university of phoenix sci256 week 2 ecosystems and populations ch 4-9, 22 ecosystems and energy,...

University of PhoenixUniversity of PhoenixSci256 Week 2Sci256 Week 2

Ecosystems and PopulationsEcosystems and Populations

Ch 4-9, 22Ecosystems and Energy,

Ecosystems and Living Organisms, Ecosystems and the Physical Environment,

Major Ecosystems of the World, Understanding Population Change,

Facing the Problems of OverpopulationControlling Pests

Ecosystems, Energy, and Trophic PyramidsEcosystems, Energy, and Trophic PyramidsChapter 4Chapter 4

Ecosystems And EnergyEcosystems And Energy

EnergyEnergyLaws of ThermodynamicsLaws of ThermodynamicsPhotosynthesis/RespirationPhotosynthesis/Respiration

Trophic PyramidsTrophic Pyramids

Energy FlowEnergy Flow

Food WebsFood Webs

ProductivityProductivity

EcologyEcology

= The study of relationships between organisms = The study of relationships between organisms and their environment.and their environment.

EnvironmentEnvironment == biotic and abiotic factors that biotic and abiotic factors that affect an organism during its lifetime.affect an organism during its lifetime.

AbioticAbiotic factors: factors: nonliving parts of thenonliving parts of the environment - water, minerals, sunlight, climate.

BioticBiotic factors: factors: organisms that are a part organisms that are a part of the environmentof the environment

Stand and DeliverStand and Deliver

Nearby (Maryland or your home) biotic components?

Laws of ThermodynamicsLaws of Thermodynamics

First Law (ConservationFirst Law (Conservation of Energy)of Energy)Energy is neither created nor destroyed; it Energy is neither created nor destroyed; it is always conserved.is always conserved.

Second LawSecond LawEnergy always tends to go from a more Energy always tends to go from a more usable form to a less usable form, so the usable form to a less usable form, so the amount of energy available to do work amount of energy available to do work decreases (entropy occurs). decreases (entropy occurs).

Consequence Of Laws Of Consequence Of Laws Of Thermodynamics For Living Thermodynamics For Living

OrganismsOrganisms

Organisms require a constant input of Organisms require a constant input of energy to maintain a high level of energy to maintain a high level of

organization.organization.

““Feed Me Seymour!” – Feed Me Seymour!” – Little Shop of HorrorsLittle Shop of Horrors

Types of Energy SystemsTypes of Energy SystemsThis Slide is Yellow

PhotosynthesisPhotosynthesis(Transformation of Light Energy)(Transformation of Light Energy)

6 CO6 CO22 + 12 H + 12 H22O + radiant energy O + radiant energy

C6H12O6 + 6 H+ 6 H22O + 6 OO + 6 O22

Stores energy in chemical bondsStores energy in chemical bonds

RespirationRespiration(Transformation of Chemical Energy)(Transformation of Chemical Energy)

CC66HH1212OO66 + 6 H + 6 H22O + 6 OO + 6 O22

6 CO6 CO22 +12 H +12 H22O + energyO + energy

Provides energy for “work”Provides energy for “work”

Ecological Studies Show How the Whole Ecological Studies Show How the Whole System Works.System Works.

Focus:Focus:

1.1. The roles played by members of a The roles played by members of a community community

2. The energy/resource structure of the 2. The energy/resource structure of the system. system.

Ecosystem OrganizationEcosystem Organization

Each system can help clarify different Each system can help clarify different issues.issues.

1. Trophic Pyramids1. Trophic Pyramids

2. Food Webs2. Food Webs

3. Nutrient Cycles3. Nutrient Cycles

(Autotrophs and Heterotrophs)

1.1. The number of The number of trophic levels are trophic levels are limited. At each limited. At each trophic level, there trophic level, there is a dramatic is a dramatic reduction in energy.reduction in energy.

2.2. Eating at lower Eating at lower trophic levels means trophic levels means more resources are more resources are available. available.

Pyramids of Pyramids of Energy Energy Suggests:Suggests:

Pyramids of Energy Suggests:Pyramids of Energy Suggests:

1.1. The number of trophic levels are limited. The number of trophic levels are limited. At each trophic level, there is a dramatic At each trophic level, there is a dramatic reduction in energy.reduction in energy.

2.2. Eating at lower trophic levels means more Eating at lower trophic levels means more resources available. resources available.

3.3. Movement up the pyramid explains the Movement up the pyramid explains the problems of problems of Biological MagnificationBiological Magnification

((DDT, PCBs, etc.)DDT, PCBs, etc.)

Biological MagnificationBiological Magnification

Concentration of a compound can increase at Concentration of a compound can increase at higher trophic levels because higher trophic levels because each individualeach individual in a higher trophic level must eat in a higher trophic level must eat manymany individuals of a lower trophic level to surviveindividuals of a lower trophic level to survive. .

Although the energy acquired by eating those Although the energy acquired by eating those organisms from a lower trophic level is used, organisms from a lower trophic level is used, the toxic compounds may remain (Especially the toxic compounds may remain (Especially true for compounds that are stored in fats and true for compounds that are stored in fats and are not easily broken down.).are not easily broken down.).

Food websFood webs

Are interlocking Are interlocking food chains food chains based on which based on which organisms eat organisms eat which. which.

Arrows show the Arrows show the direction of direction of food/energy food/energy flowflow

Ecological PyramidsEcological Pyramids

• Pyramid of energyPyramid of energy

• Pyramid of numbersPyramid of numbers

• Pyramid of biomassPyramid of biomass

Gross Primary ProductivityGross Primary Productivity = total = total amount of energy captured by amount of energy captured by photosynthesis for an ecosystem.photosynthesis for an ecosystem.

Keystone SpeciesKeystone Species

Food webs suggest that keystone species may Food webs suggest that keystone species may be important. Changes in one species may be important. Changes in one species may dramatically change the entire ecosystem dramatically change the entire ecosystem through links in the webthrough links in the web. .

Keystone Species = Keystone Species = Species whose presence is Species whose presence is essential to community function and stability essential to community function and stability (e.g., Krill in Antarctica).(e.g., Krill in Antarctica).

Evolution, Natural Selection, and Evolution, Natural Selection, and Communities Communities

Chapter 5 – Pt 1Chapter 5 – Pt 1

Topics And ObjectivesTopics And Objectives

Evolution by Natural SelectionEvolution by Natural Selection

CommunityCommunity

Species InteractionsSpecies Interactions

Species DiversitySpecies Diversity

SuccessionSuccession

Evolution and Natural SelectionEvolution and Natural Selection

The Underlying Mechanisms of Species Diversity

Charles DarwinCharles Darwin

"There is grandeur in this view of "There is grandeur in this view of life, with its several powers, having life, with its several powers, having been originally breathed by the been originally breathed by the Creator into a few forms or into Creator into a few forms or into one; and that, whilst this planet has one; and that, whilst this planet has gone on cycling on according to the gone on cycling on according to the fixed law of gravity, from so simple fixed law of gravity, from so simple a beginning endless forms most a beginning endless forms most beautiful and most wonderful have beautiful and most wonderful have been, and are being evolved.“been, and are being evolved.“

--The Origin of Species--The Origin of Species

Charles DarwinCharles Darwin

Darwin was born into the Darwin was born into the family of a prominent family of a prominent physician on February 12, physician on February 12, 1809, in Shrewsbury, England. 1809, in Shrewsbury, England. His mother was the daughter of His mother was the daughter of Josiah Wedgewood, founder of Josiah Wedgewood, founder of the famous pottery firm. In the famous pottery firm. In 1825 Charles entered the 1825 Charles entered the University of Edinburgh to University of Edinburgh to become a physician. Two become a physician. Two years later he entered years later he entered Cambridge University to study Cambridge University to study for the clergy.for the clergy.

