Biogeochemical Cycles

How Can Abiotic Impacts Affect the Environment Let’s first understand what natural processes occur on earth

Recycling in the Biosphere Energy FLOWS through an Ecosystem MATTER is the “stuff” that makes up everything Matter CYCLES

Biogeochemical Cycles Law of Conservation of Matter Matter is never CREATED nor DESTROYED Water cycle Carbon cycle Nitrogen Cycle Phosphorous cycle Sulfur cycle

Bio vs. Geo vs. Chemi Biological processes: Geological Processes: consist of any and all activities performed by living organisms. Eating, breathing, metabolizing, releasing wastes Geological Processes: Earth processes Volcanic eruptions, formation/breakdown of rock, cycling of matter through earth’s surface Chemical Processes: Ex. Formation of clouds/precipitation, chemical reactions

Water (Hydrologic) Cycle

Water (hydrologic) cycle Precipitation: any form of water that falls from the sky Snow, rain, hail, sleet Condensation: cooling of water that changes it from a gas to a liquid Example: formation of clouds Evaporation: physical change of water from a liquid to a gas Transpiration: Evaporation of water from the leaves of plants Run off: flow of water from the land Infiltration/percolation: water absorbs beneath he earth’s surface into the soil Ground water, Aquifer

Where’s all the H2O?? Ocean’s are the major reservoir for water Other places: Rivers, lakes Atmosphere (gaseous h2o) Underground Glaciers (solid h2o) Within living things

How do humans impact the water cycle? Start thinking… How do humans impact the water cycle? We’ll come back to this thought…

Carbon Cycle Carbon (C) is one of the most important elements involved in chemical cycling Atmospheric carbon is mostly in the form of CO2 (carbon dioxide) Extremely important for plants to carry out photosynthesis Also a green house gas- what helps warm the earth Other forms of carbon are organic and inorganic forms. Cycles through the atmosphere, the geosphere, the hydrosphere, and biosphere

Carbon dioxide in atmosphere Respiration Photosynthesis Animals (consumers) Burning fossil fuels Diffusion Forest fires Plants (producers) Deforestation Transportation Respiration Carbon in plants (producers) Carbon dioxide dissolved in ocean Carbon in animals (consumers) Decomposition Carbon in fossil fuels Marine food webs Producers, consumers, decomposers Figure 3.19: Natural capital. This simplified model illustrates the circulation of various chemical forms of carbon in the global carbon cycle, with major harmful impacts of human activities shown by the red arrows. Question: What are three ways in which you directly or indirectly affect the carbon cycle? Carbon in limestone or dolomite sediments Compaction Process Reservoir Pathway affected by humans Natural pathway Fig. 3-19, p. 70

Movement of Carbon Goes into the atmosphere: Dissolves into water Burning of fossil fuels (combustion) Burning forests Respiration (breathing) Dissolves into water Calcification- dissolved carbon transformed into calcium carbonate (marine organisms) Moves through living things, starting with plants and then through trophic levels Moves through soil via living wastes and decomposition Carbon in soil to water through erosion

Carbon Cycle Why is carbon important? Calcium carbonate in your bones Plants need carbon dioxide (CO2) for photosynthesis What else needs carbon? ALL living and some non living things are made out of carbon.

So what happens in the carbon cycle if.. Clearing large amounts of trees (deforestation)? Remember, plants take out CO2 from the atmosphere CO2 is one of the green house gases that helps warm the earth How else are we putting putting carbon in the atmosphere??

Nitrogen Cycle

Nitrogen Cycle Most of the nitrogen on earth is in the atmosphere as N2 (pure nitrogen gas) This is not a usable form for most living organisms Specialized bacteria transform N2 into usable forms Nitrogen Fixation Conversion of N2 into NH3 and NH4+ (ammonia and ammonium) Nitrification Conversion of NH3 and NH4+ into Nitrate ions (NO3-) Assimilation: Plants take up NO3 and convert into organic nitrogen compounds (proteins and nucleic acids) Ammonification: Decomposition of nitrogen containing detritus into ammonia and ammonium Denitrification: Conversion of NH3 and NH4 back into N2 gas

Human Impact of Nutrient Cycles Disruption of nutrient cycles has harmful effects on the biosphere Burning fossil fuels----> global warming Increases CO2 (a green house gas!) Water pollution ------> intoxicating clean water Air pollution ------> Acid Rain Destroying plants and aquatic systems Coral reef Bleaching http://www.smithsonianmag.com/video/Climate-Change- 101-With-Bill-Nye-the-Science-Guy.html

Independent Seat Work Carbon and Water Cycle Worksheet