Biogeography

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Biogeography
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What is Biogeography?

• Biogeography
• The large scale geographic pattern in the
  distribution of species, and the causes and
  history of this distribution.
• Biogeographic realms are based on evolutionary
  relationships and morphological similarities of
  animals.
• The concept of biotic province is an expansion of
  the biogeographic realm to include plants.

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Wallaces Realms Biotic Provinces

• Realm
• Major biogeographic regions of Earth that are
  based upon fundamental features of the plants and
  animals found in those regions
• Taxa
• Categories that identify groups of living
  organisms based upon evolutionary relationships
  or similarity of characteristics (ex species,
  families, orders)
• Biotic Provinces
• A geographical region (realm) inhabited by a
  characteristic set of taxa, bounded by barriers
  that prevent the spread of those distinctive
  kinds of life to other regions.

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The main biogeographic realms for animals are
based on genetic factors .
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The major vegetation realms are also based on
genetic factors
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Biomes

• A biome is a kind of ecosystem. Similar
  environments provide similar opportunities for
  life and similar constraints.
• Rainforest
• Grasslands
• Desserts

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Earths Biomes

• The Earth has 17 major biomes , each with its own
  characteristic dominant shapes and forms of life.
• Most biomes have been heavily altered by human
  action.
• People have introduced exotic species to new
  habitats sometimes creating benefits, often
  creating problems
• Primary Rule Unless there is a clear and good
  reason to introduce an exotic species into a new
  habitat, dont do it.

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17 Major Biomes

• Tundras
• - treeless plains that occur in the harsh
  climates of low rainfall and low average
  temperature
• - two types artic tundra and alpine tundra
• - parts have permafrost permanently frozen
  ground
• 2. Taiga or Boreal Forests
• - includes the forests of the cold climates of
  high latitudes and high altitudes
• - dominant life forms including moose and other
  large mammals, small flowering plants and trees
• Temperate Dedicious Forests
• - occur in warmer climates that the boreal
  forest
• 4. Temperate Rainforest
• - moderate temperatures, over 250 cm/year of
  rain

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17 Major Biomes

• 5. Temperate Woodlands
• - Slightly drier climate that the deciduous
  forests
• - fire is common and species adapt to it
• 6. Temperate Shrublands
• - also called chaparral miniature woodlands
• 7. Temperate Grasslands
• - include many North American parries
• 8. Tropical Rain Forests
• - high average temperature and rainfall
• 9. Tropical Seasonal Forest and Savannas
• - high average temperature, low latitudes,
  abundant but seasonal rainfall
• 10. Deserts
• - The driest region that vegetation can survive.

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17 Major Biomes
11. Wetlands - Include freshwater swaps,
,marshes and bogs all have standing water 12.
Freshwaters - Have phytoplankton and
estuaries 13. Intertidal Areas - Areas exposed
to alternately to air during low tide and high
tide 14. Open Ocean - Also called the pelagic
region
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17 Major Biomes

• 15. Bethos
• - Bottom portion of the ocean
• 16. Upwellings
• - Upward flows of ocean water
• 17. Hydrothermal Vents
• - Occur in the deep ocean were plate tectonic
  processes create vents

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• Convergent Evolution

• The process by which species evolve in different
  places of times and, although they have different
  genetic heritages, develop similar external forms
  and structures as a result of adaptation to
  similar environments
• Ex) shapes of sharks

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Divergent Evolution

• Organisms with the same ancestral genetic
  heritage migrate to different habitats and evolve
  into species with different external forms and
  structures, but continue to use the same type of
  habitats
• Ex) Ostrich

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Geographic Patterns of Life within a Continent
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Island Biogeography

• Theory of Island Biogeography
• Islands have fewer species than continents
• The smaller the island, the fewer the species
• Adaptive Radiation
• The process that occurs when a species enters a
  new habitat that has unoccupied niches and
  evolves into a group of new species, each adapted
  to one of these niches.
• Ecological Island
• An area that is biologically isolated so that a
  species occurring within the area rarely mixes
  with any other population of the same species

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Island Biogeography

• Islands may be considered microcosms from which
  studies of global biogeography, biodiversity and
  evolution may be extrapolated.
• Islands have fewer species and resources than
  mainlands.
• Islands have unique species primarily because of
  adaptive radiation.

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Island Biogeography

• Small islands have lower species diversity than
  large islands.
• Extinction on small islands is more likely.
• Distant islands have lower species diversity than
  nearby islands.
• Species richness on islands is constant.

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Final Thought

• The lessons learned from studying biogeography
  are very important in the development of an
  understanding of global biodiversity, species
  extinction and changing landscapes.