Dynamic Ecosystems 1 EL: To introduce the unit and define what an ecosystem is

Dynamic Dynamic Ecosystems 1Ecosystems 1

EL: To introduce the unit and define EL: To introduce the unit and define what an ecosystem iswhat an ecosystem is

Key knowledgeKey knowledge

components of ecosystems: communities of living organisms, ecological groupings; ecological niche;

relationships between organisms: feeding including parasite/host, predator/prey, of mutual benefit, including mutualism and symbiosis;

flow of energy: inputs and outputs of the system; productivity; trophic levels and trophic efficiency;

cycling of matter: principle of exchange between living and non-living components of the ecosystem, including inputs and outputs; biogeochemical systems including those of water, carbon, oxygen, nitrogen; bioaccumulation;

population dynamics: carrying capacity of ecosystems; factors affecting distribution and abundance of organisms including birth and death rates, migration;

change to ecosystems over time

– scope and intensity of regular and irregular natural changes; succession

– human activity and the sustainability of ecosystems

– historical practices of indigenous peoples and settlers; techniques for monitoring and maintaining ecosystems.

Key questionsKey questions

What are the components of Australian marine ecosystems and how do they interact?

How does matter and energy flow through the marine ecosystem?

How has the marine ecosystem changed over time and how have humans influenced this?

How do we monitor and maintain ecosystems?

Pre-testPre-test

Complete pre test and hand inComplete pre test and hand in

If you finish early, read page 410 If you finish early, read page 410 “introducing ecosystems” and write “introducing ecosystems” and write YOUR OWN definitionYOUR OWN definition

ActivityActivity

• Order from smallest to largest:

ecosystem, cell, organism, community, population and biosphere

How did you go?How did you go?• Cell: smallest living unit.

• Organism: A single living thing.

• Population: A group of the same species living in the one location at the same time.

• Community: The sum of all the species living in the location at the same time.

• Ecosystem: The sum of all abiotic and biotic factors and their interactions.

• Biosphere: All ecosystems combined

Cell

Organism

Population

Community

Ecosystem

Biosphere

What does environment What does environment mean?mean?

In everyday language ‘environment’ means the space In everyday language ‘environment’ means the space or surroundings in which we live.or surroundings in which we live.

To a ‘Biologist’ environment means the sum of ALL To a ‘Biologist’ environment means the sum of ALL the factors that affect an organism.the factors that affect an organism.

All factors that affect organisms can be All factors that affect organisms can be classified as ABIOTIC or BIOTIC. classified as ABIOTIC or BIOTIC.

Environment = Abiotic + Biotic factorsEnvironment = Abiotic + Biotic factors

What is an ecosystem?What is an ecosystem?

An ecosystem includes the communities of living An ecosystem includes the communities of living organisms in a given region, interacting with each organisms in a given region, interacting with each other, surrounded by non-living factors with which other, surrounded by non-living factors with which they also interact they also interact

An ecosystem consists of a community, its physical An ecosystem consists of a community, its physical surroundings and the physical interactions within surroundings and the physical interactions within and between themand between them

A living part and a non-living part A living part and a non-living part

Abiotic +

Biotic +

Interactions =

ecosystems

Dynamic Dynamic Ecosystems 1bEcosystems 1b

EL: To explore Victorian marine EL: To explore Victorian marine ecosystemsecosystems

Naming ecosystemsNaming ecosystems

Can be named in a variety of waysCan be named in a variety of ways a terrestrial ecosystem can be named in terms of its a terrestrial ecosystem can be named in terms of its

plant community and the growth form and the plant community and the growth form and the structure of its dominant vegetation (e.g. forest)structure of its dominant vegetation (e.g. forest)

naming the dominant flora found by its genus (eg: naming the dominant flora found by its genus (eg: tall open eucalyptus forest).tall open eucalyptus forest).

