation
Any form of water that falls from clouds and reaches Earth's surface.
Runoff
water that flows over the ground surface rather than soaking into the ground
Evaporation
The change of a substance from a liquid to a gas
Infiltration
the process by which water on the surface enters the soil
Transpiration
Evaporation of water from the leaves of a plant
Percolation
The downward movement of water through soil and rock due to gravity.
Sublimation
A change directly from the solid to the gaseous state without becoming liquid
Symbiosis
A relationship in which two different organisms live in close association with each other
Ecosystem
A biological community of interacting organisms and their physical environment.
Mutualism
A relationship between two species in which both species benefit
Parasitism
A relationship between two organisms of different species where one benefits and the other is harmed
Interspecific competition
competition between members of different species
Competition
A common demand by two or more organisms upon a limited supply of a resource; for example, food, water, light, space, mates, nesting sites. It may be intraspecific or interspecific.
Resource partitioning
The division of environmental resources by coexisting species such that the niche of each species differs by one or more significant factors from the niches of all coexisting species
Limiting factors
Conditions in the environment that put limits on where an organism can live
Ecological niches
the role an organism plays in its environment
Fundamental niche
The niche species could potentially occupy.
Realized niche
The niche species actually occupies.
Coevolution
Process by which two species evolve in response to changes in each other
Competitive exclusion
Strong competition can lead to local elimination of one of the species.
population
A group of individuals that belong to the same species and live in the same area
community
All the different populations that live together in an area
biome
A group of ecosystems that share similar climates and typical organisms
Terrestrial
relating to the land
Weather
The condition of Earth's atmosphere at a particular time and place.
Climate
The average weather conditions in an area over a long period of time
Taiga (boreal forest, northern coniferous forest)
biome with long cold winters and a few months of warm weather; dominated by coniferous evergreens; also called boreal forest
Tundra
a vast, flat, treeless Arctic region of Europe, Asia, and North America in which the subsoil is permanently frozen.
Temperate
mild, moderate
Temperate rainforest
The cool, dense, rainy forests of the northern Pacific coast; enshrouded in fog much of the time; dominated by large conifers
Tropical
warm, moist climate zone near the equator
Tropic of Capricorn
a line of latitude about 23 degrees South of the equator
Tropical rainforests
Near the equator. Warm with lots of precipitation. Little seasonal temperature variation. Most diverse biome.
Shrubland (chaparral)
Found along the California coast and the coast of the Mediterranean sea. Characterized by hot summers and mild, rainy winters. Dominated by fire-tolerant shrubs.
Temperate grasslands
dominated by grasses, trees and large shrubs are absent. Temperatures vary more from summer to winter, and the amount of rainfall is less than in savannas. Temperate grasslands have hot summers and cold winters. Occur in South Africa, Hungary, Argentina, the steppes of the former Soviet Union, and the plains and prairies of central North America.
Savanna
a grassy plain in tropical and subtropical regions, with few trees.
Desert
An extremely dry (arid) area with little water and few plants
Latitude
distance north or south of the Equator, measured in degrees
Altitude
Elevation (height) above sea level
Longitude
Distance east or west of the prime meridian, measured in degrees
Permafrost
permanently frozen layer of soil beneath the surface of the ground
Climatograms
Chart that is used to better understand climate by looking at the average temperature and precipitation
Biosphere
part of Earth in which life exists including land, water, and air or atmosphere
Aquatic
relating to water
Biotic
Describes living factors in the environment.
Abiotic
Describes non-living factors in the environment
streams
a small, narrow river.
rivers
a large natural stream of water flowing in a channel to the sea, a lake, or another such stream.
ponds
Bodies of fresh water (shallow, allows sunlight to go all the way through the water and makes plants grow)
lakes
A body of water that is surrounded by land it can be fresh water or salt water.
Water column
The vertical column of seawater that extends from the surface to the bottom
benthic zone
bottom of an aquatic ecosystem; consists of sand and sediment and supports its own community of organisms
pelagic zone
open water above the ocean floor
Benthos
organisms that live attached to or near the bottom of lakes, streams, or oceans
oceans
the largest of all the ecosystems. The ocean regions are separated into separate zones: intertidal, pelagic, abyssal, and benthic. All four zones have a great diversity of species.
coral reefs
Prominent oceanic features composed of hard, limy skeletons produced by coral animals; usually formed along edges of shallow, submerged ocean banks or along shelves in warm, shallow, tropical seas
marshlands
Consisting of low lying wetlands ; areas that typically stay flooded/waterlogged. Swamp or bog.
estuaries
the tidal mouth of a large river, where the tide meets the stream.
Algae
a very simple plant without stems or leaves that grows in or near water.
