Ecology PowerPoint

Ecology and ConservationEcology and Conservation G.1 Ecology of Species G.1 Ecology of Species

Outline the factors that affect Outline the factors that affect the distribution of plant the distribution of plant species including species including temperature, water, light, temperature, water, light, soil pH, salinity and mineral soil pH, salinity and mineral nutrientsnutrients

Explain the factors that effect Explain the factors that effect the distribution of animal the distribution of animal species including species including temperature, water, breeding temperature, water, breeding sites, food supply and sites, food supply and territoryterritory

Investigation on EcologyInvestigation on Ecology What are the possible IV’s ? Will you What are the possible IV’s ? Will you

have a range or 2 conditions? How will have a range or 2 conditions? How will you control and monitor your IV?you control and monitor your IV?

How will you measure your DV?, will How will you measure your DV?, will you sample or count all organisms? What you sample or count all organisms? What are the different techniques?are the different techniques?

Will you work in the field or model Will you work in the field or model conditions in the lab?conditions in the lab?

What is your sample size?What is your sample size? Think about how data analysis affects Think about how data analysis affects

your data collection and methodology.your data collection and methodology.

How abiotic factors affect plant How abiotic factors affect plant distributiondistribution

Different species thrive Different species thrive under different conditions. under different conditions.

Individuals within a Individuals within a population will vary population will vary somewhat and…somewhat and…

Each population has a range Each population has a range of tolerance for any abiotic of tolerance for any abiotic factorfactor

Within this range will be Within this range will be some optimum level and….some optimum level and….

Outside the range few Outside the range few individuals will surviveindividuals will survive

The law of toleranceThe law of tolerance

““The existence, abundance The existence, abundance and distribution of a species and distribution of a species in an ecosystem are in an ecosystem are determined by whether the determined by whether the levels of one or more levels of one or more physical or chemical factors physical or chemical factors fall within the range fall within the range tolerated by that species” tolerated by that species” ((Miller, Living in the Environment, p.104)Miller, Living in the Environment, p.104)

LightLight Solar energy powers almost all Solar energy powers almost all

ecosystemsecosystems Autotrophs need lightAutotrophs need light In terrestrial systems light is In terrestrial systems light is

usually NOT the limiting factor, usually NOT the limiting factor, although plants, trees may although plants, trees may compete for lightcompete for light

In aquatic systems light can only In aquatic systems light can only penetrate so far down: photic penetrate so far down: photic zone, water absorbs more red zone, water absorbs more red light.light.

Light is also important in Light is also important in behavior- organisms can sense the behavior- organisms can sense the relative amounts of day and night- relative amounts of day and night- photoperiod- affects breeding, photoperiod- affects breeding, migration, floweringmigration, flowering

WaterWater Organisms in aquatic Organisms in aquatic

environments must balance environments must balance their internal osmolarity- this their internal osmolarity- this requires some homeostatic requires some homeostatic mechanismmechanism

Terrestrial organisms need Terrestrial organisms need water, some plants have water, some plants have adaptations to low water adaptations to low water (xerophytes)(xerophytes)

Animals also have Animals also have adaptations to low water adaptations to low water environments: camels, small environments: camels, small rodents with very long Loops rodents with very long Loops of Henle, etc.of Henle, etc.

TemperatureTemperature Temperature affects Temperature affects

metabolic reactionsmetabolic reactions Some organisms cannot Some organisms cannot

regulate their internal regulate their internal temperatures: ectothermstemperatures: ectotherms

Endotherms can only Endotherms can only regulate their internal temps regulate their internal temps so much and so cannot live in so much and so cannot live in temp extremestemp extremes

Cells may rupture if below Cells may rupture if below freezingfreezing

Some organisms have Some organisms have adaptations to extreme heat: adaptations to extreme heat: thermophiles, adaptations to thermophiles, adaptations to cold, thick fat layer, furcold, thick fat layer, fur

Temp and water are 2 most important factors in climate

climatograph

pHpH

Organisms have optimal Organisms have optimal pH‘s which differ- ex. pH‘s which differ- ex. Coniferous forest like low Coniferous forest like low pH, the plant pH, the plant AsperulaAsperula likes likes alkaline soil where there is alkaline soil where there is chalk or limestonechalk or limestone