Marine ecosystemsMarine ecosystems Defined by:Defined by:

Types of plants (e.g. kelp, seagrass)Types of plants (e.g. kelp, seagrass) Tide level Tide level Type of substrate (sandy, muddy, silty Type of substrate (sandy, muddy, silty

or rocky)or rocky)

Types of Victorian marine ecosystems:Types of Victorian marine ecosystems: The coastThe coast Intertidal rocky reefIntertidal rocky reef Subtidal rocky reefSubtidal rocky reef The beach and soft substrateThe beach and soft substrate Seagrass bedsSeagrass beds Pelagic (i.e. open sea)Pelagic (i.e. open sea)

Marine ecosystemsMarine ecosystems

Ecosystem Abiotic factors Biotic factors Interactions between them

The Coast

Intertidal rocky reef

Subtidal rocky reef

Seagrass beds

Beaches and soft substrates

Pelagic

FIRST, COPY THE TABLE BELOW INTO YOUR BOOKS, LEAVING 5 LINES FOR EACH ECOSYSTEM

InstructionsInstructions

In groups of 3-4, go to one of the side benches In groups of 3-4, go to one of the side benches where there is a marine ecosystem picturewhere there is a marine ecosystem picture

Use the information and picture to fill out your Use the information and picture to fill out your tabletable

You have 15 minutes. At the end, we’ll go You have 15 minutes. At the end, we’ll go through each ecosystem and each group will through each ecosystem and each group will help the others to fill out the rest of the tablehelp the others to fill out the rest of the table

The CoastThe Coast

Intertidal Rocky ReefIntertidal Rocky Reef

Subtidal Rocky ReefSubtidal Rocky Reef

Seagrass BedsSeagrass Beds

The BeachThe Beach

PelagicPelagic

Components of Components of ecosystemsecosystems

CommunitiesCommunities SurroundingsSurroundings PopulationsPopulations InteractionsInteractions DiversityDiversity

What is a population?What is a population?

• A group of the A group of the samesame species living in the one species living in the one location at the same time.location at the same time.

• Name one population in the next pictureName one population in the next picture

The BeachThe Beach

What is a communityWhat is a community

A community is made up of populations A community is made up of populations of various organisms living in the same of various organisms living in the same location at the same timelocation at the same time

Name the community in the next pictureName the community in the next picture

Intertidal Rocky ReefIntertidal Rocky Reef

DiversityDiversity

Ecosystems can differ in their diversityEcosystems can differ in their diversity Diversity can be measured considering two Diversity can be measured considering two

factors: factors: - The richness or the number of different species The richness or the number of different species

present in the sample community present in the sample community - The evenness or the relative abundance of different The evenness or the relative abundance of different

species in the sample species in the sample

Which of the marine ecosystems was the most Which of the marine ecosystems was the most diverse and why?diverse and why?

EcologyEcology

the study of the interactions of living the study of the interactions of living things with each other and their physical things with each other and their physical environment environment

Activity/homework – ch Activity/homework – ch 1313

Read pages 409 + 410 and answer quick Read pages 409 + 410 and answer quick check questions 1&2 on page 411check questions 1&2 on page 411

Copy Key ideas on page 411 into your Copy Key ideas on page 411 into your notebooksnotebooks

Read page 411-413 about littoral Read page 411-413 about littoral communities and make an annotated communities and make an annotated diagram summarising the main pointsdiagram summarising the main points

ReflectionReflection

Define your ecosystem, including the Define your ecosystem, including the population, community and diversity. population, community and diversity.


EL: To explore ecological groupings EL: To explore ecological groupings and interactionsand interactions

Ecological GroupsEcological Groups

Although environments can differ vastly Although environments can differ vastly all organisms within an ecosystem all organisms within an ecosystem belong to one of the following groups:belong to one of the following groups: Producer/autotrophProducer/autotroph Consumer/heterotroph (primary, secondary, Consumer/heterotroph (primary, secondary,

tertiary)tertiary) DecomposerDecomposer DetritivoreDetritivore

Producers or Autotrophs Producers or Autotrophs

Producers manufacture organic compounds from Producers manufacture organic compounds from simple inorganic compounds, such as carbon simple inorganic compounds, such as carbon dioxide, using an abiotic energy source such as dioxide, using an abiotic energy source such as sunlight through PHOTSYNTHESISsunlight through PHOTSYNTHESIS

Producers use these organic compounds Producers use these organic compounds themselves for energy and for all other members themselves for energy and for all other members within that ecosystemwithin that ecosystem

What are the producers What are the producers in the marine in the marine environment?environment?

