Today’s Plan: 5/4/2010

Bellwork: Housekeeping/Test corrections (10 mins)

AP Lab 12-DO Ecology notes

Today’s Plan: 5/5/2010

Bellwork: Discuss what we’re accomplishing in the lab (10 mins)

Finish DO Lab Data collection (40 mins)

Notes (the rest of class)

Today’s Plan: 5/6/2010

Bellwork: Finish AP Lab 12 Data collection (20 mins)

Finish AP Lab 12 questions and Test corrections (30 mins)

Continue with notes (the rest of class)

Today’s Plan: 5/7/2010

Bellwork: Work on the “Can we feed the world’s population?” sheet (30 mins)

Notes (the rest of class)

Today’s Plan: 5/10/2010

China Video (60 mins) Finish misc. work (the rest of class)

Today’s Plan: 5/11/2010

Finish Ecology Notes (30 mins) Entry document for Final project (15

mins) Class K/NTK list (15 mins) Grouping and norm establishment

(the rest of class)

Today’s Plan: 5/12/2010

Bellwork: Q&A (10 mins) Ecology test (the rest of class) If you finish early, work on your

project!

5/13-5/19/2010

Work with your group on your final project

I’ll put out a workshop sign up for your NTKs each day. The last 30 mins, I’ll do the workshops you ask for.

5/20-21

Prepare for your presentations (5 mins)

Group project presentations (the rest of class)

Ecology This is the study of the distribution,

abundance, and interactions of organisms within their environments.

Levels of ecology: Organism Population Community Ecosystem Biosphere

Figure 50-1

Organismal ecology

Salmon migratefrom saltwaterto freshwaterenvironmentsto breed

How do individualsinteract with eachother and theirphysical environment?

Population ecology

Ecosystem ecologyCommunity ecology

How and why doespopulation sizechange over time?

How do energyand nutrientscycle throughthe environment?

How do speciesinteract, and what arethe consequences?

Salmon are prey aswell as predators

Each female salmonproduces thousandsof eggs. Only a fewwill survive toadulthood. Onaverage, only twowill return to thestream of their birthto breed

Salmon die and thendecompose, releasingnutrients that are usedby bacteria, archaea,plants, protists, youngsalmon, and otherorganisms

Population Ecology Demography-the study of poulations over time, including

categories into which the organism falls For individuals in populations:

Life expectancy/Life tables Immigration/emigration

For whole populations: Density=# individuals/area Dispersion=where you find the individuals in that area Age Structure=Bar graph showing ages and genders of

individuals in the population Reproductive rate, r (growth rate)=births-deaths/N N=population size Survivorship curve (3 types) Biotic potential=maximum growth possible for the

population under ideal conditions (includes things like reproductive age, clutch size, frequency of reproduction, survival rate of offspring)

Figure 50-30a

Distribution of cattle is limited by distribution of tsetse flies.

Distribution of tsetse fly(red)

Distribution of cattle(blue)

The two distributionshave little overlap(purple)

Figure 52-1-Table 52-1

Figure 52-15

2050 projections

Developed country(Sweden)

Developing country(Honduras)

2000 data2000 data

2050projections

Figure 52-2a

Three general types of survivorship curves

High survivorship

High survivorship

Lo

w su

rvivorsh

ip

Lo

w su

rvivorsh

ip

Steady survivorship

Type III

Type II

Type I

Limiting factors Limiting factors are elements of an ecosystem that

are in short supply and therefore set limits on population size

Carrying Capacity (K)-maximum number of individuals that can occupy an ecosystem

Density-dependent limiting factors-factors whose limiting effects increase as population density increases (ex: disease, famine, etc). Some cause an increase in competition.

Density-independent limiting factors-factors whose limiting effects are not tied to population density (ex: natural disasters, climate, etc)

Growth models Exponential model-also known as a J curve. Assumes

that populations can grow without limit Logistic model-also known as an S curve. Assumes

that populations know what K is, and will act accordingly This changes the reproductive rate equation: Change N/Change t=rN(K-N/K) Notice, K is taken into consideration here

Reality-models are only as good as their assumptions, which means that the graph of real population growth is slightly different.

