Option G: Ecology Option G: Ecology and Conservationand Conservation

►Outline the factors Outline the factors that affect the that affect the distribution of plant distribution of plant species:species: TemperatureTemperature WaterWater LightLight soil pHsoil pH salinitysalinity mineral nutrients mineral nutrients

(NPK etc.)(NPK etc.)

Prefers acidic soil

Salt tolerant

►Explain the factors that affect the Explain the factors that affect the distribution of animal species:distribution of animal species:

►TemperatureTemperature►waterwater►breeding sitesbreeding sites►food supplyfood supply►territoryterritory

► Describe one method of random sampling, based on quadrat Describe one method of random sampling, based on quadrat methods, that is used to compare population size of two plant or two methods, that is used to compare population size of two plant or two animal species.animal species. 1.Mark out gridlines along 2 edges of the area to be sampled.1.Mark out gridlines along 2 edges of the area to be sampled. 2. Generate two random numbers and place the corner of the 2. Generate two random numbers and place the corner of the

quadrat at the coordinatesquadrat at the coordinates 3. Count the individuals of interest in the quadrat3. Count the individuals of interest in the quadrat 4. Repeat steps 2 and 3 as much as possible.4. Repeat steps 2 and 3 as much as possible. 5. Measure the total size of the area occupied by the population 5. Measure the total size of the area occupied by the population

in square metersin square meters 6. Calculate the estimated population size for the area:6. Calculate the estimated population size for the area:

► Pop. Size = Pop. Size = mean number per quadrat x total areamean number per quadrat x total areaarea of each quadratarea of each quadrat

Compare your count to a count from another area of interest.Compare your count to a count from another area of interest.

Outline the use of a transect to correlate Outline the use of a transect to correlate the distribution of plant or animal the distribution of plant or animal species with an abiotic variable. species with an abiotic variable.

►Transect = more systematicTransect = more systematic Done along a line (not random)Done along a line (not random)

►How would this be done?How would this be done?

A trapped weaselA trapped weasel

► Describe one technique used Describe one technique used to estimate the population to estimate the population size of an animal species size of an animal species based on a capture-mark–based on a capture-mark–release–recapture method.release–recapture method.

► Knowledge of the Lincoln Knowledge of the Lincoln index (which involves oneindex (which involves one

► mark–release–recapture mark–release–recapture cycle) is required, as follows.cycle) is required, as follows.

► Population size= (Population size= (nn1 x 1 x nn2) 2) //nn33

► where where nn1 = number of 1 = number of individuals initially individuals initially caught,marked and caught,marked and released, released,

► nn2 = total number of 2 = total number of individuals caught in the individuals caught in the second sample, and second sample, and

► nn3 =number of marked 3 =number of marked individuals in the second individuals in the second sample.sample.

► Bean simulation: see p. 104 Bean simulation: see p. 104 of bio bookof bio book

The NicheThe Niche► Ecological niche~ all the Ecological niche~ all the

characteristics, biotic and abiotic, characteristics, biotic and abiotic, specific to a species. It includes:specific to a species. It includes: spatial habitatspatial habitat feeding activitiesfeeding activities Interactions with other Interactions with other

organisms.organisms.

Distinguish Fundamental vs. Distinguish Fundamental vs. realized nichesrealized niches

fundamental/theoretical~ the fundamental/theoretical~ the niche a population is theoretically niche a population is theoretically capable of occupying under ideal capable of occupying under ideal conditions conditions

realized~ the niche population realized~ the niche population actually occupiesactually occupies Ex: Barnacle sp. on the coast of Scotland

The Competitive Exclusion The Competitive Exclusion PrinciplePrinciple

► 2 species with similar 2 species with similar needs for the same needs for the same limiting resources cannot limiting resources cannot coexist in the same place coexist in the same place

► Thus, 2 species cannot Thus, 2 species cannot coexist in a community if coexist in a community if their niches are identicaltheir niches are identical

► Why?Why?

