Studied by 10 people
Anthropogenic
derived from human activities
Erosion
The process by which wind, water, ice, or gravity transports soil and sediment from one location to another
Runoff
Part of the water cycle where an excess of water runs down and does not sink into the soil and eventually makes it to the rivers, lakes, and oceans.
Denitrification
process in which fixed nitrogen compounds are converted back into nitrogen gas and returned to the atmosphere
Nitrification
ammonia (NH3) is converted to nitrate ions (NO3)-
Amonification
the part of the decomposition process where nitrogen in inorganic molecules reaction acids and nucleotides is converted to ammonium
Nitrogen Fixation
Process of converting nitrogen gas into ammonia
Abiotic
Non-living things
Biotic
Describes living factors in the environment.
keystone species
a species on which other species in an ecosystem largely depend, such that if it were removed the ecosystem would change drastically.
primary consumer
An organism that eats producers
secondary consumer
A carnivore that eats primary consumers
tertiary consumer
A carnivore that eats secondary consumers
Biodiversity
The amount of biological or living diversity per unit area. It includes the concepts of species diversity, habitat diversity and genetic diversity.
Divergent plates
Two tectonic plates that are moving away from each other
convergent plates
tectonic plates that collide with each other
Transform Plates
Plates that are moving past each other (rubbing next to each other) in opposite directions
primary succession
succession that occurs on surfaces where no soil exists
secondary succession
Succession following a disturbance that destroys a community without destroying the soil
logistic growth
Growth pattern in which a population's growth rate slows or stops following a period of exponential growth
logistic growth model
describes a population whose growth is initially exponential, but slows as the population approaches the carrying capacity of the environment
exponential growth
Population growth that is unhindered because of the abundance of resources for an ever-increasing population.
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
intrinsic growth rate
the maximum potential for growth of a population under ideal conditions with unlimited resources
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.
Generalists species
Species that can live in varying conditions
Specialists 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.
Microevolution
Change in allele frequencies in a population over generations.
Macroevolution
Evolutionary change above the species level.
Algal Bloom
an immediate increase in the amount of algae and other producers that results from a large input of a limiting nutrient
Limiting Nutrients
single essential nutrient that limits productivity in an ecosystem; Nitrogen, Phosphorus, Potassium
Hypoxic
low oxygen
Anemia
deficiency of iron
Externality
the impact of one person's actions on the well-being of a bystander
Affluence
abundance; wealth
Leaching
the transportation of dissolved molecules through the soil via groundwater
Resilience
the rate at which an ecosystem returns to its original state after a disturbance
Resistance
a measure of how much a disturbance can affect flows of energy and matter in an ecosystem
Watershed
An ecosystem where all water runoff drains into a single body of water
Specialists
species that have narrow niches
K-selected
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.
Eutrophication
A process by which nutrients, particularly phosphorus and nitrogen, become highly concentrated in a body of water, leading to increased growth of organisms such as algae or cyanobacteria.
Mutualism
A relationship between two species in which both species benefit
Commensalism
A relationship between two organisms in which one organism benefits and the other is unaffected
Parasitism
A relationship between two organisms of different species where one benefits and the other is harmed
Predation
An interaction in which one organism kills another for food.
Herbivory
interaction in which one animal (the herbivore) feeds on producers (such as plants)
Carnivores
Consumers that eat only animals
Omnivores
Consumers that eat both plants and animals.
Detrivore
a scavenger, such as an earthworm, that feeds on dead plant and animal matter
Herbivores
Consumers that eat only plants
Decomposers
organisms that break down wastes and dead organisms and return raw materials to the environment
trophic level
each of several hierarchical levels in an ecosystem, comprising organisms that share the same function in the food chain and the same nutritional relationship to the primary sources of energy.
How much energy is available/consumed at each trophic level
10%
genetic drift
A change in the allele frequency of a population as a result of chance events rather than natural selection.