Figure 52-7a

Density dependence: Growth rate slows at high density.

Later growthfalls to zero

Carrying capacity

Early growthis rapid

Growth beginsto slow

Growth and Life History These growth models are associated with 2

kinds of life-strategies for organisms: r-selected species=these exhibit rapid,

exponential growth. These are often called opportunitstic species because they quickly invade an area, reproduce and die. Offspring mature quickly and are small. (ex: grasses, insects)

K-selected species=these are species whose populations are relatively stable, usually around K. They produce a small number os offspring that are large and require lots of care. They reproduce repeatedly (ex: humans)

Human Population growth Human population worldwide is reaching 9 billion. It

was just 3 billion 100 years ago. Why the rapid rise?

Increases in food supply and travel-humans have domesticated, bred, and fine-tuned agriculture (from hunter-gatherer to farmer)

Reduction in disease-advances in medicine, like vaccines, antibiotics, etc have dropped the death rate and increased the successful birth rate

Reduction in wastes-sewage systems and water treatment have reduced health hazards

Expansion of habitat-better housing, clothing, etc have made it easier to live in more places

Figure 52-16-Table 52-2

Figure 52-17

Low

HighCurrent

Medium

Population cycles: Predator/Prey

Predator/prey describes a relationship between a hunter and an individual that is eaten.

In general, changes in the prey population cause similar changes in the predator population since the predator is dependent on the prey. Just keep in mind, the prey are usually predators of the producers, so their population changes are often due to seasonal changes in their prey population.

Figure 52-12

The hare-lynx populations cycle every11 years, on average; the size of the lynxpopulation lags behind that of the hares

LynxHare

Community Ecology Habitat-the area that an organism inhabits within an

ecosystem Niche-the role of the organism within the environment1

species per niche Gause’s principle of competitive exclusion=when 2 species

try to occupy the same niche, there will be competition until one species leaves or dies

Resource partitioning=some species can coexist even though they appear to be competing for the same resources. They are occupying slightly different niches by using the resources in different ways.

Character displacement (niche shift)=as a result of resource partitioning, certain characteristics allow organisms to obtain their partitioned resources more successfully

Realized niche=This is the niche that the organism occupies b/c of resource partitioning. If there were no competitors, they would otherwise occupy their fundamental niche, but because of niche overlap, they must adjust

Figure 53-2

Consumptive competition

These trees are competing for waterand nutrients.

Chemical competition

Few plants are growing under theseSalvia shrubs.

Grizzly bears drive off black bears.

Territorial competition

Space preempted by these barnacles isunavailable to competitors.

Preemptive competition Overgrowth competition

The large fern has overgrown other individualsand is shading them.

Encounter competition

Spotted hyenas and vultures fight over a kill.

Figure 53-4a

Competitive exclusion in two species of Paramecium

Parameciumaurelia

Parameciumcaudatum

Figure 53-4b

Competitive exclusion occurs when competition isasymmetric …

Asymmetriccompetition

Symmetriccompetition

Higher fitness

Lower fitnessSamefitness

Figure 53-4c

… and niches overlap completely.

Species 1: Strong competitor

Species 2: Weak competitor,driven to extinction

Figure 53-4d

When competition is asymmetric and niches do not overlapcompletely, weaker competitors use nonoverlapping resources.

Species 1(strong competitor)

Species 2(weak competitor)

Fundamentalniche

Realizedniche

Figure 53-3

Species 1

Species 2

One species eats seeds of a certain size range.

Partial niche overlap: competition for seeds ofintermediate size

Trophic Relationships These are the feeding relationships in an ecosystem. Recall from biology that energy transfer between

trophic levels is inefficient-only 10% of the energy is transferred, which affects the amount of biomass and the numbers of individuals at each trophic level. This also means that food chains are rarely more than 5 trophic levels.

