secondary production, energy flows, & ecological efficiency
DESCRIPTION
Secondary Production, Energy Flows, & Ecological Efficiency. Cedar Bog Lake, MN; Raymond Lindeman 1943, Ecology 23:157-176. Energy flow in a Georgia salt marsh. John Teal 1962 Ecology 43:639-649. Ecological Efficiency For entire population need a bookkeeping approach, by size or age - PowerPoint PPT PresentationTRANSCRIPT
Secondary Production, Energy Flows, &
Ecological Efficiency
Cedar Bog Lake, MN; Raymond Lindeman 1943, Ecology 23:157-176
Energy flow in a Georgia salt marsh
John Teal 1962Ecology 43:639-649
Ecological Efficiency
For entire population need a bookkeeping approach, by size or age
Elephant example Net Primary Prod. 747 kcal/m2/yr 3125 kJ/m2/yr Food consumed 71.5 299 Fecal Energy lost 40.2 168 Maint. Metabolism 31.0 130 Growth 0.34 1.44
(0.47% of food consumed; 0.046% of NPP)
Standing crop 7.1 kcal/m2 30 kJ/m2
Ingested Energy
Prey Production
Detritus
Not eatenConsumption Exploitation
Efficiency
Exploitation Efficiency - Plants %total %visible• Solar Radiation 100 100• Reflected 22 3.0• Evapotranspiration 38.4 \• Conduction, Convection 38.5 /94.8• Photosynthesis 1.1 2.2
Exploitation Efficiency - Herbivores
Mature Tropical Rainforest 7% Temperate Deciduous Forest 1.5-5%
Desert Scrub 5.5% Temperate Grassland 1-15%
7-yr South Carolina fields 12% Georgia salt marsh 8% Managed Rangeland 30-45% African Grassland - Ungulates 28-60% Open Ocean 60-99%
Assimilated Energy
Ingested Energy
Prey Production
Detritus
Egestion
Not eatenConsumption
Digestion, assimilation
Exploitation Efficiency
AssimilationEfficiency
Assimilation Efficiency Dramatic dependency on prey types.
Carnivores 90% Insectivores 70-80% Granivores 80% Grazers & Browsers 30-40% Decaying wood. Millipeds 15%
Consumer Production
Assimilated Energy
Ingested Energy
Prey Production
Detritus
Respiration
Excretion
Egestion
Not eaten
Death
Consumption
Digestion, assimilation
Growth,reproduction
Exploitation Efficiency
AssimilationEfficiency
Net ProductionEfficiency
Net Production Efficiency
1. Efficiency of biosynthesis sets the upper limit Bobolink fat deposition -- 62-65% Iguana, Embryonic growth > 48%
2. Plants (NPP/GPP) Grass-Michigan, Duckweed 85 Oak-Pine, Open Ocean, Silver Spring 45 Humid tropics 30
Respiration RatesAquatic vs Terrestrial animals (mg O2/g/hr)
Aquatic TerrestrialFish .005 - .349 Mammals 1.2 - 13.9Insects .192 - .381 Insects .63 - 1.7Worms .008 - .031 Birds 1.5 - 10.7Mollusks .002 - .186
Consumer Production
Assimilated Energy
Ingested Energy
Prey Production
Detritus
Respiration
Excretion
Egestion
Not eaten
Death
Consumption
Digestion, assimilation
Growth,reproduction
Exploitation Efficiency
AssimilationEfficiency
Net ProductionEfficiency
Eco
log
ical E
ffici
en
cy
Elton's PyramidsTypical values: production, biomass, numbers Production Biomass Numbers(mg/m2/day) (g/m2) (#/m2)
.1 .1 15 1.2 .66 100 26.8 1.25 1.5x104
280.0 17.7 7.2x1010
