Ecology and the environment
Organism in the environment
- Ecological termsPopulationCommunityHabitatEcosystem
- Quadrat practicalRandom placementMean per quadratEstimate population
- Abiotic factorsTemperatureLightWater
- Biotic factorsCompetitionPredationPredator-prey cycles
Feeding relationships
- Trophic levelsProducers (level 1)Primary, secondary, tertiary consumersDecomposers
- Food chains and websArrows: food to eaterWebs link chains
- PyramidsNumberBiomassEnergy transfer
- Energy transferAbout 10%FaecesRespiration heatUrine
- Limited chain lengthLittle energy leftLess biomass higher up
Cycles
- Carbon cyclePhotosynthesis removes CO₂Respiration adds CO₂Combustion adds CO₂
- DecomposersBacteria and fungiDecompositionRelease CO₂
Human influences
- Sulfur dioxideAcid rainLakes and treesLichens
- Carbon monoxideIncomplete combustionBinds haemoglobin
- Greenhouse gasesCO₂, CH₄, N₂OCFCsWater vapour
- Enhanced greenhouse effectInfrared absorbedGlobal warmingSea level rise
- SewageOxygen used upPathogens
- EutrophicationLeached nitratesAlgal bloomOxygen falls