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Conservation Ecology
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Communities contain species that have complex relationships with one another
A niche is an organism's role in the community
o What it eats, what eats it, where it lives, and chemicals it consumes and produces
Natural ecosystems live in a "balance"
Energy flows through the ecosystem, and all energy ultimately come from the sunlight
o Producers (plants) can turn this sunlight into organic molecules via
photosynthesis
o Consumers (animals, fungi) must eat other organisms to obtain energy
▪ Can't make organic molecules from the sun
▪ There is a hierarchy of consumers
• Primary consumers (herbivores) eat producers
• Secondary consumers eat primary consumers
• Tertiary consumers eat secondary consumers…so on and so forth
▪ Carnivores eat animals, and omnivores eat plants and animals
▪ Decomposers (fungi, bacteria, earth worms) eat dead stuff
o Food webs show the complex energy exchange and community relationships
▪ Can be affected by climate change, pollution, invasive species, and natural
disasters
▪ The number of producers and primary consumers is always much greater
than the number of secondary and tertiary consumers
▪ As you go up the levels of the food web, only 10% of the total available
energy is able to be transferred, so 90% of it is lost
• Most ecosystems do not have enough available energy to support a
huge population of predators
Human impacts on the environment
o Main causes
▪ Human population growth
• Most of human history has a stable population
• Around 4000 years ago there was steady growth due to agriculture
• Around 300 years ago the Industrial Revolution spurred rapid growth
• It is unknown when the growth would have to stop
• Continued population growth can impact the environment
• Environmental degradation
• Disruption of the food chain
• Increased global travel and transportation of non-native species
• Water use
• People in industrialized areas use up to 100x more water
than in less industrialized countries
• Depleting sources of fresh water
• In arid environments there is water scarcity and drought
• Habitat fragmentation
• Human development leads to the destruction of habitats
and ecosystems
• The resulting habitat is no longer continuous

Conservation Ecology
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Illinois used to be a continuous tallgrass prairie, but now
less than 1% of the original prairie exists
The remaining organisms live isolated from other
populations
Genetic drift may lead to decrease in genetic diversity, and
possibly eventual extinction

Pollution
• Toxins that humans emit into the environment
• Usually as a result of travel and industry
• Impacts include…
• Destruction of native habitat
• Water pollution
• Chemicals pollute freshwater sources
• Fertilizer and pesticides for agriculture
• Water can become unusable
• Eutrophication
• Excess chemicals runoff to water leading to massive
algae growth
• Use up all the oxygen, causing animals to die
• Acid rain
• Sulfur in chemicals released into the atmosphere that
come back to land in rain
• Acidifies natural environments and damages aquatic
ecosystems
• The Clean Air Act decreased a lot of sulfur pollution
• Ozone degradation
• Ozone forms the upper layer of the atmosphere, and
shields Earth from UV rays, but is susceptible to chemicals
• Chemicals called CFCs, found in aerosol sprays, degrade
the ozone layer
• CFCs phased out of aerosols in the 80s and 90s
• Hole formed in ozone layer over Antarctica
• Will take ~100 years for the ozone layer to
regenerate
• Global climate change
• Human activity leads to increased greenhouse gases in the
atmosphere, primarily carbon dioxide
• Does not allow heat from the sun to leave the atmosphere
• Global warming is raising of the global temperature
• Increased periods of drought or precipitation
• Sources of greenhouse gases
• Industry, cars, deforestation
• Deforestation

Conservation Ecology
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Trees store a lot of carbon, and cutting them
down releases the carbon
▪ Introduction of non-native species
• Occurs due to increased global travel
• Dangerous because they have no natural predators in their new
environments
• Examples of native species
• Zebra mussels from Lake Erie
• Native to Russia and brought on large shipping freighters
• Outcompete native mussels that keep the water clean
• They eat all of the plankton and leave none for the other
mussels
• Honeysuckle
• Brought to North America from Asia as an ornamental
plant
• They are extremely invasive
So what can we do about our impact on the environment?
▪ Find alternative energies that do not emit greenhouse gases
• Wind power, solar power, hydroelectric power, nuclear energy
▪ Living sustainably
• Consuming less
• Recycling more
• Sustainable agriculture
• Practices that have less impact on the environment
• Stabilizing the human population



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