GranthamGrantham

Charles DarwinCharles DarwinIn 1831 Darwin joined the In 1831 Darwin joined the HMS Beagle HMS Beagle as the naturalist for a as the naturalist for a circumnavigation of the world; the voyage lasted five years. It was circumnavigation of the world; the voyage lasted five years. It was his observations from that trip that lead to his proposal of his observations from that trip that lead to his proposal of natural natural selectionselection to explain the diversity of organisms. to explain the diversity of organisms.

It was not until 1859 that Darwin finally published his It was not until 1859 that Darwin finally published his Origin of Origin of Species.Species.

Darwin’s FinchesDarwin’s Finches

""The most curious fact is the perfect The most curious fact is the perfect gradation in the size of the beaksgradation in the size of the beaks in the in the different species of Geospiza, from one as different species of Geospiza, from one as large as that of a hawfinch to that of a large as that of a hawfinch to that of a chaffinch, and (if Mr. Gould is right in chaffinch, and (if Mr. Gould is right in including in his sub-group, Certhidea, in the including in his sub-group, Certhidea, in the main group), even to that of a warbler. The main group), even to that of a warbler. The largest beak in the genus Geospiza is show inlargest beak in the genus Geospiza is show in Fig. 1Fig. 1, and the smallest in, and the smallest in Fig. 3 Fig. 3; but instead ; but instead of their being only one intermediate species, of their being only one intermediate species, with a beak of the size shown in with a beak of the size shown in Fig. 2Fig. 2, there , there are no less than six species with insensibly are no less than six species with insensibly graduated beaks. The beak of the sub-group graduated beaks. The beak of the sub-group Certhidea, is shown inCerthidea, is shown in Fig. 4 Fig. 4. The beak of . The beak of Cactornis is somewhat like that of a starling; Cactornis is somewhat like that of a starling; and that of the fourth sub-hroup, and that of the fourth sub-hroup, Camarhynchus, is slightly parrot-shaped. Camarhynchus, is slightly parrot-shaped. Seing this gradation and diversity of Seing this gradation and diversity of structure in one small, intimately related structure in one small, intimately related group of birds, one might really fancy that group of birds, one might really fancy that from an original paicity of birds in this from an original paicity of birds in this archipelago, one species had been taken archipelago, one species had been taken and modified for different endsand modified for different ends [ [stressstress added]." Charles R. Darwin, 1845, added]." Charles R. Darwin, 1845, The The Voyage of the BeagleVoyage of the Beagle [Edited by Leonard [Edited by Leonard Engel, 1962, NY: Doubleday], pages 380-Engel, 1962, NY: Doubleday], pages 380-381.381.

Darwins’s Four PremisesDarwins’s Four Premises

1.1. Each species produces more offspring than Each species produces more offspring than will survive to maturity.will survive to maturity.

2.2. Individuals in a population exhibit variation.Individuals in a population exhibit variation.

3.3. There are limits on population growth There are limits on population growth imposed by the environment.imposed by the environment.

4.4. There is differential reproductive success There is differential reproductive success among individuals within a population.among individuals within a population.

What is Evolution?What is Evolution?

• Descent with modification.Descent with modification.

• Change in the genetic structure of a Change in the genetic structure of a population.population.

Mechanisms That Change the Mechanisms That Change the Genetic Structure of a Population Genetic Structure of a Population And Cause Evolutionary Change?And Cause Evolutionary Change?

1.1. Genetic mutationsGenetic mutations

2.2. Genetic driftGenetic drift (Isolation of populations and (Isolation of populations and different accumulations of mutations)different accumulations of mutations)

3.3. Founder effectFounder effect (Small initial reproductive (Small initial reproductive populations with limited genetic diversity)populations with limited genetic diversity)

4.4. Natural selectionNatural selection (Differential reproductive (Differential reproductive potential)potential)

What Is Natural Selection?What Is Natural Selection?

• Differential survival and reproduction Differential survival and reproduction among individuals of a population.among individuals of a population.

• Response to selection pressures.Response to selection pressures.

• Genetic variations refer to the number Genetic variations refer to the number of individuals within a population each of individuals within a population each having a unique combination of traits.having a unique combination of traits.

Relationship of Evolution and Relationship of Evolution and Selection Pressures to Selection Pressures to Environmental ScienceEnvironmental Science

1.1. Biodiversity arises through evolution.Biodiversity arises through evolution.

1.1. Human disturbance changes selective Human disturbance changes selective pressures.pressures.

2.2. Conservation of individual species.Conservation of individual species.

Process of Evolution through Natural Process of Evolution through Natural SelectionSelection

1.1. OverproductionOverproduction

2.2. Resources limit population growthResources limit population growth

3.3. Heritable variation in traitsHeritable variation in traits..

4.4. Differential survival and/or reproductionDifferential survival and/or reproduction

Potential Selective PressuresPotential Selective Pressures

AbioticAbioticTemperatureTemperaturePrecipitationPrecipitationpH (acidity)

BioticBioticPredationPredationDiseaseDiseaseCompetitionCompetition

Types of SelectionTypes of Selection

Stabilizing SelectionStabilizing Selection

Directional SelectionDirectional Selection

Disruptive SelectionDisruptive Selection

Example of Natural Selection: Example of Natural Selection: Peppered MothPeppered Moth

Peppered MothsPeppered Moths

CommunityCommunity

Association of different Association of different populations of organisms that populations of organisms that live and interact together in the live and interact together in the same place at the same time.same place at the same time.

The Underlying Bases of The Underlying Bases of Community Structure is Community Structure is

Species InteractionsSpecies Interactions

And NUH is the letter I use to spell NutchesWho live in small caves, know as Nitches, for Nutches.

These Nutches have troubles, the biggest of which isThe fact that there are many more Nutches than Nitches.

Each Nutch in a Nitch knows that some other NutchWould like to move into his Nitch very much.

So each Nutch in a Nitch has to watch that small Nitchor Nutches who haven't got Nitches will snatch.

Dr. Suess (Geisel, 1955)

Limiting FactorsLimiting Factors

Summary of Community StructureSummary of Community Structure

The numbers and types of organisms that exist in The numbers and types of organisms that exist in an ecological niche are dependent upon both the an ecological niche are dependent upon both the physiological resources available and the physiological resources available and the relationships between different species. relationships between different species.

Resources are limited in an ecosystem, and Resources are limited in an ecosystem, and species survive because of strategies that ensure species survive because of strategies that ensure adequate access to the resources and minimize adequate access to the resources and minimize competition for resources with other species. competition for resources with other species.

Summary of Community StructureSummary of Community StructureAs resources change and species interactions As resources change and species interactions change over time, those members of the species change over time, those members of the species best adapted to the new conditions are the best adapted to the new conditions are the individuals that live to reproduce and pass on individuals that live to reproduce and pass on their genetic information.their genetic information.