Adaptations allow some Adaptations allow some organisms to live at organisms to live at extremes, other organisms extremes, other organisms are very sensitive- like are very sensitive- like phytoplanktonphytoplankton

SalinitySalinity

Similar to pHSimilar to pH Organisms that can Organisms that can

withstand high salt withstand high salt concentration are called concentration are called halophileshalophiles

MineralsMinerals

Plants need to obtain Plants need to obtain minerals from the soilminerals from the soil

Nitrogen, potassium and Nitrogen, potassium and phosphorous are the phosphorous are the most importantmost important

Breeding SitesBreeding Sites

Animals require certain Animals require certain conditions to breedconditions to breed

If these are not available If these are not available they may not breed they may not breed successfullysuccessfully

Insects may need waterInsects may need water Wetlands are important sites Wetlands are important sites

for birds, destruction of for birds, destruction of these sites can drastically these sites can drastically affect a populationaffect a population

Food supplyFood supply

Animals need a food Animals need a food supply, many animals supply, many animals have very specific have very specific requirements- ex Pandas requirements- ex Pandas will only eat bamboo, will only eat bamboo, whales eat krillwhales eat krill

Other animals can adapt Other animals can adapt to different foods, to different foods, generalist, like humansgeneralist, like humans

TerritoryTerritory

Some animals are Some animals are territorial- they establish territorial- they establish and defend discreet and defend discreet areas. They must be in areas. They must be in their territory to eat or their territory to eat or breed.breed.

Animals will fight to Animals will fight to stay in the territorystay in the territory

Distribution patternsDistribution patterns

ClumpedClumped: some areas : some areas have higher density than have higher density than othersothers

fish swimming in a fish swimming in a group expend less group expend less energy.energy.

May decrease predationMay decrease predation Territoriality will cause Territoriality will cause

this patternthis pattern

Distribution patternsDistribution patterns UniformUniform: organisms are : organisms are

spread out evenlyspread out evenly Plants space out evenly to Plants space out evenly to

maximize light and watermaximize light and water Animals may have Animals may have

uniform distribution as a uniform distribution as a result of aggressive result of aggressive interactionsinteractions

This pattern is less This pattern is less common in naturecommon in nature

Distribution patternsDistribution patterns

RandomRandom: an : an unpredictable patternunpredictable pattern

Happens when there is Happens when there is no strong attraction or no strong attraction or or repulsion among or repulsion among individualsindividuals

The location of one is The location of one is not dependent on not dependent on anotheranother

Most common patternMost common pattern

NicheNiche The species way of life, The species way of life,

functional role, where it functional role, where it lives, what it eats, what eats lives, what it eats, what eats it, what abiotic factors it it, what abiotic factors it requires, how it reproduces, requires, how it reproduces, how it affects living and how it affects living and nonliving things in its nonliving things in its environment.environment.

Niche is based on 3 main Niche is based on 3 main components: components: habitathabitat, , nutritionnutrition and and relationshipsrelationships

NicheNiche What describes a palm What describes a palm

tree’s niche?tree’s niche? An autotroph- provides food An autotroph- provides food

for the animals, humansfor the animals, humans Roots help maintain water Roots help maintain water

tabletable Provides shade for plants Provides shade for plants

and animalsand animals Recycles nutrientsRecycles nutrients Provides habitats for insects Provides habitats for insects

and birdsand birds Provides support for vinesProvides support for vines

NicheNiche

Some aspects of a Some aspects of a species may overlap. species may overlap. The birds on the right The birds on the right inhabit the same tree but inhabit the same tree but have different niches.have different niches.

Two species cannot Two species cannot occupy the same nicheoccupy the same niche

Competitive exclusionCompetitive exclusion

This is the principle that This is the principle that states that 2 species states that 2 species cannot occupy the same cannot occupy the same nicheniche

If 2 species have the If 2 species have the same niche and are in same niche and are in the same environment the same environment they will compete and they will compete and one will win, the other one will win, the other will lose (be excluded)will lose (be excluded)

Fundamental and realized nicheFundamental and realized niche Fundamental nicheFundamental niche is the is the

potential way an organism potential way an organism exists, given the total range exists, given the total range of environmental conditions, of environmental conditions, due adaptations of the due adaptations of the species.species.

