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biotic factors

biological influences on organisms within an ecosystem; birds, trees, mushrooms, bacteria

abiotic factors

physical (nonliving) factors that shape ecosystems; temperature, precipitation, humidity, wind, nutrient availability, soil type, sunlight


full range of physical and biological conditions in which an organism lives


when organisms of the same or different species attempt to use an ecological resource at the same place at the same time


necessity of life; water, nutrients, light, food, space

competitive exclusion principle

no two species can occupy the same niche in the same habitat at the same time


one organism captures and feeds on another organism


organism that does the killing in predation


organism that is the food in predation


relationship in which two species live closely together


both species benefit from the relationship


one member of the association benefits and the other is neither helped or hurt


one organism lives on or inside another organism and harms it


organism from which a parasite obtains nutritional needs

ecological succession

gradual change in living communities that follows a disturbance

primary succession

succession that occurs where no soil exists

pioneer species

first species to populate an area when premary succession begins

secondary succession

follows when a disturbance changes a community without removing the soil


group of ecosystems that have the same climate and dominant communities

climate diagram

summarazes average temperature and precipitation at a given location during each month of the year


climate within a small area that differs significantly from the climate of the surrounding area

tropical rainforest

biome that occurs on or near the equator


biome that occurs near or above the 60 degree N latitude

boreal forest

forest biome that occurs almost exclusively in the Northern Hemisphere


dense covering formed by the leafy tops of tall trees


layer of shorter trees and vines

deciduous tree

sheds its leaves during a particular season each year


another name for tropical savannas


communities that are dominated by shrubs

coniferous tree

produce seed bearing cones and have thin leaves shaped like needles


material formed from decaying leaves and other organic matter


another name for boreal forests


permanently frozen subsoil in the tundra


abiotic and biotic conditions of mountain ranges vary with ___________


determines amount of light organisms recieve in water


refers to amount of dissolved chemicals on which life depends in water

flowing-water, standing-water

two main types of freshwater ecosystems


tiny, free-floating organisms that occur in aquatic environments


supported by nutrients in water; unicellular algae


feed on phytoplankton; planktonic animals


ecosystem in which water either covers the soil or is present at or near the surface of the soil for at least part of the year


salty water

bogs, marshes, swamps

three main types of freshwater wetlands


wetlands formed where rivers meet the ocean


tiny pieces of decaying plants and animals that provide food for organisms at the base of the estuary food web

salt marshes

temperate-zone estuaries dominated by salt-tolerant grasses above the low tide-line and by seagrasses under water

mangrove swamps

coastal wetland dominated by mangroves, salt tolerant woody plants

photic zone

well-lite upper layer of the oceans

aphotic zone

permanently dark zone below the photic zone

intertidal zone, coastal ocean, open ocean

three main vertical divisions of the ocean based on the depth and distance from the shore


prominent horizontal banding of organisms that live in a particular habitat

kelp forests

huge forests of giant brown algae in the coastal ocean

coral reefs

primary structure made of skeletons of coral animals; all growth occurs within 40 meters of surface

benthic zone

covers the ocean floor


organisms that live attached to or near the bottom of the ocean

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