► example experimentexample experiment

InteractionsInteractions

► InterInterspecific specific (interactions between (interactions between populations of populations of differentdifferent species species within a community):within a community):

Predation Predation HerbivoryHerbivory ParasitismParasitism Mutualism Mutualism CompetitionCompetition Give two examples Give two examples

of each of the of each of the above!above!

Commensalism (not mentioned in IB)Commensalism (not mentioned in IB)

Which Symbiosis is it?Which Symbiosis is it?

BiomassBiomass

► Biomass: the dry weight of Biomass: the dry weight of organic matter in organisms organic matter in organisms of an ecosystem.of an ecosystem.

► Describe one method for Describe one method for the measurement of the measurement of biomass of different trophic biomass of different trophic levels in an ecosystem.levels in an ecosystem. Get dry weight of Get dry weight of

organismorganism Estimation necessary Estimation necessary

sometimessometimes Can be destructive Can be destructive

(ethical issues?)(ethical issues?)

Felling a 30-year old agroforestry black walnut to measure its biomass and allometrics.

Matter and Energy Flow, IMatter and Energy Flow, I► Primary production Primary production (amount of light energy converted to chemical (amount of light energy converted to chemical

energy by autotrophs)energy by autotrophs) Gross production(GP): the total amount of organic material Gross production(GP): the total amount of organic material

produced by producers in an ecosystem produced by producers in an ecosystem

Net production (NP): gross production minus the material Net production (NP): gross production minus the material expended by producers in respiration. (stored energy available expended by producers in respiration. (stored energy available to consumers)to consumers)

R: respirationR: respiration► NP = GP - RNP = GP - R

Energy Flow, IIEnergy Flow, II► Ecological efficiencyEcological efficiency: % of E : % of E

transferred from one trophic level transferred from one trophic level to the next (5-20%) (average to the next (5-20%) (average =10%)=10%)

► Pyramid of productivityPyramid of productivity: : shows multiplicative loss of energy shows multiplicative loss of energy in trophic levelsin trophic levels

► Biomass pyramidBiomass pyramid: : trophic trophic representation of biomass in representation of biomass in ecosystemsecosystems

► Pyramid of numbersPyramid of numbers: trophic : trophic representation of the number of representation of the number of organisms in an ecosystemorganisms in an ecosystem

Check yourselfCheck yourself

►Discuss the difficulties of classifying Discuss the difficulties of classifying organisms into trophic levels.organisms into trophic levels.

►Explain the small biomass and low Explain the small biomass and low numbers of organisms in higher numbers of organisms in higher trophic levels.trophic levels.

►Construct a pyramid of energy given Construct a pyramid of energy given appropriate information.appropriate information.

SuccessionSuccession

► Ecological successionEcological succession~ ~ transition in species composition transition in species composition over timeover time

► Primary Primary ~ begun in lifeless ~ begun in lifeless area; no soil, (perhaps volcanic area; no soil, (perhaps volcanic activity or retreating glacier) activity or retreating glacier) Lichens= pioneer speciesLichens= pioneer species

► SecondarySecondary~ an existing ~ an existing community has been cleared by community has been cleared by some disturbance that leaves the some disturbance that leaves the soil intactsoil intact

► Climax communityClimax community

Check yourselfCheck yourself►Distinguish between Distinguish between primary primary and and

secondary secondary succession, using an succession, using an example of each.example of each.

►Outline the changes in species diversity Outline the changes in species diversity and production during primary and production during primary succession.succession.

►Explain the effects of living organisms Explain the effects of living organisms on the abiotic environment, with on the abiotic environment, with reference to the changes occurring reference to the changes occurring during primary succession.during primary succession.

