Ch. 6 AP Environmental Science (Species Interactions and Community Ecology)

Terms	Definitions
Competition	The struggle between organisms to survive in a habitat with limited resources
Benthic	Relating to the bottom of a lake or sea or the organisms that live there.
Crypsis	A defense against predators in which prey species have a shape or coloration that provides camouflage and allows them to avoid detection.
Predation	An interaction between species in which one species, the predator, eats the other, the prey.
Batesian mimicry	A type of mimicry in which a harmless species looks like a species that is poisonous or otherwise harmful to predators
Mutualism	Symbiotic relationship in which both organisms benefit, example is pollination
Ecosystem engineers	An organism that causes changes in the physical environment sufficient to influence the structure of landscapes, ecosystems, or communities.
Parasitism	Symbiotic relationship in which one organism(parasite) lives in or on another organism (the host) and consequently harms it
Competitive exclusion	The concept that when populations of two similar species compete for the same limited resources, one population will use the resources more efficiently and have a reproductive advantage that will eventually lead to the elimination of the other population.
Fundamental niche	The full potential range of the physical, chemical, and biological factors a species can use if there is no competition from other species.
Realized niche	The range of resources and conditions a species actually uses or can tolerate at optimal efficiency; smaller than fundamental niche
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. Can lead to character displacement
Character displacement	The tendency for characteristics to be more divergent in sympatric populations of two species than in allopatric populations of the same two species.
Mimicry	Structural adaptation that enables one species to resemble another species; may provide protection from predators or other advantages
Mullerian mimicry	Evolution of two species both of which are unpalatable and have poisonous stingers or some other defense mechanism to resemble each other.
Parasitiods	An organism that spends a significant portion of its life attached to or within a single host...ultimately kills host
Coevolution	The evolution of two or more species that is due to mutual influence, often in a way that makes the relationship more mutually beneficial
Herbivory	interaction in which one animal (the herbivore) feeds on producers (such as plants)
Symbiosis	Living together in mutually helpful association of two dissimilar organisms.
Amensalism	Relationship between two species in which one is inhibited or harmed, while the other is unaffected, an example may be allelopathy
Commensalism	Symbiotic relationship in which one member of the association benefits and the other is neither helped nor harmed. Example is facilitation
Allelopathy	The production of chemicals by plants that inhibit the growth of neighbouring plants.
Facilitation	In ecological succession, the phenomenon in which early-arriving species make conditions more favorable for later-arriving species
Trophic level	Step in the movement of energy through an ecosystem; an organism's feeding status in an ecosystem. Each successive level only contains approximately 10% of previous level.
Primary consumer	An herbivore; an organism in the trophic level of an ecosystem that eats plants or algae
Autotroph	Organism that can capture energy from sunlight or chemicals and use it to produce its own food from inorganic compounds; also called a producer
Secondary consumer	A member of the trophic level of an ecosystem consisting of carnivores that eat herbivores.
Tertiary consumers	Animals that feed on animal-eating animals. They feed at high trophic levels in food chains and webs. Examples are hawks, lions, bass, and sharks.
Detritivores	Organisms that feed on the detritus and decomposing organic material of living organisms. Recycle nutrients and make soil richer.
Food Web	Network of complex interactions formed by the feeding relationships among the various organisms in an ecosystem (Just look at Pg.151)
Littoral	The region of the shore of a lake or sea or ocean
Keystone Species	A species that is critical to the functioning of the ecosystem in which it lives because it affects the survival and abundance of many other species in its community
Trophic cascade	A series of changes in the population sizes of organisms at different trophic levels in a food chain, occurring when predators at high trophic levels indirectly promote populations of organisms at low trophic levels by keeping species at intermediate trophic levels in check. Trophic cascades may become apparent when a top predator is eliminated from a system. Also gives evidence for the existence of keystone species.
Resistance	Term given to a community that resists change and remains stable despite a disturbance.
Resilience	The rate at which an ecosystem returns to its original state after a disturbance
Succession	The gradual and orderly process of change in an ecosystem brought about by the progressive replacement of one community by another until a stable climax is established.
Primary Succession	An ecological succession that begins in an area where no biotic community previously existed or no vegetation or soil life remains.
Secondary Succession	The series of changes that occur in an area where the ecosystem has been disturbed, but where soil and organisms still exist
Pioneer Species	First species to populate an area during primary succession. Usually lichen.
Lichens	Symbiotic organism between a fungus and a photosynthetic organism
Climax community	A relatively stable long-lasting community reached in a successional series; usually determined by climax and soil type
Fredrick Clements	Botanist who attempted to understand community structure and the first to write about succession. He claimed communities developed and grew mature like a living organism.
Henry Gleason	Botanist who disagreed with Clements and believed in the individualistic hypothesis. He argued that communities were not cohesive units, but temporary associations of individual species that can reassemble into different combinations.
Invasive Species	Plants and animals that have migrated to areas where they did not originate; often displace native species by outcompeting them for resources
Dutch Elm Disease	A fungus that has seriously diminished or eliminated a very popular shade tree in Europe and North America. Transmitted by 2 species of elm bark beetles. They transfer the fungus to other trees that they borrow into.
National Invasive Species Act	1996 Act that directed the Coast Guard to ensure that ships dump their water ballast at sea and exchange it with salt water before entering the Great Lakes.
Ecological Restoration	The process of altering a site or area with the objective of reestablishing indigenous, historical ecosystems
Restoration ecology	Applying ecological principles in an effort to return ecosystems that have been disturbed by human activity to a condition as similar as possible to their natural state.
Biome	A natural community of plants and animals, its composition being largely controlled by climatic conditions. Tend to occur at similar latitudes worldwide.
Climatographs	A visual representation of a region's average monthly temperature and precipitation
Temperate deciduous forest	The biome characterized by warmer temperatures than the boreal forest and plenty of precipitation thats huge forests of broadleaf trees; covers regions in southeastern Canada, and eastern United States
Temperate Grasslands	Biome covering huge areas with low annual rainfall or uneven seasonal rainfall, not good for forests. Grazing animals. Also known as steppes or prairies.
Temperate Rainforest	Rare biome characterized by abundant moisture, mild climate, think and rish soil, and the growth of shrubs and small trees; currently found only in British Columbia, Alaska, and Chile, and parts of pacific north.
Tropical Rainforest	The biome characterized by highest rainfall and high temperatures throughout the year; believed to contain at least half of Earth's biomes, poor acidic soils. Most nutrients in plants.
Tropical Dry Forest	A terrestrial biome characterized by relatively high temperatures and precipitation overall but with a pronounced dry season lasting around 7 months.
Savanna	Tropical or subtropical grassland, either treeless or with occasional clumps of trees. Most extensive in sub-Saharan Africa but also present in South America.
Desert	A barren biome with less than 10 inches of precipitation each year with little rainfall, extreme temperatures, and sparse vegetation.
Tundra	Treeless arctic or alpine biome characterized by cold, harsh winters, a short growing season, and potential for frost any month of the year; vegetation includes low-growing perennial plants, mosses and lichens
Boreal Forest	A broad band of mixed coniferous and deciduous trees that stretches across northern North America (and also Europe and Asia); its northernmost edfe, the taiga, intergrades with the artic tundra
Chaparral	A scrubland biome of dense, spiny evergreen shrubs found at midlatitudes along coasts where cold ocean currents circulate offshore; characterized by mild, rainy winters and long, hot, dry summers.