Biological Communities

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Biological Communities

• Chapter 18

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Species often evolve in response to each other

• Interactions among species are the result of a
  long term relationships in which organisms adjust
  to one another
• Insects and flowers

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• Coevolution back and forth evolutionary
  adjustments between interacting members of an
  ecosystem

• Symbiosis
• When two or more species live together in a
  close, long-term association.

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• Parasitism when one organism feeds on and
  usually live on or in another
• Example Ticks and dogs

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• Mutualism a symbiotic relationship in which
  both benefit from the relationship
• Example flowers and bees (plants
  pollin- ated, bees food)

Commensalism a relationship in which one
organism benefits and the other neither is
benefits or is harmed Example Spanish moss and
trees -trees are not hurt nor benefit, but the
moss benefits from additional sunlight
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• Common Use of Scarce Resources leads to
  competition
• Organisms compete for food, space, light,
  minerals, and water
• Resources must be in short supply if competition
  occurs
• Competition can limit how species use resources
• Competition can lead to extinction or elimination
  of a species

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• Niche the role of a species in a
  ecosystem
• How does the organism affect the environment
• If niches overlap it may cause competition
• Niches can vary in size

NOT a part of a teacher's niche!!!
Jaguars eat mammals and fish give birth from
June to August during the rainy season and hunt
by day and by night (these are all a Jaguar's
niche)
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Major Biological Communities

• Climate largely determines where species lives
• Climate is the prevailing weather conditions of
  an area
• - the two most important elements of climate are
  Temperature and Moisture

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Temperature most organisms are adapted to a
particular range of temperatures (ex. the growing
season of plants)
Moisture all organisms require water, so the
patterns of rainfall determine an areas life-forms
p. 391
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Biome a major biological community that
occurs over a large area of land
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Types of Terrestrial Biomes

• Tundra
• Taiga
• Desert
• Grassland
• Temperate Forests
• Tropical Rain Forests

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Tundra

• extremely short growing season (6 to 10 weeks)
• long, cold, dark winters (6 to 10 months with
  mean monthly temperatures below 32 F or 0 C.)
• low precipitation (less than ten inches/year)
• Permafrost (permanently frozen ground about 3 ft
  below surface prevents drainage)

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Foxes, owls, caribou, lemmings live here ...
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Taiga
(Tahy guh)

• Long, severe winters and short summers (50 to 100
  frost-free days) are characteristic, as is a wide
  range of temperatures between the lows of winter
  and highs of summer.
• Mean annual precipitation is 15 to 20 inches,
  but low evaporation rates make this a humid
  climate.

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Vegetation and Animals Conifers (spruce and
firs) beaver, lynx, deer, elk, bears,
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Deserts

• Temperature  Average of 38C (day), average of
  -3.9C (night)
•  Precipitation  About 250 mm of rain per year
•  Vegetation  Cacti, small bushes, short grasses
  

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• Animals in the desert coyotes, lizards and
  snakes, insects, and even some birds) are adapted
  for burrowing to escape the scorching heat of the
  desert sun

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Grasslands

• Temperature  Dependent on latitude, yearly
  range can be between -20C to 30C  
• Precipitation About 500 to 900 mm of rain per
  year  
• Vegetation Grasses (prairie clover, oats,
  wheat, barley, coneflowers)

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Bison, antelope, prairie dog
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Temperate Forests

• Temperature -30C to 30C, yearly average is
  10C, hot summers, cold winters  
• Precipitation 750 to 1,500 mm of rain per year
   
• Vegetation Broadleaf trees (oaks, maples,
  beeches), shrubs, perennial herbs, and mosses

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Animals Deer, raccoons, and salamanders are
characteristic inhabitants.
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Tropical Rain Forest

• Temperature  20C to 25C, must remain warm and
  frost-free
•  Precipitation  2,000 to 10,000 millimeters of
  rain per year (6.5 to 33 Feet) (Y-town 3 ft)
•  Vegetation  Vines, palm trees, orchids,
  ferns

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Animals and plants monkeys, cat like mammals,
reptiles, insects, diverse flowers, hard wood
trees, and medicinal plants