BiomesBiomes► I. Biome= a I. Biome= a

large group large group of of ecosystems ecosystems that share that share the same the same type of type of climax climax communitycommunity

► Type of Type of biome biome determined determined largely by:largely by: PrecipitatiPrecipitati

onon temperatutemperatu

rere

► 2. Major terrestrial biomes2. Major terrestrial biomes► a. tundra—treeless (or very a. tundra—treeless (or very

small trees may be present), small trees may be present), permafrost, low nutrient soil, low permafrost, low nutrient soil, low precipitation. slow decay. Around precipitation. slow decay. Around poles.poles.

► b. taiga—northern coniferous b. taiga—northern coniferous forest—acidic/nutrient poor topsoil, forest—acidic/nutrient poor topsoil, long harsh winters, short summers. long harsh winters, short summers. Cold but no permafrost.Cold but no permafrost.

► c. desert—low precipitation, c. desert—low precipitation, warm to very hot days and cold nights, warm to very hot days and cold nights, very few plants (some store water, very few plants (some store water, some grow quickly with rain.)some grow quickly with rain.)

► d. Grassland—few trees, low d. Grassland—few trees, low rainfall, warm to hot summers, cold rainfall, warm to hot summers, cold winters. Dominated by grasses and winters. Dominated by grasses and plants tolerant of grazing. experience a plants tolerant of grazing. experience a dry season, unpredictable dry season, unpredictable precipitation, fertile soil. precipitation, fertile soil.

► e. temperate deciduous forest—e. temperate deciduous forest—trees lose leaves, warm summers, cool trees lose leaves, warm summers, cool winters. Moderate rainfall.winters. Moderate rainfall.

► f. tropical rain forest— hot in all f. tropical rain forest— hot in all seasons,soil is nutrient poor. Rains seasons,soil is nutrient poor. Rains frequently/ high precipitation. Highest frequently/ high precipitation. Highest biodiversity of terrestrial biomes. biodiversity of terrestrial biomes. Canopy prevents understory plant Canopy prevents understory plant growth. growth.

ID These BiomesID These Biomes

►Check yourself!Check yourself!►Explain how rainfall and temperature Explain how rainfall and temperature

affect the distribution of biomes.affect the distribution of biomes.►Outline the characteristics of six major Outline the characteristics of six major

biomes.biomes.

► Calculate the Simpson diversity index for two Calculate the Simpson diversity index for two local communities.local communities.

► Analyse the biodiversity of the two local Analyse the biodiversity of the two local communities using the Simpson index.communities using the Simpson index.

► The Simpson diversity index is a measure of The Simpson diversity index is a measure of species diversity species diversity D is the diversity index, D is the diversity index, N is the total number of organisms of all N is the total number of organisms of all

species foundspecies found n is the number of individuals of a n is the number of individuals of a

particular species. particular species. ► A high value of D suggests a stable and A high value of D suggests a stable and

ancient ecosystem and a low D value could ancient ecosystem and a low D value could suggest pollution, recent succession or suggest pollution, recent succession or agricultural management. agricultural management.

► The index is determined by counting The index is determined by counting organisms on randomly chosen parts of an organisms on randomly chosen parts of an area. Monitoring over time shows changes in area. Monitoring over time shows changes in an ecosystem. an ecosystem.

SpeciesSpecies Number Number FoundFound

Mayfly larvaMayfly larva 88

Dragonfly larvaDragonfly larva 55

Caddisfly larvaCaddisfly larva 44

Stonefly larvaStonefly larva 44

Pond skaterPond skater 33

Water louseWater louse 22

Water miteWater mite 11

Flatworm (Flatworm (Dendocoelum Dendocoelum sp.)sp.)

44

Flatworm (Flatworm (Dugesia sp.)Dugesia sp.) 33

LeachLeach 11

Annelid wormAnnelid worm 22

SnailSnail 44

Pearl musselPearl mussel 11

Example:

N = 42

Get n for each species and plug in.

