Chapter two and three vocabulary

Terms in this set (40)

nonliving factors such as amount of rainfall and temperature that affect the distribution of organisms and population size.

a living factor such as predation and disease that affect the distribution of organisms and population size.

the thin layer of the Earth that supports life (oceans, land, and air).

all populations in a given area. Members of populations may interact (predation, competition, symbiosis).

a symbiotic relationship in which one member is benefited and the other is not affected.

the study of the interactions between organisms and other members of the community and with the nonliving portion of the environment.

the ecological zone in which an organism lives, feeds, and reproduces

a symbiotic relationship in which each member is benefited from the the relationship.

an organism's role in the environment; this includes the resources used by the organism and its physical adaptations for survival.

a symbiotic relationship in which one member is benefited and the other member is negatively affected.

a group of organisms of one species living in the same area. For example, the population of bullfrogs in a lake.

a relationship between two individuals of different species living in close physical contact. Examples include: parasitism, mutualism, and commensalism.

Competitive exclusion principle

the idea that two species cannot share the exact same niche. One species will use the resources more effectively and eliminate the other.

an organism capable of making their own organic molecules (food) using sunlight for energy. Examples include: plants, some protists, and some bacteria.

an organism that is not capable of making its own organic molecules (food) and must consume other organisms. Examples in include: animals, fungi, some protists and bacteria.

bacteria and fungi that break down dead organic matter in the soil.

energy levels in a food chain. Organisms may feed at one or more level.

when energy is passed from one trophic level to another in a food chain, only 10% moves to the next level. The remaining 90% is lost as heat to the environment.

a diagram that show multiple connected food chains. It models all of the possible feeding relationships in a community.

a simple diagram that shows how energy moves through trophic levels. For example, algae → fish → great blue heron

Keystone species

a species that may be small in number but exerts a strong influence on the make-up of a community. Without these species the overall diversity of the community declines.

Climax community

a stable community that develops through the process of succession following a disturbance. For example, given enough time, a stable forest community would naturally replace all of the cornfields in Indiana if we stopped disturbing the soil.

Primary succession

a process that builds soil in a lifeless environment such as a new volcanic island. Lichen and moss are the first to colonize, and their eventual decomposition produces soil, setting the stage for larger plants.

Secondary succession

a change in the makeup of a community following a disturbance such as a forest fire, flood, or wind storm. The soil remains intact so the climax community reemerges much faster.

Range of tolerance

an organism's ability to respond to an abiotic factor such as salinity, temperature, moisture level. For example, too much or too little light may affect a plant's ability to survive.

Limiting factor

biotic and abiotic characteristics of the ecosystem that may affect an organism's distribution (where it is found) and population size.

the area of a body of water that receives sunlight, allowing for photosynthesis. Up to a depth of 200 meters.

the area in a body of water that does not receive sunlight. No photosynthesis occurs in this region.

large regions on Earth shaped by similar climates (temperature and precipitation). They also have similar plant and animal communities. Examples include: deserts, grasslands, and tropical forests.

a biome shaped by very low temperatures and precipitation. Permafrost prevents trees from growing.

Tropical rain forest

a biome shaped by high temperatures and precipitation and an abundance of sunlight. Hold great biodiversity. Located near the equator.

a biome just south of the tundra. These forests are dominated by coniferous trees (spruces and fir trees).

Temperate forest

forests found in the mid-latitudes and dominated by deciduous trees (trees that lose their leaves).

a biome dominated by grasses and low-lying plants. This biome is too dry to support trees. Fires are frequent and help to maintain the dominance of grasses in the plant community.

a protected body of water in which freshwater and saltwater mix. Many ocean species spend the early parts of their lives here. The Chesapeake Bay is an example.

Primary productivity

a measurement of the photosynthetic rate (plant growth) of an ecosystem. Precipitation, temperature, sunlight, and nutrients affect this rate.

the number of species found in a given habitat or ecosystem. It may be measured by species richness and relative abundance.

a layer of frozen soil found in the tundra biome and in high mountain areas. Even during the summer months, the soil remains frozen just below the surface.

the process by which lakes and rivers become rich in nutrients (nitrate and phosphate) from the surrounding watershed.

In a body of water, an area with extremely low oxygen concentration and very little life

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