Thus, because of our ever changing world, over Thus, because of our ever changing world, over time there are changes in the gene pool of a time there are changes in the gene pool of a population (i.e., evolution). population (i.e., evolution). Evolution Evolution is notis not a a directed choice, it is the consequence of natural directed choice, it is the consequence of natural selection.selection. In many cases natural selection leads In many cases natural selection leads to the loss of an entire species (e.g., the dodo).to the loss of an entire species (e.g., the dodo).

Species Diversity and SuccessionSpecies Diversity and Succession

The Dynamics of Community The Dynamics of Community StructureStructure

Chapter 5 – Pt 2

Resource PartitioningResource Partitioning

Resource partitioning is reduced competition by evolving differences in resource use.

Resource partitioning Resource partitioning occurs when natural occurs when natural selection acts to favor selection acts to favor individuals of species individuals of species that reduce competition that reduce competition by becoming more by becoming more specialized.specialized.

Warblers as Warblers as examples of examples of Resource Resource PartitioningPartitioning - - each species each species spends at least spends at least 50% of foraging 50% of foraging time in time in designated areasdesignated areas

CoevolutionCoevolution

CoevolutionCoevolution is is reciprocal evolution. That is, an reciprocal evolution. That is, an interdependent evolution of two or more species interdependent evolution of two or more species that occurs as a result of their interactions (suggests that occurs as a result of their interactions (suggests the importance of interactions for the structure of the importance of interactions for the structure of biotic communities - if one species is lost, the co-biotic communities - if one species is lost, the co-evolved species will be affected).evolved species will be affected).

For predator/prey = “Arms race” (i/.e., The evolution of predator strategies to catch prey, and the responding prey strategies to escape predators.).

Evidence of CoevolutionEvidence of CoevolutionEach of the following either improves the chance of Each of the following either improves the chance of catching prey or avoiding predator.catching prey or avoiding predator.

Predators:Predators:Rapid pursuitAmbush

Prey:SpeedSpeedCrypsis (camouflage)Crypsis (camouflage)Aposematic coloration - warningAposematic coloration - warningDistasteful nature - Monarch butterfliesDistasteful nature - Monarch butterfliesDangerous nature - Dangerous nature - wasps, beesMimicryMimicryGroup livingGroup living

Aposematic ColorationAposematic Coloration

Cryptic ColorationCryptic Coloration

Dangerous NatureDangerous Nature

Distasteful Distasteful NatureNature

MimicryMimicry

Plant ToxinsPlant Toxins

MutualismMutualism

Is an interaction between two species where Is an interaction between two species where both benefit (often co-evolved relationship)both benefit (often co-evolved relationship)

Examples:Examples:

Lichens: fungi/algae (or cyanobacteria). Protected environment in exchange for photosynthates.

Mycorrhizae: plants/fungi make connections with the roots of plants. Get photosynthates in return for nutrients, especially phosphorous.

Rhizobium bacteria/some plants: nitrogen/photosynthates

LichensLichens

Rhizobium bacteriaRhizobium bacteria

CommensalismCommensalism

Interaction wherein one species benefits, while Interaction wherein one species benefits, while the other is unaffected.the other is unaffected.

Examples:Examples:

Cattle and cattle egretsCattle and cattle egrets

Eyelash mitesEyelash mites

Cattle EgretsCattle Egrets

Eyelash MitesEyelash Mites

Benefits from DiversityBenefits from Diversity

Utilitarian Utilitarian FoodFoodDrugs and MedicinesDrugs and Medicines

AestheticAestheticRecreation/tourismRecreation/tourism

EcologicalEcologicalCommunity StabilityCommunity Stability

MoralMoral

Diverse Food SourcesDiverse Food Sources

Drugs and MedicinesDrugs and Medicines

Recreation/TourismRecreation/Tourism

Determinants of Species DiversityDeterminants of Species Diversity

1.1. AbundanceAbundance of ecological niches of ecological niches

2.2. DominanceDominance of individual species of individual species

3.3. EnvironmentalEnvironmental stress of habitat stress of habitat

Effect of Abundance of NichesEffect of Abundance of Niches

SuccessionSuccession

SuccessionSuccession is the directional changes in the is the directional changes in the community through time. Changes occur community through time. Changes occur because species alter the soil, shelter, because species alter the soil, shelter, humidity, etc. It results from the humidity, etc. It results from the differential ability of organisms to colonize differential ability of organisms to colonize disturbed areas and from environmental disturbed areas and from environmental changes.changes.

Move from Move from pioneerpioneer community through community through successional communities to a successional communities to a climaxclimax community.community.

Primary SuccessionPrimary Succession

Primary succession is at a new, sterile site. Primary succession is at a new, sterile site.

Conditions that may cause primary Conditions that may cause primary succession are glaciers, winds, fires, or succession are glaciers, winds, fires, or volcanoes producing glacial moraines, volcanoes producing glacial moraines, dunes, and lava fields. The key point is dunes, and lava fields. The key point is that the soil has been disturbed.that the soil has been disturbed.

Indiana DunesIndiana Dunes

Glacial MoraineGlacial Moraine

Mount Saint HelensMount Saint Helens

Mount Saint HelensMount Saint Helens

Lake Obscurity Lake Obscurity 10 miles N10 miles N

Secondary SuccessionSecondary Succession

Secondary succession is recovery of a Secondary succession is recovery of a disturbed site back to a climax disturbed site back to a climax community. The soil remains relatively community. The soil remains relatively intact (e.g., cause of secondary intact (e.g., cause of secondary succession is cutting oak trees from a succession is cutting oak trees from a forest)forest)

ProgressionProgression

Examples of Examples of ProgressionProgression

Lichens and Mosses of Early Lichens and Mosses of Early SuccessionSuccession

Plants of Middle Succession Plants of Middle Succession

Timeline for Hardwood Climax Timeline for Hardwood Climax ForestForest

Succession Often is the Result of Succession Often is the Result of Human InterventionHuman Intervention

Succession May Be FacilitatedSuccession May Be Facilitated

““Nurse plants”Nurse plants” may often facilitate the may often facilitate the progression toward a climax system.progression toward a climax system.

The idea of facilitating species is important The idea of facilitating species is important concept for restoration ecology).concept for restoration ecology).

Facilitation of One Species by Facilitation of One Species by AnotherAnother

e.g., Saguaro Cactuse.g., Saguaro Cactus need nurse plants need nurse plants (mesquite) to shield (mesquite) to shield seeds from seeds from consumption and to consumption and to protect young plants protect young plants from cold nights.from cold nights.

Question: Does Succession Apply Question: Does Succession Apply Only to Restoration of Land Only to Restoration of Land

Ecosystems?Ecosystems?

No!! No!! – Aquatic ecosystems go through – Aquatic ecosystems go through progressive stages to reach a stable progressive stages to reach a stable community structure.community structure.

Nutrient Nutrient (Geobiochemical) Cycles (Geobiochemical) Cycles

Chapter 6 - Pt 1Chapter 6 - Pt 1

The Underlying Bases of The Underlying Bases of AbioticAbiotic ChangesChanges

Wump World by Bill PeetWump World by Bill PeetWump World takes us to a tiny and perfect world, populated only by the gentle and sweet Wumps. But the peace is soon destroyed by the Pollutians, who arrive in strangely primitive looking spaceships. Their intent is anything but primitive though, as the Pollutians are bent on covering every surface of the Wump’s world with freeways and skyscrapers. They’ve already polluted their own world beyond livability.

