Ecology: Chapter 21: Ecosystem Energetics

 

 

Energy Fixed in the Process of Photosynthesis is Primary Production

 

 

Gross primary production

Net primary production

 

 

Ocean NPP 2007

 

 

 

Temperature, Water & Nutrients Control Primary Production in Terrestrial Ecosystems

 

NPP for a variety of terrestrial ecosystems

1000 mm = 40 inches        30oC = 86oF

 

 

 

Relationship between NPP and the length of growing season.

Each dot represents one forest site.

 

 

 

EVT depends on both precipitation and temperature

 

 

 

Primary productivity

 

 

 

 

 

 

 

 

Relationship between NPP and nutrient availability

Different forest ecosystems, Blackhawk Island, WI

Abbreviations refer to the dominant tree species in each stand:

  • Hem: hemlock
  • RP: red pine
  • RO: red oak
  • WO: white oak
  • SM: sugar maple
  • WP: white pine

 

 

 

Relationship between aboveground NPP and nitrogen availability

 

 

 

 

 

Temperature, Light & Nutrients Control Primary Production in Aquatic Ecosystems

 

 

 

 

 

 

 

 

 

 

 

Primary production in the world's oceans.

 

 

 

 

Energy Allocation and Plant Life-Form Influence Primary Production

 

Relationship between standing biomass and NPP.

 

 

 

 

Primary Production Varies With Time

 

 

 

 

Changes in proportions of biomass for white oak trees as trees age.

 

 

 

 

 

 

 

 

 

 

Ecosystems Have Two major Food Chains

Orange Arrows = energy flow associated with ingestion

Brown Arrows = dead organic matter/waste products

R = respiration