Consumers or Consumers or Heterotrophs Heterotrophs

obtain their energy by eating other organisms obtain their energy by eating other organisms or parts of themor parts of them

All animals are consumers – what are some of All animals are consumers – what are some of the categories ofthe categories ofconsumers?consumers?

Consumer organisms can be sub divided into the following Consumer organisms can be sub divided into the following groups:groups:

HerbivoresHerbivores that eat plants (animals and insects) that eat plants (animals and insects)Carnivores Carnivores that eat animals (living animals and insects)that eat animals (living animals and insects)OmnivoreOmnivores that chow down on both plants and animals s that chow down on both plants and animals such as (most) humans such as (most) humans Detritivores Detritivores that eat decomposing organic matter, such as that eat decomposing organic matter, such as rotting leaves or decaying animal remains, for example rotting leaves or decaying animal remains, for example earthworms, crabs and dung beetles earthworms, crabs and dung beetles

Nb. Detritivores differ from decomposers in that decomposers Nb. Detritivores differ from decomposers in that decomposers first break down the organic matter outside their bodies by first break down the organic matter outside their bodies by releasing enzymes and then they absorb some of the productsreleasing enzymes and then they absorb some of the products

Consumers or Consumers or Heterotrophs Heterotrophs

Australian HerbivoreAustralian Herbivore

Australian CarnivoreAustralian Carnivore

Omnivore (Stupidous Omnivore (Stupidous Americanus)Americanus)

DetrivoreDetrivore

PelagicPelagic

Interactions within Interactions within ecosystemsecosystems

In ecosystems, interactions are continually In ecosystems, interactions are continually occurring:occurring:Between the living community and abiotic Between the living community and abiotic surroundingssurroundingsWithin the abiotic surroundingsWithin the abiotic surroundingsWithin the living communityWithin the living community

Inputs and outputsInputs and outputs

Inputs and outputs?Inputs and outputs?

ActivityActivity

Go outside and choose an ecosystemGo outside and choose an ecosystem

Draw annotated diagram of the biotic Draw annotated diagram of the biotic factors (include inputs and outputs), factors (include inputs and outputs), abiotic factors and the interactions abiotic factors and the interactions between them (try to include at least 10)between them (try to include at least 10)

You have 15 minutesYou have 15 minutes

Interactions within a Interactions within a living communityliving community

Can involve members of the same Can involve members of the same (intraspecific) or other (interspecific) (intraspecific) or other (interspecific) speciesspecies

Can be classified ways such as:Can be classified ways such as:- Competition (page 421-22, 433)Competition (page 421-22, 433)- Predator- prey/Herbivore-plant (page 422-425)Predator- prey/Herbivore-plant (page 422-425)- Parasite-host (page 425-430)Parasite-host (page 425-430)- Mutualism (page 430-31)Mutualism (page 430-31)- Commensalism (page 431-432)Commensalism (page 431-432)

ActivityActivity

In four groups, read the relevant section In four groups, read the relevant section on your topic and come up with a 10 on your topic and come up with a 10 minute interactive lesson on it for the next minute interactive lesson on it for the next class (you’ll get 20 mins at the start of class (you’ll get 20 mins at the start of next class to finalise it)next class to finalise it) It can involved some multimedia (no more It can involved some multimedia (no more

than 3 minutes)than 3 minutes) It should use egs from the marine It should use egs from the marine

environment to demonstrateenvironment to demonstrate

HomeworkHomework

Read pages 415-418Read pages 415-418

Copy down key ideas on page 418Copy down key ideas on page 418

Complete quick check questions on 419Complete quick check questions on 419


Name your inputs and outputs and two Name your inputs and outputs and two other ways you interact with the biotic or other ways you interact with the biotic or abiotic factors in your ecosystemabiotic factors in your ecosystem


EL: EL: To further explore ecological interactions

ActivityActivity You have 20 minutes to finalise your lesson and You have 20 minutes to finalise your lesson and

10 minutes to present it10 minutes to present it After the lessons, complete the feeding relationships worksheetAfter the lessons, complete the feeding relationships worksheet

After the lessons (or if your group is ready early) After the lessons (or if your group is ready early) and for homework, please:and for homework, please: Copy key ideas pg 433 into your books and complete qu 5&6Copy key ideas pg 433 into your books and complete qu 5&6 Complete biochallenge pg 434 qu 1-3Complete biochallenge pg 434 qu 1-3 Chapter review qu 2-7Chapter review qu 2-7


Which lesson did you enjoy the most and Which lesson did you enjoy the most and why?why?

