Chapter 3

Ecology: Ecosystems

User: Mikala14/Wikimedia Commons/CC BY-SA3.0

a) Biosphere

b) Ecosystem

c) Communities

d) Populations

e) Organisms

Ecology = study of living things, their distribution, and their interactions with one another and their non-living environment.

> connections in nature> can look at different levels (hierarchy or

organization of life)

Which of the following levels include interactions of organisms of the same species?

Of different species?

Of biotic and abiotic factors?

1. Atmopshere> Troposphere (17-48 km, most of planet's air)> Stratosphere (ozone)> Mesosphere> Thermosphere> Exosphere

Four Spheres

http://www.isws.illinois.edu/nitro/biggraph.asp

2. Hydrosphere: Water> liquid water> ice (polar ice, icebergs, permafrost)> water vapor

Four Spheres

http://www.isws.illinois.edu/nitro/biggraph.asp

3. Lithosphere: Solid parts of the earth (part of Geosphere)> crust and upper mantle> fossil fuels and minerals> soils

Four Spheres

http://www.isws.illinois.edu/nitro/biggraph.asp

Lithosphere

1. Biosphere: All of the ecosystems> global ecosystem> all ecosystems are linked to one another> Example: terrestrial ecosystems are connected by

flow of water and migrating animals.

Four Spheres

http://www.isws.illinois.edu/nitro/biggraph.asp

Aquatic life zonesDivide aquatic parts of the biosophere into aquatic life zones.

BiomesDivide terrestrial parts of biosphere into biomes.

=Regions characterized by distinct climates and vegetation.

1. Biosphere: All of the ecosystems> global ecosystem> all ecosystems are linked to one another> Example: terrestrial ecosystems are connected by

flow of water and migrating animals.

Four Spheres

http://www.isws.illinois.edu/nitro/biggraph.asp

Biodiversity = diversity of living things found in the natural world.• Genetic diversity• Ecological diversity• Species diversity• Functional diversity

5 causes of species decline: HIPPO

H-Habitat destruction/degradation

I-invasive species

P-Pollution

P-human population growth

O-over exploitation

Why should we care?

-Natural services

-Natural resources

What are 3 ways that the various spheres interact?

Four Spheres

http://www.isws.illinois.edu/nitro/biggraph.asp

3 factors required for life on Earth

1. Flow of high-quality energy2. cycling of matter/nutrients3. gravity

Where does this "high-quality" energy come from?

Solar EnergyEnergy from sun reaches Earth as electromagnetic waves.

http://science-edu.larc.nasa.gov/EDDOCS/radiation_facts.html

Energy from sun is needed:• to warm atmosphere• for photosynthesis• for cycling of matter (most directly, water)• to drive climate and weather systems (distributes heat

and freshwater--winds, ocean currents)

Energy from Sun reaching Earth = Heat energy Earth reflects or radiates back into space. Why must this be true?

80% of energy that reaches earth warms troposphere and drives water cycle.

1% generates winds

0.1% photosynthesis

Is the greenhouse effect "bad"? Why or why not?

Greenhouse effectWarms the Earth's atmosphere.

Solar radiation absorbed by Earth's surface and is re-radiated out as infrared radiation (longer wavelength).

Infrared radiation is absorbed by greenhouse gases (H2O, CO2, CH4, NO, O3).

Environmental Factors

Biotic v. Abiotic factors

Think of a terrestrial ecosystem. List 3 biotic and 3 aboitic factors.

Biotic Factors Abiotic Factors

Organisms are adapted to specific environmental factors. (i.e. temperature, precipitation)Optimum: level at which organisms grow or survive the most (can be a range)

Range of Tolerance: entire range that allows any growth or survival

Limits of tolerance: high/low ends of range of tolerance.

Zones of stress: Between range of tolerance and optimum

http://www.ic.ucsc.edu/~wxcheng/envs23/lecture8/ecosystem.htm

Organisms are adapted to specific environmental factors.Limits a species' distribution or range: where we can find a species

http://www.ic.ucsc.edu/~wxcheng/envs23/lecture8/ecosystem.htm

Habitat v. NicheEven if many different species occupy the same habitat, competition may be slight or nonexistent. Why?

Limiting FactorA factor that limits growth.

Examples: Sunlight, specific nutrients, water, DOC, salinity.

Limiting factor principle or law of limiting factors or Leibig's Law of the Minimum states that: too much or too little of any one abioitic factor can limit or prevent growth.

Remember the two laws of thermodynamics

first law of thermodynamics: Energy cannot be created or destroyed. It can only be transformed from one form to another

second law of thermodynamics: when energy changes from one form to another, some of the usable energy is lost as as lower-quality energy (heat).

EnergyEnergy can be either categorized as:

kinetic energy: energy in action or motion

Examples: light, heat, physical motion, electrical current.

potential energy: energy in storage

Examples: chemical energy, a stretched rubber band.

Energy Flow and Matter Recycling In EcosystemsTrophic levels

Producers (autotrophs)-photosynthesis

Consumers (heterotrophs)

Primary consumers ( )

Secondary consumers ( )

Tertiary consumers

Omnivores

Decomposers

Detritivores

How do consumers use the energy stored in the foods they eat?

Aerobic respiration

Anaerobic respiration (fermentation)

On your paper, please draw a food chain involving a producer, a primary consumer, and a secondary consumer.

