Nutrient Cycles. Nutrient cycles involve flow of high quality energy from the sun through the environment & of elements.

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1 Nutrient Cycles Nutrient cycles (= biogeochemical cycles): natural processes that involve the flow of nutrients from the environment (air, water, soil, rock) to living organisms ( ) & back again. Nutrient cycles involve flow of high quality energy from the sun through the environment & of elements.

2 Major Locations (Reservoirs) of Nutrients involving flows through the hydrosphere, in the form of liquid water, compounds dissolved in water, & sediments carried by water. involving flows through the atmosphere, as gases or airborne particles (particulates). (lithospheric) involving flows through the lithosphere (Earth's crust = soil & rock), as solid minerals.

3 Water Cycle Main Processes: evaporation: conversion from liquid to vapor form (surface to atmosphere). : evaporation from leaves of water extracted from soil by roots & transported through the plant (surface to atmosphere). transportation in atmosphere: transport as vapor. condensation: conversion of vapor to liquid droplets (clouds). precipitation: movement as rain, sleet, hail, & snow (atmosphere to surface). : movement into soil. : downward flow through soil to aquifers. flow in aquifers: below ground flow of water. runoff: surface flow downslope to ocean.

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5 Review with your table partner: List one similarity and one difference between evaporation and transpiration? Both involve the change of water into. Transpiration occurs from the Evaporation is Put the following terms in the correct order that they would occur: Percolation, Precipitation, Infiltration.

6 Discuss with your table partner: How might deforestation of a tropical rainforest affect the rainfall in a region? (What process would be changed and how could this affect rainfall?) With a large amount of surface area of leaves, can return a lot of water vapor to the atmosphere. Scientists are finding that this can rainfall.

7 Water Cycle Role of Water: Necessary for life terrestrial ecosystems major factor determining of organisms aquatic ecosystems literally that surrounds & serves as environment of aquatic organisms flows of water are major means material & transport water is critical for human activities agriculture, industry, & municipal use Human Influences: withdraw large quantities of fresh water water diversion, depletion, wetland drainage clear vegetation increase, decrease infiltration & groundwater recharge, increase flooding & soil modify water quality add nutrients (P, N ) and/or Climate Change: more in water cycle system

8 Role of Carbon: building block of molecules (carbohydrates, fats, proteins, & nucleic acid) essential to life Carbon Cycle currency of energy chemical energy for life stored as bonds in organic compounds carbon dioxide (CO 2 ) is a gas traps heat near Earth's surface & plays a key role as "nature's thermostat

9 Carbon Cycle Processes photosynthesis ( = carbon ) moves C from atmosphere to organic molecules (C,H,O compounds) in organisms; movement through food web: C movement in organic form from organism to organism; movement between and atmosphere: uptake and release from aerobic : organic molecules broken down to release CO 2 back to atmosphere;

10 Carbon Cycle Processes Cont. movement to sediments and rock: C forms CaCO 3 through processes (shell formation in plankton and larger marine organisms); enters sediments after organisms die; and eventually becomes rock ( ). Fossil fuel formation: organic molecules are buried, compressed, and heated to form (oil, natural gas), and elemental carbon (coal) : organic molecules broken down by burning to release CO 2 back to atmosphere; Limestone

11 Carbon Cycle Photosynthesis, Respiration, and decay happen in both land and ocean ecosystems Plants perform both photosynthesis and Combustion inputs to the atmosphere include burning of fossil fuels, (not shown), Volcanoes erupt it (Combustion) (Photosynthesis) Fossil fuel formation Rock formation

12 Carbon Cycle Identify sources and sinks for atmospheric carbon: Sources: (Puts C into Atmosphere) (Combustion) Sinks: (Removes C from Atmosphere) (Photosynthesis) Fossil fuel formation Rock formation

13 Human Influences to Carbon Cycle: Increased (burning of fossil fuels (organic carbon compounds) Increased - reduces rate of photosynthesis

14 Nitrogen Cycle Nitrogen (N 2 ) is the most common gas in the atmosphere ( ). Nitrogen is needed by all living things. N is part of and protein. However, most organisms cannot utilize N 2 because makes it non-reactive Nutrient in many ecosystems: typically addition of N in fertilizers leads to increased productivity

15 Nitrogen Cycle Processes nitrogen : conversion of N 2 (nitrogen gas) to NH 4+ (ammonium), Performed by bacteria & blue-green algae (anaerobic), e.g., Rhizobium in nodules on roots of legumes; N 2 is also fixed by lightning : conversion of NH 4 + to NO 2- (nitrite) and to NO 3- (nitrate) by microbes; (Oxidation process) of NO 3 or NH 4+ by plants, forms proteins and other N-containing organic compounds, enters food chain;

16 Nitrogen Cycle Processes Cont. : decomposers return nitrate to NH + 4 : Conversion of NH 4+ to N 2 by combustion or microbes. Conversion of NO x to N 2 by (reduction process) N 2 returns to atmosphere

17 Nitrogen Cycle Denitrification Nitrification Ammonification Fig. 5 6

18 Review with your table partner: Name a form of nitrogen that can t be used by most organisms. Name a form of nitrogen that can be used by most organisms. Why do legume plants (bean family) have an advantage in getting enough of the usable nitrogen compounds they need? Continue to next slide

19 What three types of bacteria are involved in the nitrogen cycle? Which are involved in producing usable nitrogen compounds and which are involved in cycling nitrogen compounds back to the atmosphere?

20 Inorganic Fertilizers During WWI, developed process to convert atmospheric nitrogen into to make inorganic nitrate fertilizers. (Process happens at high temperatures, which consumes a lot of energy.) Revolutionized farming: increasing yields. Part of the REVOLUTION

21 Human Influences on the Nitrogen Cycle emit nitric oxide (NO), which leads to and acid rain; emit nitrous oxide into the atmosphere nitrous oxide (N 2 O) is a potent gas & also depletes ozone in stratosphere Use of nitrogen fertilizers which leads to of water bodies Beijing

22 Phosphorous Cycle Always occurs in the form (PO 4 ) Released from rocks by (slow process) Needed by all living things for: DNA, ATP, Phospholipids Can be limiting factor for growth No component of cycle

23 Human Influences of Phosphorous Cycle: Mining large quantities for fertilizers and Cutting down forests reduces available phosphate Add excess phosphate to aquatic systems from livestock, runoff from farmland, and discharges Bird droppings are high in Phosphorous

24 Sulfur Cycle Sulfur is a common element and S compounds are found in rocks, soil and fossil fuels (esp. ) Sulfur is emitted to atmosphere through and fossil fuel burning Sulfur combines with water in the atmosphere to form (H 2 SO 4 ) and returns to earth as acid deposition (i.e. acid rain)

25 Sulfur Cycle Sulfur is converted to sulfate (SO 4 2- ) in soil by Plants uptake form only (used in 2 amino acids)

26 Sulfur Cycle Coal Plant Human Influences: burning (especially coal) (refining of metal ores) releases SO x to atmosphere Sulfur compounds in the atmosphere cause (Sulfuric acid: H 2 SO 4 ) Acid Rain Damage Smelting

27 Where do plants get their nutrients? Nutrient Water Carbon Nitrogen Sulfur Phosphorous Major Source Reservoir (current and fossil) Most is in the oceans How plants uptake Nutrient

28 Important Nutrients for Plants