How do microorganisms maintain the health of ecosystems?

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How do microorganisms maintain the health of
ecosystems?

• Some microorganisms are decomposers that break
  down organic matter into smaller pieces,
  eventually releasing raw nutrients back to the
  ecosystem.
• Some bacteria convert nitrogen and other
  nutrients to forms that can be used by primary
  producers (plants and other photosynthetic
  organisms).
• Specialized oil-eating bacteria help restore
  ecosystems following oil spills.
• Mycorrhizal fungi seem to help ecosystems
  recover following disturbances.

4. Use Analogies How are microorganisms similar
to recycling plants?
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How do microorganisms disrupt the health of
ecosystems?

• Introduced fungi devastated populations of the
  American Chestnut in the early 1900s. The death
  of the chestnut trees affected forest ecosystems
  throughout the eastern United States.
• The nuts of the chestnut tree were consumed by
  both humans and animals.
• Chestnut leaves provided much nutrient content to
  the forest ecosystem.
• Chestnut trees were replaced by oak, hickory, red
  maple, and sugar maple trees throughout their
  range.

5. Infer The Chestnut blight fungus was
accidentally introduced to the United States
around 1900. Why might microorganisms be most
disruptive when introduced to an ecosystem where
they are not usually found?
(contd.)
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How do microorganisms disrupt the health of
ecosystems?

• Populations of some usually harmless aquatic
  microorganisms, including dinoflagellates and
  the photosynthetic protist Euglena (seen here),
  can grow exponentially following an influx of
  nutrients. Such responses to added nutrients are
  called algal blooms, andthey can be very harmful
  to ecosystems.
• Algal blooms can block sunlight and disrupt
  photosynthesis.
• Blooms of dinoflagellates, called red tides,
  release toxins into the ecosystem.
• Increased rates of decomposition following very
  large blooms can result in dead zones, areas
  devoid of oxygen that are inhospitable to
  multicellular life.

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• Why couldnt you survive a day
• without bacteria?

• They process our wastes and make them usable
  again. Without them nothing would rot.
• They purify our water.
• Keep our soils productive
• Synthesize vitamins in our intestines
• Convert our food into useful sugars and
  polysaccharides
• Wage war on alien microbes that enter our
  digestive system
• Pluck nitrogen from the air and convert it into
  useful nucleotides and amino acids for us.