Ecology of PopulationsEcology of Populations

What is Ecology?What is Ecology?“Ecology”

the study of the interactions of

organisms w/ its environment.

• Populations grow when Populations grow when birth rate exceeds rate of birth rate exceeds rate of mortalitymortality

•DEATHDEATH

Population GrowthPopulation Growth

Age DistributionAge Distribution

Horizontal axis = Number of individualsHorizontal axis = Number of individuals

Age-Structure Diagram shows Age-Structure Diagram shows growth patterns of populations growth patterns of populations

grouped into categoriesgrouped into categories

Human Age DistributionHuman Age Distribution

Developed countriesDeveloped countries Less-developed Less-developed countriescountries

Humans are part of the Earth's Humans are part of the Earth's

ecosystem.   Human activities ecosystem.   Human activities

can either deliberately or can either deliberately or

inadvertently inadvertently

alter the balance alter the balance

of an ecosystem.  of an ecosystem.  

What do you Think???What do you Think???

How do human How do human activities affect the activities affect the

environment?environment?

With more info…With more info…

Will you change your Will you change your perspective or will perspective or will you feel the same you feel the same

way?way?

Human impacts on the EnvironmentHuman impacts on the Environment Global warmingGlobal warming

Use of machinery by Use of machinery by humans seems to be humans seems to be increasing COincreasing CO22 levels in levels in

the air. COthe air. CO22 prevents prevents heat from escaping, heat from escaping, causes slight world wide causes slight world wide temperature increasestemperature increases

Rising water temperatures causes coral bleaching

Human impacts on the environmentHuman impacts on the environment

DeforestationDeforestation• Caused by demand for wood products, Caused by demand for wood products,

need for space, farmland, housing, need for space, farmland, housing,

roads roads

• Deforestation causes Deforestation causes

Habitat fragmentationHabitat fragmentation

•Animals and plants are forced into Animals and plants are forced into confined areasconfined areas

Habitat FragmentationHabitat Fragmentation

Habitat FragmentationHabitat Fragmentation

Human impacts on the EnvironmentHuman impacts on the Environment Ozone depletionOzone depletion

• Caused by aerosol chemicals called Caused by aerosol chemicals called

chlorofluorocarbons (CFCs)chlorofluorocarbons (CFCs)

• CFC’sCFC’s– Escape into atmosphere, reacts breaking down Escape into atmosphere, reacts breaking down

the ozone (Othe ozone (O33, a protective atmospheric layer), a protective atmospheric layer)

– UV rays penetrate the atmosphere and cause UV rays penetrate the atmosphere and cause harm to many organism. harm to many organism.

““HOLE” HOLE” in the in the ozone ozone (O3)(O3)

Human impacts on the EnvironmentHuman impacts on the Environment Fishing activitiesFishing activities• Demand for fish and shellfishDemand for fish and shellfish

• Commercial Commercial Fishing be harmful to Fishing be harmful to environment in many waysenvironment in many ways

Human impacts on the environmentHuman impacts on the environmentInvasive species (EXOTIC SPECIES)Invasive species (EXOTIC SPECIES)

•introduced by people accidentally or introduced by people accidentally or intentionallyintentionally

• Can cause problems if no natural enemies are Can cause problems if no natural enemies are presentpresent

•Cane toad was introduced to Australia to control cane beetles, pest insects that destroy sugar cane crops

Human impacts on the EnvironmentHuman impacts on the EnvironmentExotic pet tradeExotic pet trade

• Capture and sell wild animals from Capture and sell wild animals from

exotic locationsexotic locations

• Wealthy buyers and collectors desire Wealthy buyers and collectors desire

obscure animals obscure animals

• Animals removed from their habitat Animals removed from their habitat

causes an imbalance in the ecosystemcauses an imbalance in the ecosystem

Importance of the EnvironmentImportance of the EnvironmentBiodiversityBiodiversity = Many = Many different types of different types of organismsorganisms

• Organisms depend Organisms depend upon one another upon one another

• Interfering with one Interfering with one Organism can have a Organism can have a Ripple effect to many Ripple effect to many w/in the habitatw/in the habitat

Importance of the environmentImportance of the environmentNatural resources:Natural resources:

Non-renewable Non-renewable includes fossil fuels includes fossil fuels (petroleum, coal)(petroleum, coal)• Renewable includes Renewable includes animals, plants, water, animals, plants, water, wind, etc.wind, etc.– even renewable even renewable

resources can run out resources can run out

Importance of the Importance of the EnvironmentEnvironmentNatural resourcesNatural resources

Renewable energy sources include wind Renewable energy sources include wind power, geothermal energy, ocean currents power, geothermal energy, ocean currents

Pollution:Pollution:• AgriculturalAgricultural–DDTDDT–FertilizersFertilizers–Animal wastes (nitrogen)Animal wastes (nitrogen)

• HomesHomes– Strong cleaning agentsStrong cleaning agents

• IndustryIndustry–Toxic gases and wastesToxic gases and wastes–Acid rainAcid rain

Questions?Questions?