what are they and how do they work?

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Objective(s): SWBAT summarize each level of organization from atom to the biosphere. SWBAT summarize the components of an ecosystem. SWBAT describe how energy flows through ecosystems. SWBAT summarize Earth’s life support systems and the three interconnected factors that sustain life. SWBAT compare and contrast Photosynthesis and Respiration, including providing the balanced chemical equation.

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Chapter 3 Ecosystems:What are they and how do they work?

Objective(s): SWBAT summarize each level of organization

from atom to the biosphere. SWBAT summarize the components of an

ecosystem. SWBAT describe how energy flows through

ecosystems. SWBAT summarize Earth’s life support

systems and the three interconnected factors that sustain life.

SWBAT compare and contrast Photosynthesis and Respiration, including providing the balanced chemical equation.

Objective(s):SWBAT diagram and discuss food chains

and food webs.SWBAT explain how Carbon, Nitrogen, and

Phosphorus cycle within ecosystems.SWBAT describe what happens when

Nitrogen and Phosphorus are in excess in ecosystems.

SWBAT summarize the intermediate disturbance hypothesis.

3-1 What is Ecology? Concept 3-1: Ecology is the study of how

organisms interact with one another and with their physical environment of matter and energy.

Review

Review

Chapter 3: Ecosystem

Chapter 3: Ecosystems Ecosystem: a particular location on Earth

distinguished by its particular mix of interacting biotic and abiotic components.

Chapter 3: Ecosystems

Chapter 3: Ecosystems

Chapter 3: Ecosystems Biotic Components: living components of an

ecosystem. (bacteria, fungus, plants, animals) Abiotic Components: nonliving components

of an ecosystem; determines which organisms can live there. (sunlight, temperature, precipitation, pH, soil, nutrient availability)

Chapter 3: Ecosystems Components of an ecosystem are highly

dependent on climate.

Chapter 3: Ecosystem Ecology Some ecosystems, such as a caves and lakes

have very distinctive boundaries. However, in most ecosystems it is difficult to determine where one ecosystems stops and the next begins.

Chapter 3: Ecosystem Ecology

3-2 What Keeps Us and Other Organisms Alive? Concept 3-2: Life is sustained by the flow

of energy from the sun through the biosphere, the cycling of nutrients within the biosphere, and gravity.

Earth’s Life-Support System

Earth’s Life-Support System

Earth’s Life-Support System

Earth’s Life-Support System

Biomes Terrestrial regions inhabited by certain types

of life, especially vegetation.

Fig. 3-7, p. 55

Average annual precipitation100–125 cm (40–50 in.)75–100 cm (30–40 in.)50–75 cm (20–30 in.)25–50 cm (10–20 in.)below 25 cm (0–10 in.)

AppalachianMountains

Coastal mountainranges

Sierra Nevada

Great American

Desert

RockyMountains

GreatPlains

MississippiRiver Valley

Deciduous forestCoastal chaparraland scrub

Coniferous forest Desert Coniferous forest Prairie grassland

San Francisco

BaltimoreDenver

St. Louis

Three Factors Sustain Life on EarthOne-way flow of high-quality energy: 1st

and 2nd Law of Thermodynamics governs this.

Cycling of matter and nutrients: fixed supply of nutrients needs to constantly be recycled.

Gravity: allows planet to hold onto to atmosphere

3-3 What are the major components of an Ecosystem?

Concept 3-3A: Ecosystems contain living (biotic) and nonliving (abiotic) components.

Concept 3-3B: Some organisms produce the nutrients they need, others get their nutrients by consuming other organisms, and some recycle nutrients back to producers by decomposing the wastes and remains of organisms.

https://www.youtube.com/watch?v=v6ubvEJ3KGM

3-3 What are the Major Components of an Ecosystem?

Biosphere and its ecosystems include: biotic (living) and abiotic (nonliving) factors.

Each population in an ecosystem has a range of tolerance (range of physical and chemical conditions that must be maintained for a population to stay alive, grow, develop and function normally.

Fig. 3-10, p. 58

Feworganisms

Feworganisms

Noorganisms

Noorganisms

Lower limitof tolerance

Higher limitof tolerance

Abundance of organisms

Zone ofintolerance

Zone ofphysiological

stress

Optimum range

Temperature

Zone ofintolerance

Zone ofphysiological

stress

Low High

Popu

lati

on s

ize

3-3 Major Components of Ecosystems

Trophic Levels – Levels in the feeding structure of organisms. Higher trophic levels consume organisms from lower levels.

Energy Flow through Ecosystems Producers (Autotrophs) – Plants, algae and

other organisms that use the sun’s energy to produce usable forms of energy.