Wump World by Bill PeetWump World by Bill Peet


Departure of the PollutiansDeparture of the Pollutians

The story moves from the poor little Wumps, shivering underground and cringing at all the noise pollution, to the clueless Pollutians. Soon they dispatch more exploratory spacemen to find a new world, because the Wump World is almost all used up.


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BBuutt tthhee WWuummpp WWoorrlldd wwoouulldd nneevveerr bbee qquuiittee tthhee ssaammee..

In time the murky skies would clear up and the rains would In time the murky skies would clear up and the rains would wash the scum from the rivers and lakes. The tall buildings wash the scum from the rivers and lakes. The tall buildings would come tumbling down and the freeways would would come tumbling down and the freeways would crumble away. And in time the green growth would wind its crumble away. And in time the green growth would wind its way up through the rubble.way up through the rubble.

But the Wump World would never be quite the same.But the Wump World would never be quite the same.

Flow of Energy and MatterFlow of Energy and Matter

Energy Flow (Review)Energy Flow (Review)

Biogeochemical CyclesBiogeochemical Cycles

Biogeochemical cycles describe the ecosystem Biogeochemical cycles describe the ecosystem by the transfer of elements through the system.by the transfer of elements through the system.

By examining the cycles we can By examining the cycles we can look at the look at the fluxes of nutrients (sources and sinks) and better fluxes of nutrients (sources and sinks) and better understand human-caused imbalances.understand human-caused imbalances.

Biogeochemical Cycles Processes Biogeochemical Cycles Processes

Regulate nutrientsRegulate nutrients

Influence climate stabilityInfluence climate stability

Influence the purity of drinking waterInfluence the purity of drinking water

Basic CyclesBasic Cycles

1.1. Hydrologic (water)Hydrologic (water)

2.2. Carbon Carbon

3.3. Nitrogen Nitrogen

4.4. Phosphorus Phosphorus

5.5. Sulfur Sulfur

Water CycleWater Cycle

One estimate of global water distribution:

Estimate of Global Water Distribution – Gleick, 1996Estimate of Global Water Distribution – Gleick, 1996

VolumeVolume

(1000 km(1000 km33)) Percent of Percent of

Total WaterTotal Water Percent of Percent of

Fresh WaterFresh Water Oceans, Seas, & BaysOceans, Seas, & Bays 1,338,0001,338,000 96.596.5 --

Ice caps, Glaciers, & Ice caps, Glaciers, & Permanent SnowPermanent Snow

24,06424,064 1.741.74 68.768.7

GroundwaterGroundwater 23,40023,400 1.71.7 --

FreshFresh (10,530)(10,530) (0.76)(0.76) 30.130.1

SalineSaline (12,870)(12,870) (0.94)(0.94) --

Soil MoistureSoil Moisture 16.516.5 0.0010.001 0.050.05

Ground Ice & PermafrostGround Ice & Permafrost 300300 0.0220.022 0.860.86

LakesLakes 176.4176.4 0.0130.013 --

FreshFresh (91.0)(91.0) (0.007)(0.007) 0.260.26

SalineSaline (85.4)(85.4) (0.006)(0.006) --

AtmosphereAtmosphere 12.912.9 0.0010.001 0.040.04

Swamp WaterSwamp Water 11.4711.47 0.00080.0008 0.030.03

RiversRivers 2.122.12 0.00020.0002 0.0060.006

Biological WaterBiological Water 1.121.12 0.00010.0001 0.0030.003

TotalTotal 1,385,9841,385,984 100.0100.0 100.0100.0

Carbon Cycle/Global Warming Carbon Cycle/Global Warming Affect the Water CycleAffect the Water Cycle

Increased temperature (carbon dioxide) Increased temperature (carbon dioxide) more more evaporatoinevaporatoin increased precipitation, runoff, and soil increased precipitation, runoff, and soil moisture.moisture.

Feedback from increased temp:Feedback from increased temp:

Increased cloud cover Increased cloud cover (1) reflects light back into (1) reflects light back into the atmosphere, so decreased temp.the atmosphere, so decreased temp.

Increased cloud cover Increased cloud cover (2) water vapor absorbs heat (2) water vapor absorbs heat in the atmosphere, so in the atmosphere, so increased temp.increased temp.

Carbon CycleCarbon Cycle

Diagram of Carbon CycleDiagram of Carbon Cycle

Relevance of Carbon Cycle Relevance of Carbon Cycle to Climate Changeto Climate Change

COCO22 in atmosphere is increasing 0.4% a year (= 40% in in atmosphere is increasing 0.4% a year (= 40% in

100 yr.)100 yr.)

Increasing COIncreasing CO22 causes increased temperatures. causes increased temperatures.

(Greenhouse effect)(Greenhouse effect)

Non-water captured Heat captured by the atmosphere:Non-water captured Heat captured by the atmosphere:COCO22 = 50% = 50%

CHCH44 = 20% = 20%

CFCs = 15%CFCs = 15%NONO22, H, H22O, OO, O33 = 15% = 15%

LightLightUltraviolet lightUltraviolet light is absorbed by ozone.is absorbed by ozone.

Visible lightVisible light passes through atmosphere, then it passes through atmosphere, then it is is absorbedabsorbed by earth and water, re-radiated by earth and water, re-radiated as as direct heat or direct heat or infrared lightinfrared light (which also may be (which also may be absorbed by COabsorbed by CO22, CH, CH44 , or H , or H22O to produce heat) O to produce heat) which contributes to which contributes to the the greenhouse effectgreenhouse effect..

Light doesn’t cycle – it Light doesn’t cycle – it is in balance. is in balance.

Nitrogen CycleNitrogen Cycle

Effects of Increased NitrogenEffects of Increased Nitrogen

1.1. Loss of soil nutrients (calcium, potassium)Loss of soil nutrients (calcium, potassium)

2.2. Acidification of rivers and lakes (fertilizers Acidification of rivers and lakes (fertilizers and combustion of coal).and combustion of coal).

3.3. Increases nitrogen oxides in the atmosphereIncreases nitrogen oxides in the atmosphere

(greenhouse gas—global warming). (greenhouse gas—global warming).

(reduce ozone—increasing UV (reduce ozone—increasing UV penetration).penetration).

Effects of Increased NitrogenEffects of Increased Nitrogen

4.4. Aids in spreading weeds into nitrogen poor Aids in spreading weeds into nitrogen poor areas (+Eutrophication of lakes, ponds, areas (+Eutrophication of lakes, ponds, streams).streams).

5.5. Increasing nitrogen increases carbon fixation Increasing nitrogen increases carbon fixation (linked to carbon cycle).(linked to carbon cycle).

6.6. Increasing acidification increases weathering Increasing acidification increases weathering (increases rate of phosphorous cycle).(increases rate of phosphorous cycle).

Phosphorus CyclePhosphorus Cycle

Diagram of Phosphorus CycleDiagram of Phosphorus Cycle

SulphurSulphur Cycle Cycle

Sulphur CycleSulphur Cycle

Sulphur Sulphur CycleCycle

ConclusionsConclusions

In contrast to energy, which moves in one In contrast to energy, which moves in one direction through the ecosystem, materials direction through the ecosystem, materials are continually recycled from the are continually recycled from the abioticabiotic environment to organisms environment to organisms bioticbiotic, and , and back to the back to the abioticabiotic environment. environment.

Changes in one of the biogeochemical Changes in one of the biogeochemical cycles usually influences the other cycles usually influences the other biogeochemical cycles.biogeochemical cycles.