Realized nicheRealized niche is the is the ACTUAL way an organisms ACTUAL way an organisms exists, which results from its exists, which results from its adaptations and competitions adaptations and competitions with other specieswith other species

Realized niche is smaller Realized niche is smaller than fundamental nichethan fundamental niche

Biozone 284, Biozone 284, 286,287,288, research 286,287,288, research ONE organism from page ONE organism from page 285 for homework285 for homework

ReviewReview

What are 3 factors that affect distribution of plants?What are 3 factors that affect distribution of plants? What are 3 things that affect distribution of animals?What are 3 things that affect distribution of animals? What is the precautionary principle?What is the precautionary principle? Define niche.Define niche. What is the competitive exclusion principle?What is the competitive exclusion principle? Compare fundamental and realized niche.Compare fundamental and realized niche.

Ecology of CommunitiesEcology of Communities

Interactions between Interactions between species:species:

All organisms are All organisms are affected by interactions affected by interactions with other organisms.with other organisms.

What are some ways What are some ways organisms interact?organisms interact?

CompetitionCompetition If 2 different species are If 2 different species are

competing for the same competing for the same resource this is called resource this is called interspecific competition. The interspecific competition. The growth of one or both will be growth of one or both will be affected.affected.

Because of the competitive Because of the competitive exclusion principle there are 2 exclusion principle there are 2 possible fates when two possible fates when two species occupy the same niche: species occupy the same niche: Either the less successful one Either the less successful one will become extinct or will will become extinct or will evolve enough to use different evolve enough to use different resources.resources.

The differentiation of niches is The differentiation of niches is called resource partitioning.called resource partitioning.

CompetitionCompetition

IntraspecificIntraspecific competition is competition is when organisms of the same when organisms of the same species compete. Two species compete. Two kinds:kinds:

Adapted or programmedAdapted or programmed: : instinctual social behavior instinctual social behavior to maintain hierarchy in the to maintain hierarchy in the populationpopulation

Unadapted or incidentalUnadapted or incidental: : due to scarce resourcedue to scarce resource

HerbivoryHerbivory The consumption of an The consumption of an

autotroph is herbivoryautotroph is herbivory Plants cannot move or defend Plants cannot move or defend

themselves like animals but themselves like animals but they do have some defenses:they do have some defenses:

Spines, thorns, chemicals Spines, thorns, chemicals like strychnine, nicotine, like strychnine, nicotine, bitter tastebitter taste

Animals also have Animals also have adaptations such as sensors adaptations such as sensors to locate food, mouthparts to locate food, mouthparts adapted to shredding tough adapted to shredding tough plants or sucking nectarplants or sucking nectar

PredationPredation

The interaction between The interaction between species when one species species when one species kills and eats the otherkills and eats the other

Predator-prey relationshipPredator-prey relationship Animals have adapted to Animals have adapted to

protect themselves from protect themselves from predators in many ways:predators in many ways:

Camouflage, mechanical Camouflage, mechanical protection, chemical protection, chemical defensesdefenses

SymbiosisSymbiosis

Two or more species Two or more species live together in direct live together in direct contact.contact.

Three types are: Three types are: parasitism, parasitism, commensalism and commensalism and mutualismmutualism

ParasitismParasitism

Interaction where one Interaction where one species lives on another, species lives on another, receiving nutrition from that receiving nutrition from that organism,called the host.organism,called the host.

Parasites often do not kill Parasites often do not kill their host but the their host but the relationship is harmful to relationship is harmful to the hostthe host

Examples: tapeworms in Examples: tapeworms in humans, mistletoe and treeshumans, mistletoe and trees

MutualismMutualism

Both species benefit Both species benefit from the relationshipfrom the relationship

Examples: clown fish Examples: clown fish and anemone, and anemone, leguminous plants and leguminous plants and N-fixing bacteria, honey N-fixing bacteria, honey bee and cloverbee and clover

BiomassBiomass

Biomass is usually based on Biomass is usually based on dry mass.dry mass.

To prepare specimens for To prepare specimens for dry mass you put it into a dry mass you put it into a drying oven for about 14 drying oven for about 14 hours. All the water should hours. All the water should be gone by that point.be gone by that point.

For the most accurate data For the most accurate data you include the entire plant you include the entire plant and all the organisms- this is and all the organisms- this is called the standing crop.called the standing crop.