Photosynthesis – process by which autotrophs, like algae and plants, trap energy from the sunlight with chlorophyll and use this energy to convert carbon dioxide and water into simple sugars (glucose). The waste product of this process is oxygen.

www.schooltube.com/video/dc732e59026d90ab949d/

Energy Flow through Ecosystems

In photosynthesis, autotrophs use solar energy, water and carbon dioxide to produce glucose and the waste product, oxygen. Respiration is the opposite of photosynthesis; cells convert glucose and oxygen into energy, carbon dioxide and water.

Energy Flow through Ecosystems Consumers (Heterotrophs) – incapable of

producing their own food and must obtain their energy by consuming other organisms.

Primary Consumers – heterotrophs (herbivores) that consume producers.

Carnivores – heterotrophs that obtain energy by eating other consumers.

Secondary Consumers – Carnivores/Omnivores that eat primary consumers.

Tertiary Consumers – Carnivores/Omnivores that eat secondary consumers.

Energy Flow through Ecosystems Scavengers – Carnivores that consume dead

animals. (ex. Vultures) Detritivores – organisms that specialize in

breaking down dead tissues and waste products in smaller particles. (ex. Dung beetles)

Decomposers – organisms that complete the breakdown process by recycling the nutrients from dead tissues and wastes back into ecosystems. (ex. Fungus and bacteria)

Fig. 3-11, p. 60

Mushroom

Detritus feeders Decomposers

Long-hornedbeetle holes

Time progression Powder broken down bydecomposers into plantnutrients in soil

Bark beetleengraving

Carpenterant galleriesTermite and

carpenterant work Dry rot

fungus

Woodreducedto powder

Fig. 3-12, p. 60

Heat

HeatHeat

Decomposers(bacteria, fungi)

Abiotic chemicals(carbon dioxide,

oxygen, nitrogen,minerals)

Solarenergy

Consumers(herbivores,carnivores)

Producers(plants)

Heat Heat

3-4 What Happens to Energy in an Ecosystem? Concept 3-4A: Energy flows through

ecosystems in food chains and food webs. Concept 3-4B: As energy flows through

ecosystems in food chains and food webs, the amount of chemical energy available to organisms at each succeeding feeding level decreases.

What happens to Energy in an Ecosystem? Food Chain – the sequence of consumption

from producers through all levels of consumers. Food Web - A complex model of how energy

and matter move between trophic levels.

Energy Flows from Ecosystems Most energy and biomass is found at the

producer level and energy and biomass decrease as we move up the pyramid.

Flow of energy between trophic levels helps to determine population sizes of various species within each trophic level.

What are the implications of this on the human diet?

Energy Flows from Ecosystems Not all energy contained in a particular trophic

level is in a usable form. Some parts of plants are not digestible by all consumers and are excreted.

Of the food that is digestible, some fraction of the energy obtained is used to power the consumer’s day-to-day activities (moving, eating, etc) and some is lost as heat.

Ecological Efficiency – the proportion of consumed energy that can be passed from one trophic level to another.

Trophic Pyramid – represents the distribution of biomass among trophic levels.

Fig. 3-15, p. 63

10

Heat

Heat

Heat

Heat

HeatDecomposers

Tertiaryconsumers(human)

Secondaryconsumers(perch)

Primaryconsumers(zooplankton)

Producers(phytoplankton)

Usable energy availableat each trophic level

(in kilocalories)

1,000

10,000

100

Energy Flows from Ecosystems Biomass – the energy in an ecosystem can be

measured in biomass which is the total mass of all living matter in a specific area.

NPP establishes the rate at which biomass is produced over a given amount of time.

Standing Crop – the amount of biomass present in an ecosystem at a particular time; measure the amount of energy in a system at a given time.

Energy Flows from Ecosystem Gross Primary Productivity (GPP) – the measure of

the total amount of solar energy that the producers in an ecosystem capture via photosynthesis over a given amount of time. (does not subtract the energy lost when producers respire)

Net Primary Productivity (NPP) – the energy captured by producers minus the energy that producers respire. Allows us to compare the productivity of different ecosystems.

NPP = GPP – respiration by producers How to derive the GPP of an ecosystem per day within a

given area: CO2 taken up during photosynthesis = CO2 taken up in sunlight + CO2 produced in the dark

The GPP unit is kilograms of Carbon taken up per square meter per day (kg C/m2/day)

Fig. 3-16, p. 64

Swamps and marshesTerrestrial Ecosystems

Open oceanContinental shelf

Lakes and streamsEstuaries

Aquatic EcosystemsExtreme desert

Desert scrubTundra (arctic and alpine)

Temperate grasslandWoodland and shrubland

Agricultural landSavanna

Northern coniferous forestTemperate forest

Tropical rain forest

4,000

Average net primary productivity (kcal/m2/yr)

9,6008,800800 1,600 2,400 8,0007,2003,200 6,4005,6004,800

3-5 What happens to Matter in an Ecosystem?

