SECTION 13.5 : Biogeochemical Cycles Hydrologic cycle (water cycle) Carbon cycle Nitrogen cycle Phosphorus Cycle In an ecosystem, material is constantly cycled among organisms and the environment. Most food & oxygen is produced by primary producers through photosynthesis Energy is not cycled in the biosphere

Precipitation -- Groundwater Condensation -- Evaporation 1. Hydrologic cycle Vocabulary: Precipitation -- Groundwater Condensation -- Evaporation Transpiration -- Aquifers precipitation condensation transpiration evaporation water storage in ocean surface runoff lake groundwater seepage

Photosynthesis -- Cell. Respiration Combustion -- Decomposition 2. Carbon cycle Vocabulary: Photosynthesis -- Cell. Respiration Combustion -- Decomposition Fossil Fuels fossil fuels photosynthesis carbon dioxide dissolved in water decomposition of organisms respiration carbon dioxide in air combustion

Nitrogen fixing bacteria convert nitrogen gas (N) into ammonia (NH3) 3. Nitrogen cycle Nitrogen fixation: Nitrogen fixing bacteria convert nitrogen gas (N) into ammonia (NH3) These bacteria on the roots of plants or in the soil. Legumes are a special kind of vegetable plant -decomposers are important to this process nitrogen in atmosphere animals denitrifying bacteria nitrifying ammonium ammonification decomposers plant nitrogen-fixing bacteria in soil bacteria in roots nitrates nitrites

Nitrogen is taken in by plants/animals to make protein & nucleotides. (Ammonification) Nitrogen returns to the soil during decomposition. nitrogen in atmosphere animals denitrifying bacteria nitrifying ammonium ammonification decomposers plant nitrogen-fixing bacteria in soil bacteria in roots nitrates nitrites

Phosphate is released by the weathering of rocks. 4. Phosphorus cycle Phosphate is released by the weathering of rocks. P moves into plants (producers) and then into consumers. P returns to the soil during decomposition. P flows from the soil into groundwater and is trapped in rocks. geologic uplifting rain weathering of phosphate from rocks runoff sedimentation forms new rocks leaching phosphate in solution animals plants decomposers phosphate in soil