Matter Cycles, Energy Flows

Producers/Autotrophs Sunlight is the main energy source for life Photosynthesis is the conversion of inorganic molecules to sugars by photoautotrophes

Photosynthesis inorganic matter radiant energy organic (C) matter (chemical energy) extra atoms + +

[ Chemoautotrophes Some autotrophes rely on energy stored in chemical bonds of inorganic compounds (H2S) found at hydrothermal vents ]

Consumers /Heterotrophs Rely on other organisms for food (nutrients, fuel) Primary consumers are herbivores (plant eaters) producer primary consumer energy & matter transferred

Respiration

Secondary Consumers Carnivores that eat herbivores producer primary secondary consumer consumer energy & matter transferred energy & matter transferred

Tertiary consumers Carnivores or omnivores that eat carnivores/omnivores aka top consumers Producers etc energy & matter transferred

Detritivores consumers that derive energy from organic waste and dead organisms Bacteria, insects ,fungi aka decomposers

Food Web contains many food chains Arrows indicate energy transfer

Pyramid Power Shape reflects trophic (feeding) levels Greek: trophos = nutrition

Pyramid shape reflects energy use & transfer Only 10% is transferred on average Most energy is transformed (lost) into heat

Pyramid shape reflects number of organisms Many producers needed to support a smaller number of consumers

Pyramid shape reflects relative biomass Large base supports smaller (less productive) trophic levels

Biomagnification/Bioaccumulation Chemicals ingested that cannot be broken down or easily excreted These accumulate in tissues The more one eats, the more toxin that accumulates

Organisms higher in the web have more opportunities to ingest the toxin, increasing concentration in their tissues 10,000x 1,000x 100x 10x 1x It’s exponential

Greatest quantity of toxin per individual is in those top consumers 13.8ppm 2.07ppm 0.23ppm 0.04ppm Greatest quantity of toxin per individual is in those top consumers The pyramid is inverted

Mercury concentrates in fish Brain damage, death Limit your tuna intake: Albacore 1x/2weeks Chunk light 1x/5 days Source: EPA/FDA For a 100# person

DDT Weakens bird egg shells

PCB’s from electrical, plastics industries Linked to cancer Also immune, reproductive, neurologic, endocrine disorders