Alternate methods for measuring Alternate methods for measuring biomassbiomass

Measure the biomass of the sample and Measure the biomass of the sample and extrapolate from that what the biomass of the extrapolate from that what the biomass of the population would be.population would be.

Take samples of target species by cutting at soil Take samples of target species by cutting at soil level. Determine mean mass by multiplying by level. Determine mean mass by multiplying by mean stem densitymean stem density

Alternate methods for measuring Alternate methods for measuring biomassbiomass

Sample the area using a quadrat that is randomly Sample the area using a quadrat that is randomly selectedselected

Determine the mean height of the sampleDetermine the mean height of the sample Multiply the mean height by stem densityMultiply the mean height by stem density This gives an indirect measurement of biomassThis gives an indirect measurement of biomass Some new methods using digital image analysis can Some new methods using digital image analysis can

also be usedalso be used

Random sampling techniquesRandom sampling techniques

Determine the area to be Determine the area to be sampledsampled

Divide it into small areas or Divide it into small areas or quadratsquadrats

Use a random number table Use a random number table to determine which ones to determine which ones you will sampleyou will sample

Throw your quadrat over Throw your quadrat over your back- where it lands, is your back- where it lands, is where you samplewhere you sample

Practical EcologyPractical Ecology

Quadrat: a frame that Quadrat: a frame that forms a known area. It forms a known area. It may be subdivided into may be subdivided into smaller areas.smaller areas.

It can be used to It can be used to measure:measure:

Percentage cover, Percentage cover, density or frequencydensity or frequency

Practical EcologyPractical Ecology

Frequency:Frequency: The chance of finding a The chance of finding a

named organism within named organism within the sample area in a the sample area in a number of quadratsnumber of quadrats

May be expressed as a May be expressed as a percent of the total percent of the total number of quadrats number of quadrats sampledsampled

FrequencyFrequency

Throw the quadrat Throw the quadrat

randomly in the sample arearandomly in the sample area

Record the presence or Record the presence or

absence of a named organism absence of a named organism

within each quadratwithin each quadrat

Repeat for a number of Repeat for a number of

throwsthrows

Tabulate resultsTabulate results

Percent CoverPercent Cover

Use when it is difficult Use when it is difficult to determine individual to determine individual organisms.organisms.

Throw the quadrat Throw the quadrat randomlyrandomly

Determine the area that Determine the area that is covered by the is covered by the organismorganism

Calculate percentageCalculate percentage

DensityDensity

Throw the quadrat randomlyThrow the quadrat randomly Count the number of Count the number of

organisms in the entire organisms in the entire quadat or sample within the quadat or sample within the quadrat randomly (the quadrat randomly (the technique is dependent on technique is dependent on the size of the organism)the size of the organism)

Repeat and determine the Repeat and determine the mean and or total number mean and or total number based on area.based on area.

How many quadrats should you How many quadrats should you do?do?

Each quadrat is like a Each quadrat is like a replicatereplicate

The more you do, the The more you do, the more likely you will more likely you will have reliable resultshave reliable results

Time, size of the area, Time, size of the area, variation in distribution variation in distribution are factors that must be are factors that must be consideredconsidered

TransectTransect Line transect:Line transect:• String a line along the String a line along the

ground from two points. ground from two points. This is usually done where This is usually done where there is some gradation of there is some gradation of an abiotic factor.an abiotic factor.

• Look for presence of target Look for presence of target organism/s at some organism/s at some predetermined interval or predetermined interval or sample continuously.sample continuously.

• Analyze to see if abiotic Analyze to see if abiotic factor affects presence of factor affects presence of organismorganism

TransectTransect

Belt transectBelt transect• Same as line transect, Same as line transect,

except you are sampling except you are sampling some width rather than some width rather than just a point.just a point.