Salinity
A measure of the amount of dissolved salts in a given amount of liquid
swamps
shallow water in forested areas, dominated by trees
Mangrove forests
woody, specialized types of trees of the tropics that can live on the edge, where rainforests meet oceans
Riparian
Having to do with the banks of a body of water
Biodiversity
Variety of life forms present in a particular ecosystem,
Habitat
the natural home or environment of an animal, plant, or other organism.
Specialist species
Species with a narrow ecological niche. They may be able to live in only one type of habitat, tolerate only a narrow range of climatic and other environmental conditions, or use only one type or a few types of food.
Ecosystem
A biological community of interacting organisms and their physical environment.
Species richness
the number of different species in a community
Species evenness
the relative proportion of different species in a given area
Biodiversity hotspot
is a biogeographic region with a significant reservoir of biodiversity that is under threat from humans
Ecosystem services
The process by which natural environments provide life-supporting resources
Provisioning
products obtained from ecosystems
Regulating
benefits obtained from the regulating of ecosystems (flood prevention, water filtration, erosion control)
Cultural
Non-material benefits obtained from ecosystems, intrinsic value
Supporting
ecosystem services necessary for all other ecosystem services
Anthropogenic
Human-induced changes on the natural environment
Theory of Island Biogeography
demonstrates the dual importance of habitat size and distance in determining species richness
Generalist species
Species with a broad ecological niche. They can live in many different places, eat a variety of foods, and tolerate a wide range of environmental conditions. Examples are flies, cockroaches, mice, rats, and human beings. Compare specialist species.
Invasive species
A species, often introduced by humans, that takes hold outside its native range.
Native species
Species that normally live and thrive in a particular ecosystem
Zebra mussels
are an invasive exotic species that clogs water intake pipes at factories, power plants, and wastewater treatment facilities
Ecological tolerance
the range of conditions in which a species can survive
Salinity
The total amount of dissolved salts in a water sample.
Flow rate
The volume of fluid that moves through a system in a given period of time.
Range of tolerance
Range of chemical and physical conditions that must be maintained for populations of a particular species to stay alive and grow, develop, and function normally
Climate
The average weather conditions in an area over a long period of time
Migration
Movement from one habitat to another
adaptation
inherited characteristic that increases an organism's chance of survival
Genetic diversity
the variety of genes within a given species
Evolution
Change in a kind of organism over time; process by which modern organisms have descended from ancient organisms.
Natural selection
A process in which individuals that have certain inherited traits tend to survive and reproduce at higher rates than other individuals because of those traits.
Speciation
Formation of new species
Bottleneck effect
a reduction in the genetic diversity of a population caused by a reduction in its size
Succession
A series of predictable and orderly changes within an ecosystem over time.
Keystone species
A species that influences the survival of many other species in an ecosystem
Primary succession
An ecological succession that begins in an area where no biotic community previously existed (bare rock)
Secondary succession
Succession following a disturbance that destroys a community without destroying the soil
Opportunistic species
Species that specialize in invading newly vacated habitats
Pioneer species
First species to populate an area during primary succession
Climax Community
stable, mature ecological community with little change in the composition of species
Threatened species
A species that could become endangered in the near future
Endangered species
A species in danger of becoming extinct in the near future
Extinct/extinction
when a species has no members that are still alive; the population of that species no longer exists
Selective pressures
environmental resistance factors affect which individuals survive and reproduce
Fitness
Ability of an organism to survive and reproduce in its environment
Poaching
Illegal hunting of protected animals
Background extinction
normal extinction of various species as a result of changes in local environmental conditions
Mass extinction
event in which many types of living things become extinct at the same time
Endangered Species Act
(1973) identifies threatened and endangered species in the U.S., and puts their protection ahead of economic considerations
CITES (Convention on International Trade in Endangered Species of Wild Fauna and Flora)
A 1973 treaty formed to control the international trade of threatened plants and animals
Fauna
all the animal life in a particular region
Flora
plants of a region
Overexploitation
Practice of harvesting or hunting to such a degree that remaining individuals may not be able to replenish the population
Selective breeding
the process of selecting organisms with desired traits to be parents of the next generation
HIPPCO
Habitat destruction, Invasive Species, Population growth, Pollution, Climate Change, Overexploitations
Habitat fragmentation
Splitting of ecosystems into small fragments
Edge effects
different environmental conditions that occur along the boundaries of an ecosystem
Mitigate
to make less severe
Habitat corridors
protected strips of land that allow the migration of organisms from one wilderness area to another
Wildlife refuge
an area of land set aside to protect animals and other living things
K-selected species
Species that produce a few, often fairly large offspring but invest a great deal of time and energy to ensure that most of those offspring reach reproductive age.
r-selected species
Species that reproduce early in their life span and produce large numbers of usually small and short-lived offspring in a short period, low paternal care
Competition
the struggle between organisms to survive in a habitat with limited resources
Biotic potential
Maximum rate at which the population of a given species can increase when there are no limits on its rate of growth.