D= ___42 (42-1)______

8 (8-1) + 5 (5-1) + 4 (4-1) etc…

D = ___42 (42-1)______

140

Practice problem: Calculate the Practice problem: Calculate the Simpson diversity index for the Simpson diversity index for the

following community: following community:

SpeciesSpecies Number FoundNumber Found

Mayfly larvaMayfly larva 88

Dragonfly larvaDragonfly larva 55

Caddisfly larvaCaddisfly larva 44

Stonefly larvaStonefly larva 44

Pond skaterPond skater 33

Water louseWater louse 22

Water miteWater mite 11

►Calculate the Simpson diversity index Calculate the Simpson diversity index for two local communities.for two local communities.

►Analyse the biodiversity of the two local Analyse the biodiversity of the two local communities using the Simpson index.communities using the Simpson index.

►Good lab idea! Do a transect or random Good lab idea! Do a transect or random sampling and calculate the Simpson sampling and calculate the Simpson diversity index for two local diversity index for two local communities. communities.

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

►Think and discuss!Think and discuss!

Rainforest ExampleRainforest Example

► Economic reasonsEconomic reasons EcotourismEcotourism New products/drugsNew products/drugs

► Ecological reasonsEcological reasons Ecological Ecological

relationships/symbiosisrelationships/symbiosis ErosionErosion Carbon and oxygen cyclesCarbon and oxygen cycles Climate effectsClimate effects

► Ethical reasonsEthical reasons Intrinsic value of living thingsIntrinsic value of living things Cultural importance of native Cultural importance of native

speciesspecies Effects on future generationsEffects on future generations Medicines (potentially)Medicines (potentially)

► Aesthetic reasonsAesthetic reasons

► II. Importance of II. Importance of BiodiversityBiodiversity

► A. BeautyA. Beauty► B. ecological B. ecological

relationships between relationships between organismsorganisms

► C. Importance to C. Importance to people—medicines (Taxol-people—medicines (Taxol-Pacific Yew), mold- Pacific Yew), mold- penicillin, rosy periwinkle—penicillin, rosy periwinkle—drugs for Hodgkin’s disease drugs for Hodgkin’s disease (lymphatic cancer) and (lymphatic cancer) and leukemia, Willow bark—leukemia, Willow bark—aspirin, cinchona tree barkaspirin, cinchona tree bark—quinine) Other uses?—quinine) Other uses?

List three examples of the introduction of alien species that have List three examples of the introduction of alien species that have had significant impacts on ecosystems.had significant impacts on ecosystems.

Discuss the impacts of alien species on ecosystems.Discuss the impacts of alien species on ecosystems.

•3 examples of alien species

• Brown tree snake in Guam (see biological invaders

http://www.pbs.org/cgi-registry/2wgbh/evolution/library/search.cgi

• Cane toad in Australia (originally introduced to control sugar cane pests) http://video.nationalgeographic.com/video/player/animals/amphibians-animals/frogs-and-toads/toad_cane.html

• Fennel and European grasses in CA (more info on fennel: http://www.cal-ipc.org/ip/management/ipcw/pages/detailreport.cfm@usernumber=51&surveynumber=182.php)

Some California Native PlantsSome California Native Plants

•Island Buckwheat, Channel Islands, California •Dudleya, Channel Islands, California

Indian Paintbrush•Lemonade Berry, Channel Islands, California

Fennel: the alienFennel: the alien

► Removing Removing invasive invasive fennelfennel

Outline one example of biological control of Outline one example of biological control of invasive species.invasive species.

►http://www.sciencedaily.com/releases/2008/05/080508131953.htm see article (printed and also on see article (printed and also on computer “ Biological weapons to computer “ Biological weapons to control…)control…)

► Define Define biomagnificationbiomagnification.. Biomagnification: Biomagnification:

process by which chemical process by which chemical substances become more substances become more concentrated at each higher concentrated at each higher trophic level.trophic level.

► Explain the cause and Explain the cause and consequences of consequences of biomagnification, using biomagnification, using a named example.a named example. Cause:Cause: Consequences:Consequences: Named examples: Named examples:

Mercury in fish, DDT and Mercury in fish, DDT and pelicans, eagles, Island pelicans, eagles, Island foxes.foxes.

