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abyssal zone
the deepest part of the ocean at depths of 4000 m or greater
acid rain
a corrosive rain caused by rainwater mixing with sulfur dioxide gas as it fall through the atmosphere, turning it into weak sulfuric acid, causing damage to aquatic ecosystems
algal bloom
a rapid increase of algae in an aquatic system
apex consumer
an organism at the top of the food chain
aphotic zone
the part of the ocean where photosynthesis cannot occur
arctic tundra
a biome characterized by low average temperatures, brief growing seasons, the presence of permafrost, and limited precipitation largely in the form of snow in which the dominant vegetation are low shrubs, lichens, mosses, and small herbaceous plants
autotroph
an organism capable of synthesizing its own food molecules from smaller inorganic molecules
benthic realm
(also, benthic zone) the part of the ocean that extends along the ocean bottom from the shoreline to the deepest parts of the ocean floor
biogeochemical cycle
the cycling of minerals and nutrients through the biotic and abiotic world
biomagnification
an increasing concentration of persistent, toxic substances in organisms at each trophic level, from the producers to the apex consumers
biome
a large-scale community of organisms, primarily defined on land by the dominant plant types that exist in geographic regions of the planet with similar climatic conditions
boreal forest
a biome found in temperate and subarctic regions characterized by short growing seasons and dominated structurally by coniferous trees
canopy
the branches and foliage of trees that form a layer of overhead coverage in a forest
channel
the bed and banks of a river or stream
chaparral
a biome found in temperate coastal regions characterized by low trees and dry-adapted shrubs and forbs
chemoautotroph
an organism capable of synthesizing its own food using energy from inorganic molecules
coral reef
an ocean ridge formed by marine invertebrates living in warm shallow waters within the photic zone
cryptofauna
the invertebrates found within the calcium carbonate substrate of coral reefs
dead zone
an area in a lake and ocean near the mouths of rivers where large areas are depleted of their normal flora and fauna; these zones can be caused by eutrophication, oil spills, dumping of toxic chemicals, and other human activities
detrital food web
a type of food web that is supported by dead or decaying organisms rather than by living autotrophs; these are often associated with grazing food webs within the same ecosystem
ecosystem
a community of living organisms and their interactions with their abiotic environment
ecosystem services
the human benefits provided by natural ecosystems
emergent vegetation
the plants living in bodies of water that are rooted in the soil but have portions of leaves, stems, and flowers extending above the water’s surface
equilibrium
the steady state of a system in which the relationships between elements of the system do not change
estuary
a region where fresh water and salt water mix where a river discharges into an ocean or sea
eutrophication
the process whereby nutrient runoff causes the excess growth of microorganisms and plants in aquatic systems
fallout
the direct deposition of solid minerals on land or in the ocean from the atmosphere
food chain
a linear sequence of trophic (feeding) relationships of producers, primary consumers, and higher level consumers
food web
a web of trophic (feeding) relationships among producers, primary consumers, and higher level consumers in an ecosystem
grazing food web
a type of food web in which the producers are either plants on land or phytoplankton in the water; often associated with a detrital food web within the same ecosystem
gross primary productivity
the rate at which photosynthetic producers incorporate energy from the Sun
hydrosphere
the region of the planet in which water exists, including the atmosphere that contains water vapor and the region beneath the ground that contains groundwater
intertidal zone
the part of the ocean that is closest to land; parts extend above the water at low tide
neritic zone
the part of the ocean that extends from low tide to the edge of the continental shelf
net primary productivity
the energy that remains in the producers after accounting for the organisms’ respiration and heat loss
non-renewable resource
a resource, such as a fossil fuel, that is either regenerated very slowly or not at all
oceanic zone
the part of the ocean that begins offshore where the water measures 200 m deep or deeper
pelagic realm
(also, pelagic zone) the open ocean waters that are not close to the bottom or near the shore
permafrost
a perennially frozen portion of the Arctic tundra soil
photic zone
the upper layer of ocean water in which photosynthesis is able to take place
photoautotroph
an organism that uses sunlight as an energy source to synthesize its own food molecules
planktivore
an animal that eats plankton
primary consumer
the trophic level that obtains its energy from the producers of an ecosystem
producer
the trophic level that obtains its energy from sunlight, inorganic chemicals, or dead or decaying organic material
resilience (ecological)
the speed at which an ecosystem recovers equilibrium after being disturbed
resistance (ecological)
the ability of an ecosystem to remain at equilibrium in spite of disturbances
savanna
a biome located in the tropics with an extended dry season and characterized by a grassland with sparsely distributed trees
secondary consumer
a trophic level in an ecosystem, usually a carnivore that eats a primary consumer
source water
the point of origin of a river or stream
subduction
the movement of one tectonic plate beneath another
subtropical desert
a biome found in the subtropics with hot daily temperatures, very low and unpredictable precipitation, and characterized by a limited dry-adapted vegetation
temperate forest
a biome found in temperate regions with moderate rainfall and dominated structurally by deciduous trees
temperate grassland
a biome dominated by grasses and herbaceous plants due to low precipitation, periodic fires, and grazing
tertiary consumer
a trophic level in an ecosystem, usually carnivores that eat other carnivores
trophic level
the position of a species or group of species in a food chain or a food web
tropical rainforest
a biome found near the equator characterized by stable temperatures with abundant and seasonal rainfall in which trees form the structurally important vegetation
wetland
environment in which the soil is either permanently or periodically saturated with water
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