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Tolerance Species Niche Producer Heterotroph Scavenger Carnivore

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Transect Autotroph Sample Population Biotic Interspecific competition omnivore

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DO NOW!! What is acclimation? Describe Liebigs law

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POPULATIONS Ecology 2.5

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Things we will cover... What is a population How to measure a population Characteristics of populations Population growth curves Regulation of a population

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Population... Is a group of individuals of the SAME

species living in one area at a one particular time

Can be big (rainbow trout in Taupo) or small (kiwi on Stewart Island)

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How would you..…?

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Sampling!! Why sample??

Practicalities (time, cost, environment, types of animal)

Samples need to be representative of the whole population (stats!!)

Number of samples and position of samples (random sampling vs systematic

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How many samples? Investigation using Life Study text Pg. 37 Draw table

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Field study methods Provide estimates of populations Method is determined by the organism

being studied and the aim of the work

Most common methods include: point sampling, transect sampling, quadrat sampling and “mark and recapture”

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DO NOW!!! Define population Name four modes of life Refresh your memory of the mark and

recapture pink and green/blue roughy experiment we did last period

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Last Week’s Simulation??

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Sampling methods Mark and Recapture

Used for highly mobile animalsE.g. Air tags, leg bandings

ObservationsUsed for rare animals, look for droppings, teeth

marks and footprints, look for recorded sightings and observed behaviour

Bell bird (example)

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Class DataPair Pink (60) Green/Blue (40)1 56.25 45

2 75 28

3 225 75

4 34.1 45

5 45 28.125

6 56.25 45

7 45 45

8 75 37.5

9 45 32.1

10 45 32

Average

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To Do: On your ‘paper’ read the information in

Biozone and Bayley and do the following for each method

Briefly explain each sampling methodDraw a diagram to assist in rememberingWhat type of organisms is this method best

suited for

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Do Now!! Why is a transect normally used

What are the various ways of sampling populations with a quadrat

TRENDS quadrat

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Important sampling methods Transects: Lines drawn across a habitat. Lines

divided into intervals and at each interval the population is sampled. Often used where the distribution of a species is affected by some environmental factor such as tidal movement on rocky shore

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Quadrats Quadrats: Sampling units that are

placed on the sample area, the organisms in each quadrat are counted. Often used in conjunction with transect line

Direct Count (Purau)Area CoverageQuick estimate (data to be used in

conjunction with a kite diagram)

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TO DO... Go outside and investigate the range of

plant species in the field

IMPORTANT that you know how to do this for the internal investigation

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Review Why sample? Explain how you would use a transect

line and quadrat as part of a sampling method

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POPULATIONS!! What effects population size??

Think about the type of information that is collected to assist in determining size

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Where to next... Population characteristics

Population regulation (abiotic factors n= earthquakes etc... Biotic factors = competition, parasitism etc.. )

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Population Characteristics Population number (size) Density Distribution Age structure Natality rate (birth rate) Mortality rate (death rate) Immigration and emigration

Pg 25-29 bayleyBiozone 278-283

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To Do: The seven characteristics of populations

are on the PP

You are required to use Biozone and Bayley to take notes on each topic

(remember this is for your notes – you will be tested on this information on Monday!)

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I have, who has!!

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Cloze Activity In pairs (without showing each other

your peice of paper) fill out the following paragraph

Facing each other

NO papers should be placed on the desk

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DO NOW!! Without looking at your notes try and

remember the seven characteristics of populations?

Define community

Why might populations have a clumped, random, or uniform distribution?

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Type of DistributionPossible Explanations of Distribution

Clumped patchy distribution of resources

Uniform terrritorial species

Random random distribution of resources

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Population Characteristics Population number (size) Density Distribution Age structure Natality rate (birth rate) Mortality rate (death rate) Immigration and emigration

Pg 25-29 bayleyBiozone 278-283

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Timed Talking In pairs you will discuss all the

information to date from Ecology The first person will speak for 1 min,

second person 45 sec, 3rd person 30 sec, 4th person 15

Topics such as: biological organisation, environment, modes of life, tolerance, ecological niche etc.

