| A | B |
|---|
| abiotic | non-living chemical and physical factors such as temperature, light, water, and nutrients |
| biotic | the living components of an ecosystem |
| climate | the prevailing weather conditions in an area |
| marine ecosystems | ecosystems that have a salt concentration of approximately 3% and cover approximately 75% of the earth’s surface |
| freshwater ecosystems | ecosystems that are usually characterized by salt concentration of less than 1% and are closely linked to the soils and biotic components of the terrestrial biomes through which they pass |
| photic zone | the zone of an aquatic ecosystem through which light penetrates and photosynthesis can occur |
| aphotic zone | the zone of an aquatic ecosystem where very little light can penetrate |
| benthic zone | the bottom of any aquatic ecosystem that contains detritus, dead organic matter |
| littoral zone | the zone of a freshwater ecosystem that is shallow and close to shore |
| limnetic zone | the open surface water of a freshwater ecosystem |
| profundal zone | the deep, aphotic regions of a freshwater ecosystem |
| oligotrophic lakes | lakes that are deep, nutrient-poor and do not contain much life |
| eutrophic lakes | lakes that are shallower and have increased nutrients |
| estuaries | areas where freshwater and salt water meet |
| intertidal zone | the zone of a marine ecosystem where the land meets the water |
| neritic zone | the shallow regions of a marine ecosystem over the continental shelves |
| oceanic zone | the zone of a marine ecosystem that extends past the continental shelves, and can be very deep |
| pelagic zone | the open water of a marine ecosystem |
| permafrost | a permanently frozen stratum of the tundra that lies under ground |
| tropical rainforest | biome that is close to the equator, receive high amounts of rainfall, and contain a great variety of plants and animals |
| deserts | biome with low rainfall, are generally hot, vegetation is usually sparse, includes cacti and succulents, and • many animals are nocturnal |
| temperate grasslands | biomes that exhibit seasonal drought, occasional fires, and are usually used for grazing and agriculture |
| deciduous forests | biomes that contain dense stands of trees and have very cold winters and hot summers, the trees lose leaves and go dormant in winter |
| tiaga (coniferous forests) | the largest terrestrial biome on earth, has long, cold winters and short, wet summers, include many cone-bearing trees |
| tundra | contains low-growing plants such as lichens and moss, a layer of permafrost is found below 1 meter and does not thaw, which prevents root growth; not many animals live there |
| lichens | the first life on a surface such as bare rock is usually this |
| primary succession | succession that begins on bare rock, glacial deposits or lake beds |
| secondary succession | succession that begins with soil already present |
| climax community | succession may eventually result in this |
| tragedy of the commons | this refers to the destruction of resources by competing self-interests |
| carbon dioxide | the major greenhouse gas in the atmosphere |
| acid rain is caused by the emission of | sulfur and nitrogen oxides |
| the part of the earth devoted to human use is | 22% |
| the largest single use of land is for | cropland |
