| A | B |
|---|
| limiting factor | any biotic or abiotic factor that restricts the existence, numbers, reproduction, or distribution of organisms. |
| tolerance | the ability of an organism to withstand fluctuations in biotic and abiotic environmental factors. |
| succession | orderly, natural changes, and species replacements that take place in communities of an ecosystem over time. |
| primary succession | colonization of barren land by pioneer orgamisms. |
| climax community | a stable, mature community that undergoes little or no change in species over time. |
| secondary succession | sequence of changes that take place after a community is disrupted by natural disasters or human actions. |
| biome | group of ecosystems with the same climax communities; biomes on land are called terrestrial boimes, those in water are called aquatic biomes. |
| photic zone | portion of the marine biome that is shallow enough for sunlight to penetrate. |
| aphotic zone | deep water that never receives sunlight. |
| estuary | coastal body of water, partially surrounded by land, in which freshwater and sale water mix. |
| intertidal zone | portion of the shoreline that lies between high tide and low tide lines. |
| plankton | small organisms that drift and float in the waters of the photic zone; includes both autotrophic and heterotrophic organisms, their eggs, and the juvenile stages of many marine animals. |
| tundra | biome that surrounds the north and south poles; treeless land with long summer days and short periods of winter sunlight; characterized by permafrost. |
| taiga | biome just south of the tundra; characterized by a boreal or northern coniferous forst composed of larch, fir, hemlock, spruce trees and acidic, mineral-poor topsoils. |
| desert | arid region with sparse to almost nonexistent plant life; the driest biome, usually receives less than 25cm of precipitation annually. |
| grassland | biome bomposed of large communities covered with rich soil, grasses, and similar small plants; receives 25-75 cm of precipitation annually |
| temperate/decidious forest | biome composed of forests of broad-leaved hardwood trees that lose the fioliage annually, receives 70-150cm of precipitation annually. |
| tropical rain forest | biome near the equator with warm temperature, wet weather, and lush plant growth; receives at least 200cm of rain annually; contains more species of organisms than any other biome. |
