Transfer and Transformation of Energy and Materials B&K Sections: 5.1 to 5.5, Ch 9 Start date: 10/20/09

Transfer vs. Transformation Processes Transfers: normally flow through a system and involve a change in location Transformations: lead to an interaction within a system resulting in the formation of a new end product, or involve a change of state

Transfer or Transformation? Dead organic matter enters a lake Decomposition of dead organism 3. Using light energy, water and carbon dioxide is converted to glucose and oxygen through photosynthesis 6H2O + 6CO2 ----------> C6H12O6+ 6O2 Glucose is burned with oxygen in during respiration to produce carbon dioxide and water C6H12O6 + 6O2 --> 6CO2 + 6H2O + energy

Photosynthesis vs. Respiration Transformation(reaction) Inputs Outputs Photosynthesis Respiration ALL living things respire. Only primary producers go through photosynthesis.

Note-taking Space: Photosynthesis vs. Cellular Respiration

Photosynthesis: Respiration: Write one balanced equation for photosynthesis, and one balanced equation for respiration Photosynthesis: Respiration:

The Hydrologic Cycle

Hydrologic Cycle: Facts and Figures Breakdown of water storages: 97.2% 2.15% 0.62% 0.03% The H. cycle is primarily powered by: Absorption and release of water by plants and trees is known as:

1st and 2nd Laws of Thermodynamics First: Energy is never created nor destroyed, only transferred Second: Energy changes from a more useful, more highly organized form to a less useful, disorganized form. (Entropy, amount of disorder, increases)

Energy Flow Diagrams flows represented by: storages/sinks/ sources represented by:

Quantitative Practice: Energy Flow Diagrams Assume that you start with 7,000,000 kJ m-2 yr-1 of solar energy, with 1,7000,000 kJ m-2 yr-1 converted to chem. energy in producers If ~90% of energy is lost to surroundings at each trophic level, calculate the chemical energy in the primary, secondary, and top consumers

Pathways of incoming solar radiation in ecosystems ~20% is reflected back into space as short-wave radiation, as a result of bouncing off of clouds, dust, and aerosols in the atmosphere ~10% reflected back into space as short-wave radiation as a result of being reflected by the surface of Earth ~20% of radiation is absorbed in the atmosphere above Earth’s surface ~50% of radiation reaches Earth’s surface and is absorbed by it

Greenhouse Effect: Occurs in Troposphere (lowest layer of atmosphere) Greenhouse gases (CO2, CH4, NO2) allow visible radiation to pass through, but reflect IR radiation

Of that 50% that is “absorbed” by Earth’s surface It can be: Converted from light energy to chemical energy through photosynthesis Converted from light energy (eventually) to heat energy through photosynthesis followed by respiration Re-radiated to the atmosphere Converted to chem. energy and lost in transfer between trophic levels

Since energy is never created or destroyed… Eventually all of the energy absorbed by the surface and atmosphere (70%) is emitted back into space as long-wave radiation

How does the pyramid structure affect functioning of ecosystems? Can limit the length of food chains (natural systems usu. range from 3-4 levels, and no more than 5) marine ecosystem terrestrial ecosystem

How does the pyramid structure affect functioning of ecosystems? Vulnerability of top-level carnivores Recovery from environmental fluctuations is slower in ecosystems with longer food chains, because fluctuations at lower levels are magnified at higher levels

How does the pyramid structure affect functioning of ecosystems? Concentrations of non-biodegradable toxins in food chains increase towards top of food chain Example: DDT (dichloro, diphenyl, trichloroethane) If a pollutant is: long-lived Mobile Fat-soluble Biologically active

Biomass- the total amount of organic matter on Earth or in any ecosystem or area (excludes OM that has been transformed by geologic processes into substances like coal and petroleum) Biomass is generally reported as grams of dry organic material per square meter

Measuring Biomass Dry weight measurements of quantitative samples can be extrapolated to estimate total biomass. Ex: If there is an average of 600 g of autotroph mass per 1 m2 quadrat (low std. dev.) in a grassland ecosystem, what is the biomass (g/m2) for the entire 500m2 area?

Production and use of biomass Organism produces organic matter within it’s body (through…) Some of org. matter used for respiration Store some newly produced org. matter

Productivity- Jm-2y-1 or, gm-2y-1 The rate of creation of new organic matter (production as a noun is not a rate: Jm-2 or, gm-2 ) Primary productivity (NPP)- rate creation of organic matter (or energy) by autotrophs Gross primary productivity (GPP)- rate of production of energy (by producers) B4 its use Net primary productivity- rate of energy usage by producers (GPP – R)

Productivity of Heterotrophs Secondary productivity- production by heterotrophs (sometimes called assimilation) GSP = food eaten – fecal loss NSP = GSP – R

Quantitative Practice: Productivity all units are in kg m-2 y-1 sunlight falling on plants 6,000,000 Determine: GPP NPP GSP of primary consumers NSP of primary consumers GSP of all consumers NSP of all consumers Light energy used by plants 1,440,000 R = 60,480 primary producers 72,000 11,520 R = 6,480 primary consumers Fecal losses = 3,600 1,440 R = 1,095 secondary consumers Fecal losses = 450

Quantitative Practice Continued

Pyramids of productivity vs. pyramids of biomass vs Pyramids of productivity vs. pyramids of biomass vs. pyramids of numbers Identify which type of pyramid is described in each statement Represents the standing stock of each t. level measured in units such as g of OM per m2 or energy units of Jm-2 Can sometimes display different patterns (ex: when indiv. at lwr. T. levels are relatively large) Refer to the flow of E through a t. level and invariably show a decrease along the food chain (gm-2yr-1 or Jm-2yr-1)

Productivity- production per unit time

The Nitrogen Cycle All life requires nitrogen-containing compounds (ex: nucleic acids and proteins)

Transformations in the Nitrogen Cycle Four transformation processes in the nitrogen cycle: Nitrogen fixation (N2 gas to NH3) Decay (nitrogen in excretions to NH3) Nitrification (NH3 to NO2- to NO3-) Denitrification (NO3- to N2)

Nitrogen Fixation Atmospheric fixation Biological fixation by certain microbes Industrial fixation (Haber process)

Decay Decomposers can convert the nitrogen in urea from animal excretions into ammonia (NH3)

Nitrification by Bacteria Nitrosomonas convert NH3 to NO2- Nitrobacter oxidize NO2- to NO3-

Denitrification Replenishes N2 gas in the atmosphere (fixation, decay, and nitrification are removing nitrogen from the atmosphere) Anaerobic (non-oxygen using) bacteria such as Thiobacillius turn nitrate into nitrogen gas