Ecology

Study of interactions between organisms and their environments.

Biotic Factors Biosphere – life-supporting layer of Earth Biotic factors – all living organisms in a

biosphere

Abiotic Factors Nonliving factors in an environment Examples:

Air currents Temperature Moisture Light Soil

Organization of Life

Organisms

Populations

Communities

Ecosystems

Biosphere

Feeding Relationships Autotrophs Heterotrophs

Carnivores Omnivores Herbivores Decomposers

Trophic Relationships Autotrophs 1st level consumers (herbivores) 2nd level consumers 3rd level consumers 4th level consumers (top predators)

RULE OF 10 Only 10% of energy is transferred from

one trophic level to the next. Example:

It takes 100 kgs of plant materials (producers) to support 10 kgs of herbivores

It takes 10 kgs of herbivores to support 1 kg of 1st level predator

Symbiosis – “living together”Relationship

Type Species A Species B

Commensalism + 0

Mutualism + +

Parasitism + -

Water cycle Evaporation Transpiration Precipitation Runoff Groundwater

Carbon cycle Combustion Photosynthesis Respiration Decomposition Fossil fuels

Nitrogen cycle Atmospheric nitrogen Runoff Fertilizers Decomposition Nitrogen fixing Synthesis of amino acids