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acid rain

rain containing acids that form in the atmosphere when industrial gas emissions (especially sulfur dioxide and nitrogen oxides) combine with water

aquatic biomes

fresh water and marine water, biomes found in water

aphotic zone

deeper water that never receives sunlight


extremely dry


organisms that live on the bottom of the ocean or other body of water


a broad, regional type of ecosystem characterized by distinctive climate and soil conditions and a distinctive kind of biological community adapted to those conditions.


the regions of the surface and atmosphere of the Earth (or other planet) where living organisms exist


The total (or near total) removal of trees from a given forested area. The opposite of selective cutting.

cold desert

desert that occurs where land at high altitudes is surrounded by mountains

coniferous forest

forest populated by cone-bearing evergreen trees; mostly found in northern latitudes


the preservation and careful management of the environment and of natural resources

deciduous forest

A biome with four seasons, plants shed leaves in the fall and grow new ones in the spring.


the removal of trees


a dry area where few plants grow


wetlands formed where rivers meet the ocean

glacial lake

glaciers may leave behind large lakes in long basins


land where grass or grasslike vegetation grows and is the dominant form of plant life


water that fills the cracks and spaces in underground soil and rock layers


a form of oxygen that has three oxygen atoms in each molecule instead of two. protects us from dangerous ultraviolet radiation from the sun


ground that is permanently frozen

photic zone

Portion of the marine biome that is shallow enough for sunlight to penetrate.


a forest with heavy annual rainfall


having little rainfall and warm temperature

surface runoff

water that flows over land until it reaches lakes, rivers, or other areas


biome in which the winters are cold but summers are mild enough to allow the ground to thaw

terrestrial biomes

biomes found on land


a vast treeless plain in the arctic regions between the ice cap and the tree line


Ecosystems of several types in which vegetation is surrounded by stand water during part of the year

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