Chapter 19 “Ecosystem Essentials”
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Transcript of Chapter 19 “Ecosystem Essentials”
Chapter 19
“Ecosystem Essentials”
Geosystems 6eAn Introduction to Physical Geography
Robert W. ChristophersonCharles E. Thomsen
What is this an example of?
Ecosystem
Figure 19.2
Plants (Vegetation)Critical biotic link between solar energy and the biosphereBase of vast majority of food webs
About 20 species of plants provide 90% of the human food supply
Wheat, corn (maize), and rice are half
Convert carbon dioxide to oxygenTranspiration elevates atmospheric humidity
Photosynthesis and Respiration
Figure 19.5
Distribution of VegetationFive major factors:
Climate (temperature and precipitation)
Topography (elevation, slope)
Soils (nutrients, minerals)
Biotic Influences (dispersal mechanisms)
Disturbance (natural or anthropogenic)
Climate
Figure 19.8
Life Zones
Figure 19.9
Carbon and Oxygen Cycle
Climate Change
Figure 19.23
What’s limiting these distributions?
Figure 19.12
Soils – nutrients, minerals
http://www.cfr.washington.edu/Classes.esc.520B/ImagesNorthFork/Serpentine6SM.jpg http://www.krisweb.com/krisnavarro/krisdb/ac/dscn2166_sm.jpg
http://nrs.ucdavis.edu/mclaughlin/images/plants/Seep.jpg
Serpentine
Dispersal Mechanisms – Fruit and Seed
http://www.cas.vanderbilt.edu/bioimages/pages/fruit-seed-dispersal.htm
Osage orange (Hedge apple)These huge fruits ooze sticky, white latex when bruised.
They are large and hard - what would want, or be able to eat them?
Probably were once dispersed by extinct megafauna (large mammals) that died out soon after humans arrived in North America.
http://www.cas.vanderbilt.edu/bioimages/pages/fruit-seed-dispersal.htm
What about this fruit?
Extinct Megafauna
http://sscl.berkeley.edu/~anth122/mammoth.gif http://www.intersurf.com/~chalcedony/gomp.jpg http://mishilo.image.pbase.com/u36/zidar/upload/23675731.pbtooth1.jpg
Mammoth
Gomphothere
Tooth
Disturbance
NaturalWater, wind, volcano, fire…
Anthropogenic (human-caused)Deforestation, fire, development…
SuccessionEcological succession – when newer communities replace older communities of plants and animals
Primary succession – an area of bare rock or disturbed site with no previous community
Secondary succession – some aspects pf a previously functioning community are present
Succession
End Chapter 19
Geosystems 6eAn Introduction to Physical Geography
Robert W. ChristophersonCharles E. Thomsen