Founder Effect
genetic drift that occurs after a small number of individuals colonize a new area
Bottleneck Effect
Genetic drift resulting from the reduction of a population, typically by a natural disaster, such that the surviving population is no longer genetically representative of the original population.
Natural Selection
A natural process resulting in the evolution of organisms best adapted to the environment.
intersexual selection
Selection whereby individuals of one sex (usually females) are choosy in selecting their mates from individuals of the other sex; also called mate choice.
Atmosphere
the envelope of gases surrounding the earth or another planet.
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
3rd layer of the atmosphere, above the stratosphere; most meteors, or space rocks and metal, burn up before they can crash to the ground
Thermosphere
The uppermost layer of the atmosphere, in which temperature increases as altitude increases; contains the ionosphere
fossil fuels
a natural fuel such as coal or gas, formed in the geological past from the remains of living organisms.
nuclear fuel
substance used in nuclear reactors that releases energy due to nuclear fission
subsistence energy sources
those gathered by individuals for their own use such as wood, charcoal, and animal waste
Food security
A condition in which people have access to sufficient, safe, and nutritious food that meets their dietary needs for an active and healthy life.
Famine
a severe shortage of food (as through crop failure) resulting in violent hunger and starvation and death
Food Insecurity
a condition in which people do not have adequate access to food
Undernutrition
The condition in which not enough calories are ingested to maintain health
Overnutrition
ingestion of too many calories and a lack of balance of foods and nutrients
Industrial agriculture
Agriculture that applies the techniques of mechanization and standardization
Energy Subsidy
the fossil fuel energy and human energy input per calorie of food produced
Green Revolution
Agricultural revolution that increased production through improved seeds, fertilizers, and irrigation; helped to support rising Asian populations.
Fertilizer
a substance that provides nutrients to help crops grow better
Synthetic Fertilizer
Fertilizer produced commercially, normally with the use of fossil fuels
Organic Fertilizer
fertilizer composed of organic matter from plants and animals
Monocropping (monoculture)
An agricultural method that utilizes large plantings of a single species or variety
Pesticides
Any one of various substances used to kill harmful insects (insecticide), fungi (fungicide), vermin, or other living organisms that destroy or inhibit plant growth, carry disease, or are otherwise harmful.
Insecticides
A pesticide that targets species of insects and other invertebrates
Herbicides
A pesticide that targets plant species that compete with crops.
Broad Spectrum Pesticides
a pesticide that kills many different types of pests
Selective Pesticides
A pesticide that targets a narrower range of organisms.
Persistent Pesticides
A pesticide that remains in the environment for a long time.
Nonpersistent Pesticides
Pesticides that break down rapidly, usually in weeks or months
Pesticides Resistance
the ability of a life form to develop a tolerance to a pesticide
Fishery
a commercially harvestable population of fish within a particular ecological region
Fishery Collapse
The decline of a fish population by 90 percent or more.
Bycatch
The unintentional catch of nontarget species while fishing
Shifting Agriculture
An agricultural method in which land is cleared and used for a few years until the soil is depleted of nutrients.
Desertification
Degradation of land, especially in semiarid areas, primarily because of human actions like excessive crop planting, animal grazing, and tree cutting.
Sustainable Agriculture
Agriculture that fulfills the need for food and fiber while enhancing the quality of the soil, minimizing the use of nonrenewable resources, and allowing economic viability for the farmer.
Intercropping
An agricultural method in which two or more crop species are planted in the same field at the same time to promote a synergistic interaction.
crop rotation
The practice of rotating use of different fields from crop to crop each year, to avoid exhausting the soil.
Agroforestry
when trees and crops are planted together, creating a mutualistic symbiotic relationship between them.
Contour Plowing
An agricultural technique in which plowing and harvesting are done parallel to the topographic contours of the land
No-Till Agriculture
An agricultural method in which farmers do not turn the soil between seasons, used as a means of reducing erosion
Perennial Plants
A plant that lives for multiple years.
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