Ecosystems and Nutrient CyclesChapters 3

Prokaryotic and Eukaryotic cells

Prokaryotic cells: Have ___________________organelles. Bacteria and Archaea are composed of prokaryotic cells.Eukaryotic cells: ___________________cells, containing membrane-bound organelles that each perform a specific function.

Figure 3-2

Parts of the earth's air, water, and soil where life is found

Biosphere

Smallest unit of a chemical element that exhibits its chemical properties

Ecosystem

Community

Population

Organism

A community of different species interacting with one another and with theirnonliving environment of matter and energyPopulations of different species living in a particular place, and potentially interacting with each other

A group of individuals of the same species living in a particular place

Cell

An individual living being

The fundamental structural and functional unit of life

Molecule

Atom

Chemical combination of two or more atoms of the same or different elements

Figure 3-3

Ecosystems Have Living and Nonliving Components

Abiotic: Nonliving components– Water– Air– Nutrients– Rocks– Heat– Solar energy

Biotic:____________________________ (Ex: Leaf litter is biotic)

Abiotic Factors

Several Abiotic Factors Can Limit Population Growth

______________________Principle:Too much or too little of any abiotic factor can limit or prevent growth of a population, even if all other factors are at or near the optimal range of tolerance

Range of Tolerance for a Population of Organisms

INSERT FIGURE 3-10 HERE

Figure 3-10

Living Components of EcosystemsProducers, ________________– Photosynthesis– Chemosynthesis

Consumers, _________________– Primary– Secondary– Tertiary and higher levels…– Generally not more than 3 or 4 levels due to the

energy pyramid

Chemosynthesiso Uses the energy from certain

compounds such as hydrogen sulfide from _______________to provide the energy to produce carbohydrates.

o Performed by Bacteria and Archaea (________________).

o Occurs at __________________

Photosynthesiso Uses ____________ to provide

the energy required to produce carbohydrates from carbon dioxide and water.

6 CO2 + 6 H2O C6H12O6 + 6 O2

Photosynthesis vs. Chemosynthesis

Discuss with your table partner:

What do photosynthesis and chemosynthesis have in common?How do the two processes differ? Fill in your answers on the next slide.

____________________________________________________________________________________________________________________________________

Releasing Stored EnergyAll organisms store energy in sugars and other organic molecules. This energy is released as needed through either:

-aerobic respiration (with oxygen) C6H12O6 + 6 O2 6 CO2 + 6 H2O

- anaerobic respiration (without oxygen) also known as ___________________

Plants perform both photosynthesis and aerobic respiration.

Detritivores and DecomposersDetritivores: ____________________ dead organisms.

Decomposers: ________________to break down dead organisms. Recycle nutrients into the surrounding area.

___________________in an Ecosystem

Beetle larvae

Fig 3-11

file:///D:/Media/LITE/PowerPoint_Lectures/chapter3/videos_animations/matter_energy.html

Energy Flow Through the Ecosystem

Nutrient and Energy Flows Through the Ecosystem

Heat Heat

Heat

Heat Heat

Heat

Heat

Solarenergy

Tertiaryconsumers

(top carnivores)

First TrophicLevel

Second TrophicLevel

Third TrophicLevel

Fourth TrophicLevel

Producers(plants)

Primaryconsumers(herbivores)

Secondaryconsumers(carnivores)

Decomposers and detritus feeders

___________ Level: A step in a food chain____________ flow of energy in an ecosystem.

Living Components of Ecosystems

Gross Primary Productivity (GPP)Gross Primary Productivity is the rate at which

producers _____________________(for almost all producers) into _________________.

Usually measured in a unit of energy per unit of area over a given time span.

Example : kcal/m2/year

Some of the gross primary productivity is needed to support the producer and is not passed along the food chain.

Net Primary ProductivityNet Primary Productivity (NPP) is the amount of chemical energy available after the __________ requirements of the __________ have been _________________.

Discuss with your table partner:What could you measure to determine the NPP of an ecosystem? (Hint: Productivity = rate of photosynthesis)

Estuaries and swamps generally have a high net primary productivity. Why?

Why is the NPP compared for different ecosystems rather than the GPP?

By measuring the increase in _________________________________________or the decrease in the _______________________

__________________________________________________________________________________

NPP can be measured _______________________ ____________. GPP cannot __________________.

Estimated Annual Average NPP in Major Life Zones and Ecosystems

Figure 3-16

Nutrient CyclesNutrient cycles (= biogeochemical cycles): natural processes that involve the flow of nutrients from the nonliving environment (air, water, soil, rock) to living organisms (biota) & back again.

Fig. 4–6

Nutrient cycles involve one–way flow of high–quality energy from the sun through the environment & recycling of crucial elements.

Major Locations (Reservoirs) of Nutrientshydrologic – involving flows through the hydrosphere, in the form

of liquid water, compounds dissolved in water, & sediments carried by water.

atmospheric –involving flows through the atmosphere, as gases or airborne particles (particulates).

sedimentary (lithospheric)–involving flows through the lithosphere (Earth's crust = soil & rock), as solid minerals.

Water CycleMain 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).infiltration: movement _____________ soil.percolation: downward flow ______________ soil to aquifers.flow in aquifers: below ground flow of water._____________: surface flow downslope to ocean.

Review with your table partner:What are the similarities and differences between evaporation and transpiration?