Food chain: primary producerprimary consumersecondary consumertertiary consumerdetritovores (decomposers)

Food webs are overlapping food chains in an ecosystem.

Recall the following terms: carnivore, herbivore, omnivore

Figure 54-1

DecomposerOrganisms that feedon dead organisms ortheir waste products

ConsumersOrganisms that eatother living organisms

Primary producers (autotrophs)Organisms that can synthesizetheir own food

Abiotic environmentThe soil, climate, atmosphere,and the particulate matterand solutes in water

External energysource, usuallysolar energy butalso chemical energy

Figure 54-5

Maple tree leaves

Cricket

Dead maple leaves

Bacteria, archaea

RobinEarthworm

Robin Cooper’s hawk

Cooper’s hawk

Grazingfood chain

Decomposerfood chain

Feedingstrategy

Trophiclevel

Quaternaryconsumer

5

Tertiaryconsumer

4

Secondaryconsumer3

Primaryproducer

2

1

Primarydecomposeror consumer

Figure 54-6

Cooper’s hawk Fox

Robin Alligator lizard

Earthworm Millipede

Bracket fungus Bacteria, archaea(many species)

Puffball Pillbugs Insect larvae(maggots)

Cricket

Arrows show directionof energy flow: fromorganism consumedto consumer

Rotting logDead leaves

(many species)Dead animals

(many species)Maple tree

leaves

Figure 54-7

Tertiary consumers

Secondary consumers

Primaryproducers

Primary consumersand decomposers

Production of biomass(g/m2/year)

Efficiency ofenergy transfer

3

30

200

15%

10%

20%

1000

Types of predator/prey relationships

True predators-kills and eats another animal

Parasites-are only predatory if they kill their host

Parasitoid-insects that lay eggs on a host. The larvae are parasitic to the host

Herbivores-yes, they’re technically predators. Some are seed-eaters (granivores), some eat grasses (grazers), and some eat other plant material (browsers)

Avoiding Predation Organisms have evolved many mechanisms for

avoiding predators. Secondary Compounds-toxic chemicals produced by

plants that can make herbivores sick Camouflage (cryptic coloration)-helps the animal

blend into it’s surroundings (some predators use this as well to help them hunt)

Aposematic coloration (warning coloration)-a bright color pattern that advertises that the organism should be avoided (ex: wasp/bee stripes)

Mimicry-organisms resembling each other (shortens the predator’s learning curve) Mullerian mimicry-dangerous organisms resemble

each other Batesian mimicry-organisms without a defense

mechanism resemble a dangerous organism

Figure 53-12

Cottonwood tree felled by beavers Resprouted trees have moredefensive compounds.

Survival of beetle larvae placed on ant mound

Figure 53-10 Prey and predator

Blue mussels Crabs

Correlation between predation rate and prey defense

Figure 53-9

Constitutive defenses of animals vary.

Camouflage: blending into the background Schooling: safety in numbers Weaponry: fighting back

Batesian mimics

Mimicry can protect both dangerous and harmless species.

Müllerian mimics

Paper wasp Bumblebee Honeybee Hornet moth Wasp beetle Hoverfly

Symbiosis-a different kind of relationship

In a symbiotic relationship, organisms closely associate with one another. There are 3 types of symbiosis: Parasitism-1 organism benefits, the other

is harmed Commensalism-1 organism benefits, the

other is neither harmed nor benefitted Mutualism-both organisms benefit

Figure 53-16-Table-53-1

Coevolution in Relationships Organisms often respond to changes

in other organisms through coevolution.