• You can use a small You can use a small quadratquadrat

Biozone 347-358Biozone 347-358

ReviewReview

Discuss relationships between organisms: Predation, Discuss relationships between organisms: Predation, parasitism, mutualism, competition, herbivoryparasitism, mutualism, competition, herbivory

Report on sampling method: describe technique, Report on sampling method: describe technique, report on results, how would you analyze the report on results, how would you analyze the data?,evaluate technique: errors, what type of data?,evaluate technique: errors, what type of organism is best suited to this method, organism is best suited to this method,

G.2 Measuring Production of an G.2 Measuring Production of an ecosystemecosystem

Remember that organisms Remember that organisms are grouped into trophic are grouped into trophic levels depending on their levels depending on their feeding relationshipsfeeding relationships

The trophic level that The trophic level that supports the ecosystem is supports the ecosystem is the first, made up of primary the first, made up of primary producers. (photosynthetic, producers. (photosynthetic, chemosynthetic).chemosynthetic).

In order to measure the In order to measure the production of an ecosystem production of an ecosystem we look at how productive we look at how productive the producers arethe producers are

Measuring Production of an Measuring Production of an ecosystemecosystem

Only a very small part Only a very small part of the energy of the sun of the energy of the sun is converted into is converted into chemical energy in the chemical energy in the plant.plant.

What percentage do you What percentage do you think this is?think this is?

1%1%


Primary ProductionPrimary Production is is the amount of light the amount of light energy converted to energy converted to chemical energy during chemical energy during a given unit of time.a given unit of time.

Gross primary Gross primary productionproduction is the total is the total amount of light E amount of light E converted to chemical E converted to chemical E per unit of time. (GPP)per unit of time. (GPP)


Net production is the GPP minus the energy used by Net production is the GPP minus the energy used by the producers for respiration R.the producers for respiration R.

So NPP=GPP-RSo NPP=GPP-R NPP is a more helpful number than GPP, why?NPP is a more helpful number than GPP, why? In some cases NPP is as little as 25% of GPP- large In some cases NPP is as little as 25% of GPP- large

trees have more respiration expenditures.trees have more respiration expenditures.


Biomass is the energy Biomass is the energy of primary production of primary production per unit area per unit of per unit area per unit of time. (J/m2/yr)time. (J/m2/yr)

Biomass is expressed in Biomass is expressed in terms of the dry mass of terms of the dry mass of organic material.organic material.


Calculations: page 304 Calculations: page 304 and 305 in Biozoneand 305 in Biozone

Trophic LevelsTrophic Levels

Organisms are classified Organisms are classified into trophic levels according into trophic levels according to their feeding relationshipsto their feeding relationships

Producers on the first level, Producers on the first level, primary consumers on the primary consumers on the second, etc.second, etc.

This works well if you are This works well if you are looking at a food chain but looking at a food chain but becomes more difficult becomes more difficult when looking at real when looking at real ecosystems in a food webecosystems in a food web

Trophic LevelsTrophic Levels

As you move up trophic As you move up trophic levels there tend to be levels there tend to be less organisms and less less organisms and less energy, Why?energy, Why?

Some times one Some times one organism, like a tree, organism, like a tree, can support many small can support many small organisms, but energy organisms, but energy always decreasesalways decreases

Pyramid of EnergyPyramid of Energy

Pyramids of energy are Pyramids of energy are a way to show how a way to show how energy moves from one energy moves from one trophic level to the nexttrophic level to the next

Units are in energy/unit Units are in energy/unit area/unit timearea/unit time

Plants: 809 J/m2/yr

Herbivore:37 J/m2/yr

Small carnivore: 11 J/m2/yr

Large fish: 1.5 J/m2/yr

Parasite on fish: 0.01 J/m2/yr

SuccessionSuccession

Ecological succession is Ecological succession is a change in a a change in a community following a community following a disturbancedisturbance

There are two kinds:There are two kinds: Primary: when there are Primary: when there are

no living organismsno living organisms Secondary: some Secondary: some

organisms have organisms have survivedsurvived


The pattern of and The pattern of and causes of re-causes of re-colonization will differ colonization will differ depending on the site depending on the site and the reason for the and the reason for the disruptiondisruption

The species that The species that colonize first will alter colonize first will alter the environment and the environment and make it more hospitable make it more hospitable for future organismsfor future organisms


Research and describe Research and describe one actual example of one actual example of ecological successionecological succession


What are some of the most What are some of the most common changes to an common changes to an ecosystem during ecosystem during succession?succession?

