Nutrient Cycling What Happens to Matter in an Ecosytem?

Questions for Today: How does matter cycle through an Ecosystem? How many biogeochemical cycles do Environmental Scientists analyze? What are the major key components for each cycle? How do humans influence the different biogeochemical cycles?

What happens to Matter? The matter and nutrients in our environment move continually through the abiotic and biotic factors in our ecosystem and in the biosphere in cycles called Biogeochemical Cycles. Nutrient cycling is one of the four major principles of Sustainability.

What happens to Matter? There are 5 major cycles driven by the sun and gravity: –Hydrologic (Water) –Carbon –Nitrogen –Phosphorous –Sulfur As nutrients move through the cycle, they can spend the majority of their time in one form. –Reservoirs

Water Cycle Water Cycles (WC) collects, purifies, and distributes the earth’s fixed supply of water. The WC’s reservoirs are the atmosphere and hydrosphere. –Global Cycle

Water Cycle Parts of the WC include: –Evaporation –Condensation –Precipitation –Transpiration

Water Cycle After Precipitation, Water can take various paths: –Surface Runoff –Seepage –Glaciers –Aquifers –Groundwater –Absorption

Water Cycle Three Major Ways we alter the WC: –We withdraw large amounts of freshwater 0.024% of the water on the planets is usable freshwater –We clear vegetation for building purposes Increases runoff Reduces infiltration Increase risk of flooding, soil erosions and landslides –We increase flooding When we drain Wetlands for farming or roads

The Water Cycle

Carbon Cycle The Carbon Cycle is the Link between photosynthesis in producers and respiration in producers, consumers, and decomposers The Reservoir for Carbon is found in the geosphere. The Carbon Cycle is based on CO 2 gas.

Carbon Cycle The Major Parts of the Carbon Cycle are: –Photosynthesis –Cellular Respiration –Deposition –Lithification Carbon acts as nature’s thermostat. –Too little CO 2 in the air, the temp. goes down –Too much CO 2 in the air, the temp. goes up.

Carbon Cycles Humans affect the Carbon Cycle in two ways: –Deforestation –Burning of Fossil Fuels Both ways increase the amount of CO 2 in the atmosphere. –Computer modeling links CO 2 added by humans have increased earth’s natural greenhouse effect.

Carbon Cycle

Nitrogen Cycle The Nitrogen Cycle is important in the creation of proteins and nucleic acids for all living creatures. The Major Reservoir for Nitrogen is the atmosphere. –78% of Nitrogen is found in the Atmosphere as N 2 Plants and Animals have a hard time absorbing Atmospheric Nitrogen.

Nitrogen Cycle Four major parts of the Nitrogen Cycle: –Nitrogen Fixation Bacteria Electrical Discharges –Nitrification Biological –Ammonification Biological –Denitrification Biological

Nitrogen Cycle Humans Alter the Nitrogen Cycle in FIVE ways: –Release of Nitric Oxide (NO) into the atmosphere Acid Rain –Addition of N 2 O, nitrous oxide, through anaerobic bacteria on livestock wastes Destroys Ozone –Deforestation –Fertilizer Runoff –Overharvesting

Nitrogen Cycle

Phosphorous Cycle Phosphorous Cycle is important for plant growth and DNA production and Cellular Energy Major Reservoir is the Geosphere –NO ATMOSPHERIC PHOSPHOROUS Found in the environment as Phosphates. Really slow process. Humans affect the Phosphorous Cycle by overharvesting of Phosphorous from the soil and deforestation.

Phosphorous Cycle

Sulfur Cycle Sulfur found in organisms, ocean sediments, soil, rocks, and fossil fuels SO 2 in the atmosphere H 2 SO 4 and SO 4 - Human activities affect the sulfur cycle –Burn sulfur-containing coal and oil –Refine sulfur-containing petroleum –Convert sulfur-containing metallic mineral ores

Sulfur Cycle