For example, hummingbirds find nectar by color, so the flowers that attract them are tube-shaped, are bright red, and have virtually no scent

Often, plants can only be pollinated by one type of pollinator, so they evolve together

Biodiversity This is also called species diversity and can

be discussed in terms of Species richness-number of different species in

the community Relative abundance of different species in the

community

This is a measure of heath of an ecosystem Diseases are specific to the organism If 1 food source dies, there are others, etc

Figure 53-25

Community 1 Community 2 Community 3

Species

Species richness: 6

Species diversity: 0.59

A

B

C

D

E

F

6

0.78

5

0.69

Figure 55-4 Hotspots in terms of species richness of birds

Hotspots in terms of endemic species of birds

Hotspots in terms of high proportion of endemic plants and high threat

High Impact Species in Communities Keystone Species-These are not necessarily abundant in a

community, but play a part in many interactions within the community. You can tell a keystone species by removing it from the ecosystem and viewing the impact. (ex: sea otters, if removed don’t keep sea urchins in check, and there’s less kelp)

Invasive Species-These are species that invade (usually by being introduced by humans) an ecosystem and replace the species that are naturally there

Dominant Species-These are the most abundant species in an ecosystem, and have the most biomass

Foundation Species-These are also called Ecosystem engineers, and they cause physical changes in their environments. Beavers are examples of this type of species. Facilitators are foundation species that have a positive impact

on the environment

Figure 53-18Predator: Pisaster ochraceous

Prey: Mytilus californianus

Figure 55-7

Invasive species increase competition. Invasive species introduce disease. Invasive species increase predation.

An introduced fungus has virtually wiped outthe American chestnut.

Purple loosestrife is crowding out nativeorganisms in North American marshes.

The brown tree snake has extinguished dozensof bird species on Guam.

Figure 53-19

P. ochraceous(keystone predator)present

P. ochraceous(keystone predator)absent

Community Change Succession-a series of more-or-less orderly changes in

an ecosystem over time. Begins with a pioneer species (usually an r-selected species) and ends with a climax community (stable)

In general, as organisms inhabit the area, they changes the texture, pH, and water potential of the soil, as well as establish competition for resources as the area becomes crowded

Primary Succession-occurs on a substrate that has never before supported life.

Secondary Succession-occurs on a substrate that has gone through some sort of disturbance

Succession on land In primary succession, generally starts with

lava flow or sand. Pioneer for lava-lichens Pioneer for sand-grasses

In secondary succession, you can start at any point in the successional process, usually a field.

These used to be thought of as a predictable series of changes, however, there are instances that are more random and less orderly b/c they’re affected by climate, which species happen to arrive first, etc.

Figure 53-21-1

Old field

Disturbance (plowing) ends, site isinvaded by short-lived weedy species.

Pioneering species

Figure 53-21-2

Weedy species are replaced by longer-livedherbaceous species and grasses.

Early successionalcommunity

Shrubs and short-livedtrees begin to invade.

Mid-successionalcommunity

Figure 53-21-3

Short-lived tree species mature;long-lived trees begin to invade.

Late-successionalcommunity

Long-lived treespecies mature.

Climax community

Succession in Water

This happens when you start with a lake or pond that changes to a marsh-like state.

The marsh is followed by meadow, with lots of grasses.

Finally, there’s a climax community of native vegetation

Ecosystem Ecology Biogeochemical Cycles-this is the flow of important elements through the

ecosystem. Hydrologic cycle-mainly an abiotically-driven cycle.

Reservoirs-ocean, air, groundwater, glaciers Assimilation-plants absorb water from the soil, animals drink water

and eat organisms Release-transpiration, evaporation, etc.

Carbon cycle-mainly biotically-driven and tied to atmospheric CO2 levels that cause the greenhouse effect Reservoirs-atmosphere, fossil fuel, peat, organic material (like

cellulose) Assimilation-photosynthesis, animals eating plants and each other Release-respiration and decomposition

Nitrogen cycle-also a biotically driven cycle dependent heavily on bacteria Reservoirs-atmospheric N2, soil (nitrates, nitrites, ammonium,

amonia) Assimilation-nitrogen fixation by bacteria, nitrification by bacteria Release-denitrification by bacteria, decomposition, animal waste

Phosphorous cycle-again, a biotically-driven cycle Reservoirs-rocks and ocean sediments Assimilation-plants absorb phosphates and are eaten by animals Release-decomposition, animal waste

