| A | B |
|---|
| climate | average weather conditions over a 30-year period |
| biome | region with characteristic types of natural, undisturbed plant communities |
| precipitation | generally the limiting factor that determines whether a land area is desert, grassland, or forest |
| desert | less than 10 inches of rain per year; with little vegetation |
| grassland | enough precipitation to allow grass to grow, but drought and fire prevent large plants from growing |
| forest | undisturbed areas with moderate to high annual precipitation |
| tropical desert | make up about 1/5 of the world's desert area |
| temperate desert | cool in winter, hot in summer; example is the Mojave in southern California |
| kangaroo rat | desert animal that has adapted so much to its environment that it doesn't need to drink water at any time |
| savanna | a tropical grasslandthat has two prolonged dry seasons and abundant rain the rest of the year |
| temperate grassland | cold, cold winters; hot, dry summers; often drought and occasional fires |
| arctic tundra | treeless plains found just south of the polar ice cap |
| permafrost | thick layer of ice beneath the soil surface that remains frozen year-round |
| tropical rain forest | evergreen broadleaf forest; cover about 2% of Earth's land surface; biome with the most number of diverse species |
| temperate deciduous forest | four distinct seasons; dominated by oak, maple, sycamore, and beech trees |
| taiga | just south of the tundra with long, cold winters and short summers; dominated by spruce, fir, pine, and cedar |
| coastal wetland | covered by salt water; dilute and filter out pollutants from water; bays, mud flats, salt marshes |
| mangrove trees | a type of coastal wetland plant |
| inland wetland | covered with freshwater, located away from the coast |
| shallow marshes and swamps | among the world's most productive ecosystems per unit area |
