Ecology Lecture I

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Ecology Lecture I

• The study of complex interactions among organisms
  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
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Human Impact

• In the late 1700s an economist by the name of
  Thomas Malthus stated
• the human population is growing faster than the
  Earths resources can support
• Naturally, the rest of the world didnt believe
  these claims
• The worlds population was around 1 billion
  people worldwide at this time

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Human Impact

• Scientists tried to predict human population
  growth and vastly underestimated it!
• Today we have gone past the predicted carrying
  capacity with a world population of over 6
  billion!
• Carrying capacity the maximum number of
  individuals that the environment can normally and
  consistently support

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Human Impact

• Several human advancements have made it
  possible for the human population growth
  explosion!
• Technology
• Agriculture
• Transportation
• Medical advancements
• Sanitation

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Human Impact

• Oil and Coal
• These natural resources are what humans have
  relied upon for power for the last 258 years
• Oil and coal are considered nonrenewable
  resources
• Nonrenewable resources resources that are used
  faster than they are replenished

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Human Impact

• If humans continue at the rate of 77 million
  barrels of oil per day (and growing) we will
  quickly approach or exceed our carrying capacity!
• We must make a choice to invest in renewable
  energy technology if we wish to survive and
  preserve a planet capable of supporting life
• Renewable energy resources that cannot be used
  up or replenish themselves regularly

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Human Impact

• Water is considered a renewable resource because
  of annual rains and snow returning water back
  to the earth
• Humans are finding ways to make water a
  nonrenewable resource by polluting water sources
  and overuse!

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Human Impact

• Humans need resources in order to survive
• There is a problem when people need too much!
• An ecological footprint is the amount of land and
  resources necessary to maintain an individual
• Maintenance includes food, water, shelter,
  health, energy, and waste

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Human Impact

• What is Global Warming?
• The trend of an increasing global temperature
• What contributes to Global Warming?
• Our earth is protected by a thin layer of
  atmosphere from outer space
• Greenhouse gases are certain gases that become
  trapped by the ozone around our planet
• Gases like CO2, Methane CH4, and water vapor

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Global Warming
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Levels of Organization

• An ecologist is a scientist that studies the
  interactions of living things with other living
  things and their surroundings
• When ecologists study organisms in their
  environment they look at the levels of
  organization
• When studying nature, scientists recognize 5
  levels of organization

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Levels of Organization

• Levels of Organization
• Organism any individual living thing (example
  a single alligator)
• Population a group of the same species that
  live in the same area
• Community groups of different living species
  that live together in the same area
• Ecosystem the community and all of the
  non-living components such as water, soil,
  mountains, etc.
• Biome a major region of the planet that has a
  defined climate (ex deserts)

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Levels of Organization
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Factors in an Ecosystem

• All ecosystems are made up of living and
  nonliving components
• Biotic factors are all of the living parts of
  an ecosystem such as plants, animals, fungi, and
  bacteria
• Abiotic factors are the nonliving components
  such as temperature, water, wind, sunlight, and
  Earths landmasses

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Factors in an Ecosystem
ECOSYSTEM
Abiotic Factors
Biotic Factors
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Factors in an Ecosystem

• An ecosystem is a complex web of biotic and
  abiotic factors
• Some ecosystems have more diversity than others
• Biodiversity is the assortment or variety of
  living things in an ecosystem

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Biodiversity

• Biodiversity is the sum total of different kinds
  of organisms and it is affected by changes in the
  habitat

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Factors in an Ecosystem

• Certain ecosystems are held together because of
  the actions of one biotic factor
• A keystone species is a biotic organism that has
  an unusually large effect on its ecosystem
• For example the beaver creating a dam and a
  large body of water