OROR Were you happy with your groups Were you happy with your groups

lesson? Why/why not?lesson? Why/why not?


EL: EL: To learn about trophic levels and energy flow

A Day in the Life of KrillA Day in the Life of Krill

Read “a day in the life of krill on page 438-440. Use the information to construct a flow chart of the feeding relationships.

Read page 443-446 – add the terms and types of energy in the krill story to your flow chart

Role playRole play

Group of 4Group of 4 Person 1 = grass Person 1 = grass Person 2 = grasshopper Person 2 = grasshopper Person 3 = bird Person 3 = bird Person 4 = cat/sunPerson 4 = cat/sun

Plants capture about 1% of the energy they Plants capture about 1% of the energy they receive from the sunreceive from the sun

Person 1 – get a meter length of paper to Person 1 – get a meter length of paper to represent this as energy that’s been converted represent this as energy that’s been converted to biomassto biomass

The grasshopper consumes the entire plant.The grasshopper consumes the entire plant.

Person 1, pass the energy onto person 2. Person 1, pass the energy onto person 2.

Person 2: drop 60% of the paper as energy was Person 2: drop 60% of the paper as energy was required to find and consume the grass required to find and consume the grass

Question: What processes in this cost energy?Question: What processes in this cost energy?

Person 2: drop 20% of the energy taken from Person 2: drop 20% of the energy taken from the grass, burned while avoiding predators the grass, burned while avoiding predators

Question: What parts of the environment might Question: What parts of the environment might you make use of, in avoiding predators?you make use of, in avoiding predators?

Person 2: An infection by flukes has cost you a Person 2: An infection by flukes has cost you a further 5% of your energy intake.further 5% of your energy intake.

Question: What is the name of the biotic Question: What is the name of the biotic relationship in this case? relationship in this case?

Person 2: 5% of the energy you took from the Person 2: 5% of the energy you took from the grass is spent in reproductive activities. grass is spent in reproductive activities.

Question: What type of energy would be Question: What type of energy would be required?required?

Bad luck person 2! You weren't quite good Bad luck person 2! You weren't quite good enough at avoiding predators. You've been enough at avoiding predators. You've been eaten by a bird - give your remaining energy eaten by a bird - give your remaining energy over to person 3.over to person 3.

Lucky you'd already reproduced!Lucky you'd already reproduced!

Person 3: as a bird you use 50% of your energy Person 3: as a bird you use 50% of your energy to stay warm. to stay warm.

Question: Why does staying warm require Question: Why does staying warm require energy?energy?

Ants rummaging around and scare up insects. Ants rummaging around and scare up insects.

Person 3 - finding and consuming food only Person 3 - finding and consuming food only takes 20% of the energy you took from the takes 20% of the energy you took from the grasshopper.grasshopper.

Question 7: What example of symbiosis is this? Question 7: What example of symbiosis is this? Apart from this, why might food consumption be Apart from this, why might food consumption be less draining for a bird than a grasshopper?less draining for a bird than a grasshopper?

Birds need to care for their offspring while they Birds need to care for their offspring while they mature. Person 3, drop 20% of your energy mature. Person 3, drop 20% of your energy uptake.uptake.

Question: How is this reproduction strategy Question: How is this reproduction strategy different to that of the grasshopper?different to that of the grasshopper?

Bad luck person 3! What goes around comes Bad luck person 3! What goes around comes around. You've been eaten by a cat. around. You've been eaten by a cat.

Pass on your energy to person 4.Pass on your energy to person 4.

Staying warm is draining business. Lose 50% of Staying warm is draining business. Lose 50% of your energy.your energy.

Question: What do we call organisms like birds Question: What do we call organisms like birds and cats that generate their own body heat? and cats that generate their own body heat?

