Energy Flow in Ecosystem • Sunlight! • Producers, aka autotrophs use photosynthesis to create food. • Produce ATP and NADPH to then form gluclose
Both producers and consumers use cellular respiration to gain energy from food.
Consumers, aka heterotrophs rely on others for their food supply. • Herbivores – eat only plants • Carnivores – eat animals • Omnivores – eat both plants and animals
Scavengers – carnivores that eat already dead organisms. • Detritivores – break down dead tissue and waste products • Decomposers – complete break down of organic matter
Feeding Relationships • Energy flows one way. • Food Chain
Ecosystem Productivity • Gross Primary Productivity (GPP): total solar energy captured by producers • Net Primary Productivity (NPP): GPP minus energy respired (R) • mg/L/day • kcal/day • kcal/m2/yr
Ecological Pyramids • Energy Pyramid – “Rule of 10” • Ecological efficiency: proportion of consumed energy that can be passed on.
Biomass pyramid – total mass of living tissue within a trophic level. • Amount of biomass present at a particular time is its standing crop. • Pyramid of Numbers