Term | Definition |
Biome | a large region characterized by a specific type of climate and certain types of plant and animal communities |
tundra | a treeless plain that is located in the Arctic or Antarctic and that is characterized by very low winter temperatures; short, cool summers; and vegetation that consists of grasses, lichens, and perennial herbs |
permafrost | in arctic regions, the permanently frozen layer of soil or subsoil |
tropical forest | a forest or jungle near the equator that is characterized by large amounts of rain and little variation in temperature and that contains the greatest known diversity of organisms on Earth |
canopy | the layers of treetops that shade the forest floor |
epiphyte | a plant that uses another plant for support, but not for nourishment |
coniferous tree | a tree belonging to a group of tree species that bear their seeds in cones and tend to be evergreen |
deciduous tree | describes trees that lose their leaves at the end of the growing season |
temperate deciduous tree | a forest (or biome) that is characterized by trees that shed their leaves in the fall |
taiga | a region of evergreen, coniferous forest below the arctic and subarctic tundra regions |
temperate grassland | a community (or biome) that is dominated by grasses, has few trees, and is characterized by cold winters and rainfall that is intermediate between that of a forest and a desert |
savanna | a plain full of grasses and scattered trees and shrubs; found in tropical and subtropical habitats and mainly in regions with a dry climate, such as East Africa |
chaparral | a type of vegetation that includes broad-leafed evergreen shrubs and that is located in areas with hot, dry summers and mild, wet winters |
desert | a region that has little or no vegetation, long periods without rain, and extreme temperatures; usually found in warm climates |
aphotic zone | the deeper parts of the ocean, where there is so little light that plants cannot carry out photosynthesis |
photic zone | the area of an aquatic system that receives enough light for photosynthesis to occur |
intertidal zone | an area along ocean shorelines that lies between low and high water lines |
neritic zone | a shallow marine environment that is near the shore or over the continental shelf and that is rich in minerals and nutrients produced by biotic activity |
oceanic zone | the region of the open sea that has characteristic life-forms and geography |
pelagic zone | the region of an ocean or body of fresh water above the benthic zone |
benthic zone | the bottom region of oceans and bodies of fresh water |
plankton | the mass of mostly microscopic organisms that float or drift freely in the waters of aquatic (freshwater and marine) environments |
estuary | an area where fresh water from rivers mixes with salt water from the ocean; the part of a river where the tides meet the river current |
eutrophic lake | describes a lake or other body of water that contains a rich supply of plant nutrients |
oligotrophic lake | a lake that lacks plant nutrients and that has a lot of oxygen dissolved in its lower layer |
freshwater wetland | an area of land that is covered in fresh water for at least part of each year |