Energy flow in an ecosystem: SUN -> GRASS -> MICE -> HAWK Sunlight is the main source of energy for all living things Energy flows through an ecosystem from the sun to organisms within the ecosystem in one direction The 2 main groups of organisms in an ecosystem are: Producers- autotroph, uses the suns energy to make own food, plants (grass) Consumers- heterotrophs, can not make own food, eat other living things to get energy (mice- primary consumer, and hawk- secondary consumer)
Structure of an ecosystem: ORGANISM -> SPECIES -> POPULATION -> COMMUNITY -> ECOSYSTEM -> ENVIRONMENT Species- group of organisms that can interbred Community- groups of interacting populations Habitat- place where an organism lives Population- units of single species Ecosystem- groups of interacting communities Niche- organisms role within its habitat
Groups of organisms: Herbivore- eats plants Carnivore- groups of interacting populations Omnivore- eats plants and animals Decomposer- break down dead organisms
Symbiotic Relationships: Symbiosis- permanent, close association between one or more organisms of different species Mutualism- a symbiotic relationship where both species benefit Commensalism- symbiotic relationship in which one species benefits and the other is neither harmed or benefited Parasitism- symbiotic relationship in which one organism benefits at the expense of another, typically a different species
Food web
Interconnected food chains
shows all possible feeding relationships at each trophic level in a community
Food Chain
Path of energy from producer to consumer
Each level is called a trophic level
trophic means energy
Approximately 10% energy is transferred between levels
Cycles: Water cycle- water is recycles through evaporation, condensation, precipitation, runoff and ground water Nitrogen cycle- producers take in nitrogen compounds in the soil and pass to consumers that consume the producers, decomposers break down the nitrogen compounds and release nitrogen gas into the air Carbon cycle- carbon recycled through respiration, photosynthesis, fuel combustion, and decomposition