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 1 st level consumers (herbivores) 2 nd level consumers 3 rd level consumers 4 th 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 1 st level predator

Symbiosis – living together Relationship Type Species ASpecies 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