Put the following terms in the correct order that they would occur: Percolation, Precipitation, Infiltration.

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)

http://techalive.mtu.edu/meec/module01/Transpiration.htm

Water CycleRole of Water:

terrestrial ecosystems – major factor determining _____________ ________________________

aquatic ecosystems – literally __________ that surrounds & serves as environment of aquatic organisms

flows of water are major means material & __________ transportwater is critical for human activities – agriculture, industry, &

municipal use

Human Influences:_____________ large quantities of fresh water – water diversion,

groundwater depletion, wetland drainage

clear ________________ – increase runoff, decrease infiltration & groundwater recharge, increase flooding & soil erosion

modify water __________ – add nutrients (P, N…) and/or pollutants

Carbon CycleRole of Carbon:

building block of ________________ (carbohydrates, fats, proteins, & nucleic acid) – essential to life

currency of __________________ – chemical energy for life stored as bonds in organic compounds

carbon dioxide (CO2) is a _____________________– traps heat near Earth's surface & plays a key role as "nature's thermostat“

Carbon Cycle Processes

photosynthesis ( = carbon ___________) moves C from ______________ to ________________________ (C,H,O compounds) in organisms;

movement through food web: C movement in organic form from organism to _______________;

movement between oceans and atmosphere: uptake and release from oceans

aerobic respiration: organic molecules broken down to release _________ back to atmosphere;

Carbon Cycle Processes Cont.movement to sediments and rock: C forms CaCO3 through biological processes (______ __________ 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)combustion: organic molecules broken down by _____________ to release CO2 back to atmosphere;

Limestone

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), and _______________ (not shown).

(Photosynthesis)

Rock formation

Fossil fuel formation

(Combustion)

Review with your table partner:

What are two ways that humans are shifting the carbon cycle to increase the amount of carbon found in the atmosphere (CO2) rather than stored in organic (carbon-containing) molecules?

Human Influences to Carbon Cycle:

Nitrogen Cycle• Nitrogen (N2) is the most common gas

in the atmosphere (78%).• However, most organisms cannot

utilize N2 (don’t have the enzymes to break the triple bond)

• Nitrogen is needed by all living things. N is part of _________ and protein.

• ___________ Nutrient in many ecosystems: typically addition of N in fertilizers leads to increased productivity

Nitrogen Cycle Processes

nitrogen _____________: conversion of N2 (nitrogen gas) to NH4

+ (ammonium),

Performed by bacteria & blue-green algae (anaerobic),

e.g., Rhizobium in nodules on roots of legumes;

N2 is also fixed by lightning

nitrification: conversion of NH4+ to NO2

-

(nitrite) and to NO3-(nitrate) by

_____________; (Oxidation process)

___________ of NO3 by plants, forms proteins and other N containing organic compounds, enters ______________;

Nitrogen Cycle Processes Cont.ammonification: decomposers return nitrate to Ammonium (NH4

+) by saprophytes and ________________denitrification: conversion of NH4

+ to N2by combustion or microbes. Conversion of NOx to N2 by bacteria (reduction process)

Nitrogen Cycle

Fig. 5–6

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

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?

________________________- produce usable ammonium compounds (in soil or legume nodules)____________________-produce usable nitrate compounds_____________________-cycle nitrogen back to the atmosphere (N2)

Inorganic Fertilizers

During WWII, Fritz Haber developed process to convert atmospheric nitrogen into ammonia to make inorganic nitrate __________________.(Process happens at high temperatures, whichconsumes a lot of ________.)

Revolutionized farming:increasing yields. Part of the _______________________

http://www.youtube.com/watch?v=tdEE5uvFhOM

Human Influences on the Nitrogen Cycle• emit nitric oxide (NO), which

leads to ______________ and acid rain;

• emit nitrous oxide into the atmosphere – nitrous oxide (N2O) is a potent greenhouse gas & also depletes _______ in stratosphere

• Use of nitrogen fertilizers which leads to ___________ of water bodies

Beijing

• Can be limiting factor for growth• No ____________ component of cycle

Phosphorous Cycle

• Occurs in the form PO4)

• Released from rocks by ___________ (slow process)

• Needed by all living things for:_____, ______, Phospholipids

_________ large quantities for fertilizers and detergentsCutting down __________ reduces available phosphateAdd excess phosphate to aquatic systems from ____________ feedlots, runoff from farmland, and sewage discharges

Human Influences of Phosphorous Cycle:

Definition:

Process:

EndResult:

Addition of excess ____________ (usually phosphorous or nitrogen to a water body due to ____________________________

- Nutrients cause an overgrowth of _______. - Algae block light and start to die.- _________________ use up oxygen as they break down dead algae.

(Note it is the decomposition that uses up oxygen- algae themselves are photosynthetic.)

Low oxygen levels can kill fish_________ = low oxygen _______ = no oxygen

Eutrophication

Sulfur Cycle

• Sulfur compounds are found in rocks, soil and fossil fuels (esp. ________)• Sulfur is required by all living things (2 amino acids contain sulfur)• Sulfur is found in the ______________ as sulfur dioxide (SO2) and sulfuric

acid (H2SO4)

Sulfur CycleHuman Influences:• Fossil fuel burning

(especially coal)• ____________ (refining of

metal ores)—releases SOxto atmosphere

• Sulfur compounds in the atmosphere cause ______ ______

Smelting

Coal Plant

Acid Rain Damage