Climate Climate Chapter 6Chapter 6

Pt 2Pt 2

Ozone Hole Ozone Hole over over

AntarcticaAntarctica

Ban on Ban on fluorocarbons fluorocarbons began 1979began 1979

Solar Radiation Solar Radiation Albedo (Surface Reflectivity)Albedo (Surface Reflectivity)

AlbedoAlbedo refers to ratio of the amount of reflected refers to ratio of the amount of reflected light to incident light. The higher the number the light to incident light. The higher the number the greater the proportion of light is reflected back.greater the proportion of light is reflected back.

Glaciers and ice packs have an albedo of 0.8-0.9 Glaciers and ice packs have an albedo of 0.8-0.9 (80-90%), while oceans and forests have an (80-90%), while oceans and forests have an albedo of around 0.05 (5%).albedo of around 0.05 (5%).

On average, 30% of solar radiation is immediately On average, 30% of solar radiation is immediately reflected back into space.reflected back into space.

Global Map of Land AlbedoGlobal Map of Land Albedo

Conclusion: the greater the angle light strikes the Conclusion: the greater the angle light strikes the earth, the greater amount of area over which each earth, the greater amount of area over which each unit of energy is spread.unit of energy is spread.

Solar Radiation Solar Radiation Temperature Change with LatitudeTemperature Change with Latitude

Solar RadiationSolar Radiation

Occurs in a range of wavelengths represented by the Occurs in a range of wavelengths represented by the electromagnetic spectrumelectromagnetic spectrum..

ReachesReaches Earth's atmosphere in the form of ultraviolet Earth's atmosphere in the form of ultraviolet radiation, visible light, and infrared radiation.radiation, visible light, and infrared radiation.

Incoming short and intermediate wavelength Incoming short and intermediate wavelength radiation may be: absorbed by gases in the radiation may be: absorbed by gases in the atmosphere, reflected back into space from the atmosphere, reflected back into space from the atmosphere or earth's surface, or absorbed by the atmosphere or earth's surface, or absorbed by the earth's surfaceearth's surface..

Solar RadiationSolar RadiationIncoming Incoming andand outgoing outgoing

long wavelength long wavelength radiation is absorbed by radiation is absorbed by water vapor, carbon water vapor, carbon dioxide, and other gases dioxide, and other gases in the atmospherein the atmosphere..

The greenhouse effect The greenhouse effect occurs when long occurs when long wavelength radiation is wavelength radiation is absorbed in the absorbed in the tropospheretroposphere

Solar Patterns are the Basis of Solar Patterns are the Basis of ClimateClimate

Earth

The distance The distance through through atmosphere is atmosphere is different at different at high versus high versus low latitudes.low latitudes.

The Earth at 23.5The Earth at 23.5OO Tilt TiltSeasonal VariationSeasonal Variation..

Distinct zones of Distinct zones of contrasting temperatures contrasting temperatures and compositions.and compositions.

ThermosphereThermosphere - high - high temperature (includes temperature (includes ionosphere - auroras).ionosphere - auroras)..MesosphereMesosphere - low - low temperatures.temperatures.StratosphereStratosphere - high - high levels of Ozone. levels of Ozone. Absorbs ultraviolet rays.Absorbs ultraviolet rays.TroposphereTroposphere - nitrogen - nitrogen and oxygen; weather.and oxygen; weather..

AtmosphereAtmosphere

Structure of AtmosphereStructure of Atmosphere

The atmosphere can be divided into four thermal The atmosphere can be divided into four thermal layers: layers: troposphere, stratosphere, mesosphere, and troposphere, stratosphere, mesosphere, and thermosphere. thermosphere.

The boundary with space is at an altitude of The boundary with space is at an altitude of approximately 500 km.approximately 500 km.

Air temperatures decrease upward in the troposphere Air temperatures decrease upward in the troposphere (to a minimum of approximately -50(to a minimum of approximately -50ooC) which contains C) which contains our weather systems. Bulk of atmospheric gases our weather systems. Bulk of atmospheric gases (~75%) in this layer.(~75%) in this layer.

Structure of AtmosphereStructure of Atmosphere

Temperatures increase with Temperatures increase with altitude in the stratosphere altitude in the stratosphere as ozone absorbs incoming as ozone absorbs incoming solar radiationsolar radiation..

Temperatures decline again Temperatures decline again in the mesosphere but in the mesosphere but increase in the increase in the thermosphere. thermosphere.

What are we breathing?What are we breathing?

Air Mass FormationAir Mass Formation

General Air PatternsGeneral Air Patterns

Atmospheric Circulation PatternAtmospheric Circulation Pattern

The sun, through heating of land and air, The sun, through heating of land and air, drives the earth’s patterns of rains, winds, and drives the earth’s patterns of rains, winds, and ocean currents.ocean currents.

Air on the moveAir on the move

Coriolis Coriolis EffectEffect

Cell Names…Cell Names…

http://goes-rap.cira.colostate.edu/GOES-10/GEMS/Original/JPEG/Current/fulldisk_c01.jpg

Global Patterns of Air Global Patterns of Air Circulation/PrecipitationCirculation/Precipitation

• Air Air risesrises at the equator (equator = hot) First at the equator (equator = hot) First convection cell is highest because most energyconvection cell is highest because most energy

• Adiabatic coolingAdiabatic cooling

• Rain occurs (cool air holds less water).Rain occurs (cool air holds less water).

• Air from the North and South comes in to replace it.Air from the North and South comes in to replace it.

• Coriolis effectCoriolis effect - air is deflected because of - air is deflected because of momentummomentum.

Air PressuresAir Pressures

Areas of High and Low Pressure Areas of High and Low Pressure Generate Surface WindsGenerate Surface Winds


Responsible Responsible for where for where wind blows wind blows from; wind from; wind patterns patterns influence influence regional regional weather.weather.

WindsWindsWind is the horizontal movement of air from areas Wind is the horizontal movement of air from areas of high to low pressureof high to low pressure..

High pressure regions are dominated by cold, High pressure regions are dominated by cold, descending airdescending air, while l, while low pressure areas are ow pressure areas are associated with warm, rising air masses.associated with warm, rising air masses.

Winds blow from high pressure to low pressure.Winds blow from high pressure to low pressure.

Winds are deflected from their course by the Winds are deflected from their course by the Coriolis EffectCoriolis Effect (to the right in the Northern (to the right in the Northern Hemisphere)Hemisphere)

Ocean Currents Due to Coriolis Effect Ocean Currents Due to Coriolis Effect and Land Massesand Land Masses

Ocean waters Ocean waters warmed in the warmed in the equatorial equatorial regions regions transport heat transport heat energy to energy to other parts of other parts of the globe.the globe.

Circulation of Warm and Cool Circulation of Warm and Cool Ocean Waters has a Moderating Ocean Waters has a Moderating

Effect on Coastal CitiesEffect on Coastal Cities

Effects of Effects of Upwelling and Upwelling and Downwelling Downwelling on Currentson Currents

When the wind blows When the wind blows parallel to a Northern parallel to a Northern Hemisphere coastline Hemisphere coastline and the ocean is to the and the ocean is to the right of the wind right of the wind direction, upwelling direction, upwelling can result. Wind in the can result. Wind in the opposite direction opposite direction produces downwelling.produces downwelling.