You need to groom yourself carefully to avoid You need to groom yourself carefully to avoid fleas. This takes time; time you aren't eating fleas. This takes time; time you aren't eating birds. Lose 25% of your energy.birds. Lose 25% of your energy.

What percentage remains of the initial solar What percentage remains of the initial solar energy captured by the grass?energy captured by the grass?

Hypothetical: Hypothetical:

If a tertiary consumer was preying on cats, what If a tertiary consumer was preying on cats, what percentage of your initial energy would it receive?percentage of your initial energy would it receive?

If that consumer needed 1% of the initial energy If that consumer needed 1% of the initial energy captured, how many cats would it need to eat? captured, how many cats would it need to eat?

Is this viable?Is this viable?

Homework Homework

Copy key ideas page 446

Quick check qu 446 page 446

Read pages 447-449 and summarise


Were you surprised by the amount of Were you surprised by the amount of energy lost in our role play?energy lost in our role play?


EL: EL: To learn about food chains and webs and demonstrate them with a game!

http://www.youtube.com/watch?v=rJ2oFD9-WVc&feature=related

http://www.youtube.com/watch?v=_B-Cq8qym_w&feature=related

Activity Activity

Food web gameFood web game

ActivityActivity

Use the pictures to construct a marine Use the pictures to construct a marine food web. You can add your own food web. You can add your own drawings in toodrawings in too

Make sure you label each organism with Make sure you label each organism with its trophic levelits trophic level

HomeworkHomework

Read pages 450-52Read pages 450-52

Copy key ideas on pg 452 into your bookCopy key ideas on pg 452 into your book

Quick check qu on pg 452Quick check qu on pg 452


What key knowledge about energy What key knowledge about energy transfers in ecosystems and ecosystem transfers in ecosystems and ecosystem interactions did the game demonstrate?interactions did the game demonstrate?


EL: EL: To learn about ecological pyramids and ecosystem productivity

Organism abundanceOrganism abundance

Take a look at your food web poster from Take a look at your food web poster from yesterday. Next to each organism, write yesterday. Next to each organism, write an estimated number of that organism an estimated number of that organism using terms like “lots”, “few” etcusing terms like “lots”, “few” etc

Which organisms are there more and Which organisms are there more and less of and why?less of and why?

Ecological pyramidsEcological pyramids

Show the number of organisms at each Show the number of organisms at each trophic level (except detritivores and trophic level (except detritivores and decomposers)decomposers) Pyramid of numbers = number of organisms Pyramid of numbers = number of organisms

per unit areaper unit area

Pyramid of numbersPyramid of numbers


Show the number of organisms at each Show the number of organisms at each trophic level (except detritivores and trophic level (except detritivores and decomposers)decomposers) Pyramid of numbers = number of organisms per unit Pyramid of numbers = number of organisms per unit

areaarea

Pyramid of biomass = total dry organic Pyramid of biomass = total dry organic matter of organisms at each trophic level in matter of organisms at each trophic level in a given areaa given area

Pyramid of biomassPyramid of biomass


Show the number of organisms at each Show the number of organisms at each trophic level (except detritivores and trophic level (except detritivores and decomposers)decomposers) Pyramid of numbers = number of organisms per unit areaPyramid of numbers = number of organisms per unit area Pyramid of biomass = total dry organic matter of Pyramid of biomass = total dry organic matter of

organisms at each trophic level in a given areaorganisms at each trophic level in a given area

A A pyramid of energy pyramid of energy shows the amount of shows the amount of energy input to each trophic level in a given area energy input to each trophic level in a given area of an ecosystem over an extended period, often of an ecosystem over an extended period, often one yearone year

Pyramid of energyPyramid of energy

ActivityActivity

Construct a pyramid of numbers for your Construct a pyramid of numbers for your marine food web. Try to then construct a marine food web. Try to then construct a pyramid of biomass or energy.pyramid of biomass or energy.