Concept 3-5: Matter, in the form of nutrients, cycles within and among ecosystems and the biosphere, and human activities are altering these cycles.

Matter Cycles through the Biosphere Biosphere – the region of our planet where life

resides. Matter does not enter or leave the biosphere;

Earth is a closed system with respect to matter. Biogeochemical Cycles – the movement of

matter within and between ecosystems involving biological, geological and chemical processes.

Pools – components that contain matter (air, water, organisms)

Flows – Processes that move matter between pools.

https://www.youtube.com/watch?v=2D7hZpIYlCA

The Hydrologic Cycle

The Carbon Cycle

Carbon is the most important element in

living organisms

and comprises about 20%

of their total body

weight

What Human Activities Alter the Carbon Cycle?

Industrial Revolution Combustion of Fossil Fuels Tree harvesting

Matter Cycles through the Biosphere Macronutrients – the six key elements that

organisms need in relatively large amounts.They are: Nitrogen Phosphorus Potassium Calcium Magnesium Sulfur

Limiting Nutrient – a nutrient required for the growth of an organism but available in a lower quantity than other nutrients. (nitrogen)

The Nitrogen CycleNitrogen is

used to form amino acids and nucleic acids

Nitrogen Cycle: Major Steps

Matter Cycles through the Biosphere Leaching: Nitrate is readily transported through

the soil with water because negatively charged nitrate ions do not bind easily to soil particles, most of which are negatively charged.

Excess Nitrogen: is a limiting factor in most terrestrial ecosystems.

Increases atmospheric nitrogen May alter the distribution or abundance of species in

the disturbed ecosystem

The Phosphorus Cycle

Matter Cycles through the Biosphere Excess Phosphorus: is a limiting nutrient in many

aquatic systems. Increases growth of producers May cause algal blooms

Two major sources of phosphorus in waterways: Fertilizer-containing runoff from agriculture Fertilizer-containing runoff from residential areas Household detergents (previously)

Matter Cycles through the Biosphere Calcium, Magnesium, and Potassium are

macronutrients derived primarily from rocks and decomposed vegetation. All three dissolve as cations in water. Not present in gaseous phase.

Mg2+ and Ca2+ are strongly attracted to soil particles.

K + is weakly attracted to soil particles so it is more susceptible to leaching.

Matter Cycles through the Biosphere Sulfur Cycle: gaseous cycle

Much of earth’s sulfur is stored underground in rocks and minerals

Hydrogen sulfide is released from active volcanoes and by the breakdown of organic matter in bogs, tidal flats and swamps

Sulfur dioxide also comes from volcanoes Sulfur cycles globally through living organisms,

aquatic systems and the atmosphere

Ecosystems respond to disturbance Disturbance: An event caused by physical,

chemical or biological agents that results in changes in the population size or community composition. Natural: hurricanes, tornados, tsunamis, storms,

volcanic eruptions, earthquakes Anthropogenic: human settlements, agriculture, air

pollution, deforestation, removal of mountaintops (mining)

May occur over short time periods and long time scales

Ecosystem respond to disturbance Watershed: All of the land in a given landscape

that drains into a particular stream, river, or wetland.

Hubbard Rock EcosystemResearchers

investigated the effects of clear cutting

and subsequent suppression of plant re-growth. What was

their experimental set-up and their findings?

Ecosystems respond to disturbance Resistance: a measure of how much a

disturbance can affect the flows of energy and matter. High resistance – when a disturbance influences

populations and communities, but has no net effect on the flow of energy and matter

Resilience: the rate at which an ecosystem returns to its original state after a disturbance; often depends on specific interactions of the biochemical cycles and the hydrologic cycle.

Restoration Ecology: a new scientific discipline that is interested in restoring damaged ecosystems.

Ecosystems respond to disturbance Intermediate Disturbance Hypothesis: states

that ecosystems experiencing intermediate levels of disturbance are more diverse than those with high or low disturbance levels. When disturbances are rare there is intense

competition among species When disturbances are frequent population growth

rates must be high enough to prevent species extinction

Ecosystems provide valuable service Instrumental Value: a species has worth as an

instrument or tool. Ex. = lumber, pharmaceuticals Five categories: provisions, regulating services,

support systems, resilience and cultural services. Intrinsic Value: a species has worth

independent any of benefit it may provide to humans. Involves moral value of animal’s life; can not be quantified.

Ecosystem Services: the benefits that human obtain from natural ecosystems.

Ecosystems provide valuable service Provisions: goods that can be used directly by

humans. Ex. = lumber, food crops, medicinal plants

Regulating Services: help to regulate environmental conditions. Ex. = carbon removal

Support Systems: support services that would be costly for humans to generate. Ex. = pollination, water filtration

Resilience: depends on species diversity. Culture Services: cultural or aesthetic benefits

to humans.

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