Now add another secondary consumer, a decomposer, and a scavenger to create a food web.

Energy flows through the ecosystem as organisms eat and extract energy from the food.

How does matter get recycled? What types of organisms are crucial to matter recycling?

Energy Flow and Matter Recycling In EcosystemsTrophic levels

Producers (autotrophs)-photosynthesis

Consumers (heterotrophs)

Primary consumers ( )

Secondary consumers ( )

Tertiary consumers

Omnivores

Decomposers

Detritivores *eats organic waste and parts of dead and/or decaying organisms. Examples: Worms, termites

Scavengers *eat dead organisms. Examples: Vultures, ants

PyramidsGraphical models of the quantitative difference between trophic levels.

Different pyramids provide different information:

Pyramid of numbers: Shows you the number of organisms at each trophic level. It usually takes a large number of producers (at the bottom) to feed the consumers. Exceptions:

http://www.bbc.co.uk/schools/gcsebitesize/science/add_gateway_pre_2011/

greenworld/energyflowrev1.shtmlhttp://www.bbc.co.uk/schools/gcsebitesize/science/add_gateway_pre_2011/

greenworld/energyflowrev1.shtml

About 10% of the energy contained in one trophic level is incorporated into the bodies of the next trophic level.

http://www.bbc.co.uk/schools/gcsebitesize/science/add_gateway_pre_2011/

greenworld/energyflowrev1.shtml

http://www.bbc.co.uk/schools/gcsebitesize/science/add_gateway_pre_2011/

greenworld/energyflowrev1.shtml

PyramidsPyramid of Biomass: Shows you the amount of biomass available at each trophic level. Biomass = dry mass of living organisms. (How would you calculate the biomass at each trophic level?)

More accurate indication of how much energy is passed on at each trophic level.

The biomass in each trophic level is less than the trophic level below it. Why?

*In aquatic ecosystem, the pyramid of biomass is often inverted due to the high turnover rate of lower trophic level organisms.

PyramidsPyramid of productivity: Shows the energy flow through trophic levels by showing production of biomass at each trophic level.

Takes into account productivity over time.

Illustrates ecological efficiency.

Ecological efficiency: percentage of usable energy transferred as biomass from one trophic level to the next.

What happens to the ~90% of the energy at each trophic level as it is transferred to the next trophic level?

1) Much of mass of preceding trophic level is not consumed. (Death, decay)

2) What is consumed is used as energy to fuel cells/tissues. (Respiration, lost as heat)

3) Some of what is consumed is undigested (feces).

Only~ 10% of the energy is incorporated into the biomass of the next trophic level. (growth and reproduction)

GPP and NPPIt is important to understand the rate at which an ecosystem's producers convert solar energy into chemical energy (as biomass).

The total amount of productivity in a ecosystem is the gross primary productivity (GPP).

Plants also respire (R). The net primary productivity (NPP)= GPP - R. This translates into how fast producers can provide food for consumers.

*NPP limits the number of consumers.

SoilA thin covering over most land that is a mixture of eroded rock, mineral nutrients, decaying organic matter, water, air, and microorganisms (yeay!)

Formation of soil:

1) weathering of bedrock

-Physical

-Chemical

-Biological

2) Addition of decaying organic matter

-Lichen

-succession!

Ecological services provided by soil

Retains and delivers nutrients and water for producers.

Water purification. Water percolates through soil. (Gravity!)

Physical support for plants.

Decompose and recycle biodegradable wastes. (Nutrient cycling)

Water storage.

Removes CO2 from atmosphere, stores as organic C compounds.

Mature soils are arranged in soil horizons

-Horizontal layers

-Soil profile is a cross-section of horizons.

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Soil Profile

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O/A horizon contains most or organic matter. For "healthy" O/A horizon, want plant roots to anchor to store water and release as needed.

*Contains microorganisms (bacteria fungi), earthworms, insects

*decomposers -->break down organic compounds. Make inorganic compounds available to plants.

B/C horizon contains most of inorganic matter

Other soil fun facts:• Spaces/pores between particles contain air (nitrogen

and oxygen) and water. Why do plants need oxygen?• Infiltration = movement of water into the soil

surface• Percolation =downward movement of water

through soil matrix.> leaching = infiltration dissolves minerals and

organic matter, carries to lower layers• Soil is a mixture of 3 kinds of particles:

1. clay (very small) --> sticky2. silt (medium) --> smooth, like flour3. sand (large) --> Gritty> Determines soil texture> Loam is ideal soil for plant growth. Mixture of

all three--crumbly, spongy, with clumps of particles.

Biotic v. Abiotic

Abiotic = SWATS

Sunlight

Water

Air

Temperature

Soil*

Ecological footprint

1) environmental impact of individuals in a given country or area

2) amount of biologically productive land and water USED (your book uses needed) to supply an area with resources and to absorb the wastes and pollution produced by such resource use

3) amount of land and water area required to sustain your consumption pattern

4) measure of human demand on Earth's ecosystem

*standardized measure of demand for natural capital

http://www.isws.illinois.edu/nitro/areas.asp

Biosphere-global ecosystem where all life is interconnected

> ecosystem = community of different species interacting with one another and non-living environment.

-all living things

-all living things and factors

needed to sustain life

Image Referenceshttp://en.wikipedia.org/wiki/Biological_organization

http://en.wikipedia.org/wiki/File:Profil_glebowy.jpg