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Survivorship curves

Relative Age

Num

ber o

f sur

vivo

rs p

er 1

000

born

1000

500

10050

TYPE 1

TYPE 2

TYPE 3

TYPE 1“late loss”e.g. human

TYPE 2 “constant loss”e.g. hydra

TYPE 3“early loss”e.g. oysters

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Population Growth If a species is introduced into a new

environment, the growth of the population will give a sigmoidal (or s-shaped) growth curve as it comes into balance with the environment

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Population Growth If a species is introduced into a new

environment, the growth of the population will give a sigmoidal (or s-shaped) growth curve as it comes into balance with the environment

COPY the diagram and phase notes into your books

What is the difference between a J, S and double J shaped curve?

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Growth curves – own notes Two types of growth curves:

“J” curve (or exponential curve) “S” curve (or logistic curve)

“J” curve applies to a colonising population that has not reached the environment carrying capacity

“S” curve applies to established populations that have reached the environmental carrying capacity (K)

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Review What is the difference between a J and

S curve in relation to population growth

What is the carrying capacity of an environment?

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Review What is the difference between a J and S curve in

relation to population growth- Shape - Whether carrying capacity has been reached or not

What is the carrying capacity of an environment? (maximum size of population able to be sustained in an environment)

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Starter activity1. Natality

2. Mortality

3. “J” shaped curve

4. Emigration

5. Immigration

6. Survivorship

A. Entry of organisms into a population from outside

B. The fraction of organisms surviving over the life spanof the the organism

C. Death rate

D. Exit of organisms out of a population

E. Birth rate

F. Exponential growth curve of a population that has notmet environmental resistance and has not reachedthe environmental carrying capacity

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Population Regulation Populations are regulated by abiotic and

biotic factors

Abiotic: usually density independent factors

Affect a popuation regardless of its density!! Earthquakes, volcanoes etc.

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Population Regulation Biotic Factors

Refer to living influences on populationsIntraspecific or interspecificDensity dependent (hit harder when

population numbers are high)Usually affect a population in a predictable

fashionExamples: predation, parasitism, natural

wastes, and competition (intraspecific and interspecific)

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TO DO!! - Jigsaw Group of four = HOME GROUP Each member will go to an area of the

classroom and discuss a part of population regulation with others

You will have 20 minutes to fully understand your topic and become the ‘expert’

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To DO!!! On return to your home group each

‘expert’ will have two minutes of uninterrupted talking where they teach the rest of their home group

Following a topic of discussion the rest of the members will take notes then ask the expert for clarification

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Biotic: Parasitism Parasites are organisms that live on or

in a live host organism, using the organism as a food supply

Normally host and parasite exist in equilibrium

(diagram to copy into notes from board – ESA guide)

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Example: Parasitism Fungus Ceratocystis ulmi (Dutch elms

disese) eliminated trees in England. Controlling disease means all infected trees to be destroyed. NZ so far protection measures effective.

Fruit fly – parasite on plants – huge threat to NZ horticultural industry. Intensive trapping system and protection mechanisms in place.

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Biotic: Predation Predators usually remove the young,

old, or unhealthy individuals of a population

We are going to investigate the predator/prey relationship

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Predator/Prey cycles

Snowshoe hare - Lepus americanus

Canada Lynx - Lynx canadensis

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Predator/Prey cycles

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Biotic: Disease A pathogen (disease causing organism)

introduced into a non-resistant population causes an epidemic!!!

Have drastic effects E.g. New strain of flu virus introduced into NZ with

WW1 returning troops

NZ VERY TOUGH quarantine regulations in the world to prevent disease entering country eg. Foot and mouth disease

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Biotic: Toxic wastes Natural toxic wastes limit populations

E.g. Mould Penicillium produces penicillin which kills bacteria

E.g. Alcohol produced by yeast limits yeasts populations

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Biotic: Competition Interspecific competition

Competition for resources between different species

Producers compete for light, water, spaceConsumers compete for space, water,

shelter, breeding sites and food

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Biotic: Competition Intraspecific competition

Competition between members of the same species Increase in numbers results in increased stress as

competition for resources E.g. Food, space

Stress decreases natality rate and increased mortality causing populations to drop. Lowered population – less stress – resources more abundant population rise!!

COPY DIAGRAM from board

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Population size

Emigration Natality (births)

Mortality (deaths)

Imigration

Population Size

Population size is then regulated by the abiotic and biotic factors discussed

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Net growth rate of a population Birth rate – death rate and emigarion

etc.

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TO DO: On a new piece of paper divide it into 6 areas with each

area labelled with one of the following Disease Toxic wastes Competition Predator Prey Parasitism Abiotic factors

For the next 7 minutes in silence each member of the class will record what they can remember about each part of population regulation