Figure 54-13

THE GLOBAL WATER CYCLE

Evaporationfrom ocean: 319

All values in 1018 grams per year Net movement of water vapor by wind: 36

Precipitationover ocean: 283

Evaporation,transpiration: 59

Precipitationover land: 95

Water table(saturated soil)

Percolation

Runoff and groundwater: 36

Figure 54-14

THE GLOBAL CARBON CYCLE

Organisms, chemicalprocesses in ocean:

40,000

All values in gigatons of carbon per year Atmosphere: 778 (during 1990s)

Net uptake viaphotosynthesisby plants: 3.0

Net uptake viaphotosynthesis,

chemical processes: 1.5

Rivers (erosion):0.8

Organisms, soil,litter, peat: 2190

Aquatic ecosystems Terrestrial ecosystems Human-induced changes

Land-use change(primarily deforestation):

1.6Fossil-fuel use:

6.3

Figure 54-16

THE GLOBAL NITROGEN CYCLE

Nitrogen-fixingcyanobacteria: 15

All values in gigatons of nitrogen per year

Atmospheric nitrogen (N2)

Protein andnucleic acidsynthesis

Bacteria in muduse N-containingmolecules as energysources, excrete N2: 310

Decomposition ofdetritus into ammonia

Internal cycling:

1200

Industrialfixation: 100

Lightningand rain: 3

Internalcycling:

8000

Permanent burial: 10

Runoff: 36

Mud

Nitrogen-fixing bacteriain roots and soil: 202

Biomes These are ecosystems that have

characteristic biotic and abiotic factors Land Biomes are largely determined by

latitude (except desert which is determined by climate) As you move from the poles toward the equator,

biodiversity and biomass increase. The length of the growing season also increases.

Water Biomes are determined by salinity and depth

Land Biomes In the tropics:

Rain forest-200-400 cm of rain annually

Savanna-30-50 cm of rain annually

In the temperate zone: Deciduous forest-70-

200 cm of rain annually

Grassland-30-100 cm of rain annually

Chaparal-30-50 cm of rain annually (coastal region)

Northern Coniferous forest (Taiga)-30-100 cm of rain annually

Tundra-20-60 cm of rain annually

Desert-occurs at any latitude-less than 30 cm of rain annually

Figure 50-9

Barrow

Dawson

Konza PrairieChicago

Yuma

Belém

Figure 50-23

Low angle ofincoming sunlight

Moderate angle ofincoming sunlight

Sunlight directlyoverhead

Large amount ofsunlight per unit area

Small amount ofsunlight per unit area

North pole

Figure 54-11

Organicmatter

Boreal forest: Accumulation ofdetritus and organic matter

Organicmatter

Tropical wet forest: Almost noorganic accumulation

Figure 50-12

Tropical wet forests areextremely rich in species

Figure 50-11

Figure 50-18

Temperate forests aredominated by broad-leaved deciduous trees

Figure 50-17

Figure 50-16

Grasses are thedominant lifeformin prairies andsteppes

Figure 50-15

Figure 50-20

Boreal forests aredominated byneedled-leavedevergreens, suchas spruce and fir

Figure 50-19

Figure 50-22

Arctic tundra is dominatedby cold-tolerant shrubs,lichens, and herbaceousplants

Figure 50-21

Figure 50-26

Air rises over mountainsand cools; rain falls

WestMoisture-laden air blowsonshore from Pacific Ocean

EastDry air createsdesert conditions

CascadeMountains This area is in

a rain shadow

Figure 50-14

Saguaro cacti are a prominentfeature of the Sonoran Desert inthe southwestern part ofNorth America

Figure 50-13

Water Biomes Freshwater:

Lakes Streams and Rivers Wetlands

Brackish: Estuaries

Marine: Intertidal Zone Oceanic Pelagic-

split into the photic and aphotic zones

Coral reefs-always in the photic zone

Benthic-ocean bottom

Figure 50-5

Bogs are stagnant and acidic. Marshes have nonwoody plants. Swamps have trees and shrubs.

