BIO220H1 Lecture Notes - Lecture 9: Nitrification, Nitrogen Cycle, Radionuclide
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BIO220H1 Full Course Notes
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Us national labs (and u of t) researched radiation effects on organisms & ecosystems. Pine-oak forest irradiated by powerful gamma source (cs137), C, n, & p cycles: all tied to hydrologic cycle, carbon cycle subsumes trophic webs, n and p are the two elements most likely to limit plant productivity, key for pinkish figures from begon et al. Solid black lines = strong natural fluxes. Dashed black lines = weaker natural fluxes. As an aid to hunting (burning to open and maintain grasslands) To provide land for agriculture (cutting and burning) To remove agricultural waste (e. g. , rice straw) In n. america, easternmost prairies would revert to forest without fire: an important phenomenon since the dawn of agriculture , recently expanded to global scale, carbon sequestered in trees is released by fire. Co2 is the gaseous phase, much c in organisms (food chains), inactive sedimentary pool of carbonates. Limiting steps involve balance between creation (by photosynthesis) and respiration/combustion of organic matter.