Invasive species
plants and animals that have migrated to places where they are not native
Survivorship curves
a graph that represents the distinct patterns of species survival as a function of age
Type I survivorship curve
A survivorship curve in which newborns, juveniles, and young adults all have high survival rates and death rates do not begin to increase greatly until old age.
Type II survivorship curve
Experience roughly a constant mortality rate regardless of age. Prey animals such as birds can follow this pattern of survival.
Type III survivorship
Experience the greatest mortality early on in life, with relatively low rates of death for those surviving. Usually r-selected.
J-shaped curve (exponential growth)
Growth where there is unlimited resources and no competition
S-shaped curve (logistic growth)
Where the community has reached its carrying capacity
Carrying capacity (K)
Maximum population size that a particular environment can support.
Ecosystem
A biological community of interacting organisms and their physical environment.
Overshoot
when a population becomes larger than the environment's carrying capacity
Dieback
Sharp reduction in the population of a species when its numbers exceed the carrying capacity of its habitat.
Depletion
reduction in the number or quantity of something
Famine
an extreme shortage of food
Population growth
An increase in population over a period of time.
Finite
limited
Fecundity
fertility
Desalinization
A process of removing salt from ocean water
Pandemic
an epidemic that is geographically widespread
Epidemic
A widespread outbreak of an infectious disease.
Age structure diagrams
broad base = rapid growth; narrow base = negative growth; uniform shape = zero growth
Population growth rates
-A country's is determined by its natural increase expressed as a percentage
-For example, a country's natural increase with a CBR of 22 and a CDR of 12 is 10 per 1,000, which translates to a rate of 1 percent
Total fertility rate (TFR)
The average number of children born to a woman during her childbearing years.
Fertility
the incidence of childbearing in a country's population
replacement fertility rate
the total fertility rate needed for a population to replace itself = 2.1
Mortality
death rate
Life expectancy
A figure indicating how long, on average, a person may be expected to live
Per capita
per person
Infant mortality rates
The percentage of children who die before their first birthday within a particular area or country.
Death rates
population density
Number of individuals per unit area
Malthusian theory
focuses on how the exponential growth of a population can outpace growth of the food supply and lead to social degradation and disorder
Density-independent factors
limiting factor that affects all populations in similar ways, regardless of population size eg. flood, fire, other natural disasters
Density-dependent factors
factor that limits a population more as population density increases eg. food, shelters, water, spread of disease
Rule of 70
Doubling time (in years) = 70/(percentage growth rate).
Doubling time
The number of years needed to double a population
Crude birth rate
The total number of live births in a year for every 1,000 people
Crude death rate
The number of deaths per year per 1,000 people.
Overpopulation
The number of people in an area exceeds the capacity of the environment to support life at a decent standard of living.
Standard of living
Quality of life based on ownership of necessities and luxuries that make life easier.
Import vs. Export
Goods that are purchased are imported (into a country). Goods that are exported are sold for profit (sent out of the country).
Gross domestic product (GDP)
A measurement of the total goods and services produced within a country.
Population momentum
continued population growth that does not slow in response to growth reduction measures
Demographic transition
change in a population from high birth and death rates to low birth and death rates
4-stage demographic transition model (DTM)
Infant mortality rates
Developed countries
countries with strong economies and a high quality of life
Developing countries
countries with less productive economies and a lower quality of life
Demography
The scientific study of population characteristics.
post-industrial stage
(demographic transition) low birth & death rates
pre-industrial stage
birth and death rates high, population grows slowly, infant mortality high
Industrial stage
(demographic transition) decline in birth rate, population growth slows
Transitional stage
(demographic transition) death rate lower, better health care, population grows fast
Birth control
Any method used to reduce births, including celibacy, delayed marriage, contraception; devices or medication that prevent implantation of fertilized zygotes, and induced abortions
Immigration
Movement of individuals into a population
Emigration
movement of individuals out of a population
Rock cycle
the series of processes that change one type of rock into another type of rock
Geological
concerned with geology, the science that deals with the physical nature of the earth
Convergent boundary
A plate boundary where two plates move toward each other.
Divergent boundary
A plate boundary where two plates move away from each other.
Transform boundary
A plate boundary where two plates move past each other in opposite directions
Plate tectonic theory
the theory that the lithosphere is broken up into large plates that move and then rejoin; considered the unifying theory of geology
Tectonic plates
a block of lithosphere that consists of the crust and the rigid, outermost part of the mantle
Plate boundaries
the edges of tectonic plates.
Seafloor spreading
The process that creates new sea floor as plates move away from each other at the mid-ocean ridges
Volcanoes
openings in Earth's crust from which molten rock, dust, ash, and hot gases flow or erupt
Convergent Oceanic-Continental
Features: volcanic arcs, volcanoes, trench
Examples: , Andes Mountains
Earthquakes
sudden movements of Earth's crust followed by a series of shocks
Convergent Continent-Continent
A landform created by this boundary is mountain ranges.