Outline the effect of Outline the effect of chlorofluorocarbons chlorofluorocarbons (CFC’s) on the ozone (CFC’s) on the ozone layer. layer.

► ozone in the ozone in the stratosphere absorbs stratosphere absorbs UV radiation.UV radiation.• Chlorine breaks away Chlorine breaks away

from CFC molecules from CFC molecules (caused by UV light) (caused by UV light)

• Chlorine (highly Chlorine (highly reactive) reacts with reactive) reacts with ozone (breaks it down ozone (breaks it down to make oxygen)to make oxygen)

• One chlorine can One chlorine can break down hundreds break down hundreds of thousands of ozone of thousands of ozone molecules. molecules.

► Animation Animation http://www.bom.gov.au/lam/Students_Teachers/ozanim/ozoanim.shtml

► Outline the effects of Outline the effects of UV radiation on living UV radiation on living tissues and biological tissues and biological productivity.productivity. a) Increases the mutation a) Increases the mutation

rates in DNA.rates in DNA. b) Causes severe b) Causes severe

sunburns and damage to sunburns and damage to eyes (cataracts).eyes (cataracts).

c) Increases incidence of c) Increases incidence of cancers (melanoma).cancers (melanoma).

d) Reduces rate of d) Reduces rate of photosynthesis in plants photosynthesis in plants (lowers energy output of (lowers energy output of producers!).producers!).

► Explain the use of biotic Explain the use of biotic indices and indicator species indices and indicator species in monitoring environmental in monitoring environmental change.change.

► Indicator species—Indicator species— highly sensitive to highly sensitive to

environmental changes environmental changes their populations increase or their populations increase or

decrease significantly decrease significantly depending on changes in the depending on changes in the environment. environment.

Ex. Frogs and pollution Ex. Frogs and pollution http://environment.newscientist.com/article/dn12687-frog-http://environment.newscientist.com/article/dn12687-frog-deformities-linked-to-farm-pollution.html deformities-linked-to-farm-pollution.html

Ex. sludge worms-- indicate low Ex. sludge worms-- indicate low oxygen concentration in water.oxygen concentration in water.

► Biotic index: Biotic index: Scale for showing the Scale for showing the quality of an environment by indicating quality of an environment by indicating the types of organisms present in it (e.g. the types of organisms present in it (e.g. how clean a river is). (Source: PHC) how clean a river is). (Source: PHC) Ex.Ex. http://www.pisces-aqua.co.uk/aquatext/tables/bioticind.hthttp://www.pisces-aqua.co.uk/aquatext/tables/bioticind.ht

mm

Check yourselfCheck yourself

►Explain the use of biotic indices and Explain the use of biotic indices and indicator species in monitoring indicator species in monitoring environmental change.environmental change.

HomeworkHomework

►Outline the factors that contributed to Outline the factors that contributed to the extinction of one named animal the extinction of one named animal species.species. Pick a species that you will remember!Pick a species that you will remember! Outline the factors that contributed to it’s Outline the factors that contributed to it’s

extinction in your notes.extinction in your notes. You will present your animal tomorrow You will present your animal tomorrow

(bring in a picture/visual aid)(bring in a picture/visual aid)

► Outline the biogeographical features Outline the biogeographical features of nature reserves that promote the of nature reserves that promote the conservation of diversity.conservation of diversity. Large size (why?)Large size (why?)

► Avoid habitat fragmentation and edge effect Avoid habitat fragmentation and edge effect (ex. Cowbirds parasitize nests on forest edges)(ex. Cowbirds parasitize nests on forest edges)

Habitat corridors to connect fragmented Habitat corridors to connect fragmented habitats.habitats.

