# Chapter 20(1).docx - CHAPTER 20 Movement of Energy in...

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CHAPTER 20 – Movement of Energy in Ecosystems (how energy is quantified) Define these terms: 1. primary productivity – The rate at which solar or chemical energy is captured and converted into chemical bonds by photosynthesis or chemosynthesis How much energy is available in the ecosystem Ecosystems with a high primary productivity may or may not have a high standing mass. (ex, in lakes, algae have high productivity but consumers eat it as quick as it grows and thus has a low standing crop) There are 2 types of primary productivity (1) Gross primary productivity (GPP) (2) Net primary productivity (NPP) 2. standing crop/(biomass) – The biomass of producers present in the ecosystem at a given area at a particular moment in time. Ex, standing crop of a forest is the total mass of trees, shrubs, herbs and grass 3. net secondary productivity – rate of consumer biomass accumulation in a given area 4. trophic pyramid – a chart composed of stacked rectangles representing the amount of energy or biomass in each trophic group 5. pyramid of energy –trophic pyramid that displays the TOTAL ENERGY EXISTING at each trophic level. 6. pyramid of biomass – a trophic pyramid that represents the standing crop of ORGANISMS present in different trophic groups
7. Gross primary productivity- The rate at which energy is captured and absorbed by producers in an area. Expressed in Joules or Kilo Joules (KJ) Define these Compare/Contrast sets of terms: 1. a. gross primary productivity – Rate at which energy is captured and assimilated by producers in an area. Often express productivity in units of Joules (J) or Kilo Joules (KJ) b. net primary productivity – Rate of energy is assimilated by producers and converted into producer biomass in an area is net primary productivity (NPP) 2. a. ingested energy – The portion of energy that is used for metabolic processes and transformed into biomass b. egested energy – The portion of consumed energy that is excreted or regurgitated is known as egested energy. Eg. seeds of a fruit are excreted as a whole cause it can’t be digested. 3. a. assimilated energy – The proportion of energy that a consumer digests and absorbs. b. respired energy – Of the assimilated energy, the portion that is used for respiration. 4. a. assimilation efficiency – percentage of consumed energy that is assimilated b. net production efficiency – percentage of assimilated energy that is used for growth and reproduction Answer these Short Answer/ Short Essay Questions: