APES Unit 1 : The Living World: Ecosystems

Key Idea 1

Key Idea 1

Ecosystems are the result of biotic and abiotic interactions.

Key Idea 2

Energy can be converted from one form to another.

Predator-prey

One eats, one gets eaten.

Mutualism

Both species benefit by being in the relationship. Example: clownfish and anemone.

Commensalism

One species benefits and the other is unaffected. Example: remora and shark.

Parasitism

One species benefits and one species is harmed. Example: fleas on a dog.

Competition

Two organisms competing for the same resources. There are two types:

• Intraspecific competition is competition between members of the same species.

• Interspecific competition is competition between members of different species.

Biome

Major communities of plants and animals.

Ecosystem

Living and nonliving parts of an environment.

Taiga

Lengthy cold, wet winters with lots of coniferous trees.

Temperate rainforest

Coniferous and broadleaf trees with lots of rain.

Temperate seasonal forests

Four seasons with warm, wet summers and cold winters,

Tropical rainforests

Greatest diversity of species with rain all year and warm all year,

Shrubland

Hot, dry summers and cool, moist winters; found near coasts with short trees and grasses.

Temperate grassland

Lots of grasses, low rainfall.

Savanna

Grassland with a wet season and a dry season; wildfires are common.

Desert

Dry with little vegetation.

Tundra

Extremely cold, no trees, little rain.

Freshwater biomes

Examples: rivers, lakes, streams, ponds.

Saltwater biomes

Examples: oceans, coral reefs, kelp forests, marshlands, estuaries, mangrove forests, tidepools.

Carbon cycle

How carbon cycles in the environment. It includes both photosynthesis and cellular respiration, which is how carbon is stored in the short term. Also included are dead organisms buried for millions of years, which is long-term storage of carbon.

Nitrogen cycle

Nitrogen makes up 78 percent of our atmosphere. Bacteria are important in the nitrogen cycle. FixNAAD/ANPAN is a mnemonic way to remember the steps (see chart in this chapter).

Phosphorus cycle

Phosphorus cycles in the environment but it is a slow cycle with no atmospheric form. It is found in rocks and sediments.

Hydrologic cycle

Otherwise known as the water cycle and includes evaporation, condensation, runoff, precipitation, and transpiration.

Primary productivity

The rate at which food energy is generated by photosynthesis. It is measured in units of energy per unit area per unit time.

Gross productivity

The total rate of photosynthesis in an area, or the full amount of food produced by the producers.

Net productivity

The difference between gross productivity and the energy lost by producers for respiration.

Trophic levels

Made up of producers, primary consumers, secondary consumers, and decomposers and shows that each level has less energy available.

The 10 percent rule

90 percent of energy is used by the organism and only 10 percent moves up the pyramid because the organism below it used up the energy to heat its body and move, etc. The shape is a pyramid because energy is "lost as it goes up to each higher level.

Food chains

Visual representation of how one organism is a food source for another.

Food webs

Visual representation that is more like real life with multiple food source options for each animal.