Figure 50-3

Littoralzone

Limneticzone

Photiczone

Aphoticzone

Benthic zone

Primary Productivity This is the amount of light energy

converted to chemical energy in an ecosystem.

Gross Primary productivity-is the total primary productivity of the ecosystem

Net Primary productivity-is the gross primary productivity- the energy used by producers for respiration (R)

Formula for net primary productivity: NPP=GPP-R

Figure 54-3

NPP per unit area Area covered, byecosystem type

Total NPP

TerrestrialAquatic

Human Impact on the Biosphere Human activity over time has been damaging to the

biosphere. Ecology is really a study of balance, and as the human

population has grown, our wastes and byproducts have thrown off that balance.

There have been, in recent years, efforts to reestablish the balance and conserve our resources. Ex: Prior to the 1980s, CFCs were common

propellants used in household goods. As a result of human use of CFCs, they built up in the atmosphere, reacting with ozone (O3), and causing holes in the ozone layer. This layer surrounds the planet and shields us from damaging UV radiation. As a result of banning CFCs, and using safer alternatives, the holes in the ozone layer are repairing themselves.

Climate change Human activities have caused a buildup of

CO2 in the atmosphere. Of course, CO2 is a greenhouse gas, which means that we have additional heat building up in our atmosphere

Data indicates that the world is getting warmer, which sparks many problems like raising sea levels, changing weather patterns that could decrease agricultural output, change the trophic structure of our oceans and land

Figure 54-15b

Recent changes in atmospheric CO2 recorded in Hawaii

At Mauna Loa, atmosphericCO2 concentrations are highin winter and low in summer,forming annual cycles

Figure 54-19

Flowering times for some species in midwesternNorth America are earlier in the year.

Cold-water copepods are declining in the North Atlantic.

Baptista flowers

Warm-water copepods

Cold-water copepods

Great Britain

Figure 54-21

Global warming increases the density gradient, making itless likely for layers to mix.

Much of the ocean is stratified by density and temperature.

Surface layer: Water is warm, less dense Surface layer: Water is much warmer, less dense

Nutrient-richwater is broughtto the surfaceby currents

Muchsteeperdensitygradient

Densitygradient

Benthic zone: Water is 4°C, highest density Benthic zone: Water is 4°C, highest density

Currents are less likelyto bring nutrient-richwater to surface,against the steeperdensity gradient

Pollution Obviously, this causes destruction of water, air, and

land resources, as they become fouled by waste. This has obvious negative side-effects for orgnisms on

the planet, but there are 2 important issues associated with pollution that aren’t always discussed.

Biological magnification-while energy decreases as it moves up the food chain, pollutants and toxins, like DDT, concentrate.

Eutrophication-believe it or not, this IS a bad thing. Over-fertilization nourishes the water, causing algal blooms. Not only can these be toxic to animals, but they are r-strategists, so they die, sink, and are decomposed at the bottom of bodies of water (mainly freshwater). Decomposition is an oxygen-consuming process, which leaves the bottom waters anoxic, causing fish-kills

Other Environmental Problems Acid Rain-Sulphur-containing compounds

belched from smokestacks turn into sulphuric acid in the atmosphere

Deforestation-clear-cutting of forests for logging and expanding human population. This is particularly bad b/c the nutrients in tropical rain forests are in the canope.

Desertification-overgrazing of grasslands bordering deserts turns these into deserts.

All of these can lead to endangerment of or reduction in species and biodiversity.

Figure 55-10

Satellite view of deforestation in Rondônia, BrazilThe devastation of deforestation

1975 2001

Figure 55-6

Terrestrial

Freshwater

Marine

Sustainable Practices

These are things that humans can do to reduce our impact on the biosphere.

Examples include: reforestation, smoke-stack filters, reduction of fossil fuel consumption, smart use of fertilizers, plowing and strip cropping to reduce erosion, use of biological methods for controling pests, establishing protected areas, etc