Amount of organic material Amount of organic material increases. As plants and increases. As plants and animals die, they contribute animals die, they contribute to the organic component of to the organic component of the soil. Decomposers break the soil. Decomposers break this material down and this material down and recycle nutrientsrecycle nutrients

•Soil becomes deeper

•Soil structure improves, increasing water retention

•Soil erosion decreases

•Amounts of nutrients increase

•Diversity of organisms increases and types of organinisms will probably change


Initially: Bare Ground No plant competition for light,

space, nutrients or water. Soil mobile and liable to erosion

and loss. A more extreme surface

microclimate because the bare soil both absorbs and reflects heat more than soil covered in vegetation.

A drier environment because there is no plant cover to hold moisture above ground and little humus to hold it in the soil.

Lower nutrient levels in the soil.

Two Years Later

Intense plant competition for space and other resources.Soil bound by roots and plant cover.The plant cover provides a certain amount of ground insulation from extremes of temperature. There are now also a variety of microclimates within the vegetation.Plant cover and increasing humus levels help to retain water.The nutrient levels in the soil will have increased.

How do living things affect the How do living things affect the abiotic environment?abiotic environment?

How can biotic factors How can biotic factors affect water?affect water?

Trees and other plants Trees and other plants hold water in the hold water in the soil,and reduce soil soil,and reduce soil erosion.erosion.

deforestation causes deforestation causes desertificationdesertification


TemperatureTemperature Living things generate Living things generate

heat as a byproduct so heat as a byproduct so temperature can be temperature can be affectedaffected

Phytoplankton can Phytoplankton can cause localized cause localized increases in increases in temperatures of aquatic temperatures of aquatic systemssystems


Carbon dioxide and Carbon dioxide and oxygen levels are oxygen levels are affected by organismsaffected by organisms

Amount of nutrients in Amount of nutrients in soil are affected by soil are affected by decomposition of decomposition of organic matter, this will organic matter, this will also affect the quality of also affect the quality of the soil as seen in the soil as seen in succession.succession.

Biomes and BiosphereBiomes and Biosphere

G.2.9 Distinguish G.2.9 Distinguish between biome and between biome and biosphere. biosphere.

Biome = Communities Biome = Communities on earth that contain on earth that contain similar plant and similar plant and animal inhabitants animal inhabitants

Biosphere = part of Biosphere = part of Earth that can contain Earth that can contain life (incl: atmosphere)life (incl: atmosphere)

Abiotic factors and distribution Abiotic factors and distribution of biomesof biomes

What abiotic factors What abiotic factors most affect the most affect the distribution of biomes?distribution of biomes?

Temperature and Temperature and rainfallrainfall

Climatograph is a graph of rainfall and temperature

BiomesBiomes

Outline the characteristics of six major biomes.Outline the characteristics of six major biomes. Characteristics: temperature, moisture, characteristics Characteristics: temperature, moisture, characteristics

of vegetation.of vegetation. Biomes: desert, grassland, shrubland (chaparral, Biomes: desert, grassland, shrubland (chaparral,

matorral, marquis, garigue, dry heathlands, fynbos), matorral, marquis, garigue, dry heathlands, fynbos), temperate deciduous forest, tropical rainforest, tundratemperate deciduous forest, tropical rainforest, tundra

Example: ChaparralExample: Chaparral Found between 32 and 40

degrees latitude on the West Coast of continents.

Dry climate Precipitation is mainly in

winter Annual rainfall 300 to 750

mm in 2-4 month period. Plants: olive,shrub oak,

maritime pine, eucalyptus Many plants have thorns

ChaparralChaparral

G.3 Biodiversity and G.3 Biodiversity and ConservationConservation

Discuss reasons for the Discuss reasons for the conservation of biodiversity conservation of biodiversity using rainforests as an exampleusing rainforests as an example

EthicalEthical EcologicalEcological EconomicEconomic AestheticAesthetic Give an account including a Give an account including a

range of arguments, range of arguments, assessments of the relative assessments of the relative importance of various factors importance of various factors or comparisons of alternate or comparisons of alternate hypotheseshypotheses


Extinction of species: Extinction of species: Almost a quarter of the

world's mammals face extinction within 30 years, according to a United Nations report on the state of the global environment.

One in eight bird species is also in danger of extinction, and more than 5,000 different plants.

over 99 percent of the species that ever walked on Earth no longer exist.