Complete the food pyramid worksheetComplete the food pyramid worksheet Copy down key ideas on page 454 and Copy down key ideas on page 454 and

complete quick check questionscomplete quick check questions

Ecosystem productivityEcosystem productivity

Productivity = rate of chemical energy Productivity = rate of chemical energy production in an ecosystem, expressed in production in an ecosystem, expressed in “grams or organic matter per square “grams or organic matter per square meter per year”meter per year”

Ecosystem productivityEcosystem productivity List in order from least productive to most List in order from least productive to most

productive:productive: SwampSwamp Desert scrubDesert scrub Temperate grasslandTemperate grassland Temperate forestTemperate forest Tropical forestTropical forest Continental shelfContinental shelf Open oceanOpen ocean Upwelling zonesUpwelling zones Algae beds and coral reefsAlgae beds and coral reefs

Ecosystem productivityEcosystem productivity

Why are some ecosystems more productive than others?Why are some ecosystems more productive than others?

Activity/homeworkActivity/homework

Finish any work not yet finished from Finish any work not yet finished from earlier in the lessonearlier in the lesson

Copy down key ideas on page 457 and Copy down key ideas on page 457 and complete quick check questions on page complete quick check questions on page 458458


Thinking about human population and Thinking about human population and our food production, what shape do you our food production, what shape do you think our pyramid of numbers might take? think our pyramid of numbers might take? Is this sustainable? Is this sustainable?


EL: EL: To understand that unlike energy matter is never lost and needs to be recycled and how to create a matter cycle map.

Matter cyclesMatter cycles

Matter such as carbon, nitrogen, Matter such as carbon, nitrogen, phosphorus, oxygen, hydrogen etc phosphorus, oxygen, hydrogen etc continually cycles through an ecosystem, continually cycles through an ecosystem, and are sometimes found in biotic and are sometimes found in biotic components of the ecosystemcomponents of the ecosystem

Use the information in the example on page Use the information in the example on page 461 to construct a diagram of a carbon cycle461 to construct a diagram of a carbon cycle

Biogeochemical cyclesBiogeochemical cycles

Bio = through living thingsBio = through living things Geo = through geological thingsGeo = through geological things Chemical = C, N, P and HChemical = C, N, P and H22OO

ActivityActivity

In four groups, use the flip cameras to make In four groups, use the flip cameras to make a 2 minute video about the life of a carbon, a 2 minute video about the life of a carbon, nitrogen or phosphorus atom or water nitrogen or phosphorus atom or water moleculemolecule

It must be told from the point of view of the It must be told from the point of view of the atom/molecule and be suitable for a grade 3-atom/molecule and be suitable for a grade 3-4 audience – keep it simple and make it 4 audience – keep it simple and make it engagingengaging


Which video was more suitable to its Which video was more suitable to its target audience and why?target audience and why?


EL: EL: To begin exploring population dynamics.

BioaccumulationBioaccumulation

The progressive The progressive accumulation of non-accumulation of non-biodegradable/persistant biodegradable/persistant chemicals in living chemicals in living organisms, becoming organisms, becoming more concentrated in more concentrated in higher trophic levelshigher trophic levels

http://www.youtube.com/watch?v=052MQM3-tTc

HomeworkHomework

Complete bioaccumulation worksheetComplete bioaccumulation worksheet

Copy key ideas on page 466Copy key ideas on page 466

Complete quick check questions on page Complete quick check questions on page 467 and the biochallenge question467 and the biochallenge question

Figure 15.2 page 472Figure 15.2 page 472

How many populations can you see? How many individuals are there? Would you say this area is species rich?

Why/why not?

Figure 15.4 page 473Figure 15.4 page 473

Where would Australia sit on the graph? number of species: 147 579 147 579 Area: 7 692 024 km7 692 024 km22

Species RichnessSpecies Richness The number of different populations in terrestrial The number of different populations in terrestrial

communities in the same region is related to the communities in the same region is related to the physical size of the available area.physical size of the available area.

The number of different populations in a The number of different populations in a terrestrial area is also related to the latitude or terrestrial area is also related to the latitude or distance from the equator.distance from the equator. As we move from the poles to the equator, in As we move from the poles to the equator, in

general, species richness of general, species richness of terrestrialterrestrial communities communities increases.increases.

ActivityActivity

Copy key ideas and complete quick check questions page 475

Human populationsHuman populations

Think about a population of humans – what are some ways we can describe it?

Look at list on page 475 – did we get them all?

Refer back to figure 15.2 on page 472 – how would you now describe the abundance of the penguins?

