Ecology Unit:The Biosphere

Chapter 3

What is Ecology?• Ecology – the study of interactions among

organisms and their environment

• Biosphere – area of the planet in which all life exists

• Factors within an environment:

a. Abiotic – nonliving

b. Biotic - living

Levels of Organization

Species – Individuals that can breed with one another. (ex: Mallard duck)

Population – All the individuals of the same species in a given area. (ex: all the ducks in a pond)

Community - all the populations that live together in an area

What populations can you see in this picture?

Ecosystem – the abiotic and biotic factors in a given area.

Examples of ecosystems: (they don’t have to be huge!)

Rotting LogKoi PondMountainA hillsideClump of DirtA fieldA maple treeA puddle

Biome – a large area that has a particular climate, and particular species of plants

and animals that live there.

Biosphere - the part of the earth that supports life; Contains all biomes.

Section 3-1

Figure 3-2 Ecological Levels of OrganizationEcological Levels of Organization

Energy Flow

Section 3-2

Energy Flow and Producers

• Sunlight is the main energy source for life on earth

• Autotrophs – organisms that can use sunlight or chemicals to make their own food. Ex: plants, bacteria, algae

*also known as: PRODUCERS• The two ways to manufacture

food internally: 1. Photosynthesis 2. Chemosynthesis

Consumers

• Heterotrophs - Organisms that rely on other organisms to get their food.

**a.k.a CONSUMERS

• Types of Consumers:– Herbivores– Carnivores– Omnivores– Detritivores/Decomposers

What do these consumers eat?

Feeding Relationship

s• Food Chains – simple

chain of organisms transferring energy by eating and being eaten.

• Trophic Levels – a step in a food chain or web

• Food Webs – complex network of many food chains in an ecosystem.

Why does it matter

which way the arrows

go?

Ecological Pyramids

• A pyramid diagram showing the relative amounts of energy at each trophic level in a food chain.

• Three Types:1. Energy pyramid – amount of energy per trophic level.2. Biomass pyramid – amount of living organic

matter per trophic level.3. Pyramid of numbers – Number of organisms per trophic level.

How much

energy is available at each level?

Energy Energy PyramidPyramid

10%!

Most of the lost energy

is in form of HEAT!

Q: If primary consumers have 870 kcal of energy available, how much will the secondary consumers?

Biomass Pyramid

2 different Pyramid of Numbers