There is virtual unanimity among scientists that we have entered a period of mass extinction not seen since the age of the dinosaurs, an emerging global crisis that could have disastrous effects on our future food supplies, our search for new medicines, and on the water we drink and the air we breathe. Estimates vary, but extinction is figured by experts to be taking place between 100 to 1,000 times higher than natural "background" extinction.


What is causing this What is causing this acceleration of extinctions?acceleration of extinctions?

Introduction of invasive Introduction of invasive species. These new speicies species. These new speicies may be parasites, predators, may be parasites, predators, compete for food, habitat. compete for food, habitat. Often species are brought Often species are brought into an ecosystem to control into an ecosystem to control some unwanted organism some unwanted organism but the long term affects are but the long term affects are hard to predict.hard to predict.

The zebra mussel, accidentally brought to the United States from southern Russia, transforms aquatic habitats by consuming plankton and settling in dense masses over vast areas. At least thirty freshwater mussel species are threatened with extinction by the zebra mussel.


Habitat destructionHabitat destruction Humans destroy Humans destroy

habitats of organisms habitats of organisms when land is cleared for when land is cleared for agriculture, buildings, agriculture, buildings, roads, cutting forests, roads, cutting forests, etc.etc.


Hunting, overfishingHunting, overfishing


PollutionPollution The Artic Char is a type of The Artic Char is a type of

trout found in Lakes in trout found in Lakes in IrelandIreland

In The early 1980s these In The early 1980s these fish were plentifulfish were plentiful

By 1990, the Char had gone By 1990, the Char had gone extinct, due to pollution of extinct, due to pollution of lakes with fertilizers and lakes with fertilizers and other agricultural run off.other agricultural run off.



Magnolias are one of the Magnolias are one of the oldest flowering plants on oldest flowering plants on earth. Several species are earth. Several species are endangered due to habitat endangered due to habitat loss, clearing land for coffee loss, clearing land for coffee growing, deforestationgrowing, deforestation

Magnolia sinica grows in Magnolia sinica grows in China. There is only 1 China. There is only 1 population of 10 trees left.population of 10 trees left.


Simpsons Diversity IndexSimpsons Diversity Index Simpson's Diversity

Index(actually your syllabus uses the SI reciprocal)l is a measure of diversity. In ecology, it is often used to quantify the biodiversity of a habitat. It takes into account the number of species present, as well as the abundance of each species.


The value of this index starts with 1 as the lowest possible figure. This figure would represent a community containing only one species. The higher the value, the greater the diversity. The maximum value is the number of species (or other category being used) in the sample. For example if there are five species in the sample, then the maximum value is 5.

D= diversity index N= total number of organisms of ALL

species found n= number of individuals of a particular

species High D suggests a stable, ancient site and

low D suggests pollution, recent colonization or agricultural management


Species Number (n) n(n-1) Woodrush 2 2 Holly (seedlings) 8 56 Bramble 1 0 Yorkshire Fog 1 0 Sedge 3 6

Calculate D

N= 15

Sum of n(n-1)= 64

So the reciprocal of 64/210

D= 3.3


How would you collect How would you collect data to determine data to determine diversity in a particular diversity in a particular location?location?


Biotic Index is a way to Biotic Index is a way to determine if an determine if an ecosystem is polluted by ecosystem is polluted by looking at the type of looking at the type of organisms inhabiting organisms inhabiting that system.that system.

Some organisms are Some organisms are tolerant and some are tolerant and some are sensitive.sensitive.


Species that serve as Species that serve as early warnings of early warnings of damage to a community damage to a community are called indicator are called indicator speciesspecies

Trout is an indicator Trout is an indicator species in a river and species in a river and gives an indication of gives an indication of water quality and water quality and oxygen levelsoxygen levels


Lichens indicate levels Lichens indicate levels of sulfur dioxideof sulfur dioxide

Different species can Different species can tolerate different tolerate different amounts of sulfur so amounts of sulfur so this is a way to use a this is a way to use a biotic indicator to biotic indicator to estimate pollutionestimate pollution


Birds are good Birds are good indicators since they are indicators since they are found in almost all found in almost all communities and are communities and are sensitive to changessensitive to changes

Scientist are trying to Scientist are trying to genetically engineer genetically engineer plants to indicate plants to indicate harmful biological or harmful biological or chemical agents that can chemical agents that can be released by terroristsbe released by terrorists

