Ecology Lecture IEcology Lecture IThe study of complex interactions among The study of complex interactions among

organisms and the worldorganisms and the world

Ecology Standards:

6a ~ Students know biodiversity is the sum total of different kinds of organisms and is affected by alterations of habitats

6b ~ Students know how to analyze changes in an ecosystem resulting from changes in climate, human activity, nonnative species introduction, or changes in population size

Human ImpactHuman Impact

In the late 1700’s an economist by In the late 1700’s an economist by the name of Thomas Malthus statedthe name of Thomas Malthus stated• ““the human population is growing faster the human population is growing faster

than the Earth’s resources can support”than the Earth’s resources can support”• Naturally, the rest of the world didn’t Naturally, the rest of the world didn’t

believe these claimsbelieve these claims• The world’s population was around 1 The world’s population was around 1

billion people worldwide at this timebillion people worldwide at this time

Human ImpactHuman Impact

Scientists tried to predict human Scientists tried to predict human population growth and vastly population growth and vastly underestimated it!underestimated it!

Today we have gone past the Today we have gone past the predicted predicted carrying capacitycarrying capacity with a with a world population of over 6 billion!world population of over 6 billion!• Carrying capacityCarrying capacity – – the maximum number the maximum number

of individuals that the environment can of individuals that the environment can normally and consistently supportnormally and consistently support

Human ImpactHuman Impact

Several human “advancements” Several human “advancements” have made it possible for the human have made it possible for the human population growth explosion!population growth explosion!• TechnologyTechnology• AgricultureAgriculture• TransportationTransportation• Medical advancementsMedical advancements• SanitationSanitation

Human ImpactHuman Impact

Oil and CoalOil and Coal• These natural resources are These natural resources are

what humans have relied what humans have relied upon for power for the last upon for power for the last 258 years 258 years

• Oil and coal are considered Oil and coal are considered nonrenewable resourcesnonrenewable resources

Nonrenewable resourcesNonrenewable resources – – resources that are used faster resources that are used faster than they are replenishedthan they are replenished

Human ImpactHuman Impact

• If humans continue at the rate of 77 If humans continue at the rate of 77 million barrels of oil per day (and million barrels of oil per day (and growing) we will quickly approach or growing) we will quickly approach or exceed our exceed our carrying capacity!carrying capacity!

We We mustmust make a choice to invest in make a choice to invest in renewable energyrenewable energy technology if we technology if we wish to survive and preserve a wish to survive and preserve a planet capable of supporting lifeplanet capable of supporting life• Renewable energyRenewable energy – resources that – resources that

cannot be used up or replenish cannot be used up or replenish themselves regularlythemselves regularly

Human ImpactHuman Impact Water is considered a Water is considered a renewable renewable

resourceresource because of annual rains because of annual rains and snow ‘returning’ water back to and snow ‘returning’ water back to the earththe earth

Humans are finding ways to make Humans are finding ways to make waterwater a a nonrenewable resourcenonrenewable resource by by polluting water sources and polluting water sources and overuse!overuse!

Human ImpactHuman Impact

Humans need resources in order Humans need resources in order to surviveto survive

There is a problem when people There is a problem when people need too much! need too much!

An An ecological footprintecological footprint is is the the amount of land and resources amount of land and resources necessary to maintain an necessary to maintain an individualindividual• Maintenance includes: food, water, Maintenance includes: food, water,

shelter, health, energy, and wasteshelter, health, energy, and waste

Human ImpactHuman Impact What is What is Global WarmingGlobal Warming??

• The The trend of an increasing global trend of an increasing global temperaturetemperature

What contributes to What contributes to Global WarmingGlobal Warming??• Our earth is protected by a thin layer of Our earth is protected by a thin layer of

atmosphereatmosphere from outer space from outer space• Greenhouse gasesGreenhouse gases are certain gases that are certain gases that

become “trapped” by the ozone around our become “trapped” by the ozone around our planetplanet

Gases like COGases like CO22, Methane CH, Methane CH44, and water vapor, and water vapor

Global WarmingGlobal Warming

Levels of OrganizationLevels of Organization An An ecologistecologist is a scientist that studies the interactions is a scientist that studies the interactions

of living things with other living things and their of living things with other living things and their surroundingssurroundings

When When ecologistsecologists study organisms in their study organisms in their environment they look at the environment they look at the levels of levels of organizationorganization

When studying nature, scientists When studying nature, scientists recognize 5 recognize 5 levels of organizationlevels of organization

Levels of OrganizationLevels of Organization Levels of Organization:Levels of Organization:

• OrganismOrganism – any individual living thing – any individual living thing (example: a single alligator)(example: a single alligator)

• PopulationPopulation – a group of the same species – a group of the same species that that live in the same arealive in the same area

• CommunityCommunity – groups of different – groups of different livingliving species that live together species that live together in the same areain the same area

• EcosystemEcosystem – the – the communitycommunity and all of the and all of the non-living components such as water, soil, non-living components such as water, soil, mountains, etc.mountains, etc.

• BiomeBiome – a major region of the planet that has – a major region of the planet that has a defined climate (ex: deserts)a defined climate (ex: deserts)

Levels of OrganizationLevels of Organization

Factors in an EcosystemFactors in an Ecosystem All ecosystems are made All ecosystems are made

up of up of livingliving and and nonlivingnonliving componentscomponents

Biotic factorsBiotic factors – are all of – are all of the the living parts of an living parts of an ecosystemecosystem such as such as plants, animals, fungi, plants, animals, fungi, and bacteriaand bacteria

Abiotic factorsAbiotic factors – are the – are the nonliving components nonliving components such as temperature, such as temperature, water, wind, sunlight, and water, wind, sunlight, and Earth’s landmassesEarth’s landmasses

Factors in an EcosystemFactors in an Ecosystem

BioticBiotic Factors Factors

AbioticAbiotic Factors Factors

ECOSYSTEMECOSYSTEM

Factors in an EcosystemFactors in an Ecosystem An An ecosystemecosystem is a is a

complex complex webweb of of bioticbiotic and and abioticabiotic factorsfactors• Some ecosystems Some ecosystems

have more have more diversitydiversity than othersthan others

• BiodiversityBiodiversity – is the – is the assortment or assortment or variety of living variety of living things in an things in an ecosystemecosystem

BiodiversityBiodiversity

BiodiversityBiodiversity is is the sum total of the sum total of different kinds of organismsdifferent kinds of organisms and it is and it is affected by changes in the habitataffected by changes in the habitat

Factors in an EcosystemFactors in an Ecosystem Certain ecosystems are Certain ecosystems are

held together because of held together because of the actions of the actions of one biotic one biotic factorfactor

A A keystone specieskeystone species is a is a biotic organism that has biotic organism that has an unusually large effect an unusually large effect on its ecosystemon its ecosystem• For example: the beaver For example: the beaver

creating a dam and a creating a dam and a large body of waterlarge body of water