Hot spots
places where molten material from the mantle reaches the lithosphere
Faults
Breaks in Earth's crust where rocks have slipped past each other.
Asthenosphere
The soft layer of the mantle on which the tectonic plates move
Lithosphere
A rigid layer made up of the uppermost part of the mantle and the crust.
Crust
The thin and solid outermost layer of the Earth above the mantle
Convection currents
a current in a fluid that results from convection.
Mantle
The layer of hot, solid material between Earth's crust and core.
Soil
The loose, weathered material on Earth's surface in which plants can grow.
Erosion
Processes by which rock, sand, and soil are broken down and carried away (i.e. weathering, glaciation)
Cover crops
Plants, such as rye, alfalfa, or clover, that can be planted immediately after harvest to hold and protect the soil.
Vegetated buffers
areas of natural or established vegetation maintained to protect the water quality of neighboring areas
Parent material
the rock material from which the inorganic components of a soil are derived
Soil horizons
distinct layers of soil
Weathering
The breaking down of rocks and other materials on the Earth's surface.
Organic material
Materials that were once part of living things
Soil Fertility
Soil's ability to hold nutrients and to supply nutrients to a plant
physical properties of soil
texture and porosity
biological properties of soil
Many organisms are found in the soil including fungi, bacteria, protozoans, rodents and earthworms.
Fertilizer
a chemical or natural substance added to soil or land to increase its fertility
Clay
the finest soil, made up of particles that are less than 0.002 mm in diameter.
Sand
the coarsest soil, with particles 0.05,2.0 mm in diameter.
Silt
fine particles of fertile soil
Water holding capacity
how well soil can retain water (sand is low, clay is high)
Loam
Rich, fertile soil that is made up of about equal parts of clay, sand, and silt.
Atmosphere
A mixture of gases that surrounds a planet or moon.
Leaching
removal of dissolved materials from soil by water moving downwards
Troposphere
0-17 km above Earth's surface, site of weather, organisms, contains most atmospheric water vapor. (temperature decreases with increasing altitude, pressure decreases)
Stratosphere
2nd layer of atmosphere; extends from 10 to 30 miles up; location of ozone layer; absorbs 95% of Ultraviolet radiation; temperature increases with altitude increase.
Mesosphere
The layer of Earth's atmosphere immediately above the stratosphere
Thermosphere
The uppermost layer of the atmosphere, in which temperature increases as altitude increases
Exosphere
The outer layer of the thermosphere, extending outward into space.
ozone layer
Protective layer in atmosphere that shields earth from UV radiation.
Global wind patterns
air movements that are caused by pressure belts convection cells and earth's rotation. Warm air rises from the equator to the poles then cools and sinks back to the equator
Trade winds
prevailing winds that blow from east to west from 30 degrees latitude to the equator in both hemispheres
Wind
the movement of air caused by differences in air pressure
Solar radiation
energy from the sun
Equator
0 degrees latitude
Coriolis effect
Causes moving air and water to turn left in the southern hemisphere and turn right in the northern hemisphere due to Earth's rotation
Atmospheric circulation
redistributes heat over earth's surface by exchanging warm tropical air with cold polar air.
insolation
incoming solar radiation
Seasons
Earth has seasons because because its axis is tilted as it moves around the sun.
Latitude
Distance north or south of the equator
Axis
An imaginary line that passes through Earth's center and the North and South poles, about which Earth rotates
Infrared radiation
a form of energy with wavelengths that are longer than visible light
Climate
Overall weather in an area over a long period of time
Microclimates
Local climatic conditions that differ from the general climate of a region
weather
The condition of Earth's atmosphere at a particular time and place.
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
Elevation
height above sea level
Precipitation
Any form of water that falls from clouds and reaches Earth's surface.
leeward
The side of a mountain range that faces away from the oncoming wind.
Wayward
The side of a mountain range that faces towards the oncoming wind.
El Nino (ENSO)
A reversal of wind and water currents in the South Pacific
La Nina
"Normal" year, easterly trade winds and ocean currents pool warm water in the western Pacific, allowing upwelling of nutrient rich water off the West coast of South America.
Upwelling
The movement of deep, cold, and nutrient-rich water to the surface
convergent oceanic-oceanic
2 oceanic plates push together, older plate sub ducts and forms a chain of volcanic islands, ex. Aleutian Islands and Japanese Islands
divergent oceanic-oceanic
two ocean plates move apart. The landforms formed by this boundary are mid-ocean rigdes.
Examples: Mid-Atlantic Ridge, the Iceland volcano
divergent continental-continental
two continental plates move apart, forms rift valley