Chapter 19

1
Chapter 19 Ecosystem Essentials

• Geosystems 6e
• An Introduction to Physical Geography

Robert W. Christopherson Charles E. Thomsen
2
What is this an example of?
3
Ecosystem
Figure 19.2
4
Plants (Vegetation)

• Critical biotic link between solar energy and the
  biosphere
• Base 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 oxygen
• Transpiration elevates atmospheric humidity

5
Photosynthesis and Respiration
Figure 19.5
6
Distribution of Vegetation

• Five major factors
• Climate (temperature and precipitation)
• Topography (elevation, slope)
• Soils (nutrients, minerals)
• Biotic Influences (dispersal mechanisms)
• Disturbance (natural or anthropogenic)

7
Climate
Figure 19.8
8
Life Zones
Figure 19.9
9
Carbon and Oxygen Cycle
10
Climate Change
Figure 19.23
11
Whats limiting these distributions?
Figure 19.12
12
Soils nutrients, minerals
Serpentine
http//www.cfr.washington.edu/Classes.esc.520B/Ima
gesNorthFork/Serpentine6SM.jpg
http//www.krisweb.com/krisnavarro/krisdb/ac/dscn2
166_sm.jpg
http//nrs.ucdavis.edu/mclaughlin/images/plants/Se
ep.jpg
13
Dispersal Mechanisms Fruit and Seed
http//www.cas.vanderbilt.edu/bioimages/pages/frui
t-seed-dispersal.htm
14
What about this fruit?

• 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/frui
t-seed-dispersal.htm
15
Extinct Megafauna
Mammoth
Tooth
Gomphothere
http//sscl.berkeley.edu/anth122/mammoth.gif
http//www.intersurf.com/chalcedony/gomp.jpg
http//mishilo.image.pbase.com/u36/zidar/upload/23
675731.pbtooth1.jpg
16
Disturbance

• Natural
• Water, wind, volcano, fire
• Anthropogenic (human-caused)
• Deforestation, fire, development

17
Succession

• Ecological 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

18
Succession
19
End Chapter 19

• Geosystems 6e
• An Introduction to Physical Geography

Robert W. Christopherson Charles E. Thomsen