ecology study guide

Ecology

The study of how living things interact with each other and with their environment.

Organism

One living thing.

Population

A group of the same species living together.

Community

Different populations living together.

Ecosystem

Living and nonliving things interacting.

Biome

Large region with similar climate and organisms.

Biosphere

All ecosystems on Earth.

Biotic factors

Living things.

Abiotic factors

Nonliving things.

Food Chain Example

Grass → Grasshopper → Frog → Snake.

Producer

Grass.

Primary Consumer

Grasshopper.

Secondary Consumer

Frog.

Tertiary Consumer

Snake.

10% Rule

Only about 10% of energy passes to the next trophic level.

Earth's Energy Source

Most energy on Earth comes from the Sun.

Carbon Cycle

Carbon moves through air, plants, animals, and fossil fuels.

Phosphorus Cycle

Phosphorus comes from rocks and soil.

Nitrogen Cycle

Nitrogen in air must be changed by bacteria into usable forms.

Water Cycle

Evaporation → Condensation → Precipitation → Collection.

Grasslands

Large grasses, few trees, good soil, many grazing animals.

Savanna

Tropical grassland, warm year-round, scattered trees.

Desert

Very dry, little rainfall, hot days, cold nights.

Tundra

Very cold, frozen soil (permafrost), few plants.

Population Density

The number of individuals living in a certain area.

Carrying Capacity

The largest population an environment can support over time.

Exponential Growth

Fast growth, J-shaped curve, unlimited resources.

Logistic Growth

Growth slows near carrying capacity, S-shaped curve, limited resources.

r-selected Species

Many offspring, little parental care, grow quickly.

K-selected Species

Few offspring, lots of parental care, grow slowly.

Limiting Factor

Anything that restricts population growth.

Density-Dependent Factors

Affects crowded populations more.

Density-Independent Factors

Affects populations no matter the size.

Symbiosis

A close relationship between two species.

Mutualism

Both species benefit.

Commensalism

One benefits, the other is unaffected.

Parasitism

One benefits, the host is harmed.

Primary Succession

Starts where no soil exists, slow process.

Secondary Succession

Soil already exists, happens after disturbance, faster process.