Population abundancePopulation abundance

Abundance Abundance or or density density is defined as the is defined as the number of individuals of a given species per number of individuals of a given species per unit area. unit area.

Abundance can also be expressed qualitatively:Abundance can also be expressed qualitatively: scarce or rarescarce or rare infrequentinfrequent frequentfrequent abundantabundant very abundant (see figure 15.9).very abundant (see figure 15.9).

Our population Our population abundanceabundance

How would you describe the year 11 How would you describe the year 11 biology class population abundancebiology class population abundance

Quantitatively?Quantitatively? Qualitatively?Qualitatively?

Activity/HomeworkActivity/Homework

Read pages 476-478 (stop at pop. Read pages 476-478 (stop at pop. distribution)distribution)

Answer the following questions:Answer the following questions: How do we measure population abundance?How do we measure population abundance? Why can’t population abundance be based on Why can’t population abundance be based on

just one sampling period?just one sampling period? Outline 2 reasons why we want to know Outline 2 reasons why we want to know

population abundance.population abundance. Page 497 qu 5Page 497 qu 5


Summarise in one sentence your main Summarise in one sentence your main learning from today.learning from today.


EL: EL: To explore population distribution and population growth.

What is a population What is a population distribution?distribution?

Refers to the spread of members of a Refers to the spread of members of a population over space. population over space.

Populations may have identical densities but Populations may have identical densities but their distributions can differ. their distributions can differ.

What is a population What is a population distribution?distribution?

three populations with identical three populations with identical densities but their horizontal densities but their horizontal distributions differdistributions differ Clumped and uniform distributions are both Clumped and uniform distributions are both

non-random patterns. non-random patterns. The most common pattern observed in The most common pattern observed in

populations is a clumped distribution.populations is a clumped distribution.

Changes in the distribution of Changes in the distribution of populations can occur over time. populations can occur over time.

What type of population What type of population distribution?distribution?


Read page 480 and summarise the Read page 480 and summarise the conditions suitable for the three types of conditions suitable for the three types of population distributionpopulation distribution

Copy key ideas page 481Copy key ideas page 481 Quick check 3-6 page 482Quick check 3-6 page 482 Complete population dynamic worksheetComplete population dynamic worksheet

Population dynamicsPopulation dynamics

Population dynamics deals with changes Population dynamics deals with changes in population size over time. in population size over time.

Models of growth in closed populations Models of growth in closed populations include:include: exponential or unlimited growth modelexponential or unlimited growth model logistic or density-dependent growth model.logistic or density-dependent growth model.

.

Population

Death

Reproduction

EmigrationIm

migr

ation

Exponential growthExponential growth

Exponential growth Exponential growth is the is the unlimited growth of a unlimited growth of a population. population.

This pattern of growth can This pattern of growth can occur for several occur for several generations at least as long generations at least as long as resources are abundantas resources are abundant

Logistic growthLogistic growth

Population growth in the presence of Population growth in the presence of limiting factors follows a pattern that is limiting factors follows a pattern that is termed termed logistic growthlogistic growth, also known , also known as as density-dependent growth.density-dependent growth.

When the population size is well When the population size is well below the carrying capacity (K), the below the carrying capacity (K), the growth of the population is rapid, but growth of the population is rapid, but as the population size approaches as the population size approaches carrying capacity, growth slows and carrying capacity, growth slows and

stopsstops..

How much is too much?

Carrying capacity

The carrying capacity is the maximum population size that a habitat can support in a sustained manner

When you can’t stop increasing.

When you really can’t stop increasing.

We have looked at distribution of animals over space but how about time?

Why is there a lag between the peak in biomass of foxes compared to hares?


Copy key ideas page 492Copy key ideas page 492 Quick check 12-16Quick check 12-16 Read 492-494Read 492-494 Copy key ideas page 495 Copy key ideas page 495 Quick check 17-19Quick check 17-19 BiochallengeBiochallenge Chapter Review qu 2, 3, 6-8, 10Chapter Review qu 2, 3, 6-8, 10


What are 3 key ideas I learnt about What are 3 key ideas I learnt about today?today?

Documents

Dynamic Ecosystems 1 EL: To introduce the unit and define what an ecosystem is