Energy and biomass in ecosystems
Topic 2.2 examines how species form communities and ecosystems, including the concepts of habitat, distribution, and abundance. Students study ecosystem structure, the difference between biotic and abiotic factors, and how communities change over time.
IB ESS · Topic 2.2
Sub-topics in Topic 2.2
2.2.1Energy and matter in ecosystems2.2.2The first law of thermodynamics2.2.3Photosynthesis and respiration transform energy and matter2.2.4Photosynthesis: from light to biomass2.2.5Producers: the first trophic level2.2.6Cellular respiration: releasing energy2.2.7Respiration and heat2.2.8The second law of thermodynamics2.2.9Consumers and their feeding strategies2.2.10Producers and consumers in food chains2.2.11Food chains and trophic levels2.2.12Losses of energy and organic matter along food chains2.2.13Gross and net productivity2.2.14Why food chains are short2.2.15Food webs2.2.16Measuring biomass2.2.17Ecological pyramids2.2.18Bioaccumulation and biomagnification2.2.19Microplastics and pollutants2.2.20Human impacts on energy and matter2.2.21Autotrophs and heterotrophs