2.1.1-2.1.5 Ecosystems

ECOLOGYThe study of the

interactions between organisms

and their environment.

ENVIRONMENT = all the factors that affect an organism.

ABIOTIC FACTOR = non-living factors in an environment.

BIOTIC FACTORS = living factors in an

environment.

Buckminster Fuller on the Environment

“Environment to each must be All there is, that isn't me. Universe in turn must be All that isn't me AND ME.”

NICHE = all of the ways that the

organism interacts with everything else in the ecosystem-the

role or job of a species in an ecosystem.

HABITAT = place where an organism or population of organisms

live.

Biosphere

Ecosystems

Communities

Populations

Organisms

ECOSYSTEM includes all the biotic & abiotic factors in an

environment.

FOOD CHAIN = used to show how matter & energy move through an ecosystem.

FOOD WEB = shows all the possible food chains in an ecosystem

Each organism in food chain represents a “feeding” or TROPHIC LEVEL

1st Trophic Level

2nd Trophic Level

3rd Trophic Level

producers

1o or 2o consumer

2o or 3o consumer

decomposers

ECOLOGICAL PYRAMIDS Are graphical models of the quantitative

differences that exist between the trophic levels of a single ecosystem.

In accordance to the 2nd Law of Thermodynamics, there is a tendency for numbers and quantities to biomass and energy to decrease along food chains, therefore the pyramids become narrower toward the top.

PYRAMID OF NUMBERS represents storages found at each trophic level.

Units vary

Grassland(summer)

Temperate Forest(summer)

Producers

Primary consumers

Secondary consumers

Tertiary consumers

A few large producers (the trees) support a much larger number ofSmall primary consumers (insects) that feed on the trees.

PYRAMID OF BIOMASS represent the standing stock at each trophic

level.

Units:

J m-2

or

g m-2

Abandoned Field Ocean

Tertiary consumers

Secondary consumers

Primary consumers

Producers

In open waters of aquatic ecosystems, the biomass primary consumers(zooplankton) can exceed that of producers. The zooplankton eat the Producers (phytoplankton) as fast as they reproduce, so their populationis never very large.

PYRAMID OF PRODUCTIVITY represents the flow of energy through each trophic

level.

Units:

J m-2 yr-1

or

g m-2 yr-1

As you move up each trophic level, only 10% of the energy is transferred.

The other 90% is used for everyday life functions, metabolism.

producers

10 J m-2 yr-1

100 J m-2 yr-1

1,000 J m-2 yr-1

10,000 J m-2 yr-1

Pyramid structure affectsthe functioning of an ecosystem.

Bioaccumulation