Biogeochemical Cycles

Cycling maintains homeostasis (balance) in the environment. Nutrient Cycles Cycling maintains homeostasis (balance) in the environment. 3 common cycles we will investigate: 1. Water cycle 2. Carbon cycle 3. Nitrogen cycle

Cycling of Matter Cycles in the Biosphere Part 3: Cycling of Matter Cycling of Matter Cycles in the Biosphere Natural processes cycle matter through the atmosphere The exchange of matter through the biosphere is called the biogeochemical cycle. Bio: Involves living things Geo: Geological Processes Chemical: Chemical Processes

Cycling of Matter The Water Cycle Solar Energy Solar Energy Part 3: Cycling of Matter Cycling of Matter The Water Cycle Solar Energy Solar Energy Movement of clouds by wind Movement of clouds by wind Precipitation Precipitation Evaporation Evaporation Precipitation Precipitation Transpiration from plants Transpiration from plants Percolation in soil Percolation in soil

Cycling of Matter The Water Cycle Part 3: Cycling of Matter Cycling of Matter The Water Cycle Most precipitation falls into the ocean Over land approximately 90% of the water evaporates 10% transpires from plants Only about 2% of water is retained in a reservoir i.e., a glacier, ice cap, aquifer or lake

Nitrogen cycle- Atmospheric nitrogen (N2) makes up nearly 78%-80% of air. Organisms can not use it in that form. Lightning and bacteria convert nitrogen into usable forms.

Nitrogen cycle- Only in certain bacteria and industrial technologies can fix nitrogen. Nitrogen fixation-convert atmospheric nitrogen (N2) into ammonium (NH4+) which can be used to make organic compounds like amino acids. N2 NH4+

Nitrogen-fixing bacteria: Nitrogen cycle- Nitrogen-fixing bacteria: Some live in a symbiotic relationship with plants of the legume family (e.g., soybeans, clover, peanuts).

Nitrogen cycle- Some nitrogen-fixing bacteria live free in the soil. Nitrogen-fixing cyanobacteria are essential to maintaining the fertility of semi-aquatic environments like rice paddies.

Cycling of Matter Nitrogen Cycle Part 3: Cycling of Matter Plants Nitrogen in atmosphere Plants Assimilation Denitrifying bacteria Nitrates (NO3-) Nitrogen – fixing bacteria in root nodules of legumes Decomposers (aerobic & anaerobic bacteria and fungi) Nitrifying bacteria Ammonification Ammonium (NH4+) Nitrites (NO2-) Nitrogen – fixing bacteria in soil

Nitrogen Cycle Atmospheric nitrogen Lightning Denitrification by bacteria Animals Nitrogen fixing bacteria Plants Decomposers Nitrification by bacteria Nitrites Nitrates Ammonium

Cycling of Matter Carbon Cycle Part 3: Cycling of Matter CO2 in atmosphere Burning Cellular Respiration Photosynthesis Plants, Algae & Cyanobacteria Higher level Consumers Wood & Fossil Fuels Primary Consumer Detritivores (soil microbes & others) Detritus

Cycling of Matter Carbon Short term cycle Part 3: Cycling of Matter Cycling of Matter Carbon Short term cycle Autotrophs use CO2 for photosynthesis. Heterotrophs produce CO2 during cell respiration

Cycling of Matter Long term cycle: Fossil Fuels Part 3: Cycling of Matter Cycling of Matter Long term cycle: Fossil Fuels Organic matter is buried underground and converted to peat, coal, oil or gas deposits. 5.5 billion tons are burned each year and 3.3 billion tons stay in the atmosphere The rest dissolves in sea water turning oceans into mild acid

Cycling of Matter Long term cycle: Calcium Carbonate (CaCO3) Part 3: Cycling of Matter Cycling of Matter Long term cycle: Calcium Carbonate (CaCO3) Marine animals are able to use Carbon to build their skeletal material These organisms fall to the bottom of the ocean floor, creating limestone rock.

Cycling of Matter Oxygen makes up about 21% of the atmosphere . Part 3: Cycling of Matter Cycling of Matter Oxygen makes up about 21% of the atmosphere . Very reactive element, quickly disappears in compounds Some oxygen goes into the stratosphere, where it is converted into Ozone (O3) Ozone serves to absorb biologically damaging ultra- violet (UV) radiation from the sun.

Cycling of Matter Carbon and Oxygen Cycles Part 3: Cycling of Matter Cycling of Matter Carbon and Oxygen Cycles Carbon dioxide (CO2) is a greenhouse gas and traps heat in the atmosphere. Burning fossil fuels has added 30% more Carbon Dioxide than 150 years ago. The atmosphere has not held this much Carbon for at least 420,000 years according to data from ice cores.