Upwellings Bring Nutrients to Upwellings Bring Nutrients to SurfaceSurface

ENSO (El NiENSO (El Niñño – Southern o – Southern Oscillation)Oscillation)

The Southern oscillation is a phenomenon that refers The Southern oscillation is a phenomenon that refers to the see-saw effect of surface air pressures in the to the see-saw effect of surface air pressures in the Eastern and Western Pacific Ocean. For Example, Eastern and Western Pacific Ocean. For Example, when air pressure recordings are high in Tahiti, they when air pressure recordings are high in Tahiti, they are low in Eastern Australia. are low in Eastern Australia.

Also noted was a cycle of varying Pacific Ocean Also noted was a cycle of varying Pacific Ocean temperatures which occurs annually on a small scale. temperatures which occurs annually on a small scale. This was recognized by Peruvian fishermen who This was recognized by Peruvian fishermen who called it El Nicalled it El Niñño (Christ Child) because it occurred o (Christ Child) because it occurred during the winter close to Christmas.during the winter close to Christmas.

Normally, have warm waters and heavy precipitation in the western Pacific.

El NiEl Niñño, have o, have warm waters warm waters migrate to the migrate to the eastern Pacific eastern Pacific along with the along with the convective cell convective cell and increased and increased rainfall.rainfall.

El NiEl Niñño and La Nio and La Niññaa

La Niñña (cold conditions)

Normal Conditions

El Niñño (warm conditions)

Climate Changes Associated with Climate Changes Associated with ENSO (El Nino in the media)ENSO (El Nino in the media)

http://proa.accuweather.com/www/phoenix2/includes/professional/misc/misc-sst.htm

Weather Phenomenon are Weather Phenomenon are Produced by the Circulation of Air Produced by the Circulation of Air

and Water.and Water.

ThunderstormsThunderstormsHurricanesHurricanesTornadoesTornadoesDroughtsDroughtsFloods Floods

Mountain Effects on PrecipitationMountain Effects on Precipitation

Six Climate RegionsSix Climate Regions

Sliding into ch 7Sliding into ch 7

Repeated weather patterns climateClimate effects plant growth The biosphere.

Major Ecosystems of the World

Two climate conditions, temperature and precipitation, determine the terrestrial regions.

Biomes

Earth’s Major Biomes – related to climatic zones of Chapter 6.

2

Altitude replicates effects of increasing Latitude on large mountains or mt. ranges.

3

Lacks Permafrost

Temperate mountains lack significant length of day changes seen in Arctic regions. Temperate mountains get more UV radiation.

Individual mountains are isolated ecosystems.

How Temperature/Latitude/Precipitation affect ecosystem locations & types.

4

A Biome PoemA Biome Poem

It is a large, relatively distinct terrestrial region characterized by similar climate, soil, plants, and animals, regardless of where it occurs in the world.

The Importance of FireThe Importance of Fire

The Role of Fire in Ecosystems -Releases minerals from organic materials.Removes plant cover, stimulating some seeds.May trigger erosion & landslides with the removal of root stabilization.Removes woody plants & trees from grasslands.Some pine cones require heat to “pop open”, releasing seeds for germination.

PopulationsPopulations Chapter 8Chapter 8

Factors Affecting Population Factors Affecting Population NumbersNumbers

Locally…Locally…

Biotic PotentialBiotic PotentialThe The Biotic Biotic PotentialPotential is the is the maximum rate maximum rate at which a at which a population population could increase could increase under ideal under ideal conditions. conditions.

Different species have different biotic Different species have different biotic potentials.potentials..

Biotic Potential of BacteriaBiotic Potential of Bacteria

Biotic Potential of FliesBiotic Potential of Flies

Biotic Potential of Humans?Biotic Potential of Humans?

Exponential GrowthExponential Growth

Think of exponential growth in terms of making Think of exponential growth in terms of making money. How much you increase your money. How much you increase your earnings will depend on:earnings will depend on:

1.1. How much principle you have (population How much principle you have (population

size) size)

2.2. The interest rate at which you are earning The interest rate at which you are earning money (the biotic potential)money (the biotic potential)

Reproduction changes with ageReproduction changes with age - proportion of individuals in - proportion of individuals in each reproductive class can have a large effect on population growth.each reproductive class can have a large effect on population growth.

Expanding: Population momentumExpanding: Population momentum: when young make large : when young make large proportion of the population, potential for proportion of the population, potential for rapid increase in rapid increase in natality when young reach reproductive age. ‘Bottom heavy’natality when young reach reproductive age. ‘Bottom heavy’

Stable:Stable: stationary phase. Mortality such that each class goes to the stationary phase. Mortality such that each class goes to the next class at the size the next class was at. next class at the size the next class was at. The population is at The population is at replacement numbers for births.replacement numbers for births.

Diminishing:Diminishing: natality has fallen below replacement numbers. natality has fallen below replacement numbers. ‘‘Top heavy’Top heavy’..

HUMAN POPULATIONHUMAN POPULATION2000 years ago2000 years ago 300 million people 300 million people

200 years ago 200 years ago under a billion people under a billion people

40 years ago40 years ago 3 billion people 3 billion people

20002000 6 billion people 6 billion people

Now, the population is growing by almost 78 million Now, the population is growing by almost 78 million more people each year. more people each year.

Two possible causes:Two possible causes:Life expectancy Life expectancy (age at mortality)(age at mortality)

FertilityFertility

Mortality and death rates: The primary cause of Mortality and death rates: The primary cause of population growth has been declining mortality. population growth has been declining mortality.

In the last 100 years, average life expectancy has risen by In the last 100 years, average life expectancy has risen by about 25 years - due to modern medicine, better food, and about 25 years - due to modern medicine, better food, and better sanitation (environment changed). better sanitation (environment changed).

Declining MortalityDeclining Mortality

Population USA Year 2000Population USA Year 2000

Comparison Population USA 2000 Comparison Population USA 2000 with 2050with 2050

20002000 20502050

Pre-repro

Reproductive

Post-repro

Population ConclusionPopulation ConclusionBy changing technology (health care/education) we have By changing technology (health care/education) we have changed the carrying capacity for the earth?changed the carrying capacity for the earth?

Economics and Life ExpectancyEconomics and Life Expectancy

Although life expectancy is predicted well by annualAlthough life expectancy is predicted well by annual per capita income, the correlation is good only up toper capita income, the correlation is good only up to about $4000.about $4000.

EMPOWER WOMEN? What would EMPOWER WOMEN? What would this mean for some societies?this mean for some societies?

Fertility Rates and Fertility Rates and Female LiteracyFemale Literacy

Fertility Rates and Birth Fertility Rates and Birth control (linked to literacy?)control (linked to literacy?)

Cultural Norms

ReligiousBeliefs

Overpopulation – Overpopulation – Chapter 9Chapter 9

Issues to Be ConsideredIssues to Be Considered

Population GrowthPopulation Growth – fertility rates, social and cultural – fertility rates, social and cultural roles, government rolesroles, government roles

Economic problemsEconomic problems – debt, hunger and starvation – debt, hunger and starvation

Available resourcesAvailable resources – renewable (time frames), non- – renewable (time frames), non-renewablerenewable

ConsumptionConsumption – expectations, reality – expectations, reality

UrbanizationUrbanization – trends, benefits, problems – trends, benefits, problems

How Do You Transition from One Type How Do You Transition from One Type of Population Dynamic to Another?of Population Dynamic to Another?

