Botkin and Keller Environmental Science 5e Chapter 8 Biogeography

Botkin and KellerEnvironmental Science 5e

Chapter 8

Biogeography


Why Were Introductions of New Species into Europe So Popular

Long Ago?

• Biogeography: – The large scale geographic pattern in the

distribution of species, and the causes and history of this distribution


Wallace’s 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.


The main biogeographic realms for animals are based on genetic factors .


The major vegetation realms are also based on genetic factors


Biomes

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



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

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



Geographic Patterns of Life within a Continent



Island Biogeography• Theory of Island Biogeography

– Islands have fewer species than continents– The smaller the island, the fewer the species– The farther the island from the continent, 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. Darwin’s Finches

• 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



Species found on Caribbean Islands


Earth’s 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, don’t do it.




17 Major Biomes1. 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

3. Temperate Dedicious Forests- occur in warmer climates that the boreal forest

4. Temperate Rainforest- moderate temperatures, over 250 cm/year of rain


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.


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

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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Botkin and Keller Environmental Science 5e Chapter 8 Biogeography