Inclusion of a variety of abiotic factors Inclusion of a variety of abiotic factors also promotes diversity. (Why? Discuss)also promotes diversity. (Why? Discuss)

► Discuss the role of active management techniques in Discuss the role of active management techniques in conservation.conservation. If human disturbance has degraded a habitat, active If human disturbance has degraded a habitat, active

management may be necessary. (It won’t always return to management may be necessary. (It won’t always return to its natural state on its own)its natural state on its own)

Example: removing goats, pigs, golden eagles, and Example: removing goats, pigs, golden eagles, and invasive plants on the Channel Islandsinvasive plants on the Channel Islands

► Discuss the advantages of Discuss the advantages of in situ in situ conservation of conservation of endangered speciesendangered species (terrestrial and aquatic (terrestrial and aquatic nature reserves).nature reserves).

► In situ = In situ = Nature reservesNature reserves► Advantages:Advantages:

Species are adapted to Species are adapted to habitathabitat

Genetic diversityGenetic diversity Natural behavior Natural behavior

patternspatterns Interaction of species in Interaction of species in

ecosystemecosystem

Wolong Nature Reserve (China)

Jaguar Preserve (Belize)

►Outline the use of Outline the use of ex situ ex situ conservation conservation measures, including captive breeding measures, including captive breeding of animals, botanic gardens and seed of animals, botanic gardens and seed banks.banks. Captive breedingCaptive breeding Botanic gardensBotanic gardens Seed banks (most seeds kept cold -10Seed banks (most seeds kept cold -10--

20 C can last over 100 years)20 C can last over 100 years)

► Reproductive Reproductive patternspatterns r strategists--r strategists--

rapid life rapid life histories, rapid histories, rapid reproduction of reproduction of many small many small offspringoffspring

► in unpredictable in unpredictable unstable unstable environmentsenvironments

k strategists—k strategists—large, reproduce large, reproduce and mature and mature slowly, long-lived, slowly, long-lived, often care for often care for youngyoung

► In stable In stable environmentsenvironments

►

►Distinguish between Distinguish between r-strategies r-strategies and and K-strategiesK-strategies..

►Discuss the environmental conditions Discuss the environmental conditions that favour either r-strategies or K-that favour either r-strategies or K-strategies.strategies.

► Describe the methods used to Describe the methods used to estimate the size of estimate the size of commercial fish stocks.commercial fish stocks. Use fish catch data to get a count Use fish catch data to get a count

and age distribution. Use this to and age distribution. Use this to estimate in conjunction with estimate in conjunction with spawning rates and survivorship spawning rates and survivorship curvescurves

Capture-mark-release-recaptureCapture-mark-release-recapture► Works in lakes, but not in oceansWorks in lakes, but not in oceans

Echo sounders in conjunction with Echo sounders in conjunction with trawling to determine which trawling to determine which species have been echolocated.species have been echolocated.

None of these methods estimate None of these methods estimate with much certainty leading to with much certainty leading to disagreements.disagreements.

► Outline the concept Outline the concept of maximum of maximum sustainable yield in sustainable yield in the conservation of the conservation of fish stocks.fish stocks. Maximum Maximum

sustainable yield = sustainable yield = Largest amount of Largest amount of fish that can be fish that can be harvested without a harvested without a decline in fish stocks. decline in fish stocks.

► Discuss international Discuss international measures that would measures that would promote the conservation promote the conservation of fish.of fish. Monitoring stocks and Monitoring stocks and

repro ratesrepro rates Quotas for species with low Quotas for species with low

stocksstocks Closed seasons (esp. Closed seasons (esp.

breeding season)breeding season) Exclusion zones with no Exclusion zones with no

fishing allowedfishing allowed Moratoria on catching Moratoria on catching

endangered speciesendangered species Minimum net sizes (so Minimum net sizes (so

baby fish aren’t caught)baby fish aren’t caught) Banning of drift netsBanning of drift nets

“A lone bat ray is  tangled in the mesh of a drift net. Not considered for human consumption, this ray will likely be thrown overboard once the net is hauled in.” (Ocean.com)