Barn owl


Outline the damage Outline the damage caused to marine caused to marine ecosystems by the ecosystems by the overexploitation of fishoverexploitation of fish

About 3/4 of the About 3/4 of the world’s commercially world’s commercially valuable marine fish valuable marine fish species are overfished species are overfished or fished near their or fished near their limitslimits


Overfishing is the Overfishing is the greatest threat to greatest threat to populations that live populations that live near the surfacenear the surface

Bottom dwelling fish Bottom dwelling fish are affected by are affected by overfishing and habitat overfishing and habitat destructiondestruction

Overfishing leads to Overfishing leads to commercial extinctioncommercial extinction


• If areas are allowed to recover, reductions can be temporary

• But new methods of fishing are changing this

• Huge fleets of boats use sonar, satellite global positioning systems and aircraft to find fish

• Some ships are as large as football fields

• They deploy gigantic nets or lines that extend up to 80 k

• Modern fishing techniques can cause 80% depletion in 10-15 years


Numbers of swordfish, Numbers of swordfish, marlin, tuna, and cod have marlin, tuna, and cod have reduced by 90% since 1952reduced by 90% since 1952

North Atlantic cod may North Atlantic cod may never recover because of the never recover because of the additional problem of additional problem of habitat losshabitat loss

Larger fish are most Larger fish are most vulnerable but smaller fish vulnerable but smaller fish are also becoming affectedare also becoming affected

The problem of bycatch is The problem of bycatch is also made worse with also made worse with modern techniquesmodern techniques


Fish are more Fish are more endangered than any endangered than any other group of species other group of species to to human activities: to to human activities: pollution, habitat loss, pollution, habitat loss, over exploitation and over exploitation and introduction of non introduction of non native speciesnative species


What are international measures that could promote the What are international measures that could promote the conservation of fish?conservation of fish?

• Due to the nature of fish habitats, this requires Due to the nature of fish habitats, this requires international effortsinternational efforts

• First it is important to identify which species are in First it is important to identify which species are in danger, so countries need to work together to collect danger, so countries need to work together to collect scientific data. The International Union for the scientific data. The International Union for the Conservation of Nature and Natural Resources Conservation of Nature and Natural Resources (IUCN) keeps Red Lists of species in danger of (IUCN) keeps Red Lists of species in danger of extinctionextinction


National and International treaties to help protect National and International treaties to help protect marine species:marine species:

Convention on International Trade in Endangered Convention on International Trade in Endangered Species (CITIES), Global Treaty on Migratory Species (CITIES), Global Treaty on Migratory Species, US Marine Mammal Protection Species, US Marine Mammal Protection Act ,International Convention on Biological DiversityAct ,International Convention on Biological Diversity


Sea turtles: Kemp’s Ridley, Leatherbacks and Hawksbills are Sea turtles: Kemp’s Ridley, Leatherbacks and Hawksbills are threatened due to: loss of egg laying habitat, overexploitation threatened due to: loss of egg laying habitat, overexploitation of eggs and turtles for food and jewelry and bycatchof eggs and turtles for food and jewelry and bycatch

US shrimp trawlers used to kill as many as 55,00 sea turtles US shrimp trawlers used to kill as many as 55,00 sea turtles but since 1989 the US government requires trawlers to use but since 1989 the US government requires trawlers to use turtle exclusion devices. Just changing the shape of the hook turtle exclusion devices. Just changing the shape of the hook and bait can reduce turtle bycatch by 90%and bait can reduce turtle bycatch by 90%


Conservationist can use two methods to protect Conservationist can use two methods to protect species:species:

In situ conservation- where organisms are protected In situ conservation- where organisms are protected in aquatic and terrestrial reserves andin aquatic and terrestrial reserves and

Ex situ conservation where organisms are captured Ex situ conservation where organisms are captured and kept in zoos, gardens and seed banksand kept in zoos, gardens and seed banks

International treaties like the Convention on International treaties like the Convention on International Trade in endangered Species (CITIES) International Trade in endangered Species (CITIES) has been signed by 160 countries and lists 900 species has been signed by 160 countries and lists 900 species that can’t be traded as live specimens or wildlife that can’t be traded as live specimens or wildlife products because they are in danger of extinctionproducts because they are in danger of extinction

Documents

Ecology PowerPoint