Demographic TransitionsDemographic Transitions

How does an expanding population become a stable How does an expanding population become a stable population?population?

In a In a stable population, both the birth rates and the death stable population, both the birth rates and the death rates are high.rates are high.

If the death rate decreases because of better If the death rate decreases because of better food/medical/sanitation procedures, the population grows.food/medical/sanitation procedures, the population grows.

With technological development the birth rate drops With technological development the birth rate drops (female education? investment in offspring?)(female education? investment in offspring?)

In mature high technology society the birth rates and death In mature high technology society the birth rates and death rates are low - also producing a stable population.rates are low - also producing a stable population.

Demographic TransitionsDemographic Transitions

Estimates of Most Populous Estimates of Most Populous Countries in 2025Countries in 2025

Ratio* = 2025:1950Ratio* = 2025:1950

Examples of Fertility RatesExamples of Fertility Rates

Regional Regional Population Population Distribution Distribution for People for People

Under Age 15Under Age 15

Fertility Rates USAFertility Rates USA

The Demographics of LifeThe Demographics of Life

USASource

www.populationconnection.org/Communications/demfacts.PDF

World

284.5 million Population, Mid 2001 6.1 billion

77 Population per square mile 118

15 Births per 1,000 people 22

9 Deaths per 1,000 people 9

2.1 Total fertility rate 2.8

21 % of pop under age 15 30

13 % of pop over age 65 7


USA World

49 Births per 1,000 women aged 15-19

50

7.1 Infant deaths per 1,000 live births

56

$29,240 GNP per capita (PPP) $6,300

995 kCal Avg daily per capita calories from animal products

441 kCal

66 Grains fed to livestock as % total grain consumption

3


USA World

19,674 kg Annual per capita carbon emissions

4,157 kg

5 % energy consumption from renewable sources

14

1 % female labor force in agriculture

52

4 % male labor force in agriculture

46

1,484 Tractor per 1,000 agricultural workers

20

NameName PopulationPopulation1. Cordova, Spain1. Cordova, Spain 450,000450,0002. Kaifeng, China2. Kaifeng, China 400,000400,0003. Constantinople (Istanbul), Turkey3. Constantinople (Istanbul), Turkey 300,000300,0004. Angkor, Cambodia4. Angkor, Cambodia 200,000200,0005. Kyoto, Japan5. Kyoto, Japan 175,000175,0006. Cairo, Egypt6. Cairo, Egypt 135,000135,0007. Baghdad, Iraq7. Baghdad, Iraq 125,000125,0008. Nishapur (Neyshabur), Iran8. Nishapur (Neyshabur), Iran 125,000125,0009. Al-Hasa, Saudi Arabia9. Al-Hasa, Saudi Arabia 110,000110,00010. Patan (Anhilwara), India10. Patan (Anhilwara), India 100,000100,000

Top 10 Cities of the Year 1000Top 10 Cities of the Year 1000

Estimates of Most Populous Estimates of Most Populous Countries in 2025Countries in 2025

Ratio* = 2025:1950Ratio* = 2025:1950

NameName PopulationPopulation1. New York, United States1. New York, United States 12,463,00012,463,0002. London, United Kingdom2. London, United Kingdom 8,860,000 8,860,0003. Tokyo, Japan3. Tokyo, Japan 7,000,000 7,000,0004. Paris, France4. Paris, France 5,900,000 5,900,0005. Shanghai, China5. Shanghai, China 5,406,000 5,406,0006. Moscow, Russia6. Moscow, Russia 5,100,000 5,100,0007. Buenos Aires, Argentina7. Buenos Aires, Argentina 5,000,000 5,000,0008. Chicago, United States 8. Chicago, United States 4,906,000 4,906,0009. Essen, Germany9. Essen, Germany 4,900,000 4,900,00010. Calcutta, India10. Calcutta, India 4,800,000 4,800,000


NameName PopulationPopulation1. Tokyo, Japan 1. Tokyo, Japan 28,000,00028,000,0002. Mexico City, Mexico2. Mexico City, Mexico 18,100,00018,100,0003. Bombay, India3. Bombay, India 18,000,00018,000,0004. Sao Paulo, Brazil4. Sao Paulo, Brazil 17,700,00017,700,0005. New York, United States 5. New York, United States 16, 600,00016, 600,0006. Shanghai, China 6. Shanghai, China 14,200,00014,200,0007. Lagos, Nigeria7. Lagos, Nigeria 13,500,00013,500,0008. Los Angeles, United State 8. Los Angeles, United State 13,100,00013,100,0009. Calcutta, India9. Calcutta, India 12,900,00012,900,00010. Buenos Aires, Argentina 10. Buenos Aires, Argentina 12,400,00012,400,000


How to achieve demographic How to achieve demographic transition?transition?

Family planning in Thailand - example of Family planning in Thailand - example of success success

•Annual population growth dropped from Annual population growth dropped from 3.3% in 1972 to 1.2% in 19953.3% in 1972 to 1.2% in 1995. . Mechai Viravaidya, founder of Community- Mechai Viravaidya, founder of Community-Based Family Planning Service (CBFPS). Based Family Planning Service (CBFPS). Focused on wants and needs of poor.Focused on wants and needs of poor.

How did Thailand Accomplish How did Thailand Accomplish Transition?Transition?

• Celebrity Celebrity

• Humor/break taboos of contraception Humor/break taboos of contraception

• Condom give-a-waysCondom give-a-ways

• Financial incentivesFinancial incentives

• Reduced infant mortality due to infectious Reduced infant mortality due to infectious diseases - clean water supply diseases - clean water supply

• Altered desired number of childrenAltered desired number of children (from 8 to 3) (from 8 to 3)

Contrast Thailand with ChinaContrast Thailand with China

In China, population control is a political outcomeIn China, population control is a political outcome

Women must receive “birth coupons” prior to Women must receive “birth coupons” prior to conceptionconception

Mass murders of girl babiesMass murders of girl babies

Abortions (even at 9 months gestation)Abortions (even at 9 months gestation)

Women of reproductive age examined and Women of reproductive age examined and monitoredmonitored

World PopulationWorld PopulationWhile demographic transition is occurring in many places, the world population keeps increasing at a rate of about 1.5% to 2% per year.

So the doubling rate So the doubling rate is between 35 and 46 is between 35 and 46 years!years!

Population Growth - OptimisticPopulation Growth - Optimistic

Growing prosperity will reduce desire for large Growing prosperity will reduce desire for large families.families.

Technology/communication will spread Technology/communication will spread information faster, making transition more rapid information faster, making transition more rapid than it occurred for more developed countries.than it occurred for more developed countries.

Fertility rates are dropping and populations are Fertility rates are dropping and populations are stabilizing (except in Africa).stabilizing (except in Africa).

Population Growth - PessimisticPopulation Growth - PessimisticDemographic trapDemographic trap: : poorer countries will poorer countries will not become not become developed enough developed enough for birth rate to be for birth rate to be reduced, causing reduced, causing population growth population growth rates to remain high. rates to remain high. Local catastrophe Local catastrophe will be the only will be the only regulatory control.regulatory control.

World Population GrowthWorld Population Growth

What will this mean for the planet?What will this mean for the planet?

Will we alter the human carrying capacity by our Will we alter the human carrying capacity by our impact? impact?

What What cancan we do to help stabilize the world’s we do to help stabilize the world’s population? population?

What What shouldshould we do? we do?

Consumption ComparisonsConsumption Comparisons

One quarter of the global population living in developed countries consumes for 80% of the world’s total energy.

USA alone accounts for 6% of the global population , but consumes 30% of its resources.

20% of the global population consumes 70% of its material resources and possesses 80% of the wealth. The majority of this 20% in centered in Canada, USA, Saudi Arabia, Australia, and Japan.


A child born today in the United States will by the age of A child born today in the United States will by the age of 75 years produce 52 tons of garbage, consume 10 million 75 years produce 52 tons of garbage, consume 10 million gallons of water and use 5 times the energy of a child born gallons of water and use 5 times the energy of a child born in the developing world. in the developing world.

The The United StatesUnited States uses approximately one quarter of the uses approximately one quarter of the world's fossil fuels and is the world's fossil fuels and is the largest contributorlargest contributor of carbon of carbon dioxide, undesirable combustion products, and dioxide, undesirable combustion products, and chlorofluorocarbons, chemicals that contribute to chlorofluorocarbons, chemicals that contribute to greenhouse warming and attack the Earth's ozone shield. greenhouse warming and attack the Earth's ozone shield.


Increasing the fuel mileage of cars by just 3 mpg would save Increasing the fuel mileage of cars by just 3 mpg would save the same amount of oil that could be tapped from the Arctic the same amount of oil that could be tapped from the Arctic National Wildlife Refuge over 10 years.National Wildlife Refuge over 10 years.

Every 20 minutes, the world adds another 3,500 human lives Every 20 minutes, the world adds another 3,500 human lives but loses one or more entire species of animal or plant life - at but loses one or more entire species of animal or plant life - at least 27,000 species per year. least 27,000 species per year.

Population is growing faster than food supplies in 64 of 105 Population is growing faster than food supplies in 64 of 105 developing countries. Overcultivation, primarily due to developing countries. Overcultivation, primarily due to population pressures, has degraded some 2 billion hectares of population pressures, has degraded some 2 billion hectares of arable land - an area the size of Canada and the United States arable land - an area the size of Canada and the United States combinedcombined

Globally, the demand for fresh water exceeds the Globally, the demand for fresh water exceeds the supply by 17 percent alreadysupply by 17 percent already. Two-thirds of the . Two-thirds of the world's population will experience some form of a world's population will experience some form of a severe water shortage in the next 25 years.severe water shortage in the next 25 years.

By 2025, when world population is projected to By 2025, when world population is projected to reach 8 billionreach 8 billion, 48 countries with a total population , 48 countries with a total population of 3 billion will face chronic water shortages. In 25 of 3 billion will face chronic water shortages. In 25 years, humankind could be using over 90 percent of years, humankind could be using over 90 percent of all available freshwater, leaving just 10 percent for all available freshwater, leaving just 10 percent for the rest of the world's plants and animals.the rest of the world's plants and animals.


What is the Carry Capacity of the What is the Carry Capacity of the Planet for Humans?Planet for Humans?

Paul Erlich – Paul Erlich – Population Bomb, 1968 – predicted 2 Population Bomb, 1968 – predicted 2 billion.billion. Now at 6 billion. Now at 6 billion.

Julian Simon – there is no problem, more people Julian Simon – there is no problem, more people means more potential technology solutions.means more potential technology solutions.

Some estimate Some estimate 20 billion will be maximum20 billion will be maximum (at this (at this rate, in your lifetime!!!)rate, in your lifetime!!!)

Solution = balance of population controls and Solution = balance of population controls and consumption controls.consumption controls.

What’s bugging you? Chapter 22What’s bugging you? Chapter 22PesticidesPesticides

What is a pesticide?What is a pesticide?

A pest is something that bothers you.It may not be something that is a pest to

other species (birds like mosquitoes!)Insecticides kill insectsHerbicides hill plantsFungicides kill fungiRodenticides kill rodents (rats, mice)

Pesticides, the next Pesticides, the next generationgeneration

1st generation pesticides are derived from plants that have been fighting pests from the beginning. They are modified forms of plant compounds

2nd generation pesticides are synthetic poisons – DDT (dichlorodiphenyltrichloroethane)

– 20,000 registered commercial pesticides– 675 active ingredients

The dark sideThe dark side

DDT- banned from US use in 1972, eggshell thinning, highly toxic to aquatic life, accumulates in the biosphere

Agent Orange – Vietnam – defoliation dioxins = soft tissue cancer causing agent, birth defects for generations,

TemekTemek

In the summer of 1985, nearly 1,000 people in several Western states and Canada were poisoned by residues of the pesticide Temik in watermelons. Within two to twelve hours after eating the contaminated watermelons, people experienced nausea, vomiting, blurred vision, muscle weakness and other symptoms. Fortunately, no one died, though some of the victims were gravely ill. Reports included grand mal seizures, cardiac irregularities, a number of hospitalizations, and at least two stillbirths following maternal illness.

Apples and MilkApples and Milk During 1986, the public grew increasingly concerned over the use of

the plant growth regulator daminozide (Alar) on apples (based on flawed interpretation of 1977 rat studies). Primarily used to make the harvest easier and the apples redder, Alar leaves residues in both apple juice and applesauce. Possibly more harmful chemicals are now in use.

Also in 1986, approximately 140 dairy herds in Arkansas, Oklahoma, and Missouri were quarantined due to contamination by the banned pesticide heptachlor. Dairy products in eight states were subject to recall. Some milk contained heptachlor in amounts as much as seven times the acceptable level. Those responsible for the contamination (gasohol grain mash was fed to cattle) were sentenced to prison terms. This and an accidental contamination on one of the Hawaiian islands did not result in an increase in birth defects of childhood cancers.

The good sideThe good side

Disease Control – Malaria(Remember

GlobalWarming)

Crop ProtectionCrop Protection

Most efficient = monoculture (one variety of one crop over a vast area)

Pests and weeds can seriously decrease production

Unforeseen ConsequencesUnforeseen Consequences

Genetic resistance. What does not kill you

makes you stronger…as a species.

At least 520 species of insects and mites have evolved resistance to certain pesticides

(Similar to improper use of antibiotics and antibacterial soaps/creams)

BioconcentrationBioconcentration

Each ‘higher’ life formeats many of the ‘lower’ life forms overyears. If the pesticidecan accumulate, itdoes, rapidly, as you get to the largercreatures.

AlternativesAlternatives

Cultivation methods – interplanting of plants that attract beneficial insects or repel harmful insects

Use naturally occurring disease organism, parasites or predators to control pests.

Pheromones (lure pests to traps)and Hormones (disrupt pest life cycles)

Reproductive control – release sterile males Genetic control – develop crops that are more

resistant.

Risk again…Risk again… The bottom line:

1. These poisons ‘can’ build in the environment or living organisms and harm us.

2. These poisons kill diseases and pests that decrease the quality and quantity of food.

3. They should be analyzed on a case by case (-cide by –cide) basis.

4. The cost to the environment and us VS. the benefit of controlling the pest/disease in question.

Next ChaptersNext Chapters

Resource Management: Putting it all together…

Ch 10-13 (not 14,15) & 19-21

university of phoenix sci256 week 2 ecosystems and populations ch 4-9, 22 ecosystems and energy,...

Documents

pyramids of energy

energy available

o2stores energy

h2o energyprovides energy

lower trophic levels

trophic pyramids2

higher trophic levels

number of trophic levels