Ecology and the Biosphere

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Ecology and the Biosphere
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Ecology
the study of the interactions of organisms with
one another and with their physical environment
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What is the Biosphere?
Study these pictures of the biosphere and write a
complete definition for it in your notes
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The Biosphere
The Living Globe
The Biosphere is the part of the Earth in which
life exists
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Dimensions of the Biosphere
Includes all land, air, and water
Extends from about 8 km above the Earths
surface to as far as 8 km below the surface of
the ocean
Living organisms are not distributed uniformly
(few in polar regions and many in tropical
regions)
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Ecosystems
Small ecological units that consist of an areas
physical features along with living organisms
Nonliving Physical Features are called abiotic
factors
Water, sunlight, soil type, rocks, temperature,
humidity, elevation, and rainfall
Living organisms are called biotic factors
Bacteria, reptiles, fish, birds, animals, plants,
and fungi
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There are many different types of ecosystems in
nature
Lake
Stream
Prairie
Forest
Wetland
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All Ecosystems are Interconnected!!!!
Stream
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Community and Population
Ecologists who study ecosystems identify the
living organisms as a..
Population a collection of individuals of the
same species in a given area who can breed
with one another
Or..
Community all the populations of
organisms living in a given area
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Ecological Succession
What Does it Mean to Succeed???
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Ecological Succession is the process by which an
existing community is gradually replaced by
another community
Every organism affects environmental conditions
around it
Burrowing worms change the texture of the soil
Trees shade an area making it cooler and darker
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Ecological Succession of a Pond Community
Begins as a thriving pond community.
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Ecological Succession of a Pond Community
The pond begins to fill with organic matter like
leaves, and silt, a fine soil..
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Ecological Succession of a Pond Community
Over a period of time, the pond fills and becomes
a marsh..
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Ecological Succession of a Pond Community
Eventually the marsh becomes dry land inhabited
by a stable community called a climax community
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Succession often leads to a fairly stable
collection of organisms
Climax Community
The Biomes of the World are Large Climax
Communities with a Stable Collection of
Characteristic Plant and Animal Life!
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There are 2 types of succession that occur in
nature..
Primary Succession

Secondary Succession
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Primary Succession

• Occurs in places where no living community
  existed before (ie. On a newly formed volcanic
  island)

• Hardy organisms that can tolerate harsh
  conditions colonize these areas (Pioneer species)

• The pioneer species begin to change the area and
  make it suitable for life (Lichens that grow on
  bare rocks produce acids which break down the
  rock. After many years, a thin soil of broken
  rock and dead lichen allows other species to grow)

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Secondary Succession

• Occurs in areas where natural disasters or human
  activities have wiped out a living community

• Pioneer species colonize the